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Author Topic:   Black Holes Don't Exist
Percy
Member
Posts: 15646
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.5


Message 1 of 174 (737664)
09-25-2014 8:28 AM


Black holes don't exist, or at least so says physics professor Laura Mersini-Houghton in a paper submitted to the non-peer reviewed online journal ArXiv: Back-reaction of the Hawking radiation flux on a gravitationally collapsing star II: Fireworks instead of firewalls

Mersini-Houghton and co-author Harald P. Pfeiffer claim their computer simulations (they never use the term computer simulation but just refer briefly to "our program" in passing in the abstract, and the term "simulation" appears a couple times in the paper) show that as a collapsing star shrinks below its Schwarzschild radius that a burst of Hawking radiation "slows down the collapse of the star and substantially reduces its mass thus the star bounces before reaching the horizon."

I'm not clear on what the authors think remains behind after a supernova if not a black hole, but their research supports Stephen Hawking's recent announcement that black holes are actually grey holes with a chaotic and very hot event horizon from which energy escapes. Hawking suggests a changing event horizon subject to quantum fluctuations inside the black hole, a sort of "grey area," hence the term grey hole.

I wasn't able to find an article addressing how this research squares with the observational evidence of massive black holes at the center of most galaxies, including our own. Is this new research consistent with a quiet black hole, which is evidently the state of the Milky Way's black hole?

Where are Cave Diver and Son Goku when you need them?

--Percy


Replies to this message:
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 Message 30 by zaius137, posted 11-11-2014 2:17 AM Percy has acknowledged this reply
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Message 2 of 174 (737666)
09-28-2014 7:29 AM


Thread Copied from Proposed New Topics Forum
Thread copied here from the Black Holes Don't Exist thread in the Proposed New Topics forum.
    
Admin
Director
Posts: 12517
From: EvC Forum
Joined: 06-14-2002
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Message 3 of 174 (737667)
09-28-2014 7:30 AM


Apologies for Promoting My Own Thread
I seem to be the only active moderator this weekend.

--Percy
EvC Forum Director

    
mike the wiz
Member
Posts: 4600
From: u.k
Joined: 05-24-2003


(2)
Message 4 of 174 (737670)
09-28-2014 8:32 AM
Reply to: Message 1 by Percy
09-25-2014 8:28 AM


Where are Cave Diver and Son Goku when you need them?

I can't say of the latter, but the former will undoubtedly be down some black hole, I imagine.

Apologies in promoting my own thread

See, I'm rubbing off on you.

(I know, I know, off-topic, don't worry, like an irksome fly, I shall now buz-off.)


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nwr
Member
Posts: 5530
From: Geneva, Illinois
Joined: 08-08-2005


Message 5 of 174 (737685)
09-28-2014 12:56 PM
Reply to: Message 1 by Percy
09-25-2014 8:28 AM


Black holes don't exist, or at least so says physics professor Laura Mersini-Houghton in a paper submitted to the non-peer reviewed online journal ArXiv: Back-reaction of the Hawking radiation flux on a gravitationally collapsing star II: Fireworks instead of firewalls

I found this interesting.

I have seen several reactions to it, but none of them are definitive. Everyone seems to think that this will need more time and investigation.

No particular surprise here. I have tended to think of black holes as theoretical entities awaiting better empirical evidence.

As for the Milky Way -- there's lots of gravity, but that's not enough to be sure that there's a black hole.

I seem to be the only active moderator this weekend.

I was noticing that this seemed to be taking a long time for promotion. If I were still an admin, I would have promoted it in an instant. I haven't seen any moose activity lately. Phat has been around, but probably sees this as outside his sphere.

Fundamentalism - the anti-American, anti-Christian branch of American Christianity

This message is a reply to:
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NoNukes
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Posts: 9741
From: Central NC USA
Joined: 08-13-2010
Member Rating: 3.1


Message 6 of 174 (737687)
09-28-2014 1:20 PM


Is this new research consistent with a quiet black hole, which is evidently the state of the Milky Way's black hole?

Million solar mass black holes might still be consistent.

As I understand it, the analysis applies to the process of stellar collapse after a supernova, and is a prediction that too much energy escapes during collapse to leave a true black hole.

I would not think that the results would apply to the formation of a large black hole by the coalescing of large numbers of neutron stars and grey holes if that is indeed what supernova produce.

The other issue is that the results seem to me to be inconsistent with observation. Black holes are confirmed by making estimates of the mass of collapsed objects. Surely any produced radiation has escaped and is not part of the estimate.

What could a 5 solar mass, non-radiating object be if it is not a black hole?


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei

If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass


    
NoNukes
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Posts: 9741
From: Central NC USA
Joined: 08-13-2010
Member Rating: 3.1


Message 7 of 174 (737696)
09-28-2014 3:06 PM
Reply to: Message 5 by nwr
09-28-2014 12:56 PM


As for the Milky Way -- there's lots of gravity, but that's not enough to be sure that there's a black hole.

Lot's of gravity from a small non-radiating region should be enough. And if that description cannot be verified to apply to the Milky-way, it does appear to apply to other galaxies. What could such a region be if not a black hole?


