Difference between revisions of "Talk:Black hole"

Revision as of 17:03, November 13, 2009

Extremely high density

Technically, it's undefined, no? Tsumetai 07:52, 22 March 2007 (EDT)

did you know the 'Black Holes FAQ', which there is a link to, was written in 1995? -stevenM

Existence confirmed?

Perhaps I was hasty. I will reconsider. Any other sources I might find enlightening, perhaps from a YEC perspective? BHarlan 15:16, 7 January 2009 (EST)

Talk:Atheistic Style#Black Holes covers it quite well. I don't know of any evidence from a reliable source that shows the existence of Black holes. This "can't be directly observed" thing reminds me a bit too much of evolution. BHarlan 12:16, 9 January 2009 (EST)

Even wikipedia's article notes that all of the different pieces of evidence of a black hole are problematic and can be explained by other sources. - Rod Weathers 12:21, 9 January 2009 (EST)

This is why the article starts by stating "A black hole is a theoretical mass with an escape velocity greater than the speed of light. They cannot be observed directly, but several have been identified via indirect observation" I also don't see how NASA or UCLA Berkely are unreliable sources for astronomy. As for "can't be directly observed",there are numerous articles on CP related to Intelligent Design that don't rely on direct observations of a designer to discuss the apparent presence of design in nature.

The beauty of science that it's always open to review and reassessment as new discoveries come to light. In time man's understanding of Black Holes may be different from this article, but we owe the readers the best current explanations available. I'm not suggesting censorship - all credible alternate theories should be listed, but stating that there have been no observations of one is false - by definition they are not directly observable, so proving they exist relies on indirect observation and physics. --DinsdaleP 12:38, 9 January 2009 (EST)

There is no place called "UCLA Berkely".

ID is bolstered by the direct observation available from Genesis.

The best explanation is not always the explanation espoused by Californians.

We know how our universe began. If NASA & discovery.com deny it, they lose credibility, and their other statements come under greater scrutiny. If you met someone today who insisted that the sky is red and that Sears closes at 10, you would be wise to check the store hours yourself. BHarlan 13:58, 9 January 2009 (EST)

Okay, my mistake regarding Berkely notwithstanding, my last reversion is based on two simple things. The word "is" should not be replaced by "would be" - it is a characteristic of black holes within the theory that describes them. Second, the use of Big Science as a term on CP was started by an admitted parodist, and equating NASA with it, frankly comes across as parody as well. Instead of diluting references to good science, spend more time supporting alternate explanations constructively. --DinsdaleP 14:07, 9 January 2009 (EST)

"Would be" is appropriate for hypothetical things. We say "Dole would have been a better President than Clinton," not "Dole was a better President than Clinton," even "within a theory that describes" Dole as being elected.

"Big Science" was used in Expelled. You don't think that was parody, do you?

"Berkely" isn't a place, either.

It seems like I'm the only one trying to make constructive edits towards a compromise. I guess this is not surprising, given the content on User:DinsdaleP. BHarlan 14:26, 9 January 2009 (EST)

BHarlan, I believe that you do not understand a small but important bit of information, most astronomical discoveries are collaborative efforts usually initiated by small independent astronomers. When you say big science you could classify biosciences like that, but astronomy is totally different.--Able806 14:19, 9 January 2009 (EST)

The so-called "evidence" for Black holes does not fit a pattern like the one you describe. BHarlan 14:26, 9 January 2009 (EST)

(unindent)

I'm not making any other changes to the revision just posted by Aschlafly. To BHarlan, I make no apologies for my User Page content. If the CP leadership wishes to block me over my contributions they have the right to do so at any time, but I feel that my efforts here are constructive even when I disagree with others. Feel free to have the last word on this, I'm moving on to other topics. --DinsdaleP 14:45, 9 January 2009 (EST)

Black holes have been spotted by a number of well-respected astronomical institutes for decades, with those discoveries tested and confirmed repeatedly. Your edits are unsupported by either fact or citation Andy, so under the rules youelf created I have no choice but to revert your edits, whereas the edits saying that black holes have been spotted are fully cited with references from reputable sources including NASA, an organisation fully backed by all US Governments, including conservative governments, since its inception.-Ieuan 15:47, 9 January 2009 (EST)

Your sarcastic edit comments are not welcome here. You might want to check "youelf", else you might end up wrecking youelf.

