Black holes

[Ziggurat]

Black holes dont exist, there a good reason why the color "black" was chosen in their name to explain them, considering the universe is black; you cant see it.

Ever hear of something called "black body radiation"? Is that a contradiction?

No, it isn't. "Black" doesn't mean what you think it means. But I'll give you a hint: a black hole is black in the exact same sense as a black body is black.

 

[Zeuzzz]

Ever hear of something called "black body radiation"? Is that a contradiction?

Yea a massive contradiction. The very idea that black bodes give off more BB radiation than white bodied people do seems absurd. ..

No, it isn't. "Black" doesn't mean what you think it means. But I'll give you a hint: a black hole is black in the exact same sense as a black body is black.

Hard to detect at night without UV or other spectral devices ?

 

[Farsight]

I don't see what that has to do with anything that RC said. I don't think he thinks "his word is gospel". He simply doesn't think Marten knows what he's talking about and is looking for him to actually make clear what he thinks Hawking was wrong about. That light can't escape from (beyond the event horizon of) black holes? That's true, and I'm pretty sure you agree with it, so where do you think RC is taking Hawking's word as gospel?

I've just looked back through the thread and a bit from a previous thread, and actually, I can't say. OK, hands up, fair cop, I was wrong to post what I did.

 

[dafydd]

I've just looked back through the thread and a bit from a previous thread, and actually, I can't say. OK, hands up, fair cop, I was wrong to post what I did.

Well done, I mean it.

 

[Farsight]

Nonsense. Never make the mistake of assuming that someone agrees with you merely because they didn't respond to something you wrote. What a nasty little trick.

Aww, an adhominem. How quaint.

OK, let's not drop the point. Sol, ben, let's talk some more about whether the infalling photon gains energy. Ben, you're on. Answer the question: Does the photon actually gain energy, and if so where does that come from? What loses energy to the photon?

 

[Dinwar]

Aww, an adhominem. How quaint.

No. AN ad hominem is "You're wrong because you smell funny". Complexity basically said "You're wrong and you smell funny". The fact is that the rhetorical gambit you used--assuming that someone agrees with you in the utter absence of any evidence--is a nasty and pathetic one. As this has no bearing on the quality of your argument, it's not an ad hominem attack, merely a sidebar observation.

OK, let's not drop the point. Sol, ben, let's talk some more about whether the infalling photon gains energy. Ben, you're on.

So you're going to ignore the fact that I offered precisely the plain-English, non-mathematical argument you demanded? Can I assume, therefore, that you agree with me?

 

[Farsight]

Well done, I mean it.

Thanks. I've been wrong before, and doubtless I'll be wrong again. One can only hope to minimise the instances. If someone says you're wrong John, and here's the scientific evidence and the clearly-understandable explanation that says why you're wrong, I like to think I will examine it, discuss it sincerely, and then be man enough to eat humble pie. What I won't do is roll over when somebody like Clinger tries to pull the you don't understand the maths trick. IMHO it's the modern equivalent of you don't speak Latin.

 

[Ziggurat]

Yea a massive contradiction. The very idea that black bodes give off more BB radiation than white bodied people do seems absurd. ..



Hard to detect at night without UV or other spectral devices ?

Nope, wrong again. First off, please tell us what you think black means in this context. Then I'll tell you why you're wrong, and explain the real answer. Or alternatively, if you confess that you don't know the answer, I'll just tell you.

 

[dafydd]

Thanks. I've been wrong before, and doubtless I'll be wrong again. One can only hope to minimise the instances. If someone says you're wrong John, and here's the scientific evidence and the clearly-understandable explanation that says why you're wrong, I like to think I will examine it, discuss it sincerely, and then be man enough to eat humble pie. What I won't do is roll over when somebody like Clinger tries to pull the you don't understand the maths trick. IMHO it's the modern equivalent of you don't speak Latin.

Maths is an important part of it. Without the maths you can't prove anything.

 

[Farsight]

Mathematics is the language of science. If you don't understand the math, you don't understand the idea. Period. Full stop. Even in paleontology we acknowledge that, and we use less math than any other field of science I've yet encountered.

Get real, Dinwar. Scientific evidence and the scientific method is what defines science. Mathematics is a vital tool, but it isn't what physics is. And you don't understand the maths is no substitute for a sincere discussion about the evidence and what we can deduce from it.

