Talk:Quasar/Archive for 2009

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Can we agree that no one knows what the heck Quasars are?

Honestly, this article is confusing to a layman because it doesn't directly state the obvious. That no one knows what a Quasar is to begin with. The closest explaination, about material being fed into a supermassive black hole is a crock of shit. Lengis 17:06, 12 August 2006 (UTC)

The purpose of Wikipedia's science-related articles is to describe topics as presently understood by the scientific community. While you may feel that the explanation of quasars as being active galactic nuclei is a "crock of shit", most scientists appear to disagree with you. --Christopher Thomas 17:14, 12 August 2006 (UTC)
The problem is, most scientists wouldn't agree actually, because that's not how science works. All scientific theories are taken with a great deal of skepticism, and in this case, the theory stated is a last resort because there are no other credible explainations availible due to our lack of understanding, and technological level. Lengis 18:54, 12 August 2006 (UTC)
I think you missed his point Christopher Thomas. All scientific theories aren't scientific fact, and this article is case in point. The amount of factual evidence that states quasars are galactic nuclei is incredibly soft, being the only explaination currently avalible due to limited understanding. This article states that theory as if it's fact, which shouldn't be done. The fact is, it could be anything. It could be an alien structure created by a level 3 kardashev civilization for all we know. I will change the article to reflect this skepticism. Malamockq 15:15, 18 August 2006 (UTC)
I have a Ph.D. is astrophysics from Caltech, and my thesis concerned the demographics of quasars and other AGN. There is no serious doubt among people working in the field that AGN are caused by supermassive black holes at the centers of galaxies. While all scientific knowledge is subject to revision, there is no particular controversy about this issue at this time, and it doesn't need to be shrouded in caveats. -- Coneslayer 18:33, 18 August 2006 (UTC)
There's no controversy because there are no other explainations possible due to our limited understanding. But the current explaination is weak at best. And the revisions never stated there was controversy, just a general lack of complete understanding. This theory in particular, since the evidence is incredibly light. Ambiguity must be emphasized in this article. We don't know what quasars are, accept it. Malamockq 20:04, 18 August 2006 (UTC)
Coneslayer, if you have a PhD and your thesis concerned Quasars you should have informed us about how the scientific community tries to explain away the BIG issue of gravitational redshift. Instead you simply state a dogma, which is roughly that 'No one one in the scientific community who has a reputation worth losing thinks about other explanations'. Provide us with answers about the redshift issue, or else you need to give back your PhD. Science is about always being open to new ideas and critical of existing ones, otherwise no progress occurs. Stating the obvious fact that a large part of the scientific community adheres to one theory is zero proof of disproving the other theory. You think you're a scientist, so disprove the alternative or get the heck out of science. Crusty007 (talk) 22:58, 7 March 2009 (UTC)
Provide credible sources showing that the "explanation is weak" and that the "evidence is incredibly light." As I said, I have worked in this field, and have never heard such claims; the standard AGN model is just that--the standard. Your own doubts on the subject are original research and lack verifiability. -- Coneslayer 20:17, 18 August 2006 (UTC)
No, it isn't original research. The fact that I brought up the objection and not Malamockq, should have clued you into that. As for sources, and I quote, "No one knows what they are". Skepticism is valid in this case. Lengis 03:18, 19 August 2006 (UTC)
An anti-evolution web site is not considered a reliable source for scientific information about astrophysics. Peer-reviewed astrophysics journal articles are considered reliable sources for this type of information. --Christopher Thomas 04:27, 19 August 2006 (UTC)
Ah yes, I wasn't aware that was an anti-evolution website. Here's a better source. I will revert the changes you made and cite the new source. Lengis 18:44, 20 August 2006 (UTC)
This reference comes from the early 1980s. As is described in the article, much of the evidence for the current view of quasars was gathered more recently than that. Look at astrophysics publications from the late 1990s onwards. --Christopher Thomas 19:51, 20 August 2006 (UTC)