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei

If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass


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Colbard
Member (Idle past 864 days)
Posts: 300
From: Australia
Joined: 08-31-2014


Message 8 of 174 (739534)
10-24-2014 8:40 PM


Black Holed theory
So black holes exist or don't exist due to an agreed consensual opinion?

...


Replies to this message:
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Taz
Member (Idle past 764 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 9 of 174 (739563)
10-25-2014 7:28 AM
Reply to: Message 8 by Colbard
10-24-2014 8:40 PM


Re: Black Holed theory
We don't know for sure, therefore all science is crap and we should just follow the holy bible.
This message is a reply to:
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Colbard
Member (Idle past 864 days)
Posts: 300
From: Australia
Joined: 08-31-2014


Message 10 of 174 (739604)
10-25-2014 6:56 PM
Reply to: Message 9 by Taz
10-25-2014 7:28 AM


Re: Black Holed theory
"We don't know for sure"
But we definitely know who is wrong?
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nwr
Member
Posts: 5530
From: Geneva, Illinois
Joined: 08-08-2005


Message 11 of 174 (739636)
10-26-2014 12:42 AM
Reply to: Message 10 by Colbard
10-25-2014 6:56 PM


Re: Black Holed theory
But we definitely know who is wrong?

I think your sarcasm detector is broken.

Fundamentalism - the anti-American, anti-Christian branch of American Christianity

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Colbard
Member (Idle past 864 days)
Posts: 300
From: Australia
Joined: 08-31-2014


Message 12 of 174 (739637)
10-26-2014 3:20 AM
Reply to: Message 11 by nwr
10-26-2014 12:42 AM


Re: Black Holed theory
No, I know what sarcasm is, but I don't see the need to be sarcastic in return.
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Taz
Member (Idle past 764 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 13 of 174 (739944)
10-29-2014 7:48 PM
Reply to: Message 12 by Colbard
10-26-2014 3:20 AM


Re: Black Holed theory
The fact of the matter is science is very unreliable. Today, they say one thing. Tomorrow, they will say another. The ever changing nature of science makes it useless. There is absolutely nothing useful that has come from science.

Religion, on the other hand, is completely reliable because of its never changing nature. God has given us everything from cars to computers. I thank god everyday we continue to pray our diseases away and burn witches to keep evil from spreading. Perhaps we should add scientists to the fire-able bunch?


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Son Goku
Member
Posts: 1074
From: Ireland
Joined: 07-16-2005


(3)
Message 14 of 174 (739954)
10-30-2014 7:38 AM
Reply to: Message 8 by Colbard
10-24-2014 8:40 PM


Re: Black Holed theory
No of course. Nobody is saying that and I'm not sure what would make you think so.

The point rather is that observational evidence of super-dense objects in our galaxy shows that there are objects extremely like black holes in existence. However there is still some ambiguity in the observations and they might simply be very very dense stars. There are a couple of features of the observed objects (their high rate of rotation for example, which would rip a star apart) which make this unlikely, but it still might be the case.

So for the past two/three decades people have gone back to the mathematics to see if the equations themselves predict black holes or not. The Black Holes originally discovered in General Relativity between 1915-1950 are highly symmetric objects that seemed to require very special conditions to exist, too special to be likely to occur in reality.

In the 1960s however Hawking and Penrose discovered that General Relativity predicts that black holes form under generic conditions, even the typical collapse of a star.

However their proof approximates matter as completely classical, even though we know matter is quantum mechanical.

Since then, there have been papers trying to investigate if black holes still form even when the matter is treated as quantum mechanical.

Since the analysis is so difficult, nobody has been able to completely prove if black holes still form or not. Although the evidence points to the fact that they do.

The authors of this paper went further with the analysis of one aspect of stellar collapse with quantum matter than previous papers. They very accurately modeled the vacuum back-reaction. This is where a stream of particles are created from nothing due to the stars distortion of spacetime changing the definition of "empty"*. These extra particles seem to halt the collapse, although I know that there are approximations in the authors' calculations that others have questioned, so their paper isn't conclusive. Also note that they only accurately modeled one aspect of quantum matter (the vacuum back-reaction).

*Yes, distorting spacetime actually changes the meaning of "empty" or "devoid of mass-energy". A quantum field derives its definition of empty/vacuum/void from the spacetime around it. So initially the quantum field is in some state and it "queries" the spacetime as to the physical content of its state. The spacetime "returns" the result "that's a vacuum state". However if the spacetime changes it might return "That's a state of ten particles".

The quantum field and its state/confirguration haven't changed, just their value. Sort of like a Microsoft office block might just sit there unchanged, but its value can increase due to stock fluctuations. The quantum field in the same state is suddenly "worth" more particles and hence they exist. I want to stress they are not created from pre-existing energy.


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Colbard
Member (Idle past 864 days)
Posts: 300
From: Australia
Joined: 08-31-2014


Message 15 of 174 (739955)
10-30-2014 7:39 AM
Reply to: Message 13 by Taz
10-29-2014 7:48 PM


Re: Black Holed theory
So this forum is a place for asps to vent their frustrations?

Perhaps you would like to share some of your problems... I'm listening.


This message is a reply to:
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