And if someone claims to be overturning the laws of physics but cannot handle the basic math, it's evidence that they don't know what they're talking about.

Oh puh-lease, don't give me the laws of physics. I'm advocating the original "frozen star" black hole interpretation, not some my-theory tosh.

When they follow up their lack of understanding of math with ad homonym attacks, it's an even better sign that they don't know what they're talking about. Hawking has made many contributions to theoretical physics, as the list of his wagers amply proves.

Tell that to sol, and then list Hawking's contribution to physics.

Care to address the points I raised? I've offered actual evidence--available to anyone who can read this thread--that your idea that dark matter is merely light being bent in such a way that it never reaches us is false. That's plain English and photographic proof, precisely what you asked for.

I presume you addressed this to Maartenn100, but omitted to include a quote from him to make it clear. I didn't say dark matter is bent light.

 

[Farsight]

Yes he does. He posted a correct derivation, using precisely correct GR, that explicitly contradicts your "physics stops at the horizon" assertion... I follow it just fine. What's your problem?

The Schwarzschild mathematics tells you something important, and when you disregard it you end up with a non-real solution.

I have a question for Farsight.

You're certainly trying to project the feeling of being so obviously and transparently correct, that your handful of opponents here must be unusually and especially moronic. You're so certain that their math is wrong that you can't even bother parsing it out to find the error.

I did some parsing out here. Then later in that thread I challenged you to point out another expression or repeat it. See this post. I said Point it out or repeat it and I'll knock it down like the rest of them. You didn't. I followed up on it asked you here saying where's this expression of yours but it was not forthcoming. I don't think you're moronic, ben. I think you're hubristic and dishonest.

What if that's true? That would require two failures: (a) that we're too stupid to derive it ourselves AND (b) you're incompetent to explain it in English, and untrained to explain it mathematically. But, Farsight, you've got years and years of internet trolling. Surely you've met at least one person who "understood you" in terms of (a), and who knows enough GR to overcome (b). You would remember such a person, right? Someone who said, "Aha! Farsight, you're right. Your falling-light-clocks argument invalidates equation X which Misner used in Y to derive Z, because the Reggeon doesn't have a Hopf fibration with an odd Hausdorff (i.e., math stuff you didn't understand but that you agreed with.)" Here's a suggestion. Whether or not Complexity, WC, RC, and myself are morons or not, you are definitely incompetent to explain your theory to us. All you need to do is go find the GR-math-conversant expert who agrees with you, and ask that person to explain your idea by proxy.

Yeah yeah. Only it isn't my idea. It was Oppenheimer and Volkoff's. Here's an article mentioning Oppenheimer. It's a fairly typical black hole article, it presents the point-singularity as a given. Note the paragraph that says this:

It wasn't until 1967 - nearly 50 years after the discovery of rs - that physicists Stephen Hawking and Roger Penrose showed that not only were black holes a direct result of general relativity, but also that there was no way of halting such a collapse.

Ever asked yourself whether they might have been wrong?

(Nothing wrong with this. Oliver Heaviside was a much better explainer of Maxwell's Equations than Maxwell himself was.)

No kidding, Heaviside mangled Maxwell's Equations.

(Oh, wait, what's that? You don't have a proxy who can express your argument in standard GR terminology? Of your crowd of non-moronic supporters-who-lurk-in-the-wings, NOT ONE ever went to college, took 40 credit-hours of GR, and used that knowledge to defend you? Why not?)

I stand on my own two feet. I express my argument using patent scientific evidence and English that everybody can understand. You can't counter it. Now stop wasting my time, because I'm on a promise to sol about the Vasser paper.

 

[Dinwar]

Get real, Dinwar. Scientific evidence and the scientific method is what defines science. Mathematics is a vital tool, but it isn't what physics is.

Yes. In the same way that the products of our culture make our culture, not the language. However, if you go to China and can't speak Manderin you're not going to get very far, and arguing "But your culture isn't your language!" isn't going to help.

And you don't understand the maths is no substitute for a sincere discussion about the evidence and what we can deduce from it.

It fundamentally precludes discussion. You DON'T KNOW HOW to talk about it.

Oh puh-lease, don't give me the laws of physics. I'm advocating the original "frozen star" black hole interpretation, not some my-theory tosh.

Arrogant smugness isn't an argument. I'm married to a woman with a degree in physics--trust me, I've experienced FAR better argument from smugness.