I'm afraid at this point, you are fillibustering, and already reached a non-inclusive stance, regardless of the evidence I provide. Additionally you have violated the 3 revert rule. Lengis 00:49, 21 August 2006 (UTC)
  • correction*, you WILL violate the 3RR after this, so I'm warning you now. I've provided adequate source material which validates my inclusion. Lengis 00:52, 21 August 2006 (UTC)
I fail to see how insisting on including elements of the last 23 years of research is "filibustering". Furthermore, you appear to misunderstand WP:3RR, which forbids three reversions within a 24-hour period. --Christopher Thomas 01:35, 21 August 2006 (UTC)
Yes, requesting a more recent reference is perfectly reasonable here. And it's actually making more than 3 reversions which is prohibited. -- Avenue 01:52, 21 August 2006 (UTC)
I think you are forgetting that all recent scientific material is a) completely unreadable, b) usually involving massive amounts of statistical evidence only (Remember 'Lies, damned lies and statistics' anyone?) and most importantly c) usually colored by prevailent scientific dogma, as clearly in this case. With statistical 'evidence' you can always color the outcome of your paper, even if not so intended. The so-called scientific evidence on neutrino oscillations is a case in point (data shows between 0.27 and 0.5 of E-neutrinos present yet this is assumed to be proof of 1/3 presence. That's no proof). Unless you can show me a world-readable scientific paper (almost a contradiction in terms) which clearly disproves the alternatives you have no case, just a semi-religious belief. For me, the fact that the most redshifted observed Quasar indicates a distance of 28 Billion lightyears away violates either Big Bang theory, which indicates that the universe is between 13 and 18 Billion years old, or Relativity, which indicates that nothing can travel faster than light, or both. Sounds like something is seriously wrong with prevalent dogma. Crusty007 (talk) 22:58, 7 March 2009 (UTC)
One way of perhaps diffusing this is to change the wording of the first sentence in the last paragraph of the intro to the following:"Though the exact nature of quasars is currently unknown, the current scientific consensus holds that the most plausible explanation is that quasars are powered by accretion of material... [etc.]". My limited understanding of it is that most astrophysicists do believe that this model is (by far) the most plausible. I think that stating that the consensus is that quasars are that, though, oversteps it by half a step. I'm no expert at this but the few times that I've heard professional astrophysicists lecture on quasars to laymen (and undergraduates) they took extra pains to emphasize that their knowledge of them was unconfirmed, in a way that they didn't take those pains when it came to most other things. Just my two cents as someone who just showed up to this dispute. I think the "known to man" addition overstates it much (I don't know who else we would be referring to "known" in this context but man). --Fastfission 03:23, 21 August 2006 (UTC)
I'm not sure it's an overstatement to say that as far as science knows, they are AGNs, as it's not only considered the most plausible explanation - to the best of my knowledge, it's considered the _only_ plausible explanation at present by the vast majority of astrophysicists. If a lurking astrophysicist wants to point me to publications about alternatives that are considered plausible by the majority of the community, I'll happily backtrack on this, but the rapidity of source variation requires quasars to be extremely compact, and the fact that they've been observed to display very strong redshift and, in many cases, have been observed to correlate with optically-visible galaxies makes a pretty strong case. My impression is that any uncertainty is in the precise mechanism of relativistic jet production and the precise nature of black holes, not in the association of quasars with AGNs or the production of jets and associated emissions themselves. --Christopher Thomas 03:35, 21 August 2006 (UTC)
Chris is right. Quasar controversies are over, even though they lasted decades. The only oddballs out still pursuing alternatives are those people angry at the Big Bang. See nonstandard cosmologies for more. --ScienceApologist 06:34, 21 August 2006 (UTC)
I had a science professor who stated quite bluntly that we didn't know what quasars were. He said we knew the effects, and we observed what they emit, but we don't know what they are. Christopher Thomas, it's not so much as there are publications on alternative theories, it's just there isn't sufficient data to conclude indefintely that quasars are just stellar mass being fed into a super massive black hole. Malamockq 17:11, 21 August 2006 (UTC)