Also, you always have a choice! Do you deny this choice? That is a typical sentiment of materialists. If you do not believe in your soul, you will receive a nasty surprise pretty soon, and it won't just be the non-existence of black holes!

Also, that is not how "whereas" is used in standard English.

Also, NASA has taken a sad left turn as of late. This is one of the reasons the U.S.A.F. has its own space program. Do you see?

Also, may God bless you. BHarlan 16:10, 9 January 2009 (EST)

My my, I miss a 's' in a typo and you decide to launch an ad hominem attack… Very 'christian' of you, or then again; not.

"Also, that is not how "whereas" is used in standard English". That might not be how you use it with your standard of English, but as anyone who has been taught the correct way to use the English language knows, it's perfectly correct. Oh, and a little, free, friendly lesson regarding the use of written English : You never start consecutive paragraphs with the same word unless it is absolutely necessary, which, in your above post it wasn't. If you are having trouble with your synonyms I heartily recommend using a thesaurus.

The military space research programmes exist solely to explore the possible military applications of space. All civilian space programmes, including government projects run through the relevant Space Agencies (NASA, ESA, etc.). This is common knowledge amongst those who know anything about this subject.

Stating that black holes don't exist is akin to believing the moon landing was faked. The existence of black holes and the fact that they have been spotted is undisputed by anyone who has the knowledge and experience to know what they are looking at. I have had the privilege of seeing two of these black holes myself. They are out there and have been spotted, and that is a direct, firsthand witness statement.

May you be touched by his noodly appendage, or if that isn't your cup of tea, may you be blessed by the goat Heidrún. RAmen.-Ieuan 17:06, 10 January 2009 (EST)

• It's "an 's'", not "a 's'".
• If you missed just one 's', then that part of the sentence would read "under the rules youself created", which is still wrong.
• If you missed an 'r' and an 's', then that part of the sentence would read "under the rules yourself created", which is still wrong.
• An ad hominem attack means to reply to the logic in your arguments by attacking your character. I did no such thing. I didn't attack your character in any way. I asked if you were a materialist, then pointed out that materialists are Hell-bound. If you have a problem with your final resting place, I suggest you reconsider your path in life. I do not suggest that the Hell-bound are never able to make logical arguments.
• "Christian" is capitalized. Did you leave it uncapitalized on purpose? If so, I suggest you blaspheme somewhere else.
• That is not how semicolons are used in standard English.
• You need a comma after "but" for the aside.
• You do not need commas around "friendly", just like you don't need commas around "red" in "big red inflatable ball"
• I will not discuss the friendly lesson here, except to note that stylistic choices are different than maintaining correctness. Comma placement and word choice are different beasts.
• The sentence starting "All civilian" has no main verb, so I can't respond to it.
• Hyperbole about the moon landing is simply rhetoric. If there is no argument, there can be no response.
• Wikipedia may accept your anonymous evidence, but we are more careful here.
• Black holes can't be seen. What I suppose you mean is that you infer their existence. Your inference is not particularly convincing.
• Please take your graven goat pasta idols elsewhere. Here we show some simple respect for God.
• I am done with this pointless, blasphemous discussion. It is not encyclopedic. I suggest you contribute to this encyclopedia. It is a good way to improve your writing skills. I have been contributing partially for that reason. Maybe you could join me in adding articles and value, rather than taking the name of my Lord in vain?
• If you decide not to, you may have the last word here, as I will no longer reply to this silliness. I hope you will decide to contribute instead. BHarlan 18:33, 10 January 2009 (EST)

