Talk:Age of the universe

A few mistaken scientists and a lot of armchair scientists misinterpreting data.

Please QUIT INCLUDING THIS ARTICLE IN OTHER ARTICLES; NOTHING HERE HAS ENOUGH DATA TO MAKE ANY FIRM CONCLUSIONS.

While undoubtedly the MINIMUM age of the universe here has a consensus, the methods use say nothing of the MAXIMUM age of the universe. Therefore saying "the universe is X years old" is wrong, stupid, stupidwrong, wrongstupid and Time Cube science. Saying "the universe is at least X years old" isn't half as bad. 85.156.0.200 (talk) 18:10, 8 April 2008 (UTC)

oh my, it looks like 'someone' got up on the wrong side of the bed.--TriTertButoxy (talk) 21:29, 8 April 2008 (UTC)

No, I'm just very, VERY tired of seeing it in articles it decidedly doesn't belong to. Such as "black dwarf". In which this article is used as "proof" that black dwarves don't exist yet - while the age of the oldest white dwarf is USED to make this bloody measurement. Or roughly, circular logic. Not to mind we don't know at all how old the universe really is just because we don't have good enough space-based telescopes to measure anything of that scale. We can't even build good enough measurement instruments yet, nevermind afford sending them to space. This article is at least 100 years early. 81.197.52.13 (talk) 19:15, 9 April 2008 (UTC)

Humbug - even if there's not a singularity, but an infinite expansion from an infantesimal point or suchlike, there are no black dwarves. There are no stars from before the era of big bang nucleosynthesis. The density inhomogeneties in the CMB make it pretty clear there were no compact objects at the surface of last scattering. WilyD 20:04, 9 April 2008 (UTC)

This is a fair bit late - but - STRAWMAN ARGUMENT. We cannot measure enough of the universe to know if there are black dwarves - or heck, enough to give a good guess about the age. We can give a minimum age based on what we've observed - the age in the article - but not about the whole age of the universe until... we can measure the majority of the universe. And enough about it's borders based on empirical evidence (not this numerology some "scientists" do) to actually know how large it is. I'm personally siding with "it's infinite", but that has as little proof for as it has against. So I'm not pushing it as a fact in unrelated articles. 62.106.48.110 (talk) 22:11, 9 May 2008 (UTC)

Additional note: Circular logic. Using "age of the universe" for date of the big bang and using that again for the age of the universe. 62.106.48.110 (talk) 22:13, 9 May 2008 (UTC)

This remains patent nonsense - Age is WMAP+Clustering+Ias - that stellar ages, globs, black holes masses, metal enrichment and a host of other measurements are on board is merely icing on the cake. Age of the Universe = Time since the Big Bang = usual English meaning of the phrase. If you want to object, try sending your objections here, they print lots of exciting sounding wrong results, and then we can discuss it. Until then, you'll have to resign yourself to the fact that WMAP5 interpretation uses the phrase "age of the universe" [1] just like everyone else talking about the subject. WilyD 16:40, 10 May 2008 (UTC)

Wonderful, not only are you misguided, you are also a (Personal attack removed) (or possibly a troll). An internally coherent theory != fact. Stellar ages, black hole masses, metal enrichment... what do those things have in common? Oh right - fitting evidence to a theory rather than the reverse. Does the phrase "dark matter" ring any bells? Hint: It's not some secret matter - it's matter we cannot see? How much does that affect the calculations? More than the data we have now. We. Don't. Have. Enough. Data. To. Make. This. Conclusion. - this is not a theory by science terms, it's a hypothesis and will remain so until we have some PROOF. So quit referring to it as true and most importantly - keep it to this article. I've seen this shit in *religion* articles. It doesn't belong anywhere else than here, and even here it should be noted that it has a high possibility of being completely wrong - as the article does in parts (and doesn't in other parts). 62.106.50.124 (talk) 15:22, 11 May 2008 (UTC)