I would say that your "science professor" was not particularly knowledgable (or up-to-date) about the field. Once again, by the time I started working on quasars in the late-1990s, there was no dispute within the astronomical community about the link between black holes, AGN, and quasars. Whatever doubt there had been was quashed by the discovery that SMBHs are ubiquitous, even in normal galaxies like the Milky Way. -- Coneslayer 17:19, 21 August 2006 (UTC)
Here you go again, essentially stating that 'your science professor is an idiot'. Disprove the alternative in readable language, or agree that the topic is not closed. The idea of gravitational redshift is a MASSIVE issue that's apparently been ignored, and it should be included as an alternative explanation, even with massive caveats.Crusty007 (talk) 22:58, 7 March 2009 (UTC)
Just because everyone says something doesn't mean it's true. Let's say, that Wikipedia got shutdown. One hundred years later, everyone believes that Wikipedia never existed. Does that mean that Wikipedia didn't exist? No. Wikipedia existed. Same thing with quasars. If everyone thinks they are super massive black holes, does it mean that's how they work? No. Instead of finding the "Correct" answer, we should explain that it is not known for sure how quasars work, and then show the different theories. --Andrew Hampe Talk 01:50, 23 May 2007 (UTC)
Exactly what do you consider "unbalanced" about the Quasar emission generation section? It reads "The best explanation for quasars is that they are powered by supermassive black holes." Do you think there is a better explanation? Do you think that there is even a significant minority of astronomers that think there is a better explanation? What "different theories" do you think we should present here? Please remember, Wikipedia is not in the business of deciding what is correct or not, just of reporting what the current thinking is about a topic. And the goal is not to report every idea that somebody may have, but to present the majority opinion and significant minority opinions in a balanced way. --Art Carlson 08:02, 23 May 2007 (UTC)
To expand on Art's remarks, I wrote a thesis on high-redshift quasars. Most of that work would make no sense if quasars were not powered by accretion onto SMBHs at cosmological distances. My work was carefully reviewed by my thesis committee and the ApJ, and was presented to literally hundreds of astronomers at conferences. Any of these astronomers, if they did not accept the premises listed above, could have asked me about it. Nobody ever did. I have never met a working astronomer (since 1998, when I started grad school) who expressed any doubt about the quasar-AGN-SMBH connection. While all scientific conclusions are subject to revision, the scientific consensus on this topic is extremely strong, and that's what we're supposed to describe. -- Coneslayer 11:49, 23 May 2007 (UTC)
We aren't supposed to describe the scientific consensus. We are supposed to describe the what a quasar is/may be. --Andrew Hampe Talk 15:17, 25 May 2007 (UTC)
Well, if you're going to disregard scientific consensus, then a quasar could be anything. It could be an illusion created by the Flying Spaghetti Monster. Please review WP:SCIENCE. -- Coneslayer 16:24, 25 May 2007 (UTC)
Hold the phone, Andrew! It looks like you don't know the name of the game here. "The threshold for inclusion in Wikipedia is verifiability, not truth." The scientific consensus is verifiable. What you or I thinks a quasar really is, that's "original research". --Art Carlson 16:46, 25 May 2007 (UTC)
I agree with Art Carlson, that we should include only verifiable and objective elements. But IMHO the new introduction written by Andrew Hampe completely fulfills these criteria. Thanks for your contribution. However, Andrew, give it up: you are not the first (and probably not the last) who tries to write a "neutral" description of quasars, and who has his text deleted by one of the talibans censoring this page. These not only refuse to accept a different interpretation of quasars, but they even deny the very existence of controversy. -- Proton
Your opinion is noted but is not supported by the literature as has been carefully documented many times on this talkpage. I have modified the weaseling that was introduced by editors unfamiliar with the subject. "Thought to be" wording is best for articles about speculations not about articles written about observations and testable science. Are we to say that Maxwell's Equations are merely "thought to describe" the behavior of electric and magnetic fields? I think not. Just because there was controversy over the nature of quasars doesn't mean there is any more. Science and the opinion of the scientific community is subject to change. --ScienceApologist 15:42, 28 May 2007 (UTC)

