Talk:Big Bang

IMPORTANT: This is not the place to discuss how you think the universe began. This page is for discussing the article, which is about the Big Bang model, and about what has been presented in peer-reviewed scientific literature about it. See Wikipedia:No original research and Wikipedia:Talk page guidelines. If you wish to discuss or debate the validity of the Big Bang please do so at BAUT forum or talk.origins.

Factual review (per FA bid)

This article is very close to my day job, so I may be a very picky commentator. For sure it gives a good overview of the Big Bang and obviously represents a lot of hard work. Still, it seems to me to contain numerous half-truths, ambiguities and minor factual errors. Here is an edited list:

• Lead description of the "initial state" is weaseling and misleading; a natural reading would suggest a finite density at the singularity. As a "key premise" this needs a better explanation. "Alpha-beta-gamma theory": it's not so called: Big bang nucleosynthesis (BBN) is current. A-B-G was a famous first attempt, but its answer is radically wrong.
• History Give more dates; name Vesto Slipher, he deserves credit. Use "static" not "steady-state" for Einstein's model. Per footnote, vs. text: Lemaitre's primeval atom was 1931, his 1927 theory didn't start with a big bang. Hubble's 1929 contribution is described twice; it should emphasise that Hubble contributed the distances and used Slipher's redshifts. BB is contrasted twice with Einstein's model. Milne & Tolman appear out of sequence, they published in the 1930s, cf Steady state proposed 1950. Mention radio source & quasar count controversy (convinced many of BB prior to CMB discovery). In fact WP needs an article on evolution of the universe.
• Overview needs to point out that the earliest phases are speculative (see comment on inflation below). Sentence on production of Quark-Gluon plasma not needed, breaks up story. Needs more dates (not just "later.."): eg age of universe at hadron formation, e-/e+ annihilation. Discussion of Dark energy suggests wrongly we'd expect linear v/z relation otherwise; also signature is slower velocities at large distances than expected by extrapolation from now.
• Underpinning Copernican principle is implied by cosmological principle, not independent. Can't fathom in what way S-Z "tests" the cop. principle. Tests of parameter variability can't be naively extrapolated back to t=0, they may vary faster in the early universe. The FRW metric is kinematic, i.e. based on Reimann geometry but not Einstein's dynamic theory. I wouldn't say the metric "relies" on a coord chart, that's just one way of expressing the metric. The idea that "space expands" is perpetually debated; its not clear that there is a real difference from true motion. It's far from clear that the Hubble expansion tries to "pull apart" bound systems like solar systems, especially if embedded in a larger bound system like the local group. I don't understand the comment that the BB corresponds to a finite interval of conformal time... possible confusion with finite interval of comoving space on a conformal diagram?
• Evidence The "three pillars" is very 1970's... nowadays there are many more, e.g. cluster masses, ages of oldest stars, etc. Hubble's law: why do descriptions of this always go on about the easy bit (getting v from z) and never discuss Hubble's actual contribution (getting D)? The formula is misleading as it is true for present-day velocities, not for velocities as measured on the light cone (anyway at high redshift (1+z) is expansion factor, not directly related to v). CMB photons are produced later than baryogenesis on any definition; individual photons retain their identity from a few days after the BB, when true emission mechanisms freeze out (see 3K by Partridge), subsequent Compton scattering is not an emission process. I'd like to see recombination distinguished from decoupling: photons remain well coupled until almost all electrons recombine. Somehow COBE's most famous result (detecting fluctuations) is omitted, as is the Nobel to Smoot & Mather. Discussion of Omega=0.3 is ahistorical as clear evidence for flatness didn't turn up until the Boomerang & Maxima results in 2000. Discussion of nucleosynthesis brushes a mess under the carpet, of 4 tests, D agrees with WMAP, He-3 has lousy errors, He-4 formally disagrees, and Li-7 radically disagrees. These can be explained away but it's not a big success.
• Issues & problems Inflation is not regarded as firmly established by most cosmologists; it is just the most plausible hypothesis. Otherwise why are NASA & ESA contemplating hugely expensive space probes (see Beyond Einstein program) to see if it's true? Description of inflation implies it violates Hubble's law; not so! Also description involving horizon is too compressed to avoid misunderstandings (e.g. there are several different horizon concepts). Flatness comment uses "geometry" instead of "curvature", confusing local geometry with topology (see shape of the universe). The flatness tuning is bogus since infinitely good tuning at t=0 is required by the FRW assumption; much better to emphasise the oldness problem. AFAIK the monopole problem is outdated since GUTs consistent with modern particle physics limits don't produce monopoles in worrying quantities. Discussion of lab CPT test is out of place; this is not a serious candidate for baryogenesis. Dark matter: the universe (now) is far more lumpy than expected w/o DM. Or, the early universe (CMB fluctuations) should have been lumpier than observed to get to present state without DM. The implications of the bullet cluster for alternatives to DM (e.g. TeVeS) are still being assessed. Give it a couple of years. Dark energy the wrong idea that CMB obs. established flatness in the 1990's resurfaces. It's worth emphasising that the Omega values change radically with time & are quoted for present day.
• Future Star formation is not suppressed by cosmic expansion but by running out of interstellar gas within each galaxy. On the other hand further galaxy formation has already been suppressed, pretty much. For almost all theories, protons decay long before astrophysical black holes evaporate.
• Beyond the big bang Might discuss before the big bang, if latter is defined as state of very high density and temperature in thermal equilibrium. Several theories discussed here do imply that the BB was an event in the history of a larger universe, not the beginning; this should be made clear.
• Religion Worth saying that Fred Hoyle frequently claimed that the big bang was religiously motivated. It didn't help that Georges Lemaitre was a Jesuit priest.

PaddyLeahy 20:54, 30 April 2007 (UTC)

Hey, an interesting list. I agree with much of what you're saying, but not all (more on this below). But, um, maybe you could consider actually doing the edits? Otherwise it just seems a little inefficient to list things that you feel should be changed here, and then wait for other people to implement the suggestions that you've made (be bold).

As I said, I agree with the bulk of what you're saying. I'm sorry to focus on the negatives, but here are some examples where I don't think you're on the mark;

• Lead "...a natural reading would suggest a finite density at the singularity" not sure what you mean here, but maybe you meant infinite density?

Nope, lead asserts a finite ("tremendous") density for the initial state... begs the question, what is the initial state (if not the singularity)?

• Underpinning
  • "The FRW metric is kinematic, i.e. based on Reimann geometry but not Einstein's dynamic theory." (btw, I think you mean Riemannian geometry). Perhaps what you're trying to get at is that you only need GR to specify the differential equation satisfied by the scale factor a(t) in the FRW metric, but not the FRW metric itself. Fair enough, I don't agree that is an important point to make here. One of the assumptions of GR (which follows essentially from the equivalence principle) is that gravity should be described by a metric on spacetime, so I'm quite comfortable regarding the fact that spacetime should be described by a metric as part of Einstein's theory.

Judgement call on importance; I don't like to quote unnecessary assumptions.

• • "The idea that "space expands" is perpetually debated; its not clear that there is a real difference from true motion." Debated by whom? It's pretty well accepted. And what do you mean by "true motion" in this context?

dx/dt? There's an interesting diatribe about this on John Peacock's web site, for a start. Arguably the difference between "galaxies move" and "space expands" is just the coordinate choice.

• • "It's far from clear that the Hubble expansion tries to "pull apart" bound systems like solar systems, especially if embedded in a larger bound system like the local group." See geodesic deviation. This is a natural way to define the "force" from Hubble expansion, but it's just much smaller than the binding forces in those systems.

But this analysis ignores the space-time curvature associated with the bound system. (Which may be embedded several layers deep in systems which have already dropped out of the Hubble flow... see space-time diagrams on Ned Wright's site).

• • The conformal time issue. Whether the singularity (or whatever) is a finite conformal time to the past does depend a little bit on the assumptions you make about what goes on in the very early universe. I think the point that section's trying to make is that there are horizons in the universe (according to the model) that can be understood using conformal time.

Mea culpa, my misreading... I thought the "finite interval of conformal time" referred to the big bang itself rather than to the gap between then and now. Might be re-phrased to make it more transparent.

• Evidence
  • "...not for velocities as measured on the light cone..." do you mean high redshift here? Or what? I'm a little confused as to your meaning. For low redshifts (z<1) the Hubble's Law formula works pretty well. Also, when Hubble proposed his law, that's the formula he used. Like other laws, it can get modified as people probe more deeply (in this case to larger z).

Yes, I mean it would be good to distinguish v(t) = HD(t) (always true) from the more messy redshift-distance formula. Lots of redshifts at z > 1 nowadays!

• • "...Discussion of nucleosynthesis brushes a mess under the carpet..." What mess? BBN is incredibly successful. There are no other explanations for the abundances of primordial elements that even come close. Also, your criticism of BBN doesn't take account of any observational systematics that could be involved in these "discrepancies."

Seems like special pleading to me: 1 success, 2 failures. Obviously there are systematics but I could think up plenty if it was D wrong and Li right. The Spite plateau (constant Li-7 in oldest stars) looks so convincing... (I'm not claiming this disproves the BB, but it is not a nice clean proof).

• Issues and Problems I do agree that "Hubble's Law" is misused here.
  • "...confusing local geometry with topology..." Not sure I see it. Right now nothing is said about topology in the article...

To a naive reader geometry implies the full structure including topology, as the picture suggests. elliptical refers to a specific topology (in fact the one with poles of spherical geometry identified). Referring to curvature (esp with a suitable link) reduces scope for confusion.

• • "...The flatness tuning is bogus since infinitely good tuning at t=0 is required by the FRW assumption..." Nope, FRW accommodates arbitrary spatial curvature thanks to the k parameter that appears in the metric.

For any FRW universe with a big bang, however close you want the density to be to the critical density, it will be that close for some sufficiently early time. i.e. just saying Omega is very close to unity at (unspecified) early times doesn't add anything to the basic FRW assumption. OTOH saying the universe is still expanding after 10^61 Planck times does indicate fine tuning.

• • You're right about the lumpiness issue. But...
  • "...The implications of the bullet cluster for alternatives to DM (e.g. TeVeS) are still being assessed..." Yes... But for the majority of workers in the field, TeVeS is not a viable or attractive alternative to dark matter, although some people do (and of course should) work on it. I think TeVeS falls under undue weight here, though maybe a debate on alternatives could be in the dark matter article.

Respectfully disagree. MOND was attracting increasing support (e.g. from those working on galactic structure) even before Bekenstein relativised it. For instance Rees nods in the MOND direction when discussing dark matter in Just Six Numbers. Scientists like to have alternative ideas they can test against the standard picture. And the history of MOND is full of attempts to rule it out that proved to be just misunderstandings of the theory.

• "Dark Energy"
  • "...the wrong idea that CMB obs. established flatness in the 1990's resurfaces." CMB observations were instrumental in establishing flatness. Are you taking issue with the decade? The first measurements of the location of the first peak in the CMB, which is an excellent indicator of curvature, took place in the '90s.

Yes I'm taking issue. Despite partizan claims by supporters of experiments like QMAP and TOCO, I don't think the community (I'm in it) was convinced about the first peak until the Boomerang results (early 2000, I remember it well).

• • "...that the Omega values change radically with time..." Sure, they'll be different in the future, but it'll take tens of millions of years to notice. I see this as kind of like saying that one should note that the age of the earth is quoted as the present day value.

But the context is a discussion spanning the whole history of the universe. It's obvious to the casual reader that the age of the earth changes with time, not so for Omegas.

Like I said, sorry to focus on the negatives -- I think the other things that you mentioned would make great contributions to the article and could really improve it, if you chose to edit them in. Wesino 22:16, 30 April 2007 (UTC)

So of course that's one reason I didn't edit the article directly, the other being that I don't have time to enter into revert wars on all these points esp. to dig out supporting references. PaddyLeahy 00:03, 1 May 2007 (UTC)

You obviously have some fair amount of scientific knowledge, but I suspect you haven't really thought deeply about some of the responses above (e.g., dx/dt is "true motion"??). Without getting drawn into further arguments on these points, let me just summarize what I see as the problem with some of your proposals. You're saying that we should insert claims that

• One shouldn't assume Einstein gravity to do cosmology,

• The Hubble flow is not due to the expansion of space,

• BBN is wrong,

• The universe has nontrivial topology,

• The flatness tuning argument accepted for at least three decades (proposed by Dicke and Peebles, and used by Guth to argue for inflation) is wrong,

• MOND is an acceptable replacement for dark matter.

These are all fringe-y positions. As someone "in the community," you should know this. It's misleading to assert that these represent consensus positions in the field, and in what's essentially an introductory article on the big bang, no less. These points are worth debating, perhaps, but these are all issues where the vast majority of the community has already come down on one side, and it isn't the side you're advocating.

It's too bad that you have the time to trash the article (as well as a lot of the standard cosmological model along the way) but not enough to try to fix things! Some of the points that you originally made were pretty good, and dealt with widely accepted physics/astronomy. I was also intrigued by some of the historical points you made, as right now the article is a little weak in that area.

But there's just no point in adding references to all kinds of fringe topics, when the basic science of the consensus model isn't well represented in the article. I'm sure you'd have to agree with that. Wesino 08:10, 1 May 2007 (UTC)

(unindent) Ho, hum. First, I'm glad you agree with a lot in my original post. I'd be very pleased if all the editors also agreed on these points but it seems a bit hopeful. It wasn't obvious to me that the points you highlight above would turn out to be particularly controversial, mainly because I was not suggesting that these should be stated as facts, just that the article should be more nuanced. But from your reaction I think it would have generated a lot of heat if I'd just boldly edited the article, so I'm glad I didn't. My take on this article (and actually many WP cosmology articles) is that there is a tendency to take the simplest model that (just about) fits the data and claim that this is the community consensus position. Working scientists like to keep a bunch of different theories in the air at once, are acutely aware of the points in "standard models" where empirical support is weak or alternative models are available, and would like these to be made clear in encyclopedia articles.

On your points above, I wasn't objecting to the use of GR, just to the statement that GR was a necessary assumption for the FRW metric. I'd rather GR was brought in as an additional assumption needed to find a(t), but I'm happy to bow to consensus if this is thought too picky. I've cited a discussion by the author of a leading postgrad textbook, Cosmological Physics which argues that the phrase "expansion of space" is misleading (and he is not a one-man band); I just asked that this phrase not be stated as gospel. For the record, I don't think that BBN is wrong, but in it's current state it is incorrect to say that the observations (except of deuterium) unambiguously agree with the BBN predictions: this disrespects the observers who came up with values that as the cited review shows, are several/many sigma off (For He-3 there is apparent agreement but huge potential systematics). In a sense this "pillar" has become less persuasive recently, because the errors are getting smaller but discrepancies are not going away (presumably due to systematics, but that's my biased position). I don't think the article should claim this as a triumphant vindication, although I totally agree with the point that even qualitative agreement is quite impressive. Non-trivial topology has been the subject of numerous observational tests and even claims that it may explain some anomalies in WMAP; no part of standard cosmology relies on the topology being simple. So, I think the article should allow interesting topology as a possibility. Dicke & Peeble's discussion of flatness/oldness revolves around how long the universe has lasted, i.e. it emphasises oldness as much as flatness. Later presentations have often cheated and the version in the current article follows those, unfortunately. On MOND/TeVeS, I was objecting to the claim that this was definitively ruled out by the bullet cluster. I do think it is sufficiently notable to deserve a mention: Bekenstein (2004) had 138 citations last time I looked, which is pretty good going for a fringe theory. It would be hard to find a working scientist who would say we shouldn't thoroughly investigate it before concluding that non-baryonic DM is the only possible explanation. PaddyLeahy 11:08, 1 May 2007 (UTC)

I think that this is too much discussion and not enough action. I agree with most, if not all, of Paddy's and Wesino's commentary: including the bits which seem to be in contradiction. I encourage Paddy to go through and make edits and the rest of us will modify as we see fit.

Two comments:

• The SZ effect indeed tests the Copernican Principle by confirming the T_0/a relation for the CMB. If we lived in a universe which violated the Copernican Principle, we could explain our observations as being due to a Milne-type "explosion" and the CMB as being a radiation signature of it. However, if everybody sees the CMB at the same temperature for the same space-like interval, we must not be at such a preferred position.

• The BBN gives the right abundance for hydrogen and deuterium is extremely important. This confirmation is qualitative only in the sense that it is less well-determined than other evidences (e.g. the position of the acoustic peaks in the CMB power-spectrum). Scientists tend to be overly-skeptical when talking shop for good reason, but when the day is done it is a good idea to put all your cards on the table. Paddy is right, we spend a lot of time worrying about the holes: but this has the unintended effect of causing us to dwell on them unnecessarily in summative conversations. Wikipedia is not a conference talk, it is supposed to be an encyclopedia. That BBN works at all is amazing and while a brief mention can be made of systematics issues, dwelling on this idea opens up cans of worms that are generally unintended. Do you know how much Eric Lerner drones on-and-on about these BBN "problems"?

--ScienceApologist 13:41, 1 May 2007 (UTC)

OK, 3 editors is a consensus. Made a start; I'll do more when I have some books handy. I'd be happy for other motivated parties to do some of the work... PaddyLeahy 19:35, 1 May 2007 (UTC)

I see SA has already started. I deliberately avoided mentioning the Planck epoch in the overview, since that is definitely in the "speculative" phase, not in the "good reasons to believe" phase. Again, I was deliberately vague when this started but for me it's when kT = 1 TeV or so, i.e. the experimentally tested range. PaddyLeahy 19:49, 1 May 2007 (UTC)

I think this is a matter of taste. The Planck epoch is when the models give contradictory predictions. After that time, the models are pretty much consistent. They may yet be proved wrong, but they are inductively sound predictions that are made. Before the Planck epoch is anybody's guess, for the most part. --ScienceApologist 20:32, 1 May 2007 (UTC)

Yes, SA is right. More editing, less arguing! I hope I haven't offended with my comments, but sometimes you feel like someone's got to make the argument, you know? In any case, I think the flurry of edits that have been going on over the last few hours have definitely improved things. Wesino 20:57, 1 May 2007 (UTC)

On the Planck epoch, I've tried to steer a middle course here, so it's mentioned but in a kind of "terra incognito" way. I wonder if there's a way to denote the lines that separate physics everyone agrees on (kT < 1 TeV) from physics people kind-of sort-of agree on but is untested (1 TeV < kT < 10¹⁶ GeV) to physics where it seems like nobody has a clue (kT > 10¹⁶ GeV)? Wesino 20:57, 1 May 2007 (UTC)

I'm glad for the attention to detail and nuance being discussed above, but I hope it doesn't get in the way of the big picture in this article. Don't forget the audience. Viva la balance. Cheers, Gnixon 22:51, 2 May 2007 (UTC)

Novice says

I thought robert dicke of princeton developed big bang theory but i dont see him mentioned ???

SINGLE STATE THEORY: [...] i used to beleive in the entirety of this theory - the big bang theory )j(, but since the docu$drama that ridley scott did of steven - i have wondered that the theory he went up against as shown in the beginning 'i've worked it out - bunny',, has grown backwards against this his neo/matrix/envelope {tacyon lens} to have only have seen this once "i": and then to have to go |so that theory was called| /\ but then look at the envelope say the publiscists, here is the sound-map and the varying-degrees-charts all relating to \/ the big-bang,, 'i've forgotten the bunny';; [*], but then it comes back in between meals despite advertising of this kind;;;;; in partisan-realisations from this point, it seems to be that the theory he rebelled against had something to do with certain-orthodoxies,, ]very distracting millman[ & now particle accelerators appear - making new chart-legos M,, before you can say € they have closed some sort of office of interpretation at the same point you would have done ??? the certain-orthodox theory is like a fruit !!! [({})] !!! .. is .. so , in that case there is another theory that is like a tree and stevens theory is about a seed ||| in the lego-factory documentary it showed something like big-bang-pulse-theory, that's the fruit in that case,, the charts belong to the tree ::::::: one was a noise, one was an energy and one was ^tennis match^ <cricket match> a mastery, :the bunny wins go back two spaces: in thatc ase one was dr who;:;:;: ,,, then call big-bang-theory, single state theory hence this last realisation --- gravitational destiny the tardis --- no, i really don't know this stuff,,, either way call it that,,, call the fruit theory MATERIAL STATE THEORY and call the tree theory ENERGY STATE THEORY,,, sardis... —Preceding unsigned comment added by 86.139.116.136 (talk) 15:35, 17 March 2008 (UTC)

No limits

while the traditional approaches and theory includes ideas of limitations as the speed of light's being limited, in reality there are no limits.

entrainment STUDIES SHOW ENTRAINMENT occurs at speed & range of 66 - 125 light years / sec (quite large distances....) (500 light years divided by 8-15 seconds elapsed time)

a traditional approach would be matt breathing where one breathes in expanding to the outer edge limits (of all reality) and then exhales ... the anhk (or outer - to sept tillion light years "edge" and then collapses to the point / heart center)

/s/capt queeg sr

fiducial singularity, Planck epoch

In response to some questions raised by Art LaPella I've tried to fix the sentence in question (I don't know who the original author was), which before my edits ran something like:

Nonetheless, the physical models are consistent to within a tiny fraction of a second in advance of the fiducial singularity.

