We Will Never Know What's Inside A Black Hole!

a reply to: Arbitrageur

No longer a need for an event horizon. Just read this a while ago. This days essentially black holes would have a surface and not an endless pit. Of this is true you could walk on the surface of a super massive blackhole.
www.quantamagazine.org...

a reply to: dragonridr
I can agree with one statement in that article:

Polchinski remains staunchly agnostic: “All bets are off; everything is open for discussion.”

The video in that article is almost correct, but it talks about black holes evaporating which for black holes larger than the moon's mass probably won't happen for trillions of years due to radiation absorbed from the CMB being greater than Hawking radiation emitted.

I find that many experiments confirm relativity, and quantum mechanics. How many confirm string theory? None?

Depending on how you define event horizon, I don't see how anybody can say there isn't one, it seems like a claim that's false by definition. What that term means to me is the calculated value of the Schwarzschild radius within which the escape velocity would be greater than the speed of light. I see nothing in that article which abolishes this notion for a black hole that at some point the escape velocity is faster than light. If someone substitutes math other than relativity so they claim it's not calculated as the Schwarzschild radius, there must still be some kind of boundary where escape velocity is greater than c or it's not a black hole, right?

I'm open to the idea that boundary may not be perfectly spherical but I still think it's got to be pretty close to that, maybe it's a little fuzzy as some people have claimed. So I can't state the nature of the event horizon, or exactly what happens there, or how fuzzy it is, but I'm pretty sure there has to be something like it as explained above, because if there isn't, it's not a black hole as far as I can tell. I'll be very surprised if the Schwarzschild radius calculation turns out to be very far off, though I admit it's possible.

I won't be surprised at all if the interior of the black hole is fuzzy, in fact I expect that because the singularity calculation seems like a breakdown in the theory of relativity instead of a prediction which can be trusted.

I suppose one thing we could do is send a probe to a black hole and see if it can detect hawking radiation or not, but it would need a warp drive to give us results on a human time scales if we sent it to the black hole at the center of our galaxy. Some of the other questions are harder to answer since a probe entering the black hole wouldn't be able to send information out.

Does a black hole even have an interior? To me, it seems that the gravitational time dilation below the event horizon will be infinite, and will stop the collapse into a singularity. At the event horizon, the physical reality simply stops.

originally posted by: wildespace
Does a black hole even have an interior? To me, it seems that the gravitational time dilation below the event horizon will be infinite, and will stop the collapse into a singularity. At the event horizon, the physical reality simply stops.

That's if you're looking at someone else fall in, you see their time slow down and eventually the light from them gets so red-shifted you can no longer see it so you never see them cross the event horizon.

But if you're the person falling in, it's a different story. Time passes normally for you, right through the event horizon, if the black hole isn't feeding on infalling material in which case the radiation from that would probably kill you. So you can't make a blanket statement like you did about what happens to time. Time is relative.

Though as I said in my previous post I agree with the sentiment that "everything is open for discussion" regarding black holes, a subject where we have some theoretical gaps and not enough observations.

a reply to: Arbitrageur

Physics has been working real hard to get rid of the cingularity. Because none of the equations works including the big bang.

as I currently understand it, BH cannot evaporate. And its not a singularity per se. Space-time sill there. Black holes can merge and it says something.
In current state they lead to nowhere. But they will merge eventually into one massive BH which would explode into new universe, where space and time again would free itself from constrains releasing energy that kept it (space time) together once threshold is reached. Time arrow ensures it does not explode into same set of dimensions.
I meant does not fire back*
))


D0.

Oh cmon we know a black home leads to a white whole or what we call the big bang. Even micro black holes everywhere lead to big bangs!

This the universe is infinate everywhere, just think of superposition and the big bang, its truly everywhere.

originally posted by: darkorange
as I currently understand it, BH cannot evaporate. And its not a singularity per se. Space-time sill there. Black holes can merge and it says something.
In current state they lead to nowhere. But they will merge eventually into one massive BH which would explode into new universe, where space and time again would free itself from constrains releasing energy that kept it (space time) together once threshold is reached. Time arrow ensures it does not explode into same set of dimensions.
I meant does not fire back*
))


D0.

You lost me in fact black holes do evaporate. As far as the singularity we don't know.

originally posted by: dragonridr
You lost me in fact black holes do evaporate.

Theory says they will eventually, but it's not happening yet because the smallest black holes we know of are between 2-3 solar masses and a black hole would need to have less mass than the moon to evaporate under present conditions with the Cosmic Microwave Background at 2.7K. A black hole with the mass of the moon would absorb more radiation from the 2.7K CMB than it emits.

Black Hole

To have a Hawking temperature larger than 2.7 K (and be able to evaporate), a black hole needs to have less mass than the Moon.

There is some evaporation going on, in the sense of using your blow dryer on your hair while you're in the shower, but no NET evaporation of the massive black holes we know about.

If there are any black holes with less mass than the moon they could evaporate now, but we've never found any that small and according to some models even our own sun won't form a black hole when it dies, stellar black holes supposedly need to be at least 2 solar masses.

If we create a micro black hole in the LHC, it might evaporate instantly. We haven't done that yet either but it's a possibility.

As the CMB continues to cool to lower and lower temperatures below 2.7K, larger and larger black holes will be able to evaporate.

a reply to: Arbitrageur

Well thanks for the info. I guess I was wrong. Sorry It took so long to get back to you.