Edit conficts

Ok, I'm getting tired of fighting with ScienceApologist on edits for the article, so I'd like to get everyone's opinion on this edit. Which version of this article should be used? Edit Diff The previous edit in this diff, or current edit in the diff? --Andrew Hampe Talk 20:43, 16 June 2007 (UTC)

15-year-olds with little expertise and a seeming lack of desire to do research should not be dictating Wikipedia content. I encourage you to start reading references starting with a selection of astronomy texts. --ScienceApologist 12:00, 17 June 2007 (UTC)
If there are so many references (that are not original research) on quasars, then start adding references to the article. Also, keep my age out of it and don't tell me how much expertise I have. --Andrew Hampe Talk 22:42, 17 June 2007 (UTC)
So why don't you tell us how much experience you have. I've made my background plain throughout this talk page: I've done a Ph.D. thesis at Caltech on the subject of quasar evolution. I've told you that out of hundreds of working astronomers I've met, nobody since I began my career has suggested that quasars are other than AGN at cosmological distances, and that AGN are the result of accretion onto SMBHs. I've pointed out that any such controversy predated the discovery of SMBHs in galaxies including the Milky Way, along with other evidence like Lyman-alpha forest studies relating quasar absorption lines with galaxy halos along the line of sight. I've also referred you to Virginia Trimble's annual round-up of the state of astronomy, wherein you will not find controversy on the points I listed above. You just keep coming back claiming that there's controversy. The ball's in your court. Show that there is still, today, controversy as to the AGN nature of quasars, and that this controversy is widespread enough among professional astronomers to merit inclusion. -- Coneslayer 02:25, 18 June 2007 (UTC)
Only goes to illustrate one of the systemic problems with Wikipedia: amateurs thinking they are experts. --ScienceApologist 12:48, 18 June 2007 (UTC)
Insulting fellow people because of their age or experience is bad science. It is also irrelevant if they bring up valid critiques. Post world-readable, not pay-walled links to proper scientific articles that support your point of view or accept that you're not doing science here, but defending your dogma.Crusty007 (talk) 22:58, 7 March 2009 (UTC)
ScienceApologist's version. No question. You are, again, claiming controversy where none exists. -- Coneslayer 15:32, 17 June 2007 (UTC)
Agreed. SA's version reads like an encyclopedic article. The other contains phrases like "[...], which nicely explains why there aren't nearby quasars. In this framework, after a quasar finishes eating up gas and dust, it becomes an ordinary galaxy," which doesn't have encyclopedic wording. Antelan talk 22:51, 17 June 2007 (UTC)
I agree completely. Stick with ScienceApologist's version. -- Avenue 03:04, 18 June 2007 (UTC)
Ok, not trying to argue, but i wasn't aware of that line. — Andrew Hampe Talk 22:50, 14 August 2007 (UTC)

A mistake 12 parsecs wide?

At the top of the page for Quasar there is the following sentence "...a quasar is a compact region 10-10,000 Schwarzschild radii across...".

"Schwarzschild radii" is even a link to the appropriate wiki page explaining what the radius is.

If one bothers to read the Schwarzschild Radius page, as I did, you will discover that this radius is not a standard unit of measure, like a meter, or some such measurement that you can have more than one of (10-10,000). Rather it is a number proportional to the mass of the object in question. Every mass has it's own (singular) schwarzschild radius.

These two pages seem to be conflicting. It would seem "...a quasar is a compact region 10-10,000 Schwarzschild radii across..." is an utterly meaningless sentence.