Wikipedia doesn't decide how old the universe is. It reports prevailing opinions, not ours. I'm not a professional scientist, but as I understand the scientific consensus, they (rightly or wrongly) believe the Big Bang was 13.73 billion years ago. That is often called the "age of the universe", although they actually have no firm opinion on what, if anything, came before, so that name is arguably misleading. Art LaPella (talk) 22:28, 9 May 2008 (UTC)

I very, very strongly doubt there is a scientific consensus about this. 62.106.48.110 (talk) 22:29, 9 May 2008 (UTC)

You doubt the consensus on the time since the Big Bang, or the (non-existent) consensus on anything before? Art LaPella (talk) 22:33, 9 May 2008 (UTC)

Modified your comment to indent it. I doubt consensus on the actual age. Not big bang happening, just how long ago it was. I wouldn't be surprised to find "at least" but not something like this article. 62.106.48.110 (talk) 22:36, 9 May 2008 (UTC)

"Actual age" and "how long ago it [big bang] was" are both of the alternatives I offered, but I think you mean "how long ago the big bang was". The article bases its opinion on the WMAP study, which I thought was pretty much accepted. Do you have a reference that says otherwise? Art LaPella (talk) 22:47, 9 May 2008 (UTC)

Even the WMAP study part says there's a lot of uncertainty. Most importantly: None of us know if we're even approaching this from the right end. This is much like a blind man describing an elephant he is touching with a gramophone needle - it's impressive we have as much data as we have but we don't have half enough to draw any solid conclusions yet. 62.106.48.110 (talk) 22:57, 9 May 2008 (UTC)

Actually, reading the article in depth it becomes a lot more reasonable. The main problem is the header and the fact that "facts" from here spill into other articles. 62.106.48.110 (talk) 23:04, 9 May 2008 (UTC)

Does "the header" mean the title, "Age of the universe"? To quote the article: "Though the universe might in theory have a longer history, cosmologists presently use "age of the universe" to mean the duration of the Lambda-CDM expansion, or equivalently the elapsed time since the Big Bang." That is, "age of the universe" could be considered a widely accepted misnomer like "sunset" instead of "Earth-turn", so the article is entitled sunset. Art LaPella (talk) 23:11, 9 May 2008 (UTC)

We don't have even enough data to see if it's the age since the big bang (heck, big bang isn't exactly agreed upon - the thing wikiscientists seem to agree on is patent nonsense - if you start breaking causality in as flagrant a way as that you have veered into religion instead of science - I'm willing to accept quantum occurrences but that's a rant for an another article) - all our conclusions are based on the data *currently available* and we can obviously see (see: dark matter) that we don't even have half the data we know of the existence of. Insufficient evidence to make it scientific to put this article forth as fact instead of a coherent theory with, uh, little evidence to back it up. A little, good enough for the "at least" (assuming a big creator didn't intentionally create the stars as aged :P), but not enough to draw full conclusions. Or roughly seeing, there is no proof whatsoever that the stars we see are even close to being the oldest, especially given that the stars would be more and more likely to be dark matter as they aged enough. 62.106.50.124 (talk) 15:22, 11 May 2008 (UTC)

Anon, I think you're right that quite a few Wikipedia articles wrongly claim that the universe began with a big bang 13.7 billion years ago in which "time was created" and so on. I've certainly run across a few such statements. I should fix them as I come across them, but I can't think of a replacement that's both correct and short enough that it doesn't read like a major digression from the article's subject. It's also true that the lede of this article is misleading, but again it's hard to fix that without copying the whole body of the "Explanation" section into the lede. I can't see how to shorten the explanation without leaving out some essential element.