Part of the problem was that in advance of the singularity would have been before the Big Bang (which isn't generally discussed in the BB models, and certainly isn't a point of agreement amongst physical models!). Also I'm not sure that it's a "fiducial" singularity. True, my Merriam-Webster defines this word as "(esp. of a point or line) assumed as a fixed basis of comparison." but my understanding is that usually this word applies when you have many versions of something, but want to single out one as the basis against which others are compared. I could be wrong.

It's a tricky paragraph, though, since what you really want to say is that nobody knows what's going on in the planck epoch, and after that we make a whole lot of assumptions/guesses (though founded on QFT/GR etc) basically until BBN when you have some idea what's going on. Definitely, that paragraph can be improved. Cheers, Wesino 22:41, 2 May 2007 (UTC)

As I mentioned above in a discussion that had died off when I got to it, I think we should be very careful about discussing singularities too prominently---could be misleading to the novice reader. Gnixon 22:52, 2 May 2007 (UTC)

Hmm... Yeah, I see where you're coming from. Definitely (and especially given how looong the article is now) there's a case to be made for excising the singularity stuff. I wouldn't object myself, I think there tends to be a lot of duplication of information on Wikipedia so brevity is always a good idea (my POV). I guess I can kind of see pros and cons to discussing the singularities, something like --

Con: The singularity concept is confusing to novice readers, and it's not clear exactly how it fits in to the whole picture. We could just keep things simple and say something like "the bb theory assumes the universe started in a hot dense state, and then X happened," which would save space and make things easier to read. Interested readers could be referred to more detailed articles.

Pro: It's a nice, "hic sunt dracones" reminder that it isn't all worked out yet. It is an interesting (albeit almost... philosophical) point that when you run the equations of physics in one direction they eventually break down.

How do others feel about this? Wesino 23:09, 2 May 2007 (UTC)

Pro: most readers will have already heard of the idea that the Big Bang is an explosion "from a point" or some such, so it's worth mentioning to say that it ain't necessarily so. NB I think User:ScienceApologist introduced the "fiducial" word to mean that whether the singularity exists or not, we're using the nominal time of the singularity as a reference point. Personally I think this introduces more confusion than it solves. PaddyLeahy 23:14, 2 May 2007 (UTC)

I liked the way one part of the article (intro?) referred to some post-singularity time as the "initial state," just characterizing it as "hot and dense" or something, but I noticed from somewhere on this talk page that it caused confusion. It would probably be worth saying explicitly in the intro that we expect known physics to break down before that point (or before a "singularity".) I'm down with mentioning singularities if we can find an elegant way to make clear that they're considered unphysical. It would be great if this article could help dispel the common conception of an explosion from a point. Gnixon 17:37, 3 May 2007 (UTC)

Yikes! Just noticed "singularity" in the diagram at the top. That really makes me wince. Gnixon 17:40, 3 May 2007 (UTC)

NPOV, MOND and TeVeS

I'd like to open a discussion about our presentation of some alternative cosmological theories in this article. It's clear from this talk page that the case I'm going to focus on is controversial, so instead of just doing the edits, I want to put the argument out in the open.

I think we are vastly overstating the case for alternatives to dark matter in the article, which causes a conflict with NPOV and more importantly undue weight policies on Wikipedia.

First, an estimate of the importance of DM alternatives in the scientific community. I obtained this through searches in two databases of scholarly articles, the NASA Astrophysics Data System and the Stanford Linear Accelerator Center (SLAC) SPIRES database, both publicly available. These databases index some of the same papers, but do not overlap completely. Any paper that you publish on astronomy, astrophysics, general relativity, high-energy physics, string theory, quantum gravity, or cosmology (even if you just post to the arXiv) it will appear on one (and probably both) of these databases.

On NASA/ADS, a search for abstracts with the phrase "dark matter" returned 23,457 articles. Searching for abstracts containing "modified," "newtonian," and "dynamics" gave 550, searching for "MOND" without "modified" or "newtonian" (to avoid overcounting) gives 353, searching for "TeVeS" yields 39.

Ideally one could search for abstracts containing "tensor" "vector" and "scalar", but this gives way too much noise with articles about cosmological perturbation theory. Here are the search strings I used on the search page and the results:

 23457  "dark matter"
   550  +modified +newtonian +dynamics
   353  MOND -modified -newtonian     
    39  teves                                  

Now assuming ALL of the articles that mention MOND/TeVeS are pro (thus including titles like "Bullet Cluster Disproves MOND" in the pro camp) I get a ratio of (23457)/(550+353+39) = 24.9 dark matter articles per pro-MOND/TeVeS articles in the scholarly literature.

One can do the same thing on SPIRES with the search terms dark matter (5040) MOND (103) Modified Newtonian Dynamics (99) and TeVeS (8). This gives a weighting factor (again assuming all articles that mention MOND/TeVeS are pro) of (5040)/(103+99+8) = 24.0, similar to the number obtained above.

Now, how much weight do we give each point of view in the article? In the present revision of this article, a quick word count reveals that in the dark matter section, the explanation of the dark matter model is 178 words long, and that for MOND/TeVeS 121 words. Thus in the article the weighting ratio is something like 178/121 = 1.5.

This means that in the Wikipedia Big Bang article, we are giving alternatives to dark matter roughly 17 times more weight than does the scholarly literature. To bring the ratio in the article more in line with the 25-to-1 ratio in the existing scholarly literature, alternatives would warrant seven words. I suggest:

"Some scientists advocate alternatives to dark matter."

In place of the paragraph on MOND/TeVeS in the dark matter section.

Before you flame me -- Am I saying that no-one should research MOND/TeVeS/whatever? No. Am I saying that people who do are fools? Certainly not. Do I think that one shouldn't discuss alternative ideas? Not at all. Should science have an intellectual monoculture, where establishment ideas rule the roost and cannot be questioned? Definitely not.

In an introductory article, let's give similar weights to ideas as would the experts in the field. We don't have to say that scientists agree on everything, and it doesn't have to come down to word counts, but right now we are vastly overstating the case for some of these "alternative" models. Wesino 11:44, 5 May 2007 (UTC)

You are right, Wesino. Such advocacy does not belong in this particular article. Alternatives to dark matter are not even related to the subject of the Big Bang. I'm eliminating the entire discussion. --ScienceApologist 14:15, 5 May 2007 (UTC)

I concede Wesino's point about the unbalance, though his numerical data is exaggerated: TeVeS has existed for less than 3 years and the software tools to compare it to observations are far more primitive than for GR, which gives a sociological bias to the conventional theory in the current literature; moreover, the literature on Dark matter is substantial from the late 1970s on. (I would not be making this fuss if it was still just MOND, which cannot really be reconciled with the rest of physics, despite its empirical success). Contra SA, the issue is pretty important for the Big Bang since if you replace the theory of gravity the whole theory has to be re-calculated from scratch, which is exactly what a number of people (not including me) are currently doing with TeVeS. I think you'll find that most recent popular accounts of dark matter will at least mention the modified gravity option. So I have restored the mention of MOND/TeVeS but in a much briefer form. I think the current version is more or less what Wesino was hoping for. PaddyLeahy 15:15, 5 May 2007 (UTC)

I don't buy this as an argument for inclusion. While I submit that you would need to recalculate the Friedman equations and try to reconcile WMAP results if GR is wrong, this is true regardless of whether the model is MOND/TeVeS or any other outfit. What makes MOND/TeVeS notable for the dark matter page is that it is the most popular "alternative" explanation. However, this is one level of specificity removed from the Big Bang and doesn't add any information about this cosmological model to our article. If there actually was an alternative explanation that could modify Lambda-CDM to account for MOND, then we would have something to report. As it is, all we have are arguments from another (though plainly related) field of study. Therefore mention of this idea rightly belongs on the dark matter page, not on this page. --ScienceApologist 22:24, 5 May 2007 (UTC)

OK then, replaced specific refs to MOND/TeVeS with alternatives to general relativity. I'm resisting characterizing this as a set of mavericks challenging the establishment, because in fact perfectly establishment scientists are investigating TeVeS, and indeed mostly conclude that it does seem to do the generic business (lensing, structure formation, BBN, CMB). Specific cases like the bullet cluster are stronger tests because MOND has slightly fewer knobs to adjust than GR+DM. But I'm not trying push MOND (on the main article space, anyway), just explain why DM isn't 100% certain, and at the same time indicate why this would have a big impact on the Big Bang model. PaddyLeahy 00:06, 6 May 2007 (UTC)

Still not convinced. CDM is used as a matter of course by theoretical cosmologists in N-body simulations, for example. To build, from the ground-up, a new theory of gravity will require an explanation for why N-body simulations have been successful. There will have to be some sort of accounting for why the supposed "epicycles" of non-baryonic dark matter work so well today when and if an explanation of the "heliocentric" paradigm shift of the alternative GR formulation is offered. I'm not arguing that respectable scientists don't propose alternatives, only that these proposals are too initial to warrant comment on this general, summary page.

To further describe my point, please consider the section of the article on dark energy. It is rather blythely assumed there that dark energy is all but certainly a negative-pressure term associated with a cosmological-constant like variable in the Einstein Equations. Only don't tell Rocky Kolb that (wink, wink)! I'm of the opinion that we handle dark energy properly on this page: the alternatives are a level of specificity removed and lack the detail development and incorporation into neostandard theory. As an interesting aside I might add that the theoretical work with dark energy is minimal when compared to the theoretical work that takes place with dark matter (mostly dark energy allows for the right amount of dark matter in order that the Friedman Equations yield a flat universe). This is why I'm of the opinion that alternatives to GR should be excluded from our discussion of dark matter. If people are really interested to learn more about the subject, let them read about them in the dark matter article itself. To include them here is to document the (sidelined) debate in the wrong place.

--ScienceApologist 03:05, 6 May 2007 (UTC)

(un-indent) I think ScienceApologist makes some very good points here. I think the central point is that it's just too far removed from Big Bang topic itself (though possibly germane for the dark matter article, which already has a section on alternative explanations). There are separate objections that I have for TeVeS and such, but since it's not on the article page I won't bring them up. I believe that the off-topic nature of the paragraph/sentence/whatever is by itself sufficient reason to remove.

Another problem is that the premise for inclusion is that "if GR is wrong, then we have to recalculate everything." For one thing, this is evident. For another, it would be absurd to insert similar statements elsewhere in the article. (In the CMB section, caveats that electromagnetism or atomic physics is wrong, in BBN nuclear physics or thermodynamics, then predictions must be recalculated). I am making a valid slippery slope argument because there is exactly as much evidence that GR is wrong as there is that electrodynamics, thermodynamics, atomic physics, etc are wrong -- none.

One final point. The argument is repeatedly made that "respectable scientists work on TeVeS." No one has ever argued the opposite here. The bone of contention is whether cosmologists in general feel that things like TeVeS are reasonable replacements for GR+CDM in the contexts of lensing, structure formation, CMB, BBN, and the Bullet cluster. A careful reading of your previous post reveals that claim that scientists who work on TeVeS mostly conclude this is true. I would say there is a strong selection bias there -- people who work on theories generally believe they're true. But are these only five people out of 1,000? Or 900 out of 1,000? If you were to strengthen your claim to say that most cosmologists think it's a comparable or better option than CDM, that's just false. Most cosmologists do not think that TeVeS is a serious contender to CDM (maybe it will be, but right now it's not).

So based on the reasoning in the first two paragraphs, and SA's previous post, I'm going to remove the alternative gravity stuff. It's off-topic, and the interested reader will find an entire section in the dark matter article and a whole article on alternatives to general relativity. Wesino 10:20, 6 May 2007 (UTC)

Actually this discussion highlights a fundamental difference in philosophy about NPOV that I mentioned earlier. For Wesino and SA, the "default theory" should be presented as fact unless there is an alternative theory that a significant fraction of the community believe is true. My interpretation of NPOV is that if the majority of the community is not convinced "beyond reasonable doubt" that the default theory is true, then the general reader deserves to know this and have a pointer to some of the other ideas kicking around. Your attitude gives the misleading impression that scientists are much more sure than they really are, it denies the reader relevant links (it took me a while to find the alternatives to GR article... a naive reader would not think of looking), and your conditions for mentioning rival theories will almost never arise in a mature science: I can't imagine that it will ever happen that say 30% of cosmologists are full convinced by MOND and the rest reject the idea out of hand. Instead, there will be rough agreement on the (subjective) probability of MOND being right. (I'd give odds of 5-10% at this point, not that out of line with Wesino's paper count). Compare Martin Rees's comment (in Just Six Numbers) that the COBE results allowed him to increase his personal odds on the big bang scenario as a whole from 90% to 99%... can we be more certain today about DM than we were about the big bang in 1990?

To SA: why are people doing all these CDM simulations? Answer: to calculate the implications of the theory and compare the results with observations, i.e. to see if the theory is right. They wouldn't be doing this if the theory was regarded as fact. (They'll do the same with TeVeS, given time). In fact around 30 papers have been published recently on "f(R) gravity", a theory which purports to dispose of dark energy, so if I was consistent I'd advocate a mention there too. OTOH the Kolb dispute is essentially on who can do the GR maths correctly, Kolb et al or everyone else; it's not an empirical point and Kolb et al are definitely a "tiny minority" there.

To Wesino: Unlike gravity on galactic & larger scales, we do have compelling experimental and observational evidence the EM, thermodynamics, and nucleosynthesis "work" pretty much as currently understood in the conditions relevant for big bang theory. The article even mentions one caveat, about fundamental constants changing with time. It also mentions that n-body simulations actually show a couple of significant discrepancies with observations (cuspy halos & dwarf galaxies), so all is not hunky-dory with GR+DM... we must modify one or both. My point about "mainstream" scientists is that experts on cosmology and galaxy dynamics (e.g. Binney, Silk), who had nothing to do with proposing MOND or TeVeS, are now publishing papers containing detailed calculations using the theory in order to assess it (in some cases clearly with the intention of ruling it out, though they have not yet been successful in this), i.e. work is not just being done by its inventors. PaddyLeahy 21:53, 6 May 2007 (UTC)

Would not a theory, TeVeS, which adds vector and scalar fields to the tensor field of GTR be equivalent to GTR plus new matter fields (the vector field and the scalar field)? Should not the quanta of these new fields be observable particles? JRSpriggs 05:14, 7 May 2007 (UTC)

I don't claim to fully understand TeVeS, but as far as I do understand it, it seems to be a more radical revision of GR than just adding a couple of fields... and a quantized version would be at least as far off as a quantum gravity theory with GR as its low-energy limit. OTOH Saunders' biscalar version of relativistic MOND apparently does predict a class of DM particles as you suggest. PaddyLeahy 12:46, 7 May 2007 (UTC)

PaddyLeahy, you are spouting factual inaccuracies. SPIRES says that Joe Silk has published precisely two papers that cite Bekenstein's TeVeS paper (Phys. Rev. D70, (2004) 083509). Here is a link to the abstract of one, and the other. The first one concludes that MOND is not a CDM replacement. From the abstract of the second one:

... we find that the cold dark matter is strongly favoured with Bayesian probability ratio of about one in two hundred.

Hardly resounding support for anything other than CDM. And as far as I can tell, despite your claim to the contrary, Binney has never written a paper citing Bekenstein's PRD70 article. Here's the SPIRES link if you care to check for yourself. Wesino 21:18, 7 May 2007 (UTC)

What I said was that Silk & Binney have published papers applying the theory, with a critical point of view, but had failed to rule it out. Your quotes support that for Silk: "strongly favoured" is not the same as a definitive proof. Silk's other paper says that MOND works for clusters if and only if heavy neutrinos are invoked, which is agreed by MOND partisans. The papers by Binney I referred to were on MOND rather than TeVeS since they addressed problems in the non-rel regime: [1] and [2]. Again these highlight problems but not fatal objections. PaddyLeahy 23:05, 7 May 2007 (UTC)

MOND's agreement with galaxy rotation curves has never really been in doubt. The trouble has always been its extension to other regimes, especially to relativistic regimes and cosmological scales where it never really worked well, if at all.

Keep in mind that this was the paper cited in the context of serious people taking alternative gravity seriously, and it still clearly talks about them being disfavored.

Also, in science there are no definitive proofs, just degrees of probability. (Unless you're a sound science proponent) Anything happens with finite probability, you just wouldn't be advised to bet on it. C'mon. Wesino | t | 00:45, 8 May 2007 (UTC)

Thanks to Wesino for his sober analysis of this problem. I concur with his conclusions. --Pjacobi 12:03, 8 May 2007 (UTC)

dark matter edit

I just changed this sentence in the dark matter section --

The detection of dark matter is sensitive only to its gravitational signature...

since I wasn't clear if the assertion was that DM interacts only gravitationally, or if that's just how we've detected it thus far. Since it's free to interact in other ways besides gravity (eg, WIMPs) I thought the new version might be more accurate. Wesino 19:21, 6 May 2007 (UTC)

SZ and copernican principle

I deleted this sentence from the "Underpinnings" section. It was very unclear. SA offers an explanation above, but it seems to me that he describes a test of the big bang model as a whole (vis-a-vis one particular theory in which the CP does not hold) rather than of the Copernican principle itself. Anyway its a bit tricky because the SZ signal depends on cluster properties which are not usually independently measured. I will add a mention of tests of T/a to "observational evidence".

Also, since the underpinnings section mentions GR and had a spurious extra "assumption", I replaced this with the assumption ethat GR is right and stuck the disputed reference to alternatives in there. Maybe people will agree that this is less offensive in this context. PaddyLeahy 14:45, 7 May 2007 (UTC)

Another way to think about the SZ measurements is that they test the CP by measuring the local value of T0. That is, if observers a few Mpc "over there" measure a hotter CMB temperature (even if it obeys the correct T(a) relation) you'd see that in SZ.

I have an issue with the recent edit as it stands, since it jumps into alluding to problems with the big bang 1. before even completing the description of the theory (!!!) and, 2. without even mentioning the problems. Stylistically, the criticism of GR is in the wrong place (more on this below).

Also the edit is factually incorrect. GR is an absolutely essential element of the cosmological perturbation theory that lets you compute the CMB spectrum for l < 200 or so (eg, superhorizon scales at decoupling). So the implicit claim that it's only been tested on stellar scales is misleading.

Overall I'm very unhappy with the repeated "alternative gravity edits." I really fail to understand the POV that insists that the fact that GR is potentially wrong is an essential feature of the big bang model (despite the utter lack of evidence). Paddy, I applaud your edits in other areas, but the insistence that "alternative gravity," whose predictions are largely unknown, has made no unique predictions of its own, is not supported by the majority of cosmologists, and solves no pre-existing problem in the theory, strikes me as teach the controversy. Frankly, I think you would do well to read Will's book, then read it again, and then possibly a third time, and then start talking about the evidence for GR.

This irks me. Will's most recent book is 14 years old & therefore irrelevant for discussion of more recent theories (also way out of date on precision confirmations of GR on AU scales). You also apparently need to do some reading if you think that MOND has made no successful predictions and supplied no generic solutions of problems which need a posteriori "adjustment" with GR+DM: see the recent review by Mike Merrifield [3] (who is not a supporter of MOND). You keep requesting a list of "supporters" of MOND as if this were about competing football teams. Cosmologists are grown-ups. Read my comment under "NPOV" etc above. PaddyLeahy 22:53, 7 May 2007 (UTC)

Beyond just waking up each morning and removing these edits (which isn't really how things are supposed to work here), and posting/reading long diatribes on this talk page, I'm not really sure what we should do to reach a resolution. Does anyone else have thoughts on this? Wesino 20:56, 7 May 2007 (UTC)

Only that this is very mild compared to the archived diatribes of years past, so we must be doing something right. Art LaPella 21:28, 7 May 2007 (UTC)

Wow, glad I wasn't around.... Wesino 21:31, 7 May 2007 (UTC)

(later) Also, I am disturbed by apparent attribution errors -- see my comment at the end of the NPOV, MOND, and TeVeS section. Unfortunately, you'll have to scroll down a bit. Wesino 21:21, 7 May 2007 (UTC)

I'll cite chapter & verse on those in a minute... PaddyLeahy 22:53, 7 May 2007 (UTC)

For the last week I've been slowly correcting the problems I originally listed on this page and have now finished, so I hope the iteration will converge soon. I have not directly reverted changes that you (Wesino) and SA agreed on even when I disagreed. Wesino, I think you are confusing the amplitude of the argument about validity of GR that is going on on this page with what the article actually says. Also, you seem to think I'm an anti-GR zealot, whereas I submit that my comments here and edits to the article clearly give high probability to GR being right (if any edits don't read that way I'm happy for you to correct the article). No-one disputes that GR must break down by the Planck epoch. It is important to emphasise this because many presentations of the Big Bang identify the singularity (hence the "beginning of time") as the key element, whereas this article quite correctly makes the case that the essence of the theory is the early hot state from which all observable consequences flow... the singularity or any pre-big bang ideas are no more than interesting speculations at the moment. No one disputes that GR is one of the major assumptions of the Big Bang model (it is referred to as an assumption numerous times in the article, not as the result of my edits). Hence why not include a sentence or two on the evidence, as for the other assumptions? You might just as well complain that there is not the slightest evidence that the laws of nature are not universal, or that the cosmological principle is wrong, so why cite these as assumptions? Wesino, you keep demanding evidence that GR is wrong, whereas I want evidence that it is right before unequivocally commending it to the innocent public. No GR specialist worth their salt would cite the low-l multipole prediction as a strong test of GR; these are fitted with various cosmological parameters and several other gravity theories (yes, TeVeS is one) can also be fitted.

(sorry to intrude on your post, this just didn't fit below) Actually, the low ls are not "fitted" to GR. This is because GR has no free parameters (once you've fixed G_N). GR specialists have many other tests they can point to, but this is on the largest scales.

One way we might make some progress to a resolution is for you to respond to my comments about the different philosophies we seem to be adopting... if I'm mis-characterising your position, explain yourself more clearly. PaddyLeahy 22:53, 7 May 2007 (UTC)

(unindent) I'm not sure what the business about the Planck time has to do with this, I'll just ignore it for now (hopefully without causing offense). But I'll take you up on your suggestion to clarify my position, in the hopes of reaching some kind of resolution.

I'm also unclear of what your characterization of my position actually is, but I'll welcome the chance to clarify it in the spirit of moving things forward.

• Our main responsibility, in the Big Bang article, is to clearly explain the Big Bang model as understood by the scientific community. We should take as our reference someone who is scientifically literate, and wants to learn what scientists mean when then talk about the "big bang," and why they believe it describes our world.

From this follow some subsidary points:

• If the "alternatives" to GR are mentioned in this article, they should be much less space than discussions of dark matter, reflecting their proportion of the extant literature on these topics. Discussions of these models should be located in an appropriate section in the article, after the BB theory has been explained clearly and fairly.
• If mentioned, it should not be claimed that these are full alternatives to GR. As I'm sure you'll agree -- since you yourself have made statements to this effect -- no one really knows what the predictions of these alternative models are. (Both MOND and TeVeS have free functions and many unknown parameters, for example)
• If mentioned, it should also be noted that all of the "alternative" models under anything close to serious consideration require some form of dark matter in addition to modified gravity.
• If mentioned, in fairness to CDM should be noted that most cosmologists and astrophysicists believe that observations such as the Bullet cluster rule out modified gravity models in favor of CDM.

When you ask for evidence that GR is right, I can only point you to sources such as Will's book (despite its "age"), or for that matter any textbook on GR, where you will find any number of successful experimental predictions of GR, from the early 20^th century to the recent announcements by the Gravity Probe B team. There are simply no experiments in conflict with the theory, and a great number that are completely in accord with it.

I am fully aware of the fact that nothing can ever be known "for certain," and I do appreciate your efforts to make sure that the status quo isn't calcified, and that people understand that science is in flux. But I feel that many of these "alternative gravity" edits are falsely portraying GR as a theory in crisis. They also overstate the case for the "alternatives." Even proponents of these models admit that dark matter is still required, as well as a number of other fields, interactions, free parameters, and free functions. Also GR has been tested, and passed, in vastly more settings than any of the alternatives. A fair and complete contrast of these models belongs somewhere -- but it's off-topic for the Big Bang article.

Personally, I am making an effort, however clumsy, to try an elevate this debate to something more than personal attacks. As one approach, I've gone to two primary source databases and cited statistics. I've also looked at the sources you've cited. I've also tried to engage on this talk page whenever possible instead of simply reverting.

I'm frustrated because I'm really not seeing any response to my arguments (and those of others). It's impossible to respond to an "argument by authority," for example, without getting into the details of who works where. (And shouldn't professionals be able to argue convincingly without appealing to their own authority?) For another, to the primary source statistics, there is a claim that my numbers are skewed (How? What is the opposing analysis? What ratio do you propose, and how do you get it?). There are also a number of uncited claims, and arguments by implication that a large number of respectable scientists are secretly MONDians and so on.

I'm frustrated because I have a fear that you're set on a position from which no argument will dislodge you, and a mission to make sure your PoV is known to all, despite the arguments of others and the opinions of nearly the entire scientific community. I really hope it's not the case.

I think what we need most of all here is some kind of constructive suggestions. Here's mine. How about collecting all the points about "alternative" gravity models from their present locations, and putting a bullet point in the "Speculative Physics Beyond the Big Bang" section? It wouldn't require making the text any shorter than now, and furthermore --

• This allows a complete and uninterrupted explanation of the BB theory, while allowing for the fact that some feel alternatives are important, but in an appropriate place in the article,
• It makes clear that these are still-controversial proposals,
• We already talk about the possibility of GR breaking down in the SPBtBB section (thus modified gravity would fit naturally in the theme of "beyond GR" too)
• We already talked about alternatives to GR (eg, string models -- yes these are alternatives because the EP is violated, courtesy the dilaton, and quantum gravity effects, which may modify GR)
• In a narrow sense, when people talk about the canonical Big Bang model, they usually mean LambdaCDM+Inflation. So interpreted this way, modifying both gravity and CDM fits well here.

Of course, as is probably clear, I see no case for including "alternative gravity" suggestions in the article. However, I do understand there are other points of view regarding inclusion. Nonetheless I think that there is a strong case to be made that these do not belong in the parts of the article devoted to explaining the theory itself.

If this idea sounds good, let's go with it. Otherwise, I would welcome a clarification of your position, and especially suggestions for action. (Action that doesn't involve me talking a long walk off a short pier, that is). Wesino | t | 00:33, 8 May 2007 (UTC)

Taking your comments from the top: Mostly agree on your aim for the article, but rather than "why they believe" I'd say "How much they believe". To pick an example I hope you agree on, few would claim to be fully convinced by inflation at the moment.

Your conditions for mentioning alternates to GR require that the comment be very short and that a lot is said about it, presumably to discourage the reader from following the link. This seems a bit contradictory; I'm happy to go with short. You can always edit the article at the other end of the link if you think it's unbalanced (havn't touched it myself).

The point about successful tests of GR (which are referenced in the article) is that viable alternates give identical results in the strong-field regime (by design). The issue is the ultra-weak field regime, hence the literature debate we have both referenced. I'm not going to waste space defending MOND because it now isn't mentioned in the article and as SA pointed out it is not the only alternate theory currently under discussion in the literature. I also don't want to emphasise the personal by defending myself against charges of being unreasonable etc. I'll supply references if requested on points where the article is in dispute.

You seem to think the article contains several disputed references to alternates to GR, but I can only find one, i.e. the brief mention in "underpinnings" (I thought you were counting the edit I made to distinguish the Planck epoch from the singularity, but apparently not). If other places are in dispute, please give a list so I can see what we're talking about. As for the "underpinnings" mention, it doesn't seem to me to interrupt the flow, and seems naturally to fit in that section; it comes after the "overview" has explained the BB picture in a fairly detailed way; its very brevity suggests this is not considered a likely possibility; ie. it arguable satisfies your criteria. I'd value the input of other editors on this point.

I don't think "beyond the big bang" is the right place to put this...the name seems to imply that these are ideas which can be added to the BB picture outlined in the rest of the article without changing it significantly. (Also, I've lived long enough that I can't associate the BB purely with lambdaCDM+inflation, indeed none of those concepts seem essential to the basic idea). PaddyLeahy 10:49, 8 May 2007 (UTC)

I removed what seemed to be (perhaps unintentional) pandering to alternative gravity theories. If you look hard enough, you can find a minority-opinion alternative to just about anything in science, so why single out gravity? The existence of alternatives are not in-and-of-themselves notable enough to include in a summary article, and the fact that there are no consensus falsification tests for GR versus any alternatives means that we should stick right now to describing the status quo. Even obliquely calling GR into question is disingenuous from a summary perspective because there are many other points in cosmology which are far more debatable and yet whitewashed over simply because this is a summary general-knowledge encyclopedia article and not something published in A&AR. Unfortunately, the subtlety of identifying holes in standard theories does not translate well into mass-media publications. Take New Scientist magazine's consistent travesties in reporting as an example of how it can go very wrong. Imagine the audience for this subject: people who may have only a vague understanding of what the Big Bang theory is and carry a lot of baggage and misconceptions along for the ride. If we begin throwing around alternative gravity theories like it's our job, we'll end up obfuscating the idea rather than elucidating it. WP:WEIGHT is a policy for a reason: undue emphasis on minority opinions bogs down articles on straightforward subjects.

To put this another way, try reading a standard intro text on the Big Bang and see how often it mentions alternatives to GR. If a Frank Shu doesn't do it, why should we?

--ScienceApologist 14:11, 8 May 2007 (UTC)

As it happens I have 9 of these in my office. Excluding the one written in 1974 (pre-MOND) and the one written by Hoyle (pro-maverick), 2 mention modified gravity en passant and 5 regard dark matter as certain. I'm going to concede on this point because no other editors are supporting my position, but I would say that I think the position has changed since all these books were written. (i) A major objection to MOND has been overcome (i.e. that it has no relativistic generalisation) and (ii) strong test cases, notably the bullet cluster have become available. As I said a week ago, the jury is still out on the latter. It will be interesting to see what position the next generation of textbooks will take. PaddyLeahy 15:05, 8 May 2007 (UTC)

Indeed, this article will continue to evolve as the textbooks evolve. That's one of the beauties of Wikipedia. --ScienceApologist 17:44, 8 May 2007 (UTC)

theoretical underpinnings

From the FA review it seemed like one of the issues was that things got too jargony. While looking over the theoretical underpinnings it seemed like this might be a problem. Coordinate charts, conformal time, etc.

From the looks of it, it seemed like the section was just trying to explain the GR mathematical model for the BB, which would be in parallel with the article overview. I've tried to get these ideas across without the jargon getting too intense, and linked to articles that get more hard-core. Here's the diff if you'd like to peruse what I did.

I also took out the sentence that says we can't test alpha variation in the very early U.

Not sure about the use of hyphens, I'm worried about this after reading bits of the FA review. Can someone point me to the wp policy on --'s? Wesino | t | 17:57, 8 May 2007 (UTC)

Hyphen is the best Wikipedia hyphen guide I know of, although there seems to be little agreement on hyphens even on the Main Page, where such details are inspected more closely than they are here. Art LaPella 19:28, 8 May 2007 (UTC)

WP:DASH PaddyLeahy 21:54, 8 May 2007 (UTC)

Horizons

Big Bang#Horizons ends with "there will be future horizon as well". I almost added the word "a" before "future". Then I wondered why it's "will be". The horizon is a region of space that exists now; its definition is what depends on the future. Similarly, in the previous sentence, should "there was a past horizon" be "there is a past horizon"? Art LaPella 19:10, 8 May 2007 (UTC)

Huh, that's an interesting point. Maybe it would be better to say "spacetime has a future/past horizon," since that would reflect the fact that a horizon is a feature that depends on the whole history of the universe. Wesino | t | 19:16, 8 May 2007 (UTC)

I changed the section before seeing this discussion. I think those changes address your concerns and hope they're okay. Gnixon 20:22, 8 May 2007 (UTC)

A couple of issues the in History section -- comments invited

I'm reading through and there are a few things I'm not sure about, but which I think could stand correcting. Nothing major, just polish.

• In "History," ...Alexander Friedmann, a Russian and Soviet cosmologist and mathematician,... There seem to be too many ands. Could we eliminate either (and Soviet) or (Russian and) since in 1922 these were redundant? Or is there a reason that Soviet+Russian are both important?

• Early in the History section it talks about Hubble's 1924 measurement of the distance to "spiral nebulae," then later (next paragraph) started "Since 1924" I actually edited this second sentence to strengthen the impression that he started his measurements in 1924, but which more accurate? Should we say that he painstakingly developed the distance ladder, which enabled him to announce distances to Slipher's galaxies in 1924? What's right here?

• Later on in "History" ...the oscillatory universe (originally suggested by Friedmann, but advocated by Einstein and Richard Tolman),[9] I know Tolman advocated this model (the reference is to the book where he discussed it) but is it true that Einstein did? I always thought that he was more of a static universe guy. Is there a reference to Einstein supporting the oscillatory universe (presumably after abandoning the static one)?

Any history buffs feel like chiming in? Wesino | t | 19:43, 8 May 2007 (UTC)

(Puts on other hat). First point no opinion (I guess the distinction is important to some Russians); second & third points are mine. Actually the only nebula measured in 1924 was Andromeda (my original text got changed) though others followed soon after; this was a Cepheid distance and Hubble used Harlow Shapley's calibration (which was in substantial error). From 1924 on Hubble pushed his distances out further and further. The Einstein ref is from Tolman's book: on oscillating models (§163) Tolman says: "The first of these models was originally considered by Friedmann as early as 1922, and has since been advocated by Einstein." The ref is "Einstein, Berl. Ber. 1931, p. 235." (which I havn't consulted). Einstein suggested various options after his original model was ruled out, e.g. also the Einstein-de Sitter model. Given that the citation in the text is to Tolman's book, you could argue this is documented already... PaddyLeahy 21:17, 8 May 2007 (UTC)

Okay, number three sounds fine to me – maybe we could include the Berl. Ber. ref, but I try not to cite things I haven't read, so I'm not sure I could do it personally! Tolman's word is fine with me. From what you say it seems number two is all right as well... For the first, I guess I'll take out "Soviet" since Russian implies Soviet in '22. Hopefully if someone has an issue they'll say something. Cheers, Wesino | t | 22:05, 8 May 2007 (UTC)

While on the subject of history, the article used to credit Gamow with the CMB prediction, but as pointed out by John Mather (The Vergy First Light) this is incorrect: the prediction was made by Gamow's student, Alpher and post-doc, Herman. I've now given the correct citation. Reading this "paper" for the first time just now was a revelation: no wonder the prediction went unnoticed, since it appears at the end of what is essentially an erratum (or correction) to Gamow's earlier Nature paper, which usually gets the credit, but doesn't actually mention that the big bang radiation would still be around today! PaddyLeahy 23:12, 8 May 2007 (UTC)

Initial state?

Last week I removed the word "initial" from the description of the early high-density state, on the grounds that the big bang concept does not depend on there being no "pre-history" to the universe. I see Gnixon has put it back in the first sentence, which seems odd, given his efforts to remove the "singularity" from the accompanying picture. One of the things that has suprised me, reading around this article, is how very few prominent cosmologists seem to have taken the "beginning of time" idea literally... not even Gamow! I guess I happened to learn about the big bang when this idea was at a high point in its fortune, a few years after the Penrose-Hawking theorem. The idea seems to be out of fashion at the moment, even though Hawking still supports it. PaddyLeahy 07:48, 9 May 2007 (UTC)

Well, I think "initial" is okay in the beginning, I think it helps distinguish the Big Bang premise that things started hot and dense and then evolved from there (as opposed to being it a hot and dense state today). I find it helps to keep things clear, maybe there's a way to get across the idea without using the word.

My feeling is that many people who work on these things these days are a little bit too enamored with the mighty S-matrix for various reasons, and grow deeply uncomfortable without an asymptotic past. Wheeler took the idea of the beginning of time seriously, and seemed to think that the fact that GR suggested this was a Big Deal^TM. But of course, he's not really of the present generation. Wesino | t | 08:41, 9 May 2007 (UTC)

The funny thing with that discomfort is that it is entirely misplaced. Because the Hubble time is the only relevant scale in the early universe, with a finite absolute past physics still has an asymptotic history simply because of the density of the real numbers between 1 and zero. The logarithmic scale to the "beginning of time" will never reach that beginning. 10^-43 is not zero: it is infinitely far from zero. --ScienceApologist 12:41, 9 May 2007 (UTC)

You know it's getting hairy when physicists start talking about number theory!  ;-) Paddy, I didn't mean to contradict your earlier edit. I was a little uncomfortable with "initial" for the same reason as you, but I don't really think "initial state" has to imply "beginning of time". Mostly I think that, in the lead, we should avoid getting into details at the fuzzy edge of the model. In one sense, the Big Bang does take us all the way back to t=0 (because nanoseconds << 13.7 billion years). In another sense, there's tons left to describe after GR (presumably) breaks down. Introducing things concisely and accurately is important and tricky, and we should talk about it, but I think virtually all the possibilities are at least reasonable. I made a change to the first sentence that I think sounds better and also gets rid of "initial". Hope it's an improvement. Gnixon 16:21, 9 May 2007 (UTC)

Just because nanoseconds << 13.7 billion years doesn't mean that you can compare today's timescales to the timescales in the early universe. --ScienceApologist 18:09, 9 May 2007 (UTC)

Well, I think you're taking the usefulness of the Hubble time a little too far. The Big Bang universe is 13.7 billion years old, and that means just what the casual reader thinks it does. The fact that lots of stuff happens within the first fraction of a second doesn't invalidate that statement, even if the interesting physics is spread out over a logarithmic scale. Anyway, I think we're splitting hairs and getting off-topic---I think we basically agree. The article should say that the universe is 13.7 billion years old, and it should also point out that a huge amount of interesting stuff happened at early times because the relevant physical times scale inversely with energy. Regarding "initial," I suggest we just avoid saying anything absolutist up front and then explain the details later on. Gnixon 22:01, 9 May 2007 (UTC)

This is a bit of arguing about angels dancing on pinheads, but the logarithmic nature of lookback time is often obscured in the literature because people believe that their timescales (years) can apply throughout history when they cannot. An eternal and finite universe is simultaneously possible: they need not contradict. Currently, there is no physical mechanism yet which rules out this or any other possibility. --ScienceApologist 22:16, 9 May 2007 (UTC)

ADDED: 6. A few other problems, as very important, cf. [4]

Please help to make this section a bit better!

by wfcKehler@aol.com 84.158.89.2 20:06, 11 May 2007 (UTC)

There's already a section on "problems." I reverted those additions because they didn't fit well in the article. (My edit comment erroneously called them "uncited"; sorry.) It would be useful if a nice way could be found to incorporate them in the previous section. Gnixon 20:18, 11 May 2007 (UTC)

RESPONSE: Thanks! This is partly correctly, please add mentioned completed list for my added section (I can try to put it again better?)

6. A few other problems, cf. [[5]], University Cambridge cited:

Despite the self-consistency and remarkable success of the standard Hot Big Bang model in describing the evolution of the universe back to only one hundredth of a second, a number of unanswered questions remain regarding the initial state of the universe.

The flatness problem Why is the matter density of the universe so close to the unstable critical value between perpetual expansion and recollapse into a Big Crunch?

The horizon problem Why does the universe look the same in all directions when it arises out of causally disconnected regions? This problem is most acute for the very smooth cosmic microwave background radiation.

The density fluctuation problem The perturbations which gravitationally collapsed to form galaxies must have been primordial in origin; from whence did they arise?

The dark matter problem Of what stuff is the Universe predominantly made? Nucleosynthesis calculations suggest that the darrk matter of the Universe does not consist of ordinary matter - neutrons and protons?

The exotic relics problem Phase transitions in the early universe inevitably give rise to topological defects, such as monopoles, and exotic particles. Why don't we see them today?

The thermal state problem Why should the universe begin in thermal equilibrium when there is no mechanism by which it can be maintained at very high temperatures.

The cosmological constant problem Why is the cosmological constant 120 decimal orders of magnitude smaller than naively expected from quantum gravity?

The singularity problem The cosmological singularity at t=0 is an infinite energy density state, so general relativity predicts its own breakdown.

The timescale problem Are independent measurements of the age of the Universe consistent using Hubble's constant and stellar lifetimes?

by wfcKehler@aol.com 84.158.89.2 20:34, 11 May 2007 (UTC)

The fact that it is hosted by Cambridge does not make it a good ref - where are the jstor paper quotes or articles in Ap J? That is the sort of ref that is needed for these types of additions. Sophia 21:52, 11 May 2007 (UTC)

Well, it's not only hosted by Cambridge (as, for example, some undergraduate's homepage), but also seems part of the official pages of their cosmology group. As such, I think it's not an unreasonable citation, although of course a published (review?) article of some sort would be better. The issues pointed out are standard, and as long as they're presented as outstanding problems and not as damning criticisms of the current model, I think they represent the current thinking of cosmologists. Perhaps the label "problem" is a little too strong. For me, the main issue is how to incorporate these points smoothly within the article. Gnixon 22:42, 11 May 2007 (UTC)

ANSWER WITH DEMAND OF REVISION: Ok, may be better to name the main section "other open problems" in order to "incorporate these points smoothly", but not to eliminate them. One incredibly relevant problem is the wellknown fact - computed, and from many other sources confirmed - of really 120 decimal orders of magnitude in difference for the needed Einstein constant as an open question. All other facts are multiply found, partly already indicated within the same article (a bit later on) and mainly already confirmed in WIKI articles like in Non-standard cosmology, Dark matter, dark energy.

See at most [6]:

"Thus, the current standard model of cosmology, the Lambda-CDM model, includes the cosmological constant, which is measured to be on the order of 10^-35s^-2, or 10^-47GeV⁴, or 10^-29g/cm³, or about 10^-120 in reduced Planck units." Let's try it for the last time with the needed smooth incorporation.

wfcK 84.158.88.175 22:57, 11 May 2007 (UTC)

Apologies for not making my point clearer - never edit when tired. For the record I do hold reservations about the BB model for the some of reasons they have given but I do know we won't be able to stabilise the addition unless each point is backed by some meaty link with content. I have been surprised myself how anything not conforming to the BB model has been attacked on wikipedia (note that the Non-standard cosmology article is in the category pseudophysics - there was even a long running attempt last summer to include creationist cosmologies in the article which I saw as an attempt to discredit the non-standard theories by association). So let's take it point by point and see how and where the content will best fit - but I do feel a list on a Cambridge site will not be enough to convince others of their merits. Sophia 05:35, 12 May 2007 (UTC)

I think in some cases there may be an over-reaction by editors who are concerned that Non-standard cosmology or edits like this most recent might be motivated by a religious agenda. I think WP:AGF is key. Gnixon 11:49, 12 May 2007 (UTC)

"Non-standard" is a well recognised term that does not denote "psuedo" in the physics world. The problems stated are active areas of research as these are the "missing links" for the BB. Don't get me wrong - the BB is the best explanation there is but there are still significant areas to be explained so we should be able to include some of this stuff with quality references. Sophia 13:45, 12 May 2007 (UTC)

Ok, this was our last attempt

We have experiend now as true what is written in "An Open Letter to the Scientific Community" [7]. We could not believe it and have logged it for our proposal in BIG BANG:

Other open questions, briefly

See here below, e.g. from University Cambridge [8] and other here named references.

The problem cosmological constant

There cited: "Thus, the current standard model of cosmology, the Lambda-CDM model, includes the cosmological constant, which is measured to be on the order of 10^-35s^-2, or 10^-47GeV⁴, or 10^-29g/cm³, or about 10^-120 in reduced Planck units." Why is Einstein's cosmological constant 120 decimal orders(!) of magnitude smaller than naively expected from quantum gravity?

Not a big bang problem, this is a quantum gravity problem. --ScienceApologist 14:47, 12 May 2007 (UTC)

The current article says:

In the best current model of the Big Bang, dark energy is explained by the presence of a cosmological constant in the theory of General Relativity. However, the size of the constant that properly explains dark energy is surprisingly small relative to naive estimates based on ideas about quantum gravity.

Apart from the omission of numerical values, this makes the exact point mentioned (indeed, As ScienceApologist's answers below point out, all these points were already mentioned in the "Problems and features" section of the article.) PaddyLeahy 23:08, 12 May 2007 (UTC)

singularity problem

Why the necessary cosmological singularity at t=0 is an infinite energy density state, so that the general relativity predicts its own breakdown. - One probable solution: see below under "Speculative physics beyond the Big Bang".

Already discussed to death in the article and it is not a "problem" for the Big Bang -- it is a problem for theoretical quantum gravity models. --ScienceApologist 14:48, 12 May 2007 (UTC)

search of "exotic relics"

Phase transitions in the early universe inevitably give rise to topological defects, such as mentioned Magnetic monopoles and other here never experiences "exotic particles" (e.g.: Our sun is situated in our galaxy rather peripherally, but within about 100 lightyears there could not yet be measured the - for each above mentioned theory of rotating galaxies - needed dark matter). - Why don't we see or measure them here and today?

Yes, already mentioned at magnetic monopoles. --ScienceApologist 14:48, 12 May 2007 (UTC)

a probable timescale problem

Are independent measurements of the age of the Universe consistent using Hubble's constant and stellar lifetimes?

See so-called "globular cluster problem". --ScienceApologist 14:49, 12 May 2007 (UTC)

a thermal state problem

How could the universe begin in thermal equilibrium when there exist no experienced mechanism by which it can exist or be maintained at very high temperatures?

wfck for our friends and for our club 84.158.85.75 00:45, 12 May 2007 (UTC)

Horizon problem explains the resolution to this. --ScienceApologist 14:50, 12 May 2007 (UTC)

Just to be clear, there's pretty solid consensus in physics that some extension of the Big Bang model correctly describes our universe. Most of the points you've raised are recognized as outstanding problems, but are expected to be resolved by upcoming measurements that will distinguish between possible explanations. Some of the points raised look like they might be based on misunderstandings. None of them are considered a threat to the current understanding. The letter you linked to seems to imply that the Big Bang is a theory in crisis, but in fact it is extremely well-established and virtually universally accepted by cosmologists and by astronomers and physicists in general. The view of the scientists who wrote that letter represents the opinion of such a small minority that it would be undue weight to include it in this article. On the other hand, improving the article's discussion of outstanding issues and how they relate to current research would be quite useful. I don't think it's necessary to talk about "demands" and "last attempts" to make edits. Improving these articles is always sort of a back and forth effort, and it takes time. Gnixon 11:39, 12 May 2007 (UTC)

Links removed

I have removed the following links from the bottom of the page, as I don't think that they are that useful as further reading (which I have repurposed the section to be). If anyone disagrees, then please read Wikipedia:External links and discuss the individual links here before adding them back. If any of them are references to material in the article, then please add them back as footnotes as per the other references.

• PBS.org, "From the Big Bang to the End of the universe. The Mysteries of Deep Space Timeline"
• "Welcome to the History of the universe". Penny Press Ltd.
• Cambridge University Cosmology, "The Hot Big Bang Model". Includes a discussion of the problems with the Big Bang.
• Smithsonian Institution, "UNIVERSE! - The Big Bang and what came before".
• D'Agnese, Joseph, "The last Big Bang man left standing, physicist Ralph Alpher devised Big Bang Theory of universe". Discover, July 1999.
• Felder, Gary, "The Expanding universe".
• LaRocco, Chris and Blair Rothstein, "THE BIG BANG: It sure was BIG!!".
• Shestople, Paul, ""Big Bang Primer".
• Wright, Edward L., "Brief History of the universe".
• "Proof of Big Bang Seen by Space Probe, Scientists Say" —National Geographic News
• The Sabanci University School of Languages Podcasts: Origin of Elements by Alpay Taralp.
• The Big Bang and Cosmic Microwave Background and More Evidence for the Big Bang, episodes of the Astronomy Cast podcast dealing with the Big Bang.

I have also removed the following, on the basis that they don't appear to actually talk about the Big Bang, but about creation/religion in general. I would have no objections to them being used as references (with specific page references) in the "Philosophical and religious interpretations" if they are appropriate there, but otherwise they don't belong in this article.

• Leeming, David Adams, and Margaret Adams Leeming, A Dictionary of Creation Myths. Oxford University Press (1995), ISBN 0-19-510275-4.
• Pius XII (1952), "Modern Science and the Existence of God," The Catholic Mind 49:182–192.
• Ahmad, Mirza Tahir, Revelation, Rationality, Knowledge & Truth Islam International Publications Ltd (1987), ISBN 1-85372-640-0. The Quran and Cosmology

I've re-instated the last two as in-line cites. I think the first was intended to back up the claim that the big bang itself is considered by some as a creation myth... but that claim has been expurgated. PaddyLeahy 23:15, 16 May 2007 (UTC)

Finally, the "Preprints" section:

"Most scientific papers about cosmology are initially released as preprints on arxiv.org. They are generally technical, but sometimes have introductions in plain English. The most relevant archives, which cover experiment and theory, are the astrophysics archive, where papers closely grounded in observations are released, and the general relativity and quantum cosmology archive, which covers more speculative ground. Papers of interest to cosmologists also frequently appear on the high energy phenomenology and high energy theory archives."

Those that work in the area will already know about the ArXiV, so there's not much point linking to it for them. For newcomers, it's not the best place to start reading around the subject - going for the reviews and books would be a much better start. They will doubtless come across it in references in those reviews and books, if they go far enough. So what's the benefit of having it at the end of this article?

Thanks. Mike Peel 19:26, 16 May 2007 (UTC)

While on the topic of citations, one FARC comment is that this article is under-cited in general (e.g. now no cites in the Dark matter section at all). But this article is an introductory summary of such topics, some of which (Dark matter again) are very well referenced on their main article pages. Do we really need to provide cites on this page as well? PaddyLeahy 23:15, 16 May 2007 (UTC)

According to WP:SUMMARY, "There is no need to repeat all specific references for the subtopics in the main "Summary style" article: the "Summary style" article summarizes the content of each of the subtopics, without need to give detailed references for each of them in the main article: these detailed references can be found in the subarticles. The "Summary style" article only contains the main references that apply to that article as a whole." Mike Peel 09:37, 17 May 2007 (UTC)

Logical Nitpicker

In the introduction, there are words to the effect that at (near) time zero "energy was at high temperature and density". Matter yes but energy? I don't think so. What do we mean by the density of energy? I have tried to reword this to reflect the logical inconsistency but have been instantly stomped on by zealots who have apparently bought the article from Wikipedia. Any other opinions? Are we going to continue to say that energy has a temperature? Or are we going to say that matter and energy were constrained within a minute domain where temperature and density tended to infinity? Or am I the Lone Nitpicker? — Preceding unsigned comment added by Captainbeefart (talk • contribs) 13:24, 19 May 2007 (UTC)

Energy density is fine, but energy temperature is wrong (temperature is a form of energy). I've simply removed "and energy" from the sentence; just saying that matter was at a high temperature and density is fine, isn't it? Mike Peel 13:38, 19 May 2007 (UTC)

Temperature is not a form of energy. Temperature is a thermodynamic property. Energy being of high temperature is a bit mushy, but it could allude to electromagnetic radiation of high frequency. I suggest reverting the rewording as it only made matters worse. --Dschwen 14:29, 19 May 2007 (UTC)

"The temperature of a system is defined as simply the average energy of microscopic motions of a single particle in the system." I guess it is more a characterization of the kinetic energy than it is actually energy, but it still boils down to energy.

To a certain extent, having "matter and energy" is a bit of a duplication - after all, E=mc^2 (or rather, $E^{2}=m^{2}c^{4}+p^{2}c^{2}$). How about something like "in which everything (i.e. all matter, including photons) was at an immense temperature and density"? Mike Peel 17:32, 19 May 2007 (UTC)

Photons have a temperature: T = hf/k. --ScienceApologist 14:16, 22 May 2007 (UTC)

It's awkward. Actually its the photon distribution that has the temperature but that's too picky for the lead. Why not cut out matter and energy (after all, "all the matter and energy" is the universe) and just say the universe has the temperature? PaddyLeahy 17:05, 22 May 2007 (UTC)

The tyranny of the distributions! I suppose you're one of those people who hates it when people talk about color temperatures? In any case, temperature itself is an eighteenth century abstraction invented to quantify hot and cold. It was only after statistical mechanics was fully realized that the connection between the Maxwellian, the Planckian, and thermodynamic equilibrium would be realized. These are all, however, statistical mechanics and have nothing to do with individual particles. If you truly believe that higher energy photons are not "hotter" than lower energy photons, then I guess you can complain about distributions. I, however, see no value in holding on to old macroscopic notions when dealing with individual elementary particles. (Who cares to what distribution a particular photon belongs? It still has plenty of measurable properties and follows all the known laws of physics.) In any case, this whole discussion is rather absurd because the CMB is so close to a blackbody, we might as well talk about the temperature of the universe as you suggest. --ScienceApologist 17:15, 22 May 2007 (UTC)

Being picky about these things comes with the territory...I'm marking exams at the moment. But I'd advise, if you want your students to understand thermodynamics, to keep temperature & energy carefully distinct. (And colour temp /= brightness temp /= thermodynamic temp, though all are perfectly legitimate concepts). Aren't we way off topic now? PaddyLeahy 18:55, 22 May 2007 (UTC)

Energy and temperature are indeed distinct just as the period of an orbit squared is distinct from the semi-major axis of the orbit cubed. Way off topic, indeed. --ScienceApologist 20:19, 22 May 2007 (UTC)

In the hope of resolving this, I've changed the sentence to read "Extrapolation of this expansion back in time yields a state in the distant past in which the universe was in a state of immense density and temperature." Are there any problems with this phrasing? Mike Peel 11:33, 27 May 2007 (UTC)

Cosmic egg

ScienceApologist, do you have a reference for the "cosmic egg", especially for it being different from and earlier than the 1931 "primeval atom"? I know it's mentioned at Georges Lemaitre, but without a citation there either. The most detailed account I have access to is Kragh's book, which says that a short Nature letter in 1931 is the origin of the idea of starting at (effectively) a singularity, and Lemaitre used the phrase "primeval atom" in his British Assoc talk, also written up in Nature. (My guess is that "cosmic egg" was used in private only, it would have looked very informal in the context of papers of the time). PaddyLeahy 19:50, 23 May 2007 (UTC)

I have found a number of sources which attribute the "cosmic egg" description to Lemaitre ([9]) but it may also be that "cosmic egg" phrasing may be a bit of historical revisionism. Please help research this more fully. I'll look into my sources a bit more carefully.--ScienceApologist 15:52, 28 May 2007 (UTC)

By the way, the secondary source I list above cites Bernstein, J., Feinberg, G., Eds. (1986), Cosmological Constants: Papers in Modern Cosmology, New York: Columbia University Press as a source as well as Dick Teresi's provactive book. I think that we should definitely look into this more deeply and it may help improve the cosmic egg article as well! -ScienceApologist 16:11, 28 May 2007 (UTC)

Removed paragraphs from article - citations?

I've removed the following paragraphs from the article, as they are uncited and I can't currently find references for them. If anyone else knows of a reference for them, then please add them back along with the reference.

From Hubble's law expansion:

The relation between redshift and distance is more complicated than the simple relation for velocity, for it depends on past behavior of $H$ and thus the detailed content (matter, dark energy etc.) of the model. Also, in practice, the proper distance between two objects at a given time is not measurable, and so the redshift–distance relation also depends on the operational definition of "distance" that is chosen. By coincidence, the redshift–luminosity distance relation for ΛCDM is reasonably linear to high redshift.

From Philosophical and religious interpretations:

Certain theistic branches of Hinduism, such as in Vaishnavism, conceive of a creation event with similarities to the Big Bang. For example in the third book of the Bhagavata Purana (primarily, chapters 10 and 26), describes a primordial state which bursts forth as the Great Vishnu glances over it, transforming into the active state of the sum-total of matter ("prakriti"). Other forms of Hinduism assert a universe without beginning or end.

Buddhism has a concept of universes that have no initial creation event, but instead go through infinitely repeated cycles of expansion, stability, destruction, and quiescence. The Big Bang may be reconciled with this view, since there are ways to conceive an eternal creation and destruction of universes within the paradigm. A number of popular Zen philosophers were intrigued, in particular, by the concept of the oscillatory universe.— Preceding unsigned comment added by Mike Peel (talk • contribs) 16:39, 28 May 2007 (UTC)

maybe we should have a 2 sections added

1. 1 flaws of the big bang theory and #2. good points of the big bang theory, it would make it so that people can form their own opinions.Jammerocker 13:38, 9 June 2007 (UTC)

ok my bad someone already did it but there is one thing that i saw that wasnt there...listen to this. "ok there is this theory...i forgot the name but I'm trying to find it now, anyway...the theory states that if anything implodes while spinning, every single piece will move at the exact same rate of speed and spin at the exact same speed, now if this little molecuel imploded then how can the matter from it colide and make earth?" i just thought maybe we could add that to the problem section.Jammerocker 13:45, 9 June 2007 (UTC)

The objection that the conservation of angular momentum denies the Big Bang is typical creationist pablum. You'd be best to stick to editing articles on subjects that you have researched more carefully. Also, don't rely on religious authorities to teach you science. --ScienceApologist 13:46, 9 June 2007 (UTC)

ok #1. thanks for the theory name. #2. creationist pablum, im just trying to point out something to maybe make this topic better thank you. and #3. I looked it up, i didnt get it from a "religious athority" as you put it.Jammerocker 14:01, 9 June 2007 (UTC)

I'm going to go out on a limb and say that you looked it up in a creationist source. The "conservation of angular momentum" objection really derives from a complete misunderstanding of what the Big Bang is saying. There are still a lot of people, including most creationists, who think that the Big Bang describes an explosion of matter out into an empty universe that then forms all the features we observe. Only this is plainly not the Big Bang theory. We are under no obligation to include the objections made by people who are not reliable. If you can find a source that is reliable and makes this objection, show us here. --ScienceApologist 14:13, 9 June 2007 (UTC)

well you got me...lol...good debate (it kinda was a debate...sorta lol) NASA agrees with you...nice job lolJammerocker 14:49, 9 June 2007 (UTC)

ok i just found a website that supports what i was saying...http://liftoff.msfc.nasa.gov/academy/universe/b_bang.html

Jammerocker 08:23, 18 June 2007 (UTC)

That website says nothing about the conservation of angular momentum. --ScienceApologist 13:00, 18 June 2007 (UTC)

No but you had told me that i had the theory wrong...well i dont...unless 1. of 2. things happened...#1. The theory keeps changing which means that the theory does not have any true value, or #2. YOU have the theory wrong...in which case so does this whole article.Jammerocker 06:06, 19 June 2007 (UTC)

So which one is it?Jammerocker 12:01, 19 June 2007 (UTC)

The article is well-referenced and in accordance with the latest in modern cosmology. I'm not sure what you think the children's NASA website you found is supposed to show in terms of editorial revision of this article. --ScienceApologist 13:12, 19 June 2007 (UTC)

So in other words the Big Bang theory just keeps changing...and what do you mean childrens site...I didnt get from PBS...and I'm just saying that you said that i didnt even know what the big bang theory is and that if I had a reliable sorce to put it here...well I did. And now your saying that this article is "up to date" in modern cosmology...and i never said it wasnt.Jammerocker 13:27, 19 June 2007 (UTC)

Well, not precisely children, indeed, but Liftoff is a teenager's (and older) site maintained by NASA. All theories in science keep changing in the sense that new observations may indicate refinements or modifications of parts of any scientific theory. That's one of the main features of science. See philosophy of science. --ScienceApologist 14:11, 19 June 2007 (UTC)

But my point is that we arnt just talking about a couple little changes with this theory, what I'm seeing is this whole theory being completely changed, now granted i dont know why but what I want to know is how we went from one big bang to big bang version 2.0.-Jammerocker 15:14, 19 June 2007 (UTC)

(rmv indent)The Liftoff page is wrong (or at least it is a misleading oversimplification). It says that the Big Bang was "a cosmic explosion that hurled matter in all directions". In fact, it was space itself that expanded rapidly, carrying matter with it. The matter that filled the early universe was incredibly hot and dense but it was not exploding - it had nowhere to explode into. Gandalf61 16:29, 19 June 2007 (UTC)

A "lie-to-children" - a concept simplified to the extent of being incorrect - but sufficiently close to reality so that it will help in education. [10] :-) --Kim D. Petersen 00:30, 21 June 2007 (UTC)

Evidence for the Big Bang

A good site supporting the Big-Bang theory:

http://www.talkorigins.org/faqs/astronomy/bigbang.html

The Big Bang VS God

Here is one of the reasons I say that God is false. First of all, if God created space and time, then he could not have existed in space and time. And I know for a fact that only space and time exist in reality. Everything else is a figment, and that includes God. Here is another reason I say God is nonexistent. No force other than the Big Four (you know, strong, weak, elecromagnetism, and gravitation) can ever choose to put all those fermions and bosons in neat order; therefore, you can't say, "Hey you virtual pions! Bind the protons and neutrons in the atom together!" and have the protons and neutrons pull together. No one can. The force just happens. Therefore, I say it is perfectly logical for the Big Bang to just happen. No outside force can make matter and energy appear. It does not work that way.--67.10.200.101 17:55, 30 June 2007 (UTC)

God fails as a hypothesis. That's all that really needs to be said on the subject. It's unscientific, bronze age mysticism.