I am no expert in cosmology and have no idea if I'm making some sort of simple error in understanding here. Perhaps if you know how to correct me or this information, you will.

@@@ Now someone sent me a message saying "The statement: "...a quasar is a compact region 10-10,000 Schwarzschild radii across..." Refers to the density of the galaxy, not the size or mass." which, to me, raises more questions than it answers. Wish I knew how to respond to that person individually because I completely fail to understand their response. @@@ (talk) 06:47, 25 March 2009 (UTC)

I've removed the tag. The size of the central source in a quasar (which has essentially nothing to do with either the size, or "density" of the host galaxy) is dependent on the amount of accreting material and the mass of the central black hole. Thus, it will vary from object to object, and the best unit of measure is the "size" of the black hole, which is its Schwarzchild Radius. - Parejkoj (talk) 02:16, 30 March 2009 (UTC)

Ok, but that's my whole point. The "size" of the black hole is it's (singular) Schwarzschild Radius. Unless I'm really retarded or something, it's my understanding that an object can't have more than one Schwarzschild Radius. The term 10-10,000 Radii for one object is meaningless. Right???

Oh, and I found a NASA page that estimated the average width of a quasar to be 3200 light years. I believe the term it used was 1 kiloparsec, but since the page seemed to be geared towards children I'm not sure it's something good enough to use as a reference source. (talk) 05:37, 30 March 2009 (UTC)

You are confusing the quasar and the black hole that produces it. The thing we see as the quasar consists of the black hole's accretion disk and its associated winds, corona, etc. This region is roughly the size given in the article, which is best measured using the size of the associated black hole, because it depends on the size of that black hole. If this makes sense, can you suggest a way to clarify the wording?
As to the NASA page, please link it here in the Talk page, because I think you may be misreading something. If not, the NASA page should be fixed. - Parejkoj (talk) 14:57, 30 March 2009 (UTC)

Let's see if I get this now. The term "10-10,000 Schwarzschild Radii" was supposed to refer to the quasar being 10-10,000 TIMES the size of it's corresponding black hole (aka it's Schwarzschild Radius)? If this is indeed so, my initial conclusion was right; the pluralisation of Radius is incorrect. Perhaps it could say "...a quasar is a compact region 10-10,000 times wider than the Schwarzschild Radius of it's associated black hole...". Of course if this is correct it will take some finagling of the entire last sentence to make all the information fit together well grammatically.

As requested, the NASA page: where it clearly states "A quasar is approximately 1 kiloparsec in width".

I found the user responsible for making the "10-10,000" edit and asked him to comment here. Hopefully he'll be able to best explain what he meant to say, and for that matter, where he got his information. (talk) 21:45, 30 March 2009 (UTC)

"XXXX Schwarzschild radii" is common usage in astronomy, with the central black hole being implied. But I can see how that might be confusing here. I've given a shot at rewording it. Is it better?
The Starchild page is sort-of correct; their number includes jets and/or the narrow-line region, which is 100-1000 pc away from the central source. For a kid's webpage (Starchild is geared toward elementary students), it's acceptable but not perfect. But Starchild certainly isn't a good reference for wikipedia... - Parejkoj (talk) 23:04, 30 March 2009 (UTC)

Ahhhhh :-D Much better! I think it is much clearer now to the average user of wikipedia. I know it's at least clearer to me. I've noticed lots of this phenomenon before on wiki pages, as the technical entries tend to be written by experts in the related field, and they use jargon specific to their field. I wondered from the start if this was possibly the source of confusion, just me not being an expert in cosmology. Thank you Parejkoj for your assistance. You also confirmed my initial suspicion that the Starchild page was not "Wiki-worthy". (talk) 03:22, 31 March 2009 (UTC)

Regression in the quality of the Wikipedia 'Quasar' entry

I work on quasars for a living, and I made some major edits to this entry last Summer, adding content and correcting a number of mistakes. After that I watched for a while and the entry improved. I hadn't looked for about 3 months, but just yesterday I looked through it again, and through the 'discussion' at length. I am pretty disappointed. The entry has regressed and includes many statements that are more vague and less informed than in December (2008). The discussion is clearly failing to converge on the well-known scientific consensus.