But big bang cosmology (which has nothing to do with any big bang event) is much better understood that you seem to think. We do have enough evidence to predict confidently that there are no black dwarfs. That doesn't depend on quantum gravity or the details of how the universe began, it only depends on straightforward and well-understood parts of the model. We have explored the whole universe in the limited sense that's relevant to this prediction. -- BenRG (talk) 21:05, 11 May 2008 (UTC)

I strongly disagree with you in parts but at least you have grasped the crux of the matter. Debate here is fine, references to this article as "facts" elsewhere are not. Anyway, I'm outta this discussion, trying to improve the science side of wikipedia is like debating with creationists. Even with those that think they're discussing science. Wikiscientists. *sigh* 85.156.7.138 (talk) 11:52, 19 May 2008 (UTC)

I've noticed quite a few references to the fact that it is meaningless to talk about 'time' before the Big Bang. But if you accept String Theory as part of modern science, (a big IF for some, I know) then this problem doesn't really exist. Well perhaps, more specifically, by String Theory I mean the theory of branes and M-Theory. Time exists both before and after the big bang, at least in the calculations I've seen so far in that subject. It is no problem to talk about time before the big bang, although the 't' coordinate in the relevant equations will be a slightly different 't' to the one that measures time in our universe. Of course, if you don't accept string theory then, yes, it is meaningless to talk about time before the Big Bang. —Preceding unsigned comment added by 82.45.88.14 (talk) 14:11, 23 May 2008 (UTC)

It's not only in string theory that you can talk about times before the big bang. But there's little or no empirical evidence to support any of these ideas (whereas there's tons of evidence for the evolution of the universe over the last 13.7 billion years). I don't think any Wikipedia article should claim either that times before the big bang make sense or that they don't. We just don't know. -- BenRG (talk) 19:11, 23 May 2008 (UTC)

(Geneses 1:1)In the beginning God created the heaven and the earth .I will be praying for all of you because some day your going to face GOD weather you believe it or not and you can be a good person and do all the works in the world but that's not going to get you to heaven (Ephesians 2:8-9)but it's only by the grace of the lord Jesus Christ that you can be saved . So i urge you before it's too late to get right with God ,Repent from you evil minds and evil way's of the world and pursue the things of Christ . For I Testify to every man that hears the words of the prophecy of this book , If any man shall add to these things , God shall add to him the plagues that are written in this book (Revelation 22:18)God loves you but he hates your sin , we are very undeserving of his mercy but he loved us so much he paid the price for our sins so that we may live with him some day in heaven for all eternity (John 3:16). But if you reject his cure to be saved you will burn in hell forever and hell is a very very serious place and very much real.

Thank you for reading and i really hope you take this this message to Heart because He's coming back some day and if you aren't ready then i really feel for you. por4kid16@yahoo.com —Preceding unsigned comment added by 24.101.90.222 (talk) 07:39, 13 February 2009 (UTC)

Common Misconceptions

There is this section "Common Misconceptions" which seems to be written in light of the recent religion/science debate. This makes Wikipedia read like the ugly Conservepdia, so I feel it should be removed. Or, at the very least, it should be pushed to the bottom of the article or its contents be intersperced throughout the article. How do other editors feel? --TriTertButoxy (talk) 21:29, 8 April 2008 (UTC)

Yeah, that obviously needed to be removed. Needs sources, totally OR, un-encyclopedic tone. johnpseudo 22:26, 8 April 2008 (UTC)

13,7 or younger

I have found a news article according to which it has been found that the universe is 350 million years younger than previously estimated. Should this be added to the article? --Eleassar ^{my talk} 20:05, 7 May 2008 (UTC)

I'm the wrong person to answer this, but probably not at this point. Unfortunately the problem of determining the age of the universe is a lot more complicated than our "13.73 +/- 0.12" makes it sound. The WMAP five-year report actually includes numbers derived from dozens of model/dataset combinations. The 13.73 figure comes from this one (ΛCDM+SZ+LENS model, WMAP5+BAO+SNALL data). This incorporates data from Riess's group (SNALL). If they've revised their results, as the article suggests, then the combined figure probably needs to be revised also, but I think we need to wait for the WMAP people to do that (or Riess, or someone who knows what they're doing). I think the change will be much smaller than 350 million years because there isn't nearly that much variation among the predictions in the top row of the matrix. -- BenRG (talk) 21:27, 11 May 2008 (UTC)

Observational limits on the age of the universe

Very close to the beginning of the article we read:

Since the universe must be at least as old as the oldest thing in it, there are a number of observations which limit the age of the universe. These include the temperature of the coolest white dwarfs, and the turnoff point of the red dwarfs.