Here is a reason why God can exist: Science is the effort to understand, or to understand better, how nature works, with observable physical evidence as the basis of that understanding. The 'Big Bang' is a scientific theory that is un-provable. It is absolute science-fiction. It does not physically exist, nor can it be measured. The ‘Big Bang’ is an [arrogant] guess at how this world and universe could have come to exist without divine intervention. GregRowles 14:56, 7 Jan 2008 (UTC)

If you really think the Big Bang is "absolute science-fiction", then please review the article's second and third paragraphs, which summarize the evidence for the Big Bang. Comment on the evidence if you like, but please don't pretend there isn't any. Art LaPella (talk) 21:31, 7 January 2008 (UTC)

I've skimmed this article and I don't see any mention of the most fundamental problem with the big bang theory: where did the very first quantum of matter or energy come from? Why can't someone put this into layman's terms? Is it because perhaps there just isn't an answer? It does not take a genius to understand that something cannot come from nothing. You can disguise this problem with all the scientific terms you want, but at the end of the day, the physical universe (space and time) cannot be all there is because that first particle had to have come from somewhere. It doesn't make sense to say that it was just always there. The only way to explain it is to allow yourself to believe in a Creator who transcends space and time and is not bound by the universe, that's where the first writer above goes wrong in his understanding of God. Since I am apparently the only person who has the faith to believe in something that cannot be measured by scientific instruments, I fully expect to receive a deluge of sarcastic and condescending replies. That's ok, I'm used to people getting offended when confronted with the possibility that there is something out there greater than themselves. 208.22.45.148 19:27, 26 July 2007 (UTC)Scott W July 26, 2007.

You are correct that "there just isn't an answer" to "where did the very first quantum" (I think you mean zillions of quanta) "come from", although we don't take it for granted that "something cannot come from nothing" because it was unique (or at least unusual). Christians don't claim to know everything about God, and scientists (Christian or whatever) don't claim to know where the Big Bang came from. Art LaPella 01:56, 27 July 2007 (UTC)

i would support a religious interpretation page in order to move this sort of debate out of what should be essentially a purely scientific subject matter. If separate Christian, Hindu, Islamic or whatever pages are required then so be it. In my view once religious philosophy starts getting mixed up with what is essentially a scientific subject then the overall clarity of the article will be damaged and the discussion will move away from the actual science to more religious interpretations. Not a good idea imho.--Joflaitheamhain 21:17, 2 August 2007 (UTC)

The Big Bang Theory cannot be proven through the Scientific method. It is outside of naturalists belief system. Therefore, naturalists are inconsistant. Although this is in many Christian arguments, I will state it again. Think, can random atoms collide, explode, and then create a world with living microscopic cells? Open a puzzle box, and throw it on the ground. What do you see? Mixed up puzzle pieces. If you pick them up and throw them again, will you get the picture on the front of the box? Doing this and hoping your puzzle will connect is as illogical as the Big Bang. Sure, you can't see God. But can you prove He doesn't exist? And how logical is it to believe that macro-evolution exists? Darwin said that you will find thousands of links between animals. We haven't found any of them. For all we know, the cavemen could've been mutated from a bone disease. -Yancyfry 03:07, 21 September 2007 (UTC)

Neither Yancyfry nor his opposite 67.10.200.101 above has suggested any specific change to the article. So I ask them to review the boxes at the top of this page, especially the one that starts with "IMPORTANT: This is not the place to discuss how you think the universe began..." Art LaPella 04:03, 21 September 2007 (UTC)

As the top of the talk page shows, debate on the Big Bang should be hosted at talk.origins and not here. Besides, the Big Bang isn't about the origin of the universe. SkepticBanner (talk) 06:28, 21 January 2008 (UTC)

A couple of questions

First, it says that the universe was infinitely dense, which is fine, but it also says 'infinite energy'. Is this a side effect of the infinite density, or a mistake? I certainly have the idea that the universe can't (or shouldn't, based on my understanding) have infinite energy, because of ideas like http://en.wikipedia.org/wiki/Conservation_of_energy.

Secondly, this is just a clarification question: the article seems to state that the matter in the universe has always existed (as opposed to ex nihilo creation) -- did the entire universe occupy an area smaller than a Planck length? I understand that the universe was at a singularity -- if so, does this have similar consequences for other existing singularities like the Black Hole?

Thanks in advance. Piepants 15:45, 18 July 2007 (UTC)Piepants

Good question. We don't have a very clear idea of what was happening during the Planck epoch. The fact that naive extrapolation backwards in time leads to an infinitely dense singularity is, as you perceive, a good indication that we do not yet know the full picture. The resolution may lie in quantum gravity, string theory, or some other theory of everything. As for the origin of the matter in the universe, that depends on how you count it. Most of the protons and neutrons in the current universe came into existence during the hadron epoch - actually, they are the bits that were left over after most of the particles and anti-particles annihilated each other. Their constituent quarks came into existence even earlier, but as I think quarks are continually interacting through the strong force by exchanging gluons, it may be meaningless to try to assign a long-term identity to one particular quark anyway. Certainly before the quark epoch the energy density of the universe was so high that there was no meaningful distinction between matter and energy - elementary particles were being created and annihilated very, very rapidly. Gandalf61 16:21, 18 July 2007 (UTC)

I guess I have some reading to do to understanding everything you've mentioned. One more clarification: "matter" (energy) doesn't ever get destroyed, so the universe has 'always' existed, albeit in a causally meaningless way prior to being 'created'?

I'm basically asking if the philosophical question of creationism can be resolved using the Big Bang. Prior to my line of questioning, it was still asked 'well how did matter get created?' which required me to consider ex nihilo creation. Piepants 16:49, 19 July 2007 (UTC)Piepants

"We don't have a very clear idea of what was happening during the Planck epoch". We don't know if conservation of mass and energy applied at that moment because we can't recreate it with an experiment. So we don't know if that moment is better described as "ex nihilo" (with or without an intelligence or deity) or as a phase in an older universe. Art LaPella 23:01, 19 July 2007 (UTC)

First Paragraph

I have a degree in this subject and find the first paragraph very hard to understand. I think I understand the distinctions that are attempted between the usage of the term "Big Bang" but it is put so incredibly badly and the major use of the term is given last. The first usage is marginal at best and the second and third are closely interrelated. Also what's with the Giga-annum business as it really isn't that widely used as far as I can see (I have never actually seen it used) and where it is used it is often qualified which implies it is a little recognised term. I'm not changing it at the moment as I know this article is closely watched but it really shouldn't be a featured article with that poor a first paragraph. Contrast with these randomly chosen from a google search [11][12][13][14]. Is it just me? Sophia 22:36, 25 July 2007 (UTC)

No it isn't. I'm not a professional scientist, but I have expressed a similar philosophy at User:Art LaPella#"Encyclopedic" obscurity. Now that plasma cosmology wars are at a lull, it might be possible to get some attention to making the article more understandable. Art LaPella 23:29, 25 July 2007 (UTC)

No, it isn't just you. The entire first paragraph looks dubious to me. I've been trying to clean it up by tagging, but it's not much better yet. Jayjg ^(talk) 01:57, 26 July 2007 (UTC)

I would say it is extremely dubious and am mulling over alternatives. Sophia 06:41, 26 July 2007 (UTC)

I've done some simplification, what do you think? Jayjg ^(talk) 05:27, 29 July 2007 (UTC)

It's good - much better than what it replaced! I hadn't got around to doing the research to see if the major usage these days is the "event" followed by the cosmological model that is based on expansion from a singularity or the other way around. I'll still look into it but hopefully a real cosmologist will correct it if necessary. Sophia 10:18, 29 July 2007 (UTC)

or tag

I've tagged the first sentence of this article original research. It brings an example of usage of the term "big bang", and then tries to draw a novel conclusion based on that usage. This, of course, is original research. What we need are sources that explicitly state "The Big Bang is..." or "The term Big Bang is used to mean..." or something similar. If we simply rely on usages we find, then we end up including things like the Bristol sessions. Jayjg ^(talk) 01:55, 26 July 2007 (UTC)

Jayjg - you demanded a source in which the term "Big Bang" is used to describe an observable feature of the universe; I provided one; you say that looking for and providing a source is OR ! Looks like a Catch-22 to me. I don't like wasting my time on such games, so I have reverted to your tagged version before I attempted to provide a source, and as of now this page is off my watchlist. Gandalf61 11:46, 26 July 2007 (UTC)

No, I asked for a source which stated that the "Big Bang" refers to the observable facts of the evolution of the universe, not an example of someone using it as an adjective describing observable facts of the universe. One you start bringing examples of usage, you are doing original research; instead, bring clear statements from reliable sources saying "The Big Bang is..." or "The Big Bang refers to..." It shouldn't be hard, I get 140,000 google hits for the phrases; I'm not inserting them myself because I'm hoping someone with more expertise will provide top-notch sourcing for this. See also the section above this one. Jayjg ^(talk) 15:41, 26 July 2007 (UTC)

Religion additions reverted, July 28

I have just reverted additions that refer to Islam and Hinduism. If such input had a direct association to the Big Bang, there might be a place for it. There is already mention in the article now as it stands. I reverted a new Hindu related addition that seems to have no connection with the Big Bang at all, and a new Islamic addition that did nothing except assert that modern cosmology confirmed prophecy. Also, this is a secular encyclopedia, and so will not be worded in the same way as writings for a particular religion. In particular, the traditional asides "PBUH" or "sawas" used in Islamic writings will be removed. No disrespect is intended, just as no disrespect is intended to anyone else mentioned by their name only. Diff for reverts [15]. —Duae Quartunciae (talk · cont) 11:21, 28 July 2007 (UTC)

i think that all religious references should be removed, as no religion in the world ever predicted the Big Bang. Instead spurious claims at prophecy happened AFTER the Big Bang theory was confirmed by science. A page on the Islamic, or Christian or Flying Spagetti Monster interpretations of the Big Bang theory should be created which this page could link to. --Joflaitheamhain 21:12, 2 August 2007 (UTC)

• • • The Koran states that the world is flat and that mountains hold it place, much like tent pegs. Bible states that 'god' made the world in 7 days. etc. etc. Can we please remove all references to ignorant religious guesswork from these articles?

I undid someone's Notice, "Go religion!!! oh yeah!!! big bang is bulL!!! go religioN!! woot!!! shalalalala in the morning oh yeah!!!" This user User_talk:204.81.150.184 has been warned before for vandalism.

That message was routine vandalism you can revert all you want, and of course a truly religious person wouldn't have written that. Art LaPella 00:20, 28 September 2007 (UTC)

I find it odd that this article doesn't mention the Quran, it being our first ever reference to the big bang. 21.30: "Don't the unbelievers see that the heavens and the earth were joined together as one, before we pulled them apart?" And by the way, the Quran doesn't say the earth is flat, it was delivered 1,400 years ago when people thought the earth was flat. Jsha 19:07, 7 November 2007 (UTC)

Please find discussion of religious interpretations in the article Philosophical and religious interpretations of the Big Bang theory. ScienceApologist 19:06, 7 November 2007 (UTC)

Additional Suggestion for Origin Problem

I and others have noted that there is no mention in the article that no one (as far as I know) has provided any explanation as to how the original material of the universe (matter, anti-matter, energy, etc.) came into existence. Every theory starts with the assumption of the pre-existence of the material. Could a note be added stating that there is not yet any known method for the original material to appear out of nothing? (At least outside of the proposition that the matter always existed in some form.) Dogrun81 19:50, 2 August 2007 (UTC)

You might want to look at, and follow the links under "Speculative physics beyond the Big Bang" again.Dugodugo 22:27, 2 August 2007 (UTC)

Lead sentence

In a recent edit, EMC125 added the phrase "and scientifcally accepted understanding" to the first sentence. The sentence current reads (with my emphasis added to the new phrase):

EMC125 is correct that the Big Bang is the dominant model used in cosmology. In my view it is about as solidly established as any scientific theory can get; at least in the broad outline as described in this sentence. There are all kinds of competing ideas in cosmology, but the primary assertion listed here is the foundation for just about all of them... except that the word "start" is an issue, because in fact we don't have a good handle on the very "start". However, although I agree with the EMC125 that the Big Bang is the accepted understanding used in science, I think the addition is not a good one. It is grammatically awkward. It detracts from what should be a plain simple neutral statement of what this model actually IS. It is WP:POV, in the sense that it is a little bit too anxious to defend the primacy of the model in the face of a cottage industry of Big Bang skeptics most of whom have a very poor grasp of the observations and the data and the models involved.

I don't think the Big Bang needs to be that concerned. The primacy of the model comes through in the article just fine. I don't like the word "start", because there are in fact various ideas about conditions prior to the Big Bang, in various senses of the word "prior"; and science cannot at present resolve them. So I am proposing the following for consideration.

What do people think? —Duae Quartunciae (talk · cont) 11:45, 15 August 2007 (UTC)

I have been WP:BOLD and gone ahead with the change proposed. I am still interested in criticism or approval from other editors. —Duae Quartunciae (talk · cont) 23:39, 15 August 2007 (UTC)

It sounds fine to me. Mike Peel 08:06, 16 August 2007 (UTC)

A recent edit inserted an extra sentence, right at the start. The sentence read: In modern cosmology it is ragarded as both: the ultimate end of the universe and its very first beginning. I have removed it. The Big Bang is not the necessarily the ultimate end; indeed the preferred model now is for an unending accelerating expansion. That could change, of course; but it's certainly untrue to merely state that the BB is the ultimate end. It is also not the very first beginning. Conventional BB cosmology does not take us all the way back to the conditions where classical GR becomes singular, and there is plenty of open research into a whole variety of different ideas for how the "bang" forming the expanding region of spacetime we inhabit got started. I appreciate this addition was likely in good faith; but it was unsourced and inaccurate. —Duae Quartunciae (talk · cont) 15:02, 19 August 2007 (UTC)

removed supposedly

A recent edit added "supposedly" to the lead paragraph. I have removed it. This was probably an attempt to add neutrality, but the phrase is one of words to avoid in the manual of style. The context makes plain that this is according to the model; and the existence of a condition of extreme heat and density near t=0 in proper time co-ordinates (a technical term) is very solid indeed as a part of our knowledge of the history of the universe. There may be some dispute on details; but the "Big Bang" as a time of explosive expansion near t=0 is very solid. —Duae Quartunciae (talk · cont) 00:40, 21 August 2007 (UTC)

Issue with primacy and supremacy of the theory in the lead

There is an issue here of the primacy and supremacy of the Big Bang as a description of the universe. The sentence as it previously read made two problematic assertions:

1. The big bang is "a" theory. The indefinite article is technically correct (there are other theories) but it is misleading because the Big Bang is the only theory left in mainstream contention. We should be clear about this from the start in the wording.
2. The big bang is described by its features but not by its popularity as a description. That is to say that the current lead doesn't do a good job of indicating that the big bang is science's best explanation of the universe as it currently exists. This needs to be explained fully and completely from the get-go.

These issues are important because there are a number of people who dispute mainstream science who do not believe the big bang should have supremacy and primacy. Unfortunately for them, the supremacy and primacy of this theory is not up for debate in this article.

Nondistinguished 23:48, 25 August 2007 (UTC)

The theory itself should be up for debate - if the Big Bang is so sensitive to parameters relating to dark energy (which was only proposed after the 1997 discovery of accelerating redshift in QSOs, thanks to the long lost cosmological constant) and dark matter which particle physicists have been searching for but never found since the 1980s, shouldn't at least these two very weak points (with no experimental evidence of their existence) be a question mark on the validity of what the Big Bang proposes? Does non-baryonic matter exist in the laboratory (as the cosmological principle says it should) or is it just an "epi-cycle"? —Preceding unsigned comment added by 71.213.51.36 (talk) 05:01, 21 October 2007 (UTC)

Lead section

The lead section is now way too long - it should ideally be ~ 3 paragraphs. I'd trim it down myself, but I haven't the time (and won't have for the next few weeks). Could someone give it a good prune, please? Mike Peel 21:08, 3 September 2007 (UTC)

Agree. —Duae Quartunciae (talk · cont) 22:18, 3 September 2007 (UTC)

I have put up a new more concise lead section. Please let me know what you think. —Duae Quartunciae (talk · cont) 22:38, 3 September 2007 (UTC)

Some dolt messed around with the first paragraph under the "History" header. Not to sound too much like a luddite, but I'm not sure how to change this. Just wanted to alert you to childish rubbish.

The text in question is as follows:

"The Bang Theory was a giant fart type wind that hit a bang that scienteists explained to judges to be the begining of man kind. Jemilio Hmesa discovered that the world could have been started by this fart from a bang that created us. The reason he came up with this discovery was he was trying to find a way to prove god's unexistince but as you can see its a bunch of crap." —Preceding unsigned comment added by 76.180.165.214 (talk) 02:33, 5 September 2007 (UTC)

Observational evidence

Under Observational evidence the article claims that red shift proves the big bang, it does not, all it proves is that the universe is expanding, and that could be the of god, for example. —Preceding unsigned comment added by 82.46.20.206 (talk • contribs)

This could be the what of god exactly? You seem to have missed out the most important word there. More generally, this being an encyclopedia, we would need a reliable source for this information, not least to confirm its notability. Cheers, --Plumbago 07:55, 7 September 2007 (UTC)

I think 82.46.20.206 means this sentence: "The earliest and most direct kinds of observational evidence (sometimes called the three pillars of the Big Bang theory) are the Hubble-type expansion seen in the redshifts of galaxies..." Please note the difference between the words "evidence" and "proves". Art LaPella 20:11, 7 September 2007 (UTC)

Inflation and the CMB

I have just applied a fairly significant edit to a new paragraph added on the CMB and inflation. There is indeed an important role for inflation in explaining the exceptional smoothness of the CMB, but the previous description had some subtle technical issues. It's not actually correct to speak of inflation as "expanding faster that light". The rate of expansion is not a velocity in the normal sense of the word. Even with a conventional linear expansion, there are galaxies that are receding faster than the speed of light, and which are still visible. The distinguishing feature of inflationary expansion is that photons from a galaxy that is receding from an observer faster than the speed of light can never actually "overtake" the expansion and reach that observer. But with other expansion rates, photons can actually pass from a galaxy to an observer, even when the galaxy is receding faster than the speed of light from that observer.

The edit I applied can be reviewed here.[16] —Duae Quartunciae (talk · cont) 00:40, 11 September 2007 (UTC)

Capitalization

Three different dictionaries (Webster, Random House, and American Heritage) say it's "big bang" and not "Big Bang." Is there an authority that states otherwise? ←Ben^B4 16:41, 14 September 2007 (UTC)

The five scientific and technical dictionaries listed at the bottom of [17] capitalize "Big Bang". The general dictionaries listed there don't, with a couple exceptions including wikt:Big Bang. (Ignore the unrelated references to Big Bang (financial markets).) Google [18] shows Big Bang is capitalized more often than not, but not much more often. My policy has been to try to keep the capitalization or non-capitalization of the phrase consistent within each Wikipedia article, but after looking around I see it hasn't stayed that way. Art LaPella 02:55, 16 September 2007 (UTC)

How do you use Google to compare capitalizations? ←Ben^B4 20:43, 16 September 2007 (UTC)

Not automatically. Click the link I provided above after the word "Google", which I produced by Googling the phrase "Big Bang" ("big bang" would have produced the same results). The page shows 7 hits whose sample text has the capitalized phrase "Big Bang" bolded, one hit with the uncapitalized "big bang" bolded, one showing it both ways, and one that doesn't show the phrase in the sample text at all. If you then click "Next" several times at the bottom of the screen for more hits, you will find a greater proportion of uncapitalized "big bang"'s than on the first Google screen, but capitalized "Big Bang"'s continue to predominate. Note I'm using the sample text, not the blue title text where everything is likely to be capitalized. I also disregard titles embedded in the text for the same reason. I also disregard Google hits related to Big Bang (financial markets). Art LaPella 22:11, 16 September 2007 (UTC)

Tone

The tone of this article is much too opinonated. ex.)The first line of this article states, "The Big Bang is". While the first line of the article on creationism states, "Creationism is the belief". Although it explains that the Big Bang theory is just that, a theory, it lacks a neutral stance on the topic. 71.58.51.134 23:23, 15 September 2007 (UTC) —Preceding unsigned comment added by 71.58.51.134 (talk) 15:28, 15 September 2007 (UTC)

You might have noted that Big Bang#Philosophical and religious interpretations links to Philosophical and religious interpretations of the Big Bang theory which briefly mentions creationism, so the issue is whether that is enough recognition of creationism without violating WP:Undue weight. You might also have noted that this issue comes up regularly throughout the talk page archives listed at the top of this page and related pages. The existing article is the result of much, much debate on this repetitive issue, and it would be very difficult to say anything new about it. Art LaPella 03:20, 16 September 2007 (UTC)

Probable diameters of the Universe

I think that in addition to the measurements in fractions of a second, seconds, minutes and other time units, and the measurements in energy levels, also some information should be offered on possible diameters of the universe at a given moment. For instance, when it says:

“A few minutes into the expansion, when the temperature was about a billion (one thousand million; 109; SI prefix giga) Kelvin and the density was about that of air” [...] This is a very interesting stage, and some idea of the diameter of the universe at that point would be useful. The same at previous and latter points, particularly in the first few minutes and later on. That would also give some idea of the speed of expansion at different points of the universe's evolution.

