Thread: Blackhole

You would die.
Other than that, your body would be compressed into an infinitely small and infinitely dense singularity.

Crushing implies outward forces that act in on the object. You wouldn't be crushed if you were to encounter a black hole. A black hole is also not technically a hole. It's a mass that takes up less space than it previously had as a star (and what an understatement that is!). Because you can get so much closer to the mass's center of gravity now the force of gravity can grow immensely, so much so that there is a distance from it that visible light can no longer escape (and we call this distance from the center the "event horizon"), although there are other forms of radiation that a black hole can give off. Whether or not a black hole is a singularity (a point in space, dimensionless) or not is beyond me.

Originally Posted by Invader

Crushing implies outward forces that act in on the object. You wouldn't be crushed if you were to encounter a black hole.

"Crushing" might imply outward forces, but do you have a better word to describe that you get compressed to virtually nothing?

"Pulled" into virtually nothing, I suppose, since gravity is doing all the work. Gravity does pull.

black holes dont take yo anywhere once you get "sucked in", they just compress you, its basically just really really really strong gravity

Yeah you have to understand that black holes aren't really holes.

They're essentially just infinitely small points with infinitely high gravitational fields which crush anything which enters them.

They appear bigger than points, as black circles, because light gