Black holes

[quantumcrack]

If black holes suck in energy, would the particles of matter and the energy particles mingle???

And would highly reactive gases collide and affect the space time continuant??????

[Sayonara]

What do you mean by "mingle"?

 

I can't think of any possible meaning of the word that fails to apply outside black holes.

[quantumcrack]

Sayonara,

You must not understand anything i have said,

what i mean is to react!!!

[Ophiolite]

React in what way? A black hole is a singularity. The density of matter in a stellar black hole may not be infinitely dense, but it is, arguably, unimaginably dense. Any distinction between 'particles' has been obliterated, so what are you actually asking?

[J.C.MacSwell]

React in what way? A black hole is a singularity. The density of matter in a stellar black hole may not be infinitely dense, but it is, arguably, unimaginably dense. Any distinction between 'particles' has been obliterated, so what are you actually asking?

 

If you travelled past the horizon of a large enough black hole you would still be alive and functioning. Correct?

[Sayonara]

Sayonara' date='

You must not understand anything i have said,

what i mean is to react!!![/quote']

Clearly I don't, and I'm not sure that it's my problem.

[Ophiolite]

If you travelled past the horizon of a large enough black hole you would still be alive and functioning. Correct?

I'm on very shaky ground here. That was why I specifically specified a stellar black hole. You would be torn apart by the tides, because the gravitational force would be dramatically different from one end of your body to the other. I'm sure someone here can do the math faster than it would take me to find the relevant equations, then check my answers a dozen times. (pretty please.)

However, how large did you mean. I believe some see the Universe as being a black hole, and we are alive and functioning inside it. Of course, we didn't fall through the event horizon.....

[J.C.MacSwell]

I'm on very shaky ground here. That was why I specifically specified a stellar black hole. You would be torn apart by the tides' date=' because the gravitational force would be dramatically different from one end of your body to the other. I'm sure someone here can do the math faster than it would take me to find the relevant equations, then check my answers a dozen times. (pretty please.)

However, how large did you mean. I believe some see the Universe as being a black hole, and we are alive and functioning inside it. Of course, we didn't fall through the event horizon.....[/quote']

 

Sorry, missed the "stellar".

[C60]

Did any of you guys ever hear of that theory that our universe was created by a black. It goes something along these lines since black holes suck in matter they would eventually gather a substantial amount of matter some people think that the matter would eventually have a rain drop effect like rain gather on the underside of your roof. They then go on to say that it would detach itself from the black hole and still be a singularity and then exploded therefore accounting for the big bang and how the universe first formed. I know that this does not explain how or where that matter came from in the first place but i dont know much about this theory

[quantumcrack]

If you travelled past the horizon of a large enough black hole you would still be alive and functioning. Correct?

No, you are not correct.

[J.C.MacSwell]

No, you are not correct.

 

The gravitational gradient at the horizon of a large enough black hole would be very slight.

 

So what is the concern?

[Johnny5]

However' date=' how large did you mean. I believe some see the Universe as being a black hole, and we are alive and functioning inside it. Of course, we didn't fall through the event horizon.....[/quote']

 

Who sees the universe this way, and why?

[Martin]

I agree with both Ophiolite and MacSwell, Ted Bunn is a distinguished relativist (familiar to people on sci.physics.research) and has an FAQ about it, the gist being:

 

falling thru the horizon of a million solar hole would be OK

 

but with a one solar mass hole the tidal force would be lethal

even before reaching the event horizon

 

Here is Ted Bunn FAQ

http://cosmology.berkeley.edu/Education/BHfaq.html

 

here is a relevant exerpt from it:

 

"What would happen to me if I fell into a black hole?

----------------------------------------------------

Let's suppose that you get into your spaceship and point it straight towards the million-solar-mass black hole in the center of our galaxy. (Actually, there's some debate about whether our galaxy contains a central black hole, but let's assume it does for the moment.) Starting from a long way away from the black hole, you just turn off your rockets and coast in. What happens?