*Sigh* "a wit, an arrow, across the head it passed, an apple not pierced today", an 'r' and an 's', my apologies, how can such typos be left to pass, expecially when they are nothing to do with the argument at hand, well done for picking up such niggling detail, and yet avoiding the point of the argument. Admittedly I missed the n in an, but again, a typo, they happen. "Wikipedia may accept your anonymous evidence, but we are more careful here", how does evidence from NASA count as anonymous evidence?…at all?…in any way?…whatsoever? As for an ad hominen attack, your argument provided no evidence against the existence of black holes, merely an attack on myself, the purest definition of ad hominen (a course in Latin will help you there). Christian or christian, depends on how you want to write it and on your own beliefs. Me, not my belief, and as I don't believe I cannot blaspheme, after all, how can you blaspheme against something that does not exist to be blasphemed? Use of semicolons in standard English? Again, I refer you to the fact the your standard of English might not be sufficient to use them in such regard. I recommend increasing your quality of English by beginning with Chaucer and reading your way up. At some point you will realise that the use of English in any form is an art, not a science, and that language is to be used in such a way as to provoke delight, wonder and thought with its writing, and beyond the obvious rules of form, there are no hard and fast rules, merely that of metre, pace and illumination. "The sentence starting "All civilian" has no main verb, so I can't respond to it", run, it's a verb, hard to miss, I'll admit to missing a comma (the sentence should read "All civilian space programmes, including government projects, run through the relevant Space Agencies (NASA, ESA, etc.)", but missing the word run *shakes head in disbelief*: if you insist on a purer form for that sentence, how about "All civilian space programmes, including government projects, are run through the relevant Space Agencies (NASA, ESA, etc.)", but all things being equal, both sentences say the same thing. Moon landing = the sum of evidence gathered concerning the existence of black holes, and that they have been spotted, is greater than the evidence that the moon landing occurred in 1969, hence the corollary. "Please take your graven goat pasta idols elsewhere. Here we show some simple respect for God", I found it offensive that you forced your beliefs on me, now you have found it offensive when I have forced my beliefs on you, with luck you will have learnt a lesson there, don't force your beliefs and prayers on me and I will return the favour by not blessing you with a little sarcastic FSM (oh, and a little FYI, the word graven means carved and I'm sure that the old FSM hasn't been carved yet and, in addition, I doubt that there are any extant carvings of Thor's goats, although I'm willing to admit that I might be wrong in that regard.)--Ieuan 22:13, 13 January 2009 (EST)

I have researched an extensive amount about black holes, and am about to add more information to the article that I hope will prove to be interesting and useful (I will, of course, cite my sources). I am also adding a couple of updates, as some of the information in the article is dated. As a topic about which scientists are still learning, that happens a lot. I hope the updates will improve the quality of the article and its use for educational purposes. BlueMoon 15:26, 24 June 2009 (EDT)

Impossible?

"A black hole is a theoretical prediction of the theory of relativity. It is impossible to prove that a black hole does not exist, and thus it fails the falsifiability requirement of science."

Actually in science we cannot prove with 100% certainty that anything does not exist, you cannot prove a negative. This opening sentence needs to be rewritten first for that reason, also for the fact that black holes have been indirectly observed via Accretion disks, gas jets, gravity lensing, radiation emissions, and other orbits of other stellar bodies. Also there is no other valid explanation in science for the aforementioned effects of a black hole that we observe. --BMcP 17:00, 1 July 2009 (EST)

No, that's the point- to be scientific, something has to be able to be proven wrong. That is a major part of the scientific method. For example, God is not a scientific concept, because you cannot disprove God. But to be science, one of the criterion is that the idea be able to be disproven.

Falsifiability is not the only criterion for whether something is scientific, so perhaps black holes are not unscientific. But that opening is pretty much accurate. AddisonDM 17:50, 1 July 2009 (EDT)

Black holes are falsifiable as a theory, because the observations generally accepted as caused by black holes could be causes something else, however there is no alternative theory at present to explain the phenomenon. However you cannot prove that a black hole could never exist just as you cannot prove atoms, or anything, could never exist. God is not a scientific theory not because it is impossible to absolutely disprove God (impossible to prove that God could never possibly exist) but because the supernatural cannot be shown to exist through science, which deals only with the natural universe, if you could present a theory God existed in science, that god would no longer be supernatural by definition.

Honestly I don't understand the objection to black holes, there is no conservative reason for it. --BMcP 19:04, 1 July 2009 (EST)

The existence of black holes is not falsifiable. Surely you agree with that. Black holes cannot be observed either. Addison explained the flaw well above, but you seem intent on sticking with your beliefs. Believe what you like, but black holes do not satisfy any sensible definition of science.--Andy Schlafly 20:37, 1 July 2009 (EDT)

The possible existence of anything is not falsifiable, black holes, quarks, gods, even godzilla, only theories are falsifiable, such as the theory that explain what black holes are and how they work. The present theories of black holes are falsifiable, but so far no one has successfully debunked them, or offer an alternate scientific theory for the phenomenon attributed to the effects and properties of black holes. We cannot observe an isolated quark directly, but we accept that theory.