Daniel_C 10:10, 4 October 2007 (UTC)

The diameter is only meaningfully set by the speed of light times the age of the universe. That's the definition of the relevant cosmological horizon and there is an entire section in the article about this. ScienceApologist 14:12, 4 October 2007 (UTC)

I think a clarification is merited. Regarding probable diameters, these estimates must specifically relate to the observable universe. There are both spatial and temporal limits to what we are able to observe. Thus, there is no (present) manner to estimate the size or age of the universe ... in fact there is no compelling evidence suggesting that the universe has an end or an origin. Bpabbott 18:29, 1 December 2007 (UTC)

Not Objective

One of the crucial elements of the Wikipedia sites and its predecessors is an objective perspective. This article lacks that. It should also be included that the Big Bang at present is only a theory no matter how much evidence there is to support it. It is technically a theory still as it cannot be observed. Only the repercussions can be observed. Therefore it will remain a theory. I apologize if this in itself is biased but hey everyone is biased towards something.Apocalyptica is taken —Preceding signed but undated comment was added at 18:04, 8 October 2007 (UTC)

The first sentence of the article says that the Big Bang is a model, which is another word for theory. I think that addresses your objections.--VAcharon 09:23, 9 October 2007 (UTC)

The wonderful aspect is that we do indeed have direct observations of the big bang, as much as sunlight is the evidence of nuclear reactions in our star, per the following section. Publicola 17:35, 28 October 2007 (UTC)

"In the beginning, there was darkness, and then... BANG."

The above phrase comes at the beginning of every episode of the current History Channel documentary The Universe (TV series). My understanding is that this is a perfect example of the misconception that the Big Bang "exploded" out into empty space - because really there was never any period or place of "darkness" at the beginning of the universe, no matter what measurements of space and time nor what model of particle physics you prefer. Unfortunately this show is the best current high-profile scientific television production addressing the Big Bang, and seems sure to cement this misconception in the popular consciousness for years to come. 70.15.116.59 19:21, 27 October 2007 (UTC)

I would like to know, and I hope someone more scientifically-minded can answer in a way I can understand: What is the evidence that there was no space or time prior to the big bang, and why is that evidence stronger than what I would think is the default Occam's Razor assumption that there was either prior? Publicola 07:32, 28 October 2007 (UTC)

Spacetime as we know it behaves in certain ways (time marching forward, three dimensions of space in all directions, etc.) only as long as the universe is not squished to an unimaginable density. However, in the early universe, with all matter and energy at a very high density, the detailed equations that determine how spacetime behaves breaks down. Therefore, it is a very pragmatic statement to say that space and time did not exist as we know it before a certain time in the past. However, that's not to say that spacetime didn't exist, only that it was in a very different form. There are still theorists trying to figure out exactly what kind of form spacetime would have in those first few moments. ScienceApologist 15:13, 28 October 2007 (UTC)

Thank you, but I have to admit I'm still baffled. Let me try to take this step by step: Ignoring time for a moment, what is the evidence that space itself was compressed in the early universe, as opposed to space as we know it today containing all the matter compressed into a small part of space? As for time, there are theories like "big crunch" and oscillatory universe -- are those ruled out? Is there evidence saying more than that it's just not meaningful to talk about what preceded the big bang, or is there evidence that there was no prior moment of time? (By the way, I have read the article carefully, but I cant find the connection between this concept of expanding spacetime in the "overview" with the information presented in "Observational evidence." Redshifts, for example: why are they not just the Doppler effect of matter flying apart as the debris from the explosion of the big bang?) Publicola 15:25, 28 October 2007 (UTC)

Please see metric expansion of space for more on space being compressed. You can also read about big crunch and oscillatory universe at their respective pages. The short of it is that they aren't completely ruled out, but we currently look to be living in an open universe that will reach heat death or maybe a Big Rip. As for "prior moments in time", since time is intricately dependent on space in spacetime, our models indicate that there is a t=0. The only problem is that our current models of physics also don't tell us what the universe was like at and near this point (see quantum gravity). So "before the Big Bang" is either shorthand for describing models that can explain the Big Bang or it is a misnomer since t=0 is the (fiducial) starting point and there is no time before it. Finally, the expansion of space, redshift, and to some extent the Milne universe articles answer your last question. ScienceApologist 15:41, 28 October 2007 (UTC)

Thank you! In fact I did just come across Metric_expansion_of_space#Observational_evidence as I was thinking about this question. Now I wonder why I didn't come across it reading the article. Publicola 15:44, 28 October 2007 (UTC)

On reflection I find the "Hubble's law expansion" section of this article to be critically lacking. It explains the observational evidence of the redshift, but it does not connect that to metric expansion of space. I just inserted a see-also to metric expansion of space#Observational evidence I think is clearly superior to the pre-existing distance measures (cosmology) see-also which only talks about the different means of determining the distance of faraway objects, and says nothing about the observational evidence of expanding spacetime. Their are at least two points from metric expansion of space#Observational evidence which I believe should be added to the "Hubble's law expansion" section, paraphrasing:

That space is undergoing metric expansion is supported by direct observation of the Cosmological Principle and the Copernican Principle, which together have no other explanation. Astronomical redshifts are extremely isotropic and homogenous, supporting the Cosmological Principle that the universe looks the same way in all directions. If the redshifts were the result of an explosion from a distant center instead of the expansion of space, then they would be observed to be smaller in the direction of the center and greater facing from it, but they are not. Measurements of the effects of the cosmic microwave background radiation in the dynamics of distant astrophysical systems have proved the Copernican Principle on a cosmological scale in 2000. The radiation that pervades the universe is demonstrably warmer at earlier times. Uniform cooling of the cosmic microwave background over billions of years is explainable only if the universe is experiencing a metric expansion.

This is important for explaining why the redshifts are not the result of explosion, in which case they would not have those properties unless we happened to be in the center of the explosion which is unlikely. I think this is obviously a common fallacy. I think I will be bold about this. Publicola 16:19, 28 October 2007 (UTC)

Well I added a considerably improved revision of that paragraph to the section which I renamed from "Hubble's law expansion" to "Hubble's law and the expansion of space", because the distinction from expansion of matter is critically important. Someone please proofread the last two paragraphs at the end of that section. The reason that I was troubled was that there was no suggestion that the Copernican principle was a cosmological fact, which is the point of the last paragraph. The paragraph before that states that Hubble's observations were uniform and thus agreed with the Cosmological principle -- that was just barely implicit if at all in the earlier version today. Publicola 17:07, 28 October 2007 (UTC)

I hope that those who understand this better than I do, will especially proofread this sentence: "If the redshifts were the result of an explosion from a center distant from us, they would not be so uniform." I thought that uniform redshifts in all directions proved only that the universe is uniformly expanding/exploding, which wouldn't indicate a center as demonstrated at [19]. Something more would be required to determine whether the expansion was originally caused by an expansion or an explosion. Art LaPella 21:36, 28 October 2007 (UTC)

What I think is intended here is for uniform=isotropic, but I'm not sure. ScienceApologist 21:59, 28 October 2007 (UTC)

Yes; I changed it to "similar in all directions."

After having delved in, I am feeling the dilemma about vocabulary level usage. (e.g., use introductory simplicity or the language professionals choose?) Publicola 22:08, 28 October 2007 (UTC)

Art, you are exactly right: the Cosmological principle (supported by isotropic redshifts along with much other evidence) is supplemented by the newly-proven Copernican principle (shown from the 2000 research cited in the final paragraph of that section.) Publicola 23:13, 28 October 2007 (UTC)

This is a digression, but I think that there could be many ways to interpret the Big Bang. I find the idea of logarithmic time intuitively appealing - if you use a unit of time that is proportional to the age of the universe, and a distance unit related to it by a constant speed of light, then the overall size of the universe really didn't change very much - maybe 10,000 fold, if I remember correctly. Similarly the redshift would not have been so much and the temperature could be seen as changing only slightly, I think. Or you could use a unit of time defined so that there is no redshift. The problem with such views of the universe of course is that all constructs such as electrons, protons, atoms, and such would be variable in size over time. But I think it indicates that you could see the "early universe" subjectively not as a short bang, but as an infinitely long period of time with a large universe in which there was constant activity. Still, no matter how you look at it, there is no space outside the Universe, by definition, and there's no empty, cold, dark place available at the beginning. 70.15.116.59 05:24, 29 October 2007 (UTC)

expansion considered in general relativity before Hubble

Does "universal expansion was considered mathematically in the context of general relativity well before Hubble made his analysis and observations," mean that GR predicted metric expansion? If possible, I think we should say that, or at least something stronger than "considered mathematically". Publicola 15:13, 29 October 2007 (UTC)

It was predicted, but since very few people understood general relativity at the time, few people were aware of the prediction. ScienceApologist 16:29, 29 October 2007 (UTC)

A source for this would be fantastic. Publicola 04:08, 31 October 2007 (UTC)

The canonical references for that are Alexander Friedman's 1922 "Über die Krümmung des Raumes" in Z. Phys and Georges Lemaitre in a 1927 Annales de la Societe scientifique de Bruxelles article. 122.145.8.149 13:24, 11 November 2007 (UTC)

A few thoughts to ponder

If all matter in the universe was once in a single collected location, would it not be too dense and have too much mass to escape itself and "bang"? Could the "expanding" scientists are seeing simply be a "breathing" action of a larger universe we do not understand yet? Perhaps it grows and shrinks after long periods of time. I find it interesting that while scientific theory cannot be proven with today's knowledge people tend to rely on it as fact and completely dismiss the idea of intelligent design, sure it is only theory as well. Why not, as scientists, be open to the possibility of a higher form of energy of intellectual properties which could have created us? I've noticed too often that people claim we have evolved, they teach this in school but they ban prayer, either one is just theory. One person may have a miraculous experience and say it is evidence of a creator, but they still can't prove it. One might compare two fossils and say it is the process of evolution, again it cannot be proven. Why is there such bias towards science alone and against the idea of a creator? We, mankind, have not been here long enough to make such solid claims as "the universe is expanding" it may be expanding now, but perhaps it will shrink in another 8,000,000,000 years.. either destroying itself and banging again, or just expanding again. The expansion we witness may appear to us as a large scale, or HUGE but it all depends how large the observer is, the expansion may be very very small from another perspective. For all we know, we are inside of a quark, inside of an electron, inside of an atom inside of a snow globe which rests on a child's dresser. Davidthewavid —Preceding comment was added at 04:12, 1 November 2007 (UTC)

I deleted this section as I don't really feel it contributes in any way to the discussion about the Big Bang Wikipedia entry, and someone reversed my deletion. I don't think I was out of line as the talk page guidelines specify deletion of entries is acceptable if the entry is, "not relevant to improving the article." The above paragraph represents mostly fanciful speculation. thryllkill (talk) 22:55, 16 November 2007 (UTC)

Falsifiability of Dark Energy and the Big Bang

There seems to be little discussion of the weakest links in the logical chain of thought regarding the Big Bang, especially the lambda CDM version, the so called standard model. For instance, the argument concerning acceleration of expansion since 9 billion years ago depends critically on an interpretation of the high z SN-1a results. These supernovae seem to be further away than they should be based on a value of H₀. Which value? They are not further if some values are used and are even further if others are used. Why use the value that was used and why discount other values?

As a matter of fact, Tony Smith's Cosconsensus website identified several H₀ values that are purportedly of high quality and are probably reliable. They were determined by the use of standard candles at various ranges of distances. If these values are plotted versus the average distances of the ranges, H₀ is seen to be not a constant at all, so it is useful only for objects in the respective ranges of distances. This is why H is often referred to as a parameter. To use H₀ properly, one must zero in on an answer by successive approximations.

More importantly, H₀ increases substantially along a very tight linear regression line as distance from us increases. If an inappropriate value for H₀ was used to compare the present expansion rate of the universe with the distances to high z SN-1a objects and with the expansion rate therein implied, the conclusion that the expansion rate of the universe is accelerating could be wrong.

Curiously, one can use the high z SN-1a results to find a new value of H₀. One also finds a value for H₀ using CMB data. According to data compiled by Smith, I find that these and the earlier determinations all fall on the same tight linear regression line having negative or decreasing slope toward the present era or position. But, if the universe is enlarging at an accelerating rate, H₀ should be increasing toward the present.

It is a mistake to state that high z SN-1a results imply that the expansion rate was lower in the distant past, as stated in the article. H₀ calculated from the high z supernovae absolute luminosity distances and actual redshifts is higher than all but the CMB determinations.

This is not my data nor my research. It is plain fact available for anyone to analyze. H₀ increases linearly with distance away from us or decreases on approach to our present position or time. At least a half dozen truly independent measurements show this. Contrary evidence for the Big Bang, Inflation or Dark Energy should not be so easily swept under a cover. Why should an encyclopedic article be so chained to consensus? Consensus has frequently been wrong. I call this the H₀ paradox or the Hubble problem of the Dark Energy hypothesis.

Other weak points are the codependence of several phenomena that are used to "independently" corroborate this acceleration conclusion and the implied existence of Dark Energy, like the pattern of clusters or the large scale structure of the universe. Corroboration must come from truly independent lines of observation or experiment not from corrolated measurements. Also, the unsupported premise of Dark Matter is used to help reinforce the Dark Energy hypothesis, as if the existence of dark matter had already been proven.

For any theory to be considered valid, it must be falsifiable. A null hypothesis must be constructed and the evidence for or against it must be evaluated. The null hypothesis is one that nullifies the original hypothesis, it must be contradictory. If the null hypothesis can be proven true or false by means of a critical experiment, the theory or hypothesis in question is denied or proven. More attention should be given to null hypotheses and their disproof. This is especially true regarding Dark Energy because statements have been made regarding it by prominent scientists that threaten the integrity of science itself.

We cannot relax our grip on science by loosening our standards for proof, as has been suggested. If Dark Energy, quintessence or a nonzero cosmological constant are not experimentally falsifiable hypotheses, they do not deserve to be regarded as viable hypotheses at all in the first place.

The biggest objection to Dark Energy is that it indeed appears to be unfalsifiable - miraculous. How ironic it is that the scientific method has brought us so far that we may feel free to begin to doubt it. We doubt in order to embrace an ad hoc hypothesis for our convenience and to cloak our lack of imagination. It is no small matter that experiments to determine the repulsive effect of vacuum energy due to quantum fluctuations show that it is a hundred orders of magnitude too large to account for Dark Energy. The real paradox is that problems like this are minimized or dismissed by we who profess allegiance to the scientific method.

So, the best resolution to the paradox of Dark Energy and Neo Inflation or Acceleration is that they do not exist. It is simpler to believe that a short sequence of misconceptions, misinterpretations, mistakes and mistatements has resulted in propagation of a big error than to believe in such a momentous miracle.

I am sorry. I cannot remain neutral when the discussion touches on the scientific method. I support it.

Gary Kent

Kentgen1 05:58, 9 November 2007 (UTC)

I'm not qualified to debate you scientifically, but that isn't what this page is for anyway. Have you read the infoboxes at the top of the page, especially the one that begins, "IMPORTANT: This is not the place to discuss how you think the universe began..."? Following those links will give you extensive answers to "Why should an encyclopedic article be so chained to consensus?" "Consensus has often been wrong", but more often it has been right, especially on Wikipedia which attracts people with much stranger ideas than yours. Art LaPella 21:18, 9 November 2007 (UTC)

Exactly, Art. Gary's post, largely about dark energy, is not at all integral to the big bang theory, at least not yet. Gary, you should present your argument on the BAUT Forum - www.bautforum.com . --Cougar --64.122.177.153 (talk) 17:43, 17 January 2008 (UTC)

BUT EVEN IF THE BIG BANG HAPPENED WHO CREATED THAT LIL DOT THAT CAUSED THE BIG BANG?

THINK ABOUT THAT 1 —Preceding unsigned comment added by 24.188.17.249 (talk) 08:50, 11 November 2007 (UTC)

Why does it need to be a "who"? What's wrong with a "what"? In which case, lots of people are thinking about that. Mike Peel 09:42, 11 November 2007 (UTC)

Take note of the opening paragraph. "The Big Bang is the cosmological model of the universe whose primary assertion is that the universe has expanded into its current state from a primordial condition of enormous density and temperature. The term is also used in a narrower sense to describe the fundamental "fireball" that erupted at or close to an initial time-point in the history of our observed spacetime." ... it is essential to understand that the event often called the Big Bang, refers to the origin of "observed spacetime". It is erroneous to assume that observation coincided with the origin of the universe. That we cannot see beyond this temporal curtain, does not mean that there is nothing beyond it. Bpabbott 17:45, 1 December 2007 (UTC)

Cause of Big Bang

Disclaimer: this is not a creationist rant.

This article is quite large, and by just skimming through it I can't find any discussion of origins of Big Bang. Not origins of the theory, but "what caused Big Bang to happen". I remember reading something about fluctuation of energy in vacuum that might have caused creation of great amount of energy which then triggered the Big Bang or something like that. Anyway, is there a section in this article which presents scientific theories of origin of Big Bang? --78.0.90.120 09:16, 13 November 2007 (UTC)

Second-to-last section. ScienceApologist 15:33, 13 November 2007 (UTC)

"Speculative physics beyond the Big Bang"? I don't see anything about what caused Bing Bang there. If that section truly is supposed to answer that question, then the section need serious rewrite for clarity... --78.1.107.253 18:17, 13 November 2007 (UTC)

From the overview: "How closely we can extrapolate towards the singularity is debated—certainly not earlier than the Planck epoch. The early hot, dense phase is itself referred to as "the Big Bang". There is no consensus about how long the Big Bang phase lasted: for some writers this denotes only the initial singularity, for others the whole history of the universe." If you are looking for first causes, that's as good as you're going to get. ScienceApologist 20:57, 13 November 2007 (UTC)

There appears (to me) to be some confusion on what constitutes the event referred to as the Big Bang. This event marks the origin of the observable universe. The question isn't what created the content of the universe, but what conditions/phenomena enabled observation to become eternal. In my opinion, past versions of this page were less misleading on this point. I'm tempted to edit the page to add the term "observable" in several instances where the word "universe" is used in the context of its evolution or origin. Comments? Bpabbott 18:08, 1 December 2007 (UTC)

Bpabbott, you are quite right that there is a lot of confusion about "the big bang." The name of this widely encompassing theory is a terrible misnomer. As I've mentioned elsewhere, we know next to nothing about the "event". We do know a remarkable amount about what happened after that, even as little as one second after. Besides, the big bang is not an event. It is a scientific theory built on observations. With no evidence of the so-called event, it is simply not part of the theory. -- Cougar --64.122.177.153 (talk) 20:45, 17 January 2008 (UTC)

"The Big Bang Theory

Typing "the big bang theory" into the search now directs to a tv show. Good as the show is, isn't the origin of the universe a bit more significant? —Preceding unsigned comment added by 68.230.161.164 (talk) 01:05, 3 December 2007 (UTC)

I like the show too, but the redirection should go to the more important issue not the one that is more like.216.49.97.10 (talk) 03:20, 2 January 2008 (UTC)

A Google search shows that "The Big Bang Theory" means the scientific theory about twice as often as it means the TV show. The history page for The Big Bang Theory (TV series) shows it was moved to The Big Bang Theory on November 20 by User:David Levy with the comment "unnecessary qualifier". Although there is a Wikipedia:Hatnote, I think it's more important to direct readers to Big Bang, although we also need a way to find the TV series. So I suggest a disambiguation page, with a See Also link to Big Bang Theory (album). Art LaPella (talk) 06:05, 2 January 2008 (UTC)

I performed the page move simply because The Big Bang Theory was a redirect to The Big Bang Theory (TV series) (which defied our naming conventions and served no practical purpose).