 

At first, you don't feel any gravitational forces at all. Since you're in free fall, every part of your body and your spaceship is being pulled in the same way, and so you feel weightless. (This is exactly the same thing that happens to astronauts in Earth orbit: even though both astronauts and space shuttle are being pulled by the Earth's gravity, they don't feel any gravitational force because everything is being pulled in exactly the same way.) As you get closer and closer to the center of the hole, though, you start to feel "tidal" gravitational forces. Imagine that your feet are closer to the center than your head. The gravitational pull gets stronger as you get closer to the center of the hole, so your feet feel a stronger pull than your head does. As a result you feel "stretched." (This force is called a tidal force because it is exactly like the forces that cause tides on earth.) These tidal forces get more and more intense as you get closer to the center, and eventually they will rip you apart.

 

For a very large black hole like the one you're falling into, the tidal forces are not really noticeable until you get within about 600,000 kilometers of the center. Note that this is after you've crossed the horizon. If you were falling into a smaller black hole, say one that weighed as much as the Sun, tidal forces would start to make you quite uncomfortable when you were about 6000 kilometers away from the center, and you would have been torn apart by them long before you crossed the horizon. (That's why we decided to let you jump into a big black hole instead of a small one: we wanted you to survive at least until you got inside.)

 

What do you see as you are falling in? Surprisingly, you don't necessarily see anything particularly interesting. Images of faraway objects may be distorted in strange ways, since the black hole's gravity bends light, but that's about it. In particular, nothing special happens at the moment when you cross the horizon. Even after you've crossed the horizon, you can still see things on the outside: after all, the light from the things on the outside can still reach you. No one on the outside can see you, of course, since the light from you can't escape past the horizon.

 

How long does the whole process take? Well, of course, it depends on how far away you start from. Let's say you start at rest from a point whose distance from the singularity is ten times the black hole's radius. Then for a million-solar-mass black hole, it takes you about 8 minutes to reach the horizon. Once you've gotten that far, it takes you only another seven seconds to hit the singularity. By the way, this time scales with the size of the black hole, so if you'd jumped into a smaller black hole, your time of death would be that much sooner..."

[J.C.MacSwell]

Who sees the universe this way, and why?

 

If the Big Crunch Model is correct we can consider ourselves in a back hole.

[Martin]

Did any of you guys ever hear of that theory that our universe was created by a black [hole']...?

 

Yes, at least I am familiar with Lee Smolin's version of the theory. It is a very interesting theory and it has testable consequences.

 

It predicts, for example, that no neutron star will ever be discovered with a mass of greater than 3 solar masses.

 

So far, although people look for neutron stars and catalog them, they have not found one >3 solar, which would refute the theory.

 

HOW the theory happens to predict this upper limit on neutron star mass is complicated. If you want to read more there is a paper by Smolin called

"Scientific alternatives to the anthropic principle"(2004)

which discusses it.

 

I would caution you to be skeptical of this theory---Smolin has merely offered it for observational testing, not advocated it.

but some recent research on black holes (Bojowald 2005) actually adds credibility to the idea.

[quick silver]

If you travelled past the horizon of a large enough black hole you would still be alive and functioning. Correct?

 

yes for a while. the thought goes: when you travel into a black hole, you begin to lengthen and eventually your atoms will be ripped apart. this goes for all atoms that finds it's way into a black hole.

[quantumcrack]

To quicksilver,

your atoms wouldn't rip apart in my view, hence the theory of democratus

[ed84c]

yeh, but since einstein we know thats wrong.

 

Im pretty sure that if you stuck your leg in, and right on the event horizon it cut through half a nuleuce, and you had a jet pack of near infinate power, the atom would be ripped in part. You would just need enough energy to escape as it is to rip a nucleus in half.

[ed84c]

If black holes suck in energy' date=' would the particles of matter and the energy particles mingle???

And would highly reactive gases collide and affect the space time continuant??????[/quote']

 

Please dont use the word suck, it suggests some kind of vacuum cleaner model.

 

In reality a black hole is gravitationally speaking the same as the star it was made from, except if you fall into the roche limit, here rater than falling into a burning start you would fall inot the event horizon.