However I cannot change one's mind, that is fine, I made my objections known, I am not going to step on people's toes by attempting to change the page, I just believe it is scientifically incorrect in it's proclamation and could stand to be improved for a better article. I have said what I believe needed to be said and will end my part here, anyone feel free to respond with the last word or contact me privately. --BMcP 21:07, 1 July 2009 (EST)

Thank you for your interest. Note that atoms have actually been observed (in refutation of what you said above, "you cannot prove atoms, or anything, could never exist". I don't think the article will be changed though. Black holes are sort of on the fence between observable, testable physics, and "theoretical" physics, e.g. string theory. There are a million sources where you can get the standard overview of black holes. Why not have a different view here? Wikipedia does not even mention the issue of falsifiability, so we are doing a service to the scientific method by at least bringing it up- even if you think the article's conclusion is wrong. AddisonDM 21:23, 1 July 2009 (EDT)

In addition to Addison's comments, note that some theories are falsifiable (such as Newton's theory of gravity), while other theories are not falsifiable, such as the theory that black holes must exist or string theory. And when a theory is not falsifiable, it is not science. If BMcP proposes an alternative definition of science, then let's hear it, but I doubt he'll do better than Karl Popper in making falsifiability part of the definition.--Andy Schlafly 21:45, 1 July 2009 (EDT)

Guys, this is becoming quite the argument; however, it is unnecessary because the idea that black holes exist is falsifiable. If NASA sends probes out to nearby black holes (which would take a long time, but it's possible), and they all turn out to be ancient Spartans in spaceships or whatever, then scientists will conclude that black holes don't exist and start working on how Spartans came to be in space and why they have accretion disks, etc. So black holes are falsifiable, and this argument is a source of unnecessary tension. BlueMoon 12:55, 8 July 2009 (EDT)

I don't get this non-falsifiable argument. If we see light from a star, then it is not a black hole. Any claim that it is a black hole is then falsified. Black hole theory says that a star becomes a black hole whenever its mass goes inside its Schwarzschild radius, it becomes a black hole. So if we ever find a star that emits light and has its mass inside its Schwarzschild radius, then the theory is falsified. RSchlafly 10:32, 28 July 2009 (EDT)

The problem with that argument is that we live light years away, so what we could be seeing at one moment could be just the beginning before the light is swallowed into the black hole. --ChrisZ 11:01, 28 July 2009 (EDT)

No, we can observe the radius, mass, and light all at the same time. RSchlafly 12:07, 28 July 2009 (EDT)

Should we change the article then, seeing how there's no rebuttal to RSchlafly's post regarding the falsifiability of the black hole theory? ATang 11:03, 6 August 2009 (EDT)

RSchlafly is absolutely right, as far as anything a graduate student could say might "validate" the statements of an actual PhD. But an additional argument: it wouldn't even be necessary to use astronomical observations to invalidate the theory of black holes. A large enough super collider - perhaps the LHC, perhaps a more powerful device - could discover a quark degeneracy pressure, or some other currently-unknown mechanism, which might offer a potentially infinite resistance to collapse, or, pressure so great at certain densities that an impossibly large amount of matter would be necessary to form a black hole.

I'm not going to remove this material yet, since I see Andy put it there, but I hope Mr. Schlafly will read this page and reconsider. JacobB 14:46, 8 August 2009 (EDT)

There are some untestable statements that are commonly made about black holes. One might even argue that statements about the interior of a black hole are unfalsifiable, because we cannot see the inside. But black hole theory does have a lot of observable consequences, so I think that the article is misleading. RSchlafly 10:12, 9 August 2009 (EDT)

How might one falsify the basic assertion about black holes: that black holes exist such that light cannot escape? Every time one observes light escaping, he simply concludes that it is not a black hole.--Andy Schlafly 11:31, 9 August 2009 (EDT)

Mr. Schlafly, you're absolutely right that the general claim, "There are mysterious regions of space from which light cannot escape" is an unverifiable claim. Black holes don't refer to this statement - they refer to the specific statement, "It is possible to concentrate a certain amount of mass, so that the gravity of that mass prevents light from escaping." This could be falsified by experiments in particle accelerators (possibly the LHC, I'm not familiar enough with it to know) which could demonstrate that such concentration of matter is impossible - that degeneracy pressures, currently unknown, prevent such it. This would falsify the claim that black holes exist. JacobB 11:52, 9 August 2009 (EDT)