Since you seem incapable of being civil--or even really addressing the points being raised--I'm out.

 

[Farsight]

I've got a question for the physicists here: Let's say I'm in a ship and I fall into a black hole, normal to the event horizon. Let's say I also have two laser pointers--one pointed in the direction of motion, and one pointed in the direction I came (ie, outside the black hole). Outside the event horizon, the light would hit both walls. What would happen once I crossed the horizon?

You never do. Clinger and co will tell you that you cross the horizon in finite proper time. But this takes infinite coordinate time, and never happens. If you started your fall into the black hole a million years ago, you haven't crossed the horizon yet.

My intuitive understanding is that it would still hit both walls. Things CAN go in the opposite direction of gravity at lower than escape velocity, after all. I just want to be sure that my intuitive understanding matches what the physics says. And I figure a minor derail like this isn't too big of an issue.

At the horizon, the light is stopped, and you're stopped too. That's why the light pointing vertically upwards can't get out. It doesn't curve round, it doesn't slow down, it doesn't fall back. The light doesn't get out because (for observers in the universe at large like me and sol and ben etc) the coordinate speed of light at that location is zero. Hence it's a "frozen star", this label dating back to Oppenheimer's time. A modern variant is gravastar, have a look on arXiv for papers. Note that the gravastar features "a void in the fabric of space and time", and so is even more of a hole than the point-singularity interpretation.

 

[Farsight]

Yes. In the same way that the products of our culture make our culture, not the language. However, if you go to China and can't speak Manderin you're not going to get very far, and arguing "But your culture isn't your language!" isn't going to help.

It fundamentally precludes discussion. You DON'T KNOW HOW to talk about it.

Arrogant smugness isn't an argument. I'm married to a woman with a degree in physics--trust me, I've experienced FAR better argument from smugness.

Since you seem incapable of being civil--or even really addressing the points being raised--I'm out.

I'm the civil one here, Dinwar. Read back through the thread, check it out. Tell your wife what I've said. Discuss it with her.


Sol: sorry, I have to go. I haven't looked at that 1997 Matt Visser paper. See my post above where I mentioned the gravastar. And note that Matt Visser's most recent paper appears to be a gravastar paper:

http://arxiv.org/find/grp_physics/1/au:+visser_matt/0/1/0/all/0/1

 

[Ziggurat]

You never do. Clinger and co will tell you that you cross the horizon in finite proper time. But this takes infinite coordinate time, and never happens. If you started your fall into the black hole a million years ago, you haven't crossed the horizon yet.

It's only infinite coordinate time in certain coordinate systems (like Schwarzchild coordinates). But in other coordinate systems (such as Kruskal–Szekeres coordinates), it happens in finite coordinate time as well. There isn't any reason to think that Schwarzchild coordinates are really more fundamental than other coordinates. In fact, given that the event horizon is a coordinate singularity in the Schwarzchild metric even though it's not a geometric singularity, there is in fact good reason to prefer other coordinates which do not have a coordinate singularity at the event horizon.

 

[Zeuzzz]

Posting in the science section when drunk is never advised ...

Nope, wrong again. First off, please tell us what you think black means in this context. Then I'll tell you why you're wrong, and explain the real answer. Or alternatively, if you confess that you don't know the answer, I'll just tell you.

Black is just one frequency of the EM spectrum responsible for visible light. Black body means it absorbs all local radiation, true for a black hole unless incident radiations λ > its radius.

 

[Ziggurat]

Black is just one frequency of the EM spectrum responsible for visible light.

Not even close.

Black body means it absorbs all local radiation, true for a black hole unless incident radiations λ > its radius.

Almost. Black means it absorbs all incoming radiation. Unlike the non-technical definition, it does NOT mean that it does not emit any radiation.

The sun is almost black.

 

[dafydd]

Not even close.



Almost. Black means it absorbs all incoming radiation. Unlike the non-technical definition, it does NOT mean that it does not emit any radiation.

The sun is almost black.

Perhaps Zeusss should investigate Max Planck and the ultraviolet catastrophe.

 

[Zeuzzz]

Not even close.

In what context are you looking for the definition of black then?

 

[Vorpal]

In no context does "black" mean some frequency of the EM spectrum responsible for visible light. Even as a possible misunderstanding caused by a term from one context misapplied to another, it makes no sense.