Why black holes are "black"

[TheBigDog]

I am not a deep scholar of astro-physics, but I have a theory on why black holes are black. Feedback on this idea is appreciated...

 

It is said that the gravitational force of a black hole is so extreme that not even light can escape it. I disagree. I think that because of time dilution within the event horizon, the reason that there is no light coming out of the hole is because from our perspective there is no passage of time within the hole. Someone caught in the hole would not know that time had stopped, for them life proceeds at the same pace in an ever growing universe. It is just that there is a critical difference between time in the hole and time out of the hole so significant that they become incomprehensible to one another. What escapes from the hole is happening so slowly that we have no way of recognizing it. So it is not that no energy is escaping, just that the frequency slows to nearly zero.

 

Bill

[C1ay]

I am not a deep scholar of astro-physics...

 

It is said that the gravitational force of a black hole is so extreme that not even light can escape it. I disagree.

That is of course the reason given by Stephen Hawking, a deep scholar of astro-physics. How do your credentials compare with his?

[cwes99_03]

I believe you mean frequency (which is 1/T) goes to infinity. Hence the source creating the light would be sending out light waves that would never leave because time had stopped. Think about that for a second.

 

And I believe it was Einstein that first postulated that intense gravity would have enough of an effect to dialate (not dilute) time.

[Tormod]

Someone caught in the hole would not know that time had stopped, for them life proceeds at the same pace in an ever growing universe. It is just that there is a critical difference between time in the hole and time out of the hole so significant that they become incomprehensible to one another.

 

What would be causing the time dilation? And why would it just be apparent to people outside the black hole? What would the people inside the black hole see of the outside? Would it appear that the universe outside froze?

 

What escapes from the hole is happening so slowly that we have no way of recognizing it. So it is not that no energy is escaping, just that the frequency slows to nearly zero.Bill

 

I am not sure what frequency has to do with anything here. Since energy *is* evaporating from black holes, why is this energy coming out at all if time dilaton causes the passage of time to freeze? :shrug:

[TheBigDog]

OK, let me try this one more time (meaning that I just spent 30 minutes replying to this and lost it all with a bad keystroke).

 

That is of course the reason given by Stephen Hawking, a deep scholar of astro-physics. How do your credentials compare with his?

 

I have never read any of Prof. Hawking's work. In fact I am more familiar with his work as an actor than as a scientist. Although I have never seen him in a role other than playing himself. I am familiar with his reputation as one of the world's foremost thinkers on the somewhat speculative subject of black holes. I also figure he is pretty good at math.

 

I was captain of the math team my senior year of high school. And my 8 year old thinks I am the smartest person in the world. I leave it up to you to compare the credentials. However that works out, it doesn't change the fact that I have as much PRACTICAL experience with black holes as anyone. If I am wrong in what I am thinking I am sure I will find that out here if anywhere.

 

I believe you mean frequency (which is 1/T) goes to infinity. Hence the source creating the light would be sending out light waves that would never leave because time had stopped. Think about that for a second.

 

And I believe it was Einstein that first postulated that intense gravity would have enough of an effect to dialate (not dilute) time.

 

That is almost it. I am saying that light (energy) is coming out of the black hole. I don't believe that time stops in the hole. It just becomes incredibly slow. So slow that the nature the "light" which escapes is not recognizable to us. I am trying to stay with what I understand from Einstein, and may have used a wrong word in my description.

 

What would be causing the time dilation? And why would it just be apparent to people outside the black hole? What would the people inside the black hole see of the outside? Would it appear that the universe outside froze?

 

I am not sure what frequency has to do with anything here. Since energy *is* evaporating from black holes, why is this energy coming out at all if time dilaton causes the passage of time to freeze? :shrug:

 

I was thinking about the perspective from inside the hole when I wrote the post, but deleted what I typed because I was unhappy with the way it was expressed. I am still thinking about that, and I don't know if it would ever be provable in any event. But for the sake of our conversation, inside the whole you would see the event horizon as the edge of the universe. You would perceive the hole as a rapidly exploding/expanding universe. For the second point, I am proposing that time never actually stops. It just get very slow, and at a certain point near zero there is a fundamental change where "light" becomes dark.

 

Bill

[C1ay]

I have never read any of Prof. Hawking's work. In fact I am more familiar with his work as an actor than as a scientist. Although I have never seen him in a role other than playing himself. I am familiar with his reputation as one of the world's foremost thinkers on the somewhat speculative subject of black holes. I also figure he is pretty good at math.

I think maybe you should browse these results. He is considered one of the world's leading theoretical physicists. He is also the Lucasian Professor of Mathematics at Cambridge, the same chair held by Issac Newton, "pretty good at math" is a bit of an understatement. Some of his lectures are here if you'd like to get familiar with his work as a physicist.

[TheBigDog]

C1ay, I took the time today to read two of Prof Hawkings lectures. I found them to be very interesting and educational. And they had a levity to them that I didn't expect.

 

I believe that he is on the right track with most of what he is saying. However there are some generalities that he makes that I don't think play out. He is making an argument about how black holes prevent determinism because everything that enters a black hole in any form exits as uniform radiation. Are we to accept that at face value? There were no supporting arguments, just that assertion. What evidence is there that there are no distinguishable characteristics to "things" within a black hole?

 

Another point he made is that over time black holes will ... uh... dissolve? The reasoning as I understand it is that there are virtual particles near the influence of the hole. These virtual particles are in pairs that in the normal course of events would cancel each other out and cease to exists. But because they are near the influence of the hole some of the pairs would be split apart, with one half going into the hole, and the other half hurtling into space. When the half not in the hole is observed it will appear to have come from the hole. He indicates that this constant emission of energy by the hole would eventually reduce it to nothing. There are two parts of this that I don't understand...

 

1) While the particles appear to be coming from the hole, they in fact are not. If the cause of the radiation is as he describes then there is an equal quantity of particles being absorbed as radiated. So the hole would in fact be getting bigger as it radiates.

 

2) If the hole is getting smaller, it would eventually reach an point where it would still have huge mass, but would cease to be a black hole. The gravity would be insufficient to maintain the "singularity". What happens to the hole, and the space/time under its influence when this "unblack" phase is reached?

 

The Uncertainty Principal does not allow for time to stop within a black hole. If time were actually stopped in the hole then we would know the precise location and speed of every particle within the hole. Stopping time would require an energy even beyond the capability of a black hole. Like the amount of energy required to accelerate an object to the speed of light.

 

A question for you mathmaticians... how big does a number need to be for you to leap to calling it infinity? Does infinity as a quantity exist in nature? And if it doesn't exist, in nature, then why do we apply it to naturally occurring phenomena?

 

Bill

[cwes99_03]

Well, considering how no one has ever actually proven that Black Holes (or even that there are Black Holes to an absolute) radiate anything, it is all suposition. Or have I missed some huge scientific discovery of Hawking Radiation?

[lindagarrette]

I think maybe you should browse these results. He is considered one of the world's leading theoretical physicists. He is also the Lucasian Professor of Mathematics at Cambridge, the same chair held by Issac Newton, "pretty good at math" is a bit of an understatement. Some of his lectures are here if you'd like to get familiar with his work as a physicist.

 

Thanks for the link. Great lecture on Quantum Cosmology. Wish and hope for more up to date info.