I have an open mind about this, but fail to see how an inability to generate a black hole using a generator would falsify the existence of black holes in outer space. Most likely those who believe in black holes would simply say that higher and higher energies or densities are needed to generate it in particle accelerators.--Andy Schlafly 12:16, 9 August 2009 (EDT)

You're right that failure to create a microscopic black hole in a lab wouldn't falsify the idea that they can form. What I'm claiming is that research which aims, not to create microscopic black holes, but to gain more insight into the forces that govern the behavior of sub atomic particles, might unearth evidence that would refute black holes.

Here's how: right now, the theory on black hole formation states that as matter accumulates, first electron degeneracy pressure is overcome (that is, the structure of the matter in question would be not atoms side by side, but atomic nuclei side by side with no electrons in between), then the nuclear degeneracy pressure is overcome, that is, one would not longer have nuclei side by side, but neutrons and protons side by side (a neutron star), and then finally, this neutron degeneracy pressure is overcome and the matter becomes so dense it is contained by its own Schwarzchild radius and becomes a black hole.

It is entirely plausible that a particle accelerator of sufficient power could concentrate matter to overcome the neutron degeneracy pressure only to discover a quark degeneracy pressure, or some other force. It is also possible that this new force would require SO MUCH matter to be overcome, as to be unphysical (for example, it might take more matter than is currently believed to exist to overcome the pressure). If this pressure was to prevent matter from being denser than the Schwarzschild limit, then the claim that black holes exist would be forever disproven and falsified. JacobB 12:43, 9 August 2009 (EDT)

Additional note: As RSchlafly points out, there are many claims about black holes which ARE unfalsifiable, currently - as he points out, claims about the interior of the event horizon are not falsifiable. Similarly, predictions regarding their presence in certain locations are not falsifiable by any means we yet possess. The same criticism could be leveled at my above description of an experiment in nuclear-density matter. JacobB 12:56, 9 August 2009 (EDT)

We cannot determine what is happening in the "interior" (inside the event horizon) but that doesn't make a black hole itself not falsifiable. We are not sure what the interior of a neutron star is at all, but I think everyone here agrees they do exist. Also just because you cannot visually see something (such as a black hole, where light cannot escape from inside the event horizon) doesn't mean it isn't there or falsifiable. Most astronomical study of space is not in the visual spectrum, and there are many ways to determine the existence of a black hole. I also must point out, there has been no alternative hypotheses to explain the gravitational effects we presently attribute to black holes. Also, as pointed out before, if we are able to find an object of sufficient mass within the Schwarzschild radius, which normally would continue to collapse into a gravitational singularity (Black Hole) but has not, that would disprove the theory of Black holes right there, or in other words falsify them. For example, if we found an object the same mass of our Sun, and was smaller then its Schwarzschild radius of around 3 km (the Schwarzschild radius for an object of that mass) and it did not collapse into a black hole, then the theory of Black Holes would be proven false. --BMcP 08:14, 12 August 2009 (EDT)

I hate to disagree with BMcP, because we share the same goal here (getting the non-falsifiability statement removed from the article), but there was a lot of bad science in that response and we should have an argument based in facts and truth.

I also must point out, there has been no alternative hypotheses to explain the gravitational effects we presently attribute to black holes.

That's not entirely true. In my previous posts, I mentioned that discovering a sufficiently powerful quark degeneracy pressure could disprove the existence of "black holes." Objects which are prevent from gravitational collapse by quark degeneracy pressure, "quark stars," could explain a good deal of phenomenon currently attributed to black holes could be very adequately explained by such phenomenon - extraordinary x-ray sources, quasars, all these rely on on the affects of a large amount of mass concentrated in a small space, not necessarily a Schwarschild radius. Which brings me to

if we are able to find an object of sufficient mass within the Schwarzschild radius, which normally would continue to collapse into a gravitational singularity (Black Hole) but has not, that would disprove the theory of Black holes right there, or in other words falsify them."

Any object which is completely contained in a Schwarzschild radius is automatically a black hole, regardless of whether or not it has collapsed into a singularity or not. Furthermore, since the gravitation field exterior to the schwarzschild radius would be the same regardless of where the mass inside was a singularity or not, so there would be no way to tell.