I do, however, believe that the former is an appropriate title for the article about the television show. The phrase unquestionably refers to the scientific theory with greater frequency, but not in title case (with an uppercase "T" in "Theory"). The title also includes the word "The," the presence of which Wikipedia's naming conventions would not allow in an article about the scientific theory.

Note that the above (legitimate) complaint about "the big bang theory" leading to the article about the TV series was due to the fact that The big bang theory (without title case) was redirecting there. I just edited it to redirect to Big Bang instead. —David Levy 07:31, 2 January 2008 (UTC)

OK. Art LaPella (talk) 21:33, 2 January 2008 (UTC)

Age of the universe and Hubble Deep Field

In the Big Bang article, it says the age of the universe is about 13.7 billion years. In the Hubble Deep Field (HDF) article, it says that the galaxies seen there are about 12 billion light years away. If everything in the universe was at the location of the Big Bang 13.7 billion years ago, how did those galaxies manage to get 12 billion light years away from us by now? I thought that only very light things like, um, light, could travel at the speed of light, and galaxies aren't light, they are very heavy!

If we assume that the HDF region is unremarkable, as its article says, then presumably looking in the opposite direction, somewhere "south" of the Earth, would reveal lots of galaxies 12 billion light years away in that direction too. That would make the universe have a diameter of 24 billion light years. However, I wouldn't be surprised if astronomers discovered more galaxies even further away than the HDF galaxies once better telescopes are built.

So this is what I find hard to understand. If the Big Bang was about 14 billion years ago, then those galaxies in the HDF must have been travelling very quickly to get 12 billion light years away. I'm finding it hard to calculate exactly how fast they must have travelled. Here's what I'm thinking. The galaxies are 12 billion light years away, which means that the light from them must have taken 12 billion years to get to us. In other words, they were 12 billion light years away from where we are now, 12 billion years ago. Doesn't that mean that they must have travelled to 12 billion light years away from here in only 1.7 billion years from the Big Bang? (I'm not saying they travelled faster than the speed of light, since I'm not assuming that the Big Bang was right here.)

How would one calculate how fast those galaxies must have been going to get from the Big Bang to 12 billion light years away? How would one calculate the amount of energy needed to get a galaxy moving fast enough to get that far away?

I'm not an astrophysicist, so I might have made some really basic errors or wrong assumptions there. But if I got it basically right, then it seems to me that the existence of galaxies 12 billion light years away in one direction, and presumably the same distance away in the opposite direction, proves that the Big Bang either didn't happen, or was a lot longer ago than 14 billion years, or the distance of 12 billion years to HDF galaxies is wrong, or something really weird happens at the "edge of the universe". Thanks for reading, and please tell me what you think. —Preceding unsigned comment added by 220.253.80.200 (talk) 10:31, 11 December 2007 (UTC)

You're obliquely referring to the horizon problem which is an issue scientists have been aware of for some time. However, I think your misconceptions may run a bit deeper. In particulary, there are two assumptions you have made which are problematic: 1) you assume that the initial condition for the Big Bang was such that everything was causally connected (in other words, everything started from the same place), but this needn't be the case 2) that galaxies are "traveling" when they follow the metric expansion of space, but this is also incorrect. Both of these misconceptions together lead to some rather bizarre twists of logic as you have demonstrated. —Preceding unsigned comment added by ScienceApologist (talk • contribs) 14:35, 11 December 2007 (UTC)

Something to think about..

Okay.. so space is everything right...what contains space though? can u posable see something being "endless" [or at least our (being humanity's) understanding of the word]? Just picture it and the posibilities are endless. and to all think that mabye everything in the entire...I csn't even beginnin to think of a word..how about Everything...mabye everything that is everything that ever was or is now, could have all been once a single body of mass... it drives me crazy just trying to think about it. 69.248.209.198 (talk) 01:22, 19 December 2007 (UTC)

122.167.240.91 (talk) 21:04, 24 December 2007 (UTC)About the basic idea

122.167.240.91 (talk) 21:04, 24 December 2007 (UTC)I am a student of Engineering in India and i wanna know some basic ideas about the big bang theory. Can any one please tel me on what basis the universe was said to be expanding,is it only based on the positions of the objects determined by the images got by the observations made(ie. is it based on the received light from the objects or other type of emittions made by the objects) or is there any other basis how it has been theorised.And can anyone please tel me how wide the universe is? and on what basis it has be caliculated

All of the information you ask is in this article. Did you read it? 209.77.205.9 (talk) 00:47, 27 December 2007 (UTC)

Did he understand it? See WP:BITE. You could either direct him to the WP:Reference desk, or to the last 2 paragraphs of Big Bang#Hubble's law and the expansion of space which gives some idea of an answer to his first question - I didn't find answers here to the other questions. Art LaPella (talk) 02:10, 27 December 2007 (UTC)

Comparison with global warming

Looking at the treatment of dissenting views here, it seems that WP:WEIGHT is being applied much more rigorously than in relation to Global warming. At least if you just count heads, it seems as if dissenters from the Big Bang model with relevant qualifications in physics are at least as numerous as dissenters from AGW with relevant qualifications in climate science. Not that I'm objecting, but I was surprised to find (via a trawl through Conservapedia I have to admit), this "scientists dispute Big Bang" statement [20] of a kind familiar from the AGW debate. The signatories seem rather more high-powered than those of the typical AGW letter (fewer "retired" this and "consultant" that, for example) and some of the retired signatories are names even I recognise. I suspect the problem is more with the GW piece than here, but perhaps the statement could be modified a little. JQ (talk) 07:54, 28 December 2007 (UTC)

Most of the signatories to the cosmology statement are either "usual suspects" or not cosmologists. There really is no controversy in the scientific field and, unlike global warming, there is very little in the way of a media controversy either (despite the attempts of Halton Arp, Jayant Narlikar, and others to get their views more visibility). This article used to be riddled with "controversy". However, it was easily determined through citation analysis that the people supporting the existence of a "controversy" and who disputed the Big Bang were of such a minority that their opinions could be relegated to one or two sentences. Those sentences are still there in the article giving the appropriate weight to these ideas. I encourage you to use this article as a standard for global warming if you'd like. We went through a lot of headaches to get it to the state it is today. ScienceApologist (talk) 15:01, 28 December 2007 (UTC)

Thanks for this. I'll see if there's a way I can promote this as a model for GW.JQ (talk) 20:09, 28 December 2007 (UTC)

BB Doesn't Address Origin of Universe

I note that the third paragraph of this article makes the following statement:

"...its [the CMB's] discovery led to general acceptance among physicists that the Big Bang is the best model for the origin and evolution of the universe."

It is indeed the best model for the evolution of the universe, but since there is no evidence of the conditions at "t=0", the "big bang model" currently says nothing about the origin of the universe. --64.122.177.153 (talk) 17:20, 17 January 2008 (UTC)Cougar

first time editor has a question about the Universe

I may have overstepped my boundaries here so someone please help out. I don't know where or how to make a general comment so I am placing it here in hopes that someone who works for Wiki can answer my question. I was perusing the "universe" page and I saw that there was a statement about the Big Bang. Now I believe that the Big Bang actually happened, but there was a subjective viewpoint expressed therein. The statement was something to the effect of, "the beginning of the universe is called the Big Bang." I changed this to say, "the moment God initiated the universe is called the Big Bang, in the scientific community." UH-OH! I should have known that someone would not like that, (RYAN I believe his name was) can he, or anyone else tell me how we can change this to represent an unbiased explanation. I thought mine was ok but knew it was not perfect. —Preceding unsigned comment added by 128.138.64.32 (talk) 23:33, 28 January 2008 (UTC)

Posting anything even remotely in favor of God on Wikipedia is suicide. Now, I'm not atheist or anything, but it is generally accepted that on pages dealing with matters of science, the consensus of the scientific community should be represented. Something like, "The creation of the universe is believed by scientists to be the result of the Big Bang," or, "The Big Bang is believed by scientists to be the cause of the universe." is better. Or you could think of something better. And don't worry about overstepping your boundaries, Wikipedia is all about being bold. Trust me, you will encounter a lot of bold people here. Well, happy editing. I suggest you make an account. Welcome to the team.--Asderoff (talk) 22:11, 30 January 2008 (UTC)

I think the issue was clearer than that. That statement wasn't just "remotely in favor of God". It was claiming as fact that a singular God existed and created the Universe, a point of view that excludes many religions as well as non-believers. And "believed by scientists" in a scientific article is redundant. The various gods that people believe in have their say in the creation myth article, where the Big Bang makes but a brief guest appearance. rspeer / ɹəədsɹ 10:25, 31 January 2008 (UTC)

Latest Mod

Thats cool, I was just demonstrating to a friend the fundamental nature of wikipedia, and you were most co-operative. Thankyou:-) —Preceding unsigned comment added by 134.159.111.66 (talk) 06:19, 3 February 2008 (UTC)

second photo contains incorrect information "http://en.wikipedia.org/wiki/Image:3duniverse.png"

http://en.wikipedia.org/wiki/Image:3duniverse.png

This photo contains text whihch states that the human species has existed for "a few million years". However the wikipedia article on the human species (http://en.wikipedia.org/wiki/Human) states that "DNA evidence indicates that modern humans originated in Africa about 200,000 years ago"

I suggest removing this document.

Enrizzl (talk) 19:46, 9 February 2008 (UTC)

It was removed by Irishguy. Art LaPella (talk) 04:58, 10 February 2008 (UTC)

Proof the scientest need change the name of this.

The Big Bang, that's impossible. Now, I DON'T argue that there WAS and explosion that created the universe. However, there was NO BANG!!! Ya see it's simple, there is no air in space, thus nothin' for sound waves to travel through, thus no sound, which means that the "Big Bang" never occoured. Yes, they was an explosion but no actual bang. Just proved that scientest don't ALWAYS know best after all. --Crash Underride 18:47, 23 February 2008 (UTC)

It's called the "Big Bang" for the same reason sunset is called "sunset", even though "Earth-turn" would be more accurate. It's the name everyone uses and recognizes. (Anyway, there probably was a bang within the expanding matter.) Art LaPella (talk) 18:44, 24 February 2008 (UTC)

I suggest instead The Horrendous Space KABLOOIE.--BirdKr (talk) 01:30, 27 February 2008 (UTC)

big bang universe end theory

if the big bang is said to continuesly repeat itself wouldnt that break the whole fact of religion exept for the belief in reincarnation —Preceding unsigned comment added by 203.122.104.28 (talk) 09:47, 27 February 2008 (UTC)

In my opinion, religion (with or without reincarnation) could adapt to an oscillating universe, in the same ways it has adapted to the current scientific consensus. Art LaPella (talk) 22:08, 27 February 2008 (UTC)

Religion And The Big Bang

Shouldn't There be a section about Religion and the Big Bang. Like how they support, or Contradicts with each other?--Obaidz96 (talk) 23:49, 2 March 2008 (UTC)

Support

• There Should Be one, many verses in the Quran say that the Universe/Space is constantly Expanding. And I am pretty sure the bible has some verses tha contradict with the theory. --Obaidz96 (talk) 23:49, 2 March 2008 (UTC)
• Adding a section like this would be useful in showing these contrasts, and in providing perspective with a different POV. scetoaux ^{(talk) (My contributions.)} 23:53, 2 March 2008 (UTC)

Oppose

• Oppose- I believe this has already been mentioned, and rejected, under criticism discussions, and there is already an article for this called Philosophical and religious interpretations of the Big Bang theory which does talk about the differences and that article is pointed out in the Big Bang article. --BirdKr (talk) 04:33, 3 March 2008 (UTC)

• Oppose - per BirdKr. Geologyguy (talk) 04:44, 3 March 2008 (UTC)

Neutral

1. There already is one. It's called Big Bang#Philosophical and religious interpretations. It's vague, but it links to a larger, more specific article Philosophical and religious interpretations of the Big Bang theory. Art LaPella (talk) 03:07, 3 March 2008 (UTC)
2. The sub-section pointed to by Art LaPella is fine and enough imo. --Childhood's End (talk) 14:33, 3 March 2008 (UTC)

Hoyle

This edit duplicates material about Hoyle in the fourth paragraph of Big Bang#History. Art LaPella (talk) 18:33, 8 March 2008 (UTC)

Agree. I would vote to remove it, although the last sentence is new and could be kept if you think it's relevant. --Childhood's End (talk) 08:51, 9 March 2008 (UTC)

Criticism

I removed an unsourced bit about criticism from the intro that didn't seem to relate to the existing criticsm section - unless I've mis-interpreted. Also removed the rather overdone Lerner quote - so he's complaining about the "powers that be", so what. If there are other sources that back up his sour-grapism then let's see 'em. Vsmith (talk) 15:28, 9 March 2008 (UTC)

I rephrased the support for Big Bang that looked like criticism to Vsmith and so it was removed by him. Jim (talk) 15:55, 9 March 2008 (UTC)

Intro Trashed?

I pretty much rewrote the introductory paragraphs, which to me appeared to have been thoroughly trashed by creationists or some such. It was gobbledegook. I haven't done a lot of Wiki editing, and I didn't look into previous versions, but I've done some considerable study on this topic, and the Intro is now intelligible and accurate to my knowledge. Comments, criticisms, and nitpicks welcome. Go ahead and make it better. If you're unsure, ask first. DCCougar (talk) 21:41, 11 March 2008 (UTC)

I have very mixed feelings about your changes to the introduction. Would you mind saying why, specifically, you felt the version you changed was trashed? CKCortez (talk) 23:36, 11 March 2008 (UTC)

Well, the previous version is gone now, so I can't address specific points. (Is the old version available somewhere?) Basically, it contained numerous inaccuracies, it contained side-trips out into areas that are not central to the theory, and Jim's claim about the "most important achievement" (see below) is terribly far off the mark. It was scattered and unintelligible. The theory is simple at its base. I try to inform, not confuse. DCCougar (talk) 13:32, 12 March 2008 (UTC)

Click here for the old version. To find old versions without me, go to the Big Bang article, click the tab that says "history" near the top of the screen, and click one of the time and date stamps. Each represents a different historical version of the page you want - in this case, the version you want is 14:12 March 10, 2008, just below your first (lowest) edit, which is labeled with DCCougar. Art LaPella (talk) 20:48, 12 March 2008 (UTC)

Thanks, Art. A good example of the inaccurate or unintelligible introductory description that I was mortified to find is as follows: "The model is based on a theoretical lack of the Hubble type redshift in a stationary universe and so on a constant creation of the energy necessary to compensate for the dynamical friction of photons in such a universe." I still can't make out what is trying to be said here. The model is based on observational evidence. That evidence pretty much ruled out Hoyle's "eternal" model. Hoyle was one stubborn scientist, though, and like Arp, he scrambled to find some explanation, however unlikely, for the inconsistencies between his model and observation. DCCougar (talk) 15:17, 13 March 2008 (UTC)

I also don't see what was wrong with the previous version - perhaps you can explain what part you felt was 'gobbledegook' or why you felt it was 'trashed by creationists'. PhySusie (talk) 01:22, 12 March 2008 (UTC)

Why have you deleted my edits about the most important achievement of the Big Bang Theory: the invalidation of the principle of conservation of energy and finally allowing for unity of science and spiritual life?

It's new physics, unknown before the Big Bang Theory, when every physicist and his brother thought that "energy can't be created out of nothing". The expanding universe theory showed conclusively that it can be created out of nothing and it is easily created in sufficient amounts. I hope you appreciate the fact that if energy were strictly conserved the expanding universe wouldn't be possible and all the astronomical observations had to be explained also in Einstein's universe (as they are explained with a possibly phony "Einsteinian gravitation" by cranks). Since the fact of creation of energy is taught in all general relativity courses around the world, even if your POV is different, it is not allowed in wikipedia since it goes against the mainstream science. TELL THE WIKITRUTH Jim (talk) 09:50, 12 March 2008 (UTC)

"Mainstream science" does not teach that the Big Bang invalidates the principle of conservation of energy: the Big Bang is regarded as containing all the energy that is now distributed throughout the Universe. Also, I've never seen "the fact of creation of energy" taught in any general relativity tutorial (nor is it presented in the Wikipedia article on GR). And what does "finally allowing for unity of science and spiritual life" mean? --Robert Stevens (talk) 11:31, 12 March 2008 (UTC)

Thank you, Rob Stevens. Yes, Jim, you seem to be in the wrong place. This theory has nothing to do with "unity of science and spiritual life." Please do not attempt to impose your beliefs where they do not belong. DCCougar (talk) 13:33, 12 March 2008 (UTC)

Ah - thank you for catching that - the older version that I looked at didn't have all that. Good catch. PhySusie (talk) 14:45, 12 March 2008 (UTC)

That the Big Bang invalidates the principle of conservation of energy is a common knowledge even if it is not known to the wikipedia editors. It comes from the Noether theorem applied to the expanding universe. You may check it with the university where I'm doing my PhD in general realtivity. The head of "Cosmology and Gravitation" is prof. Demianski (click on "Authorities and people" and slect his e-mail). If he's not enough then prof. Meissner told me that my proof of validity of Einstein's universe has to be rejected on grounds of invalidity of conservation of energy. Otherwise Einstein's idea is fine, and it would explain the illusion of accelerating expansion and even Pioneer anomaly. Its only problem is that the validity of Einstein's universe is based on conservation of energy which according to mainstream science is false. If this principle were true the university could get first Nobel Prize in its history. So you are adding insult to injury by maintainig that "mainstream science" allows conservation of energy. It does not and the result is the Big Bang and invalidity of Einstein's universe.

The "unity of science and spiritual life" is something that theist want to push through, using the Big Bang as a vehicle, since the Big Bang contradicts the conservation of energy. Just yesterday a Catholic theologian, prof. Michael Heller got $1,600,000 prize (biger than Nobel Prize) for cosmology. Supporting guess what. The scientists from U. of Kansas maintain that support of Einstein's universe is an atheist plot. So I just wanted you to be consistent in your belief in possibility of creation of matter from nothing. Jim (talk) 16:13, 13 March 2008 (UTC)

Jim wrote: "That the Big Bang invalidates the principle of conservation of energy is a common knowledge even if it is not known to the wikipedia editors." Please provide peer-reviewed journal articles supporting this position. More to the point, however, explain how this is central to a general understanding of the Big Bang theory. I have no problem with violating the law of conservation of energy -- dark energy, if accurately described by the cosmological constant, does that -- however, I don't see how this is at all central to the theory, and its positioning in the introductory paragraphs can only confuse, rather than inform wiki-readers. DCCougar (talk) 18:32, 13 March 2008 (UTC)

Jim wrote: "The "unity of science and spiritual life" is something that theist want to push through, using the Big Bang as a vehicle, since the Big Bang contradicts the conservation of energy." So why are you even talking about it? DCCougar (talk) 18:34, 13 March 2008 (UTC)

...Huh? Jim, "Einstein's Universe" refers to a static-Universe, steady-state theory which Einstein later considered to be a mistake (his "biggest blunder", in fact). You tried to "prove" that it was valid? Why? And your "proof" failed? How is this relevant to the Big Bang theory? And steady-state theory is NOT "fine", it is contradicted by numerous observations (not just redshift). And Heller was awarded the Templeton Prize, which doesn't mean much in academic circles anyhow: it's a religious prize. But if it was for musings on the Big Bang: so what? According to mainstream science, the Big Bang happened, regardless of whatever "spin" theologians want to put on it. --Robert Stevens (talk) 19:21, 13 March 2008 (UTC)

Also, Jim, you might want to review Wiki's No original research policy. DCCougar (talk) 22:22, 13 March 2008 (UTC)

Hi DCCougar and Robert Stevens. If I wanted to talk about all subjects I'd have to violate No original research policy since those things are the subject of my PhD work and a PhD work by definition is an original research.

While I can't show my original research I can answer your questions. That the conservation of enrgy is not valid in the Big Bang model you may ask any general relativity professor from any university in the world. All of them know that the Big Bang does not allow conservation of energy.

I can also "explain how this is central to a general understanding of the Big Bang theory" in other words "why the Big Bang does not allow conservation of energy?".