A while back one contributor (who I believe I know, and who works professionally on quasars) said he found his Wikikpedia experience with this entry highly offputting. At the time I disagreed. I use Wikipedia all the time in other fields and it almost always checks out 100% with detailed, careful and correct information. Why is this not working for the Quasar entry? Closely related entries (which I won't name in case they become targets of poor editing) are excellent. Perhaps the name 'quasar' conjures up a mysterious sci-fi aura that makes it a target? Some of the editors clearly have strong ideas about quasars, which they keep editing back in. Unfortunately these ideas are not well-informed, and often misunderstand not only basic astronomy, but how science actually works, as well as the purpose of Wikipedia.

Right now the entry is so garbled that it would be better to dump the whole entry and start afresh. Maybe I"ll try a fresh start, but I'm not sure how to put that in for consideration. I am strongly tempted, though, to give up and help instead at an expert based '-pedia', which is unfortunate. —Preceding unsigned comment added by MartinElvis (talkcontribs) 19:51, 13 April 2009 (UTC)

I don't know much about quasars, but it doesn't look like much has changed since December. -- BenRG (talk) 12:00, 19 April 2009 (UTC)

As someone who knows nothing about Quasars, I can also say that this entry seems poorly written and vague. The section "Properties of quasars" seems especially bad. Just try reading it out loud - it's a train wreck. (talk) 00:27, 16 May 2009 (UTC)

Quasars as distant AGN (again)

[unindent] Most of the remarks here are quite old, so I don't know how long it will be before this comment is seen.... Anyway, I skimmed the quasar article and one aspect of the "Active galactic nucleus" scenario seems to be missing. It might be there and I simply missed it, but in case I didn't...this is a very simple matter of statistics. We know that some percentage of galaxies have an AGN. We know that quite a few such galaxies are associated with at least one jet of particles and energy, emerging from its AGN. The orientations of those jets, relative to intergalactic space, are random. We know that there are lots more galaxies far away than nearby. Statistically, therefore, some percentage of the AGNs of those extremely many distant galaxies must have their energy jets "aimed" toward us. This is simple obvious logic that belongs in the article even if there is no reference for it. Looking at such a jet face-on, what do you think we would see? An extremely bright source of energy, that would make it difficult to detect a galaxy surrounding an AGN!!! And very red-shifted due to its distance, of course. Note one aspect of this description is that the total energy output of a quasar becomes distinctly less-than-ridiculous (it is not radiating energy in all directions); we are basically talking about a well-documented type of galaxy (and in its early years at that). V (talk) 16:31, 4 November 2009 (UTC)

Triple quasar

The article triple quasar had been on the requested astronomy articles list for over two years, so I put together a brief article. However, there is an existing double quasar article that is tagged for improvement. Somebody may want to consider merging them into this article under a section on multiple quasars. Thank you.—RJH (talk) 19:17, 23 April 2009 (UTC)

Hy, I think this statement is in need of correction,

"there is now a scientific consensus that a quasar is a compact region 10-10,000 times the Schwarzschild radius of the central supermassive black hole of a galaxy"

This implies that there is a black hole inside a Quasar. I think this line should be rewritten, I am reasonably sure that the Quasar is the central object to the galaxy and not something around the central black hole. I'm afraid i don't have a reference, I'm a student so its from my supervisor.

I don't know how to edit Wiki and am quite dyslexic, so not really a good person to write a clear article.

If any one can help that would be grand.

cheers Eglington (talk) 10:58, 12 December 2009 (UTC)

I copy-edited the text. Ruslik_Zero 12:51, 12 December 2009 (UTC)