I still think the best argument for falsifiability is the experiment I presented earlier into quark degeneracy pressure. JacobB 12:18, 12 August 2009 (EDT)

I was not aware of a hypothesis that offers a possibility of quark degeneracy pressure that would be powerful enough to resist the effects of gravity even if the mass would normally be large enough to collapse into a black hole. I agree if such pressure existed it would disprove our current theories of black hole formation.

You are right, it doesn't have to be a singularity, although that is what current theories suggest happens, that gravity continues to collapse the matter inside the event horizon to the point of a singularity.[1] However that does not have to be true for the mass to collapse within the Schwarzschild radius to be a black hole, just that their is sufficient gravity to force particles within the horizon to be deformed in their path so they cannot leave. It is just theorized at the center of a black hole is the singularity[2]. That being said, it expected that a theory of quantum gravity will feature black holes without singularities.[3] [4]. It isn't important either way, what is important is the question, are black holes falsifiable? I think you and others have already offered examples of yes. --BMcP 13:23, 12 August 2009 (EDT)

Falsifiability

(no text was inserted here, but the edit summary was "the falsifiability is undeniable and should not be censored, Physicists should be taught about falsifiability as part of their curriculum")

Based on KSorenson's remarks and what I know about the curricula at schools I've attended, physicists are indeed taught about it. It seems a stretch to say that the falsifiability is "undeniable" when in fact every editor except you has denied it. --MarkGall 23:15, 12 November 2009 (EST)

Sorry, somehow my text above was misplaced. Thanks for substituting in what I meant!

Those who have denied that black holes lack falsifiability really seem to be denying that falsifiability should be a limit on physics.

KSorenson cited a laundry list of philosophy-type requirements of physics majors, but conspicuously absent was emphasis on falsifiability.

Like most college majors, physics students repeat what they're taught. If they received good grades, then it becomes even harder for them to question it. But keep in mind that the people doing the teaching are the most liberal group in the world, and they almost never encourage the student to open his mind and think critically for himself.--Andy Schlafly 23:23, 12 November 2009 (EST)

Please read again, Aschlafly. I specifically cited Karl Popper as part of the curriculum in undergraduate courses on the philosophy of science. In case it's slipped your mind, Popper basically invented falsifiability as the criterion for distinguishing science from non-science.

Incidentally, Popper cited Einstein's theories as exemplars of rigorously falsifiable science when he constructed his criterion. He wrote about it in contrast to the quote-unquote "scientific" theories of Marx. By a happy coincidence, the very same theories of Einstein's that Popper found so admirable are the ones we're talking about here. So can you please, and I'm asking for the third time now, clarify just exactly what your gripe is?--KSorenson 00:36, 13 November 2009 (EST)

Hello; I'm the user who edited this article after KSorenson. If I may jump in to this heated discussion going on at at least two places : I think what Andy's saying is that black holes themselves can never be proven to not exist, because (by definition) no one can see them or visit them and return. I think what KSorenson's saying is that general relativity states black holes are possible, and that general relativity can be falsified (e.g. by sending probes to probe the earth's gravitational field).

Of course, just because general relativity hasn't been disproven doesn't mean that it's been proven. There could be a better theory which accounts for all the gravity-probe data and states that black holes don't exist. We don't know yet; that's the wonder of science: God's always put more out there for us to discover! So, we don't know that black holes do exist - that claim isn't falsifiable; we'd need to survey every square millimeter of space and say "there isn't a black hole here!". But, the theory that states they can exist is falsifiable. I tried to reflect this dichotomy in my edits to this article. -- EvanW 00:46, 13 November 2009 (EST)

You make excellent points, particularly in your last paragraph above. The introductory paragraph to black hole would benefit from this, and please feel free to edit it again (I apologize if others deleted your work). Note, however, that it is not very practical to devise a test that could falsify General Relativity, and falsifying General Relativity would not falsify the claim that black holes exist. Black holes are far too popular in science magazines and liberal publications like the New York Times to "go away" that easily.--Andy Schlafly 09:52, 13 November 2009 (EST)