I find this confusing. To "limit" X usually means that something requires or implies that X cannot be greater than some boundary extent. But in this case "limit" seems to be used in the opposite sense: that the age of the universe cannot possibly be less than some number of years. Toddcs (talk) 22:21, 11 May 2008 (UTC)

Aren't there several reputable groups of physicists that have dated stars to be much older than the age reported for the universe in this article? (I am soooo not an expert. My Ph.D. is in a behavioral science. Just a curious reader.)97.96.62.148 (talk) 16:15, 13 March 2009 (UTC)

Much ado about 0.1 standard deviation

An anonymous editor has changed the article to say that the age is 13.73 or 13.72 billion years, giving two different references, both from the WMAP team. The problem is that the WMAP team has released dozens of different values for the parameters, as I mentioned in an earlier thread. And anyway it's silly to give two values that differ by only 10 million years when the error margin on both of them is twelve times that.

I reverted the change but I'm not happy with the old version of the article either; I don't think we should baldly claim that the age is 13.73 billion years, since the real situation is more complicated. I propose that we either (A) say that the age is about 13.7 billion years, with an uncertainty of about 100 million years, and add that the value depends somewhat on which version of ΛCDM you use and which experimental data you take into account, or (B) use one of the "WMAP Recommended Parameter Values" given here, with a footnote mentioning that this is a WMAP recommended value and assumes a particular model etc. etc. In case (B) I think we should use the WMAP+BAO+SN value (13.73), not the WMAP-only value (13.69). Whatever we do here, other articles that mention the age of the universe should be edited to agree with the value given here and link to this article for a fuller explanation. Anyone else have an opinion? -- BenRG (talk) 22:37, 15 October 2008 (UTC)

Speaking as a newcomer to the world of "error" it seems to me that we would be better to exagerate it rather than attempt to minimise it, thus avoiding any accusation of spurious accuracy ... my suggestion is 13.5 - 14.0 billion years which gives an idea of the level of uncerainty but at the same time points decidedly to 13.75 or thereabouts. Abtract (talk) 06:22, 16 October 2008 (UTC)

Disagree, error bars are well defined in this case (and much smaller then you suggest). There is no need to purposefully mislead people in order to look... unbiased? --Falcorian ^(talk) 19:45, 16 October 2008 (UTC)

I kind of like Abtract's idea. The ±0.12 billion is a 68% CL error, so (assuming the errors are normal) the WMAP team is only about 95% confident that the true age of the universe is in the range 13.5–14 billion years. I think the typical Wikipedia reader is likely to gloss over error margins and take the central value as the value. If we say 13.73 ± 0.12 people will remember 13.73. If we say 13.5–14 they'll remember 13.5–14, which is closer to the right idea. -- BenRG (talk) 14:12, 17 October 2008 (UTC)

In the lead, we should say 13.7. That agrees with everything to the number of significant figures given. Discussion of the error bars should be moved later in the article. The introduction should be as readable was possible while still being accurate! -- SCZenz (talk) 17:36, 16 October 2008 (UTC)

I disagree, I think the lead is clear and concise with: "Current observations suggest that this is about 13.73 billion years, with an uncertainty of about ±120 million years." Maybe I'm not really clear on what you mean, but certainly 13.8 and 13.6 are within the error bars currently quoted (13.73+-0.12 Gyr)... So I don't see what you mean by "That agrees with everything to the number of significant figures given." --Falcorian ^(talk) 19:45, 16 October 2008 (UTC)

I would still prefer "Current observations suggest that this is about 13.7 billion years, with an uncertainty of about 0.1 billion years". The "±" sign is not necessary in this sentence. --Friendly Neighbour (talk) 20:16, 16 October 2008 (UTC)

I agree that the ± is not necessary, and that the errors should probably be in billions (for clarity). --Falcorian ^(talk) 21:30, 16 October 2008 (UTC)