The short answer is that conservation of energy implies a redshift in a stationary universe and so if we want to have the expansion of space we have to get rid of conservation of energy since we can't have two reasons for the same effect (then the effect would be twice as big and it's not).

The long answer is that in general any object moving through the universe is a subject to so called dynamical friction. It is on average a loss of kinetic energy of the moving object to the surroundings (if it is gain then it is called sling effect). The effect can be calculated applying the principle of conservation of energy and when surroundings gain the energy the object is assumed to lose the equal amount of energy. When we calculate this loss for photon's energy in a static universe of desity of ours, we get redshift of the same order of magnitude as the Hubble redshift. It looks like a "tired light effect" (the same equation) but we know that in Einstein's gravitation, there is no "tired light effect" since there are no gravitational forces acting at the distance. So this effect can only be either a relativistic effect of time dilation at the source of light (similar time dilation as in gravitational redshift) or the priniciple of conservation of energy is not valid for photons and the redshift is Doppler and so the space is expanding. Since the former would require the time runing slower "simultaneously" at two points in space (which was too radical a physics at that time to admit, even for Einstein, not anymore though since relativity got stronger) the former possibility has been abandoned and invalidation of the principle of conservation of enrgy admitted for the construction of the Big Bang model. So the principle of conservation of energy has been assumed not to be valid for photons and the dynamical friction for photons was assumed to be exactly zero and the reason for the redshift has been assumed to be an expansion of space. That's why it is essential for the model. We don't see any expansion, we just assume it indirectly, assuming that in a static universe there wouldn't be any Hubble type redshift (since the principle of conservation of energy is assumed not to be valid for photons). It might look like a lousy physics but it is cosmologists who accept it not physicists.

The subject of my work is basically that "some physical theories are wiser than their creators" (Hertz). In my work I'm showing the things that Einstein didn't want to argue about with the cosmologists and I'm showing why if the energy is conserved the observations show that the universe is stationary. It's an observational result. No theory except Einstein's.

Einstein was a physicist who had litle appreciation for math ("As far as the laws of mathematics refer to reality, they are not certain, as far as they are certain, they do not refer to reality.") so he didn't want to argue with cosmologists who were applied mathematicians. He already said that the biggest blunder of his life was discovering the cosmological constant which started this madness of each cosmologist subscribing to his pet value while its obvious value was $c^{2}/(4\pi G\rho )$. Something that after a while made to the urban legend as "Einstein admitting his blunder of discovering cosmological constant". Repeated by many as if discovering anything might be a blunder. He also told his secretary not to let in anybody who wants to talk to him about the universe (source: his associate Roy Glauber, my teacher at Harvard).

So if you are patient and the principle of conservation of energy, which Einstein as a patent office clerk must have understood better than any applied matematician, makes back into the mainstream science you may see all of these things explained successfully by the "mainstream science" in a few years. If you are curious though how Einstein's theory explains things that cosmologists can't explain without inventing new physics (dark energy) and if you are able to assume that the principle of conseation of energy is valid, agree to the fact that the space might be curved and that the time is delated accordingly, luckily all controlled by simpler than Newtonian equations -- and luckily there isn't anything else in Einstein's theory, you will see then how Einstein's theory can explain and predict numerical values of Hubble constant, accelerating expansion, CMBR, Pioneer anomaly, such phenomena as local quasars, all calculated only from the first principles, agreeing with observations up to one standard deviation. At the same time contradicting the priest's science (as Einstein called the Big Bang) that the church supports with awards bigger than the Nobel Prize. Einstein's "crank physics" (so far) is only supported by the principle of conservation of energy. An ungodly principle preventing God from creation universes out of nothing and even preventing the universe from expanding or shrinking and that's why the "mainstream science" had to drop this principle to stay internally consistent. So this fact shouldn't be hidden from the public opinion since this is the only difference between the Einstein's "crank physics" -- with the principle of conservation of energy -- and the priest's science -- without it, but instead with such mighty protectors as Wikipedia and the Catholic Church. Jim (talk) 15:49, 14 March 2008 (UTC)

...Except that it isn't "the only difference". You're essentially claiming that the astronomers are ignorant of the relevant physics, whereas it actually seems that the steady-state advocates are ignorant of the relevant astronomy. Plenty of people over the years have proposed that redshift might be due to causes other than the expansion of the Universe (this isn't exactly some new groundbreaking idea), but all have come unstuck due to the inability to explain the other astronomical evidences of the Big Bang. See Steady state theory. --Robert Stevens (talk) 17:20, 14 March 2008 (UTC)

You are right, it isn't "the only difference". I should say it is the only fundamental difference since most other things in both theories are the same, except that the Big Bang does not produce any verifiable predictions and so it can't be falsified (and in this sense it is not a theory but an unverifiable hypothesis contradicting the standard physics -- the principle of conservation of energy). Einstein's stationary universe on the other hand produces at least five verifiable predictions (that I mentioned earlier) so it can be falsified if it fails just in one of its predictions. The Steady state theory of Hoyle etc. has the same problem as the Big Bang, an unverified so far creation of matter from nothing, so all other problems become irrelevant and it is irrelevant how many things the steady-state advocates are ignorant of.

It would be interesting if you could present those "other astronomical evidences of the Big Bang theory" that Einstein's stationary universe explain falsly (produces wrong numbers) since then Einstein's stationary universe would be falsified. Could you do this? Jim (talk) 20:18, 14 March 2008 (UTC)

Jim wrote: So if you are patient and the principle of conservation of energy... makes [it] back into the mainstream science you may see all of these things explained successfully by the "mainstream science" in a few years.

Until that time, it has no place in this article. DCCougar (talk) 21:09, 14 March 2008 (UTC)

Jim wrote: ...the Big Bang does not produce any verifiable predictions and so it can't be falsified...

With statements like this, I am forced to seriously doubt you are a doctoral candidate, and further discussion is pointless. You do not seem to realize that the big bang theory does not make any claims about times earlier than 10^-19 seconds -- we are unable to simulate conditions earlier than that since our particle accelerators are currently not the size of the solar system. The big bang is a theory about the evolution of the universe after that early time. It says NOTHING about the ultimate origin of the universe. How can it? There is no evidence. Scientific theories are based on evidence! I have recently read current books by leading physicists and cosmologists such as Alex Vilenkin, Paul Steinhardt & Neil Turok, Leonard Susskind, and Lee Smolin. It is interesting that they ALL agree that the big bang theory is essentially correct from 1 second after the "bang" to the present day. Their only disagreements come in what happened before 1 second. DCCougar (talk) 21:09, 14 March 2008 (UTC)

DCCougar wrote: "With statements like this, I am forced to seriously doubt you are a doctoral candidate". Actually you may be forced only to doubt whether I'm a serious PhD candidate i.e. whether I manage to make my PhD when the "mainstream science" is pushing an opinion that matter can be created from nothing, the only argument the Cosmology and Gravitation professors at my university are able to present for the Big Bang. Which is silly since a theory without the necessity of making matter from nothing, as Einstein's universe is, and predicting all the same observations, providing also a reason for them, is a better theory. Why not?

Even if "ALL agree that the big bang theory is essentially correct" four centuries ago ALL agreed that the Ptolemaic system is essentially correct (which of course is, just the Copernican system is better). And luckily, I can prove since 1985 that Einstein's stationary universe is a better theory than the Big Bang, which might be worth a PhD. You just lose the creation of matter from nothing and all that nonsense about the history of the universe "before it was created" and "what happened before 1 second [after it was created]". The Big Bang moves into the history of science like Ptolemaic system did in 1543. Do you think it would be bad for the science (or for the religion)? Jim (talk) 10:13, 15 March 2008 (UTC)

You must think that something is bad with the Big Bang if you block the access to the information about it. Do you think that the public would lose faith in the Big Bang if it knew everything? Jim (talk) 12:28, 15 March 2008 (UTC)

You must have missed this warning at the top of this page:

"IMPORTANT: This is not the place to discuss how you think the universe began. This page is for discussing the article, which is about the Big Bang model, and about what has been presented in peer-reviewed scientific literature about it. See Wikipedia:No original research and Wikipedia:Talk page guidelines. If you wish to discuss or debate the validity of the Big Bang please do so at BAUT forum or talk.origins." (Emphasis added.) DCCougar (talk) 17:38, 15 March 2008 (UTC)

You must have missed my statement "If I wanted to talk about all subjects I'd have to violate no original research policy since those things are the subject of my PhD work and a PhD work by definition is an original research." It means that I'm not discussing the Big Bang here but only your removal of the most important feature of the Big Bang. We discuss just what we are expected to discuss: your edits.

I'm supporting the Wikipedia rules, arguing for the mainstream science, even against my personal POV. You are ignoring Wikipedia rules by removing the important parts of the article since your POV is against the mainstream science (against the lack of conservation of energy in expanding universe, which obviously follows from prof. John Baez's texts and from the presented reliable sources). If you don't understand the subject of the article then maybe you should leave the editing to those who do? Jim (talk) 08:39, 19 March 2008 (UTC)

You know, Jim, I have read over 100 books on this subject, many by Nobel laureates. Mainstream science books. I don't recall ONE of those books giving the slightest mention to your notion of "lack of conservation of energy in expanding universe." So your claim that this is "the most important feature of the Big Bang" is drastically subjective at best, and as far as I'm concerned, it lacks any degree of credibility. DCCougar (talk) 15:45, 19 March 2008 (UTC)

And by the way, would you care to clarify and provide peer-reviewed papers to support your following claim? "...the most important achievement of the Big Bang Theory: the invalidation of the principle of conservation of energy and finally allowing for unity of science and spiritual life?" You're claiming this is mainstream science? DCCougar (talk) 15:51, 19 March 2008 (UTC)

DCCougar, you see, you read over 100 books on this subject and you didn't know that, so it turns out to be "the most important feature of the Big Bang". Because nobody knew this. Such a thing is called a discovery. Phony duscovery in my opnion, but my opinion is not "mainstream". Prof. John Baez's opinion is nowadays "mainstream". And you know prof. Baez opinion. I was shocked, when I learned that "mathematical physicists" started maintaining that "energy is not conserved in general realtivity". I've always known that the expanding universe hypothesis violates the principle of conservation of energy so I didn't take the expansion seriously and I just kept using it as an argument against the expanding universe. I was glad that "mathematical physicists" found finally the same thing but to my bewilderment, instead of rejecting the expanding universe (which would be a painless thing to do), they rejected the principle of conservation of energy (a thing impossible to explain without a supernatural). But they were applied mathematicians, not physicists, so they didn't need to know all the evidence against the creation of matter from nothing. And that's why we have the "mainstream science" going along with religion. Which amuses me a lot. It is the same problem with "mathematical physicists" that Feynman wrote already about.

"The most important achievement of the Big Bang Theory" was an ironic statement as well as the "unity of science and spiritual life". But it is really there in the "mainstream science" even if not yet documented as clearly as it is in professor Baez's statements. In my university most students already believe that energy can be created out of nothing (with some proper magic perhaps) since they are told by "mathematical phisicists" that "the expanding universe is a proof of this". I don't believe in any of it since I know enough physics to understand how it really works (rather simple knolwdge explained already by Einstein) but how a physics student who doesn't have all that knowledge yet, or you, is to find out what is true? So I don't blame you for not knowing just for getting involved in the things that you don't understand instead of asking how it works, and using your brain to decide whether it may work this way. Jim (talk) 23:17, 19 March 2008 (UTC)

Wikipedia is NOT the place to announce "discoveries": WP:OR, WP:SYN, WP:V. --Robert Stevens (talk) 10:19, 20 March 2008 (UTC)

The Big Bang Theory Basics

The base of evolution is the Big Bang theory. This is the general theory: Before anything, even time nothing (flaw number one) packed together so tightly exploded(NOTE: I can not say it because it was nothing). The explosion was so big planets,suns(stars),galaxys, everything. But they aren't going the same way(flaw number two). So Billions of years later the rocks absorbed the oxygen before it existed (flaw number three) and about one billion years later it rained on the rocks for millions of years (where did it come from and where did it go?) and made Primordial Soup and that became life (what did it eat, how did it reproduce?) and thus Evolution began. —Preceding unsigned comment added by 76.229.179.200 (talk) 20:02, 16 March 2008 (UTC)

At the top of this page, did you notice the red octagon with a hand in the middle? We're well aware of Big Bang and evolution basics, so please debate them at talk.origins. Art LaPella (talk) 21:49, 16 March 2008 (UTC)

Just how correct is it?

The big bang as you know consisted of nothing. But how did nothing become something? I read "The Big bang Theory Basics" and the big bang is completely absurd and I'm sure whoever made it up wasn't thinking very hard. Also, you've been wondering why there are all these shootings and stabbings, well Evolution has no absolutes, and the people that did those things are taught thier animals! Wich means you can do what feels right, Evolution is to get rid of the Authority of the Law, wich is Chaotic. —Preceding unsigned comment added by 76.229.222.104 (talk) 16:46, 17 March 2008 (UTC)

Thanks for sharing your thoughts - but please see the top of the page. This is for discussing the article - not the merits of the theory. PhySusie (talk) 15:16, 19 March 2008 (UTC)

Science?

Science is something that can be demonstrated over and over again. If you can demonstrate the big bang and make another universe why haven't you done it yet? —Preceding unsigned comment added by 76.229.222.104 (talk) 16:48, 17 March 2008 (UTC)

Again, thanks for sharing your thoughts - but please see the top of the page. This is for discussing the article - not the merits of the theory. There are other more appropriate places to discuss your ideas. PhySusie (talk) 15:19, 19 March 2008 (UTC)

Guys, why can't you accept that Wikipedia is not to publish the scientific truth but only the opinion of majority of editors? If the majority happen to be idiots or mystics, this is what Wikipedia is to publish. If you happen to know the truth (or you think so since you tested it observationally which is the only way to test the truth) you should keep it to yourself since in some fields of science (cosmology and gravitation is an example) it won't be accepted by the majority of editors.

The truth about the Big Bang was aready told by Feynman many years ago so it doesn't need to be repeated. The tuth is absolute and eternal. Like laws of Pythagoras and Archimedes and so it can't be changed. What would you understand about the nature if laws of Pythagoras and Archimedes were modified every time someone coms with a better idea and tries to modify the Wikipedia article according to her idea, removing from the article what majority of editors already agreed upon, or adding what she tested as the truth?

The proper place for scientific truth are a few scientific journals (the fewer the better) since it allows those who control the science a better control over it and it prevents the spread of truths that might hurt the important people in science. Imagine the Big Bang got falsified. Where all the mathematical pysicists would find new jobs in our collapsing economy? Jim (talk) 09:43, 20 March 2008 (UTC)

Ironically, we have here a religious fundamentalist (76.229.222.104) who rejects the Big Bang because it's "evolutionist", and is being supported by someone (Jim) who is apparently a militant atheist and rejects the Big Bang because it's "supernatural"! However, neither view is helpful here (furthermore, observation supports the theory that the Universe is of finite age and has changed over time: if it didn't expand from a point, then presumably it was "poofed" into existence at its current size: would this not be "supernatural"?) --Robert Stevens (talk) 10:20, 20 March 2008 (UTC)

This would be extremely supernatural. So the best approximation (at least for Jim) it is that the universe was always here, not even evolving too much (to keep the Copernican principle as a perfect cosmological principle). Jim (talk) 11:11, 20 March 2008 (UTC)

What the editors, specifically the consensus of the editors, go by is scientific consensus. It doesn't matter what the majority believes, but what the scientific community does. Editors here merely determine how it should be explained for the sake of us common man. It seems your original research was rejected for inclusion multiple times (that, or I got the wrong user), if so, then it did violate what Wikipedia stood for and does not warrant for you to say that these editors are idiots or mystics. You seem to forget the fact that we are a secondary source, getting information from primary and secondary reliable/credible sources, not trying to outline a new horizon in the knowledge of a subject. Here's an example: if the absolute truth was that 2 + 2 = 4, yet most if not all primary and secondary sources claimed 2 + 2 = 5, then Wikipedia must say 2 + 2 = 5. It's a poor example and implies the Big Bang is bogus (I am in no way claiming that), but it does reflect how critical the consensus of credible sources are to Wikipedia. --BirdKr (talk) 06:52, 21 March 2008 (UTC)

Hi BirdKr, Excelent example but you may have a wrong user since I understand that Wikipedia is meant for a common man, epecially the high school kid. So I never try to confuse her neither with any unscientific stuff nor with my original research (which of course I have as any guy who works in science). I understand all those things, just some editors don't, and they try to fix 2+2=5 as 2+2=12, which might be the same thing, just in different notation. What I'm doing then is to explain to those editors that the right notation (understood by the common man and woman) is 2+2=5. I may tell him that I'm not pushing my POV since privately I think that 2+2=4 but we aren't to write private articles that would produce chaos and confuse common man. I said that "if the majority [of scientists] happen to be idiots or mystics, this is what Wikipedia is to publish" (your example with 2+2=5, so as you see we both agree on it). But some editors vote 9:1 on 2+2=3 while mainsteam science says 2+2=4. E.g. it happens with gravitation "a natural phenomenon by which all objects with mass attract each other" according to those editors, who voted 9:1 for Newtonian gravitation (and prevailed) over Einstein's which they didn't understand and of course the mainstream science is 10:0 for Einstein. That's why I think you might have the wrong guy. Because of this and since I'm using Wikipedia to popularize Einstein's theory which is rarely understood and then it might look like pushing my POV. And incidentally, Einstein's theory doesn't support the BB despite the attempts to patch in the support for the BB. Einstein's idea of metric tensor being non symmetric coincides with Jim's but Jim is even more crazy since his metric is also degenerate (although it approximates Minkowski) i.e. it has a property that the spacetime volume ($dt\times dx\times dy\times dz$) is zero everywhere. Jim (talk) 14:06, 21 March 2008 (UTC)

Note that I'm only a physics and math undergraduate student right now so some of the things you've said may have been ignored. Basically it seems you're trying to explain Big Bang under Relativistic and Quantum physics in substitution for the Newtonian physics, after all, Newtonian physics merely provides an approximation to the other two physics mentioned which are regarded to be "better" (for the lack of words), more accurate, and preferred by the scientific community. However, despite all this, how does one explain the Big Bang? You wrote that using Einstein's theories (part of relativistic physics I should assume) disproves the Big Bang theory so there's no sense on using that to explain the Big Bang. If this true, you should note it in the criticism section of Big Bang, forwarding readers to quantum and relativistic physics and Superseded scientific theories. Or you can write another section in this article explaining the Big Bang under non-Newtonian physics and how there are some disagreements or total rejection, just try to add credible sources as much as possible if you do. If you do go ahead with this, it is advisable that you post your draft in the Talk page just so you can respond and clarify to other editor's comments to avoid a revert war. Overall though, is to use credible sources to state your claims, avoiding subjective terms, and keep your agendas as far away as possible when contributing. We're here to improve the article, not to redefine it to a "more correct" or "preferred" view (I put in quotations to note that "correct" to one person may be "more false" to another).

If you can't find any reliable and credible sources (such as scientific journals that to you "dictate" scientific truths) to substantiate the statements, then I'm sorry to say that it has no right to be posted on Wikipedia, regardless of whether it is the truth or not or accepted by the "silent" scientific community.--BirdKr (talk) 16:31, 21 March 2008 (UTC)

Jim wrote: "I never try to confuse her neither with any unscientific stuff nor with my original research (which of course I have as any guy who works in science). I understand all those things..." Jim, I find it difficult to fathom how you can be so self-assured that you are so much smarter than anyone else on the internet, but at the same time your own webpage relates how your so-called research has been rejected for publication, and that all your subsequent contacts with numerous professionals, apparently in an attempt at some small validation, has only confirmed that such rejection was appropriate. Methinks thou art a bit too full of thyself.

By the way, your webpage appears to be infected with a virus that attempts to infect visitors. And you used to be into programming? Hmmm.... DCCougar (talk) 02:10, 22 March 2008 (UTC)

Is the universe expanding?

I was wondering what is the proof that the universe is expanding? Is it because the redshift on standard candles? Is there other proof?

My understanding is that gravity can bend space. If a great mass passes in front of light could one see a redshift since the distance now is farther than it was? the speed of light should be constant but I think that it relatively has to go father in the same time. thus the redshift. Is this correct?

Also if the above is correct. What would be the effect of mass that was spread over great distances. Where I am going with this is :

Could dark matter spread out over billions of light years cause a red shift in the light from a star that is not moving away from us in absolute terms? The thought is that the amount of dark matter that the light passed through could have quite a bit of gravity. Thus making far away objects appear that they are moving farther away from us quicker than they actually are.

--Tommac2