On Popper and relativity, Christoph von Mettenheim (http://elm.eeng.dcu.ie/~tkpw/tcr/volume-01/number-03/node3.html) writes: "Most of you will know of Popper's admiration for Einstein, and how he was inspired by the theory of relativity (and by its high refutability in contrast to the irrefutability of psychoanalysis) more than by anything else to develop the criterion of falsifiability as a demarcation between science and metaphysics (Popper 1976, pp. 37-38)." As KSorenson has already noted, relativity was the theory that inspired the notion of falsifiability in the first place. The claim that "it is not very practical to devise a test that could falsify General Relativity" is absurd on the face of it. --MarkGall 10:02, 13 November 2009 (EST)

Popper's personal views are irrelevant; no one here says that Popper was a genius who was always right. It's falsifiability that is at issue, and the resistance to that simple, logical concept is astounding. People can teach Popper all they like, but it's clear that physics majors are not learning fully about falsifiability. String theory wouldn't exist in physics departments if they were.

If tests existed that might falsify General Relativity, then in the nearly 100 years since its proposal we would have seen many of them. Instead, as the latest discussion (and the famous 1919 solar eclipse) illustrate, margins of error in the experiments are typically greater than the deviations predicted by the theory.--Andy Schlafly 10:13, 13 November 2009 (EST)

(unindent)

Andy raises an interesting point. In theory, it's easy to test general relativity - take KSorenson's gravity probe, for example. This wouldn't absolutely prove it; there might always be a better theory out there. But nothing can ever be absolutely proven in science - the point is that this test could disprove it. So, in theory, it's falsifiable. "[falsifiable|A proposition or theory is falsifiable if it is hypothetically possible for a test or observation to prove it false]." Of course, a hypothetical future theory might still include black holes (there's an infinite number of possible theories), but the possibility of black holes according to general relativity (how's that for a mouthful?) is falsifiable, because general relativity is falsifiable. Or, to try to say it more simply: the possibility of the particular sort of black hole predicted by general relativity (with exactly these properties, et cetera) is falsifiable. I hope I made my verbiage understandable enough for you all to agree or disagree?

But as you point out, the solar eclipse experiment didn't test general relativity in practice: the margins of error were too big. (I don't know if that's still true with modern experiments; could someone who knows more about that fill me in?) So, while it's theoretically falsifiable, it's possible that general relativity hasn't actually been tested yet... -- EvanW 10:36, 13 November 2009 (EST)

Here is a nice review of a variety of experimental tests of general relativity, along with discussion of other experiments that may be undertaken in the future. --MarkGall 10:43, 13 November 2009 (EST)

That all sounds basically right to me, EvanW. (Can I call you EvanW?) But from where I sit, it's even simpler.

• General relativity has been and is being tested, and so far the tests have confirmed the theory. That might change any minute, but it's still true so far.

• General relativity says that black holes are possible, and that if they exist they'll have certain properties.

• We've seen objects in the sky that have those properties, and that aren't predicted by any other existing theory. We're studying those objects as hard as we can given the limits of distance, to see if they really do walk and quack like ducks. Until we see something un-ducky, we say "Yeah, those look like ducks to us."

This really isn't complicated as far as I can tell, and I'm really baffled as to why we're still yaking about it amongst ourselves.

Aschlafly, if you want to expand the living daylights out of the "Controversy" section, I'll be right there by your side, cheering you on and helping in any way I can. As long as your contributions aren't misleading or incorrect. I don't want to speak for anyone else, but my gut tells me that EvanW and MarkGall would make the same promise. So why are we still bickering? Can't we improve the article instead? I know having to respond here is taking away from the time I set aside today to add to the general theory of relativity article. --KSorenson 10:54, 13 November 2009 (EST)

Mark cited Clifford Will's government-funded 2004 article on proof for General Relativity, but that paper is very "thin" and in a mere 15-minute review several weaknesses are apparent. But thanks for the citation, Mark.

This is a site where logic prevails. If you want to say that black holes are consistent with General Relativity (though rejected by Einstein), and General Relativity might be falsifiable (though tests will sufficient accuracy are difficult and expensive), that's fine. But black holes themselves, like life in outer space, are not falsifiable. It's basic logic, and that doesn't change whether all accept the logic or not.

There's a broader point here. Why the big push for black holes by liberals, and big protests against any objection to them? If it turned out empirically that promoting black holes tends to cause people to read the Bible less, would you still push this so much? Certainly there is no practical justification to pushing black holes; no one will ever be helped by them in any way.--Andy Schlafly 12:03, 13 November 2009 (EST)