Mathematica 6.0 Code

<<PhysicalConstants`

AgeOfUniverse

4.7*10^17 Second

SecondsPerDay = 24 * 60 * 60 Second

86400 Second

SecondsPerYear = 365.2424 * SecondsPerDay

3.15569*10^7 Second

AgeOfUniverse/SecondsPerYear/Year

1.48937*10^10 Year

14.8937 Billion Years ? Where's (my/the) mistake? —Preceding unsigned comment added by 92.73.161.246 (talk) 17:30, 19 October 2008 (UTC)

Yes, it looks like Mathematica's value is way off. Judging from this page, it hasn't been updated in at least 18 years. Their HubbleConstant is wrong too. -- BenRG (talk) 14:40, 20 October 2008 (UTC)

I was going to add that Mathematica will do the unit conversion for you if you say Convert[AgeOfUniverse,Year], but it turns out that Mathematica thinks that years are 365 days long:

Convert[Year,Day]

365 Day

Convert[100 Year,Day]

36500 Day

So be careful out there. Incidentally a Gregorian year is 365.2425 days (not 365.2424) and cosmologists usually use Julian years of 365.25 days (of 86400 seconds each). The age of the universe isn't known accurately enough for it to matter, though. -- BenRG (talk) 14:50, 20 October 2008 (UTC)

Age and size of universe.

The age of universe is 13.27 billion years approximatly. But we can detect stars at a distance more than 100 billion light years . How is it possible. —Preceding unsigned comment added by 117.96.139.190 (talk) 07:16, 19 November 2008 (UTC)

Short answer: The universe is expanding, so a star which was 13.27 bly away when the light left it is actually much further away now. Since the expansion of the Universe is accelerating and time is curved, it could even be more than 26.5 bly away now, even though this seems impossible. For a long answer, try [2] from Distance measures (cosmology)#External links. Ben Standeven (talk) 01:09, 14 January 2009 (UTC)

mention more approaches?

I have to say I love this debate going on here, though lacking links to facts and scientific publications... why won't you guys just ADD A SECTION to the article listing the other calculation methods? or maybe, like in Age of the Earth, add list a timeline of the different theories from the different sources? (someone did that in the Hebrew version of this article, I see). Also, I think this item has both cultural and scientific points of interest (just see the number of articles linking to it!). It would be fun/interesting to create a "in popular culture" section as well, listing the AOU in different Sci-Fi/Fantasy/Religious universes (at least 4 quadrillion according to Hubbard's OT3, 5769 years according to Judaism (and probably many christians and creationists) etc.) and link back to Dating Creation, just for completeness :-) --SeeFood (talk) 10:45, 16 January 2009 (UTC)

Revert to 13.73+- 0.12

Should it be written that the universe is "13.73 +- 0.12 billion years old" or "13.61 to 13.85 billion years old". I find the first example better, because it also says that the universe is "about 13.73 billion years old". Quarkde (talk) 05:47, 29 January 2009 (UTC)

As I said last time this was discussed, I believe it should be written "between 13.5 and 14 billion years" because anything more accurate is pushing measurement/calculation beyond credibility, imho. We must remember this is an encyclopedia not a scientific paper. Abtract (talk) 08:01, 29 January 2009 (UTC)

The first example is sticking to the sources, the second example is applying our own ideas to the errors. Per WP:NOR, we should be using the error bars that're being reported in the sources (and WMAP5+BAO+SNIa+... is the most reliable source, yes). WilyD 11:30, 13 February 2009 (UTC)

mathematical/gravitational singularity

I'm not much of an astronomer, but I was confused when the link on the word singularity (in the phrase "mathematical singularity") went to the gravitational singularity page. Is this a mistake or am I just in the wrong area of Wikipedia?

I figure it should either say "mathematical singularity" and link to http://en.wikipedia.org/wiki/Mathematical_singularity

or say "gravitational singularity" and link to http://en.wikipedia.org/wiki/Gravitational_singularity

but certainly not half/half. fogus (talk) 06:46, 14 March 2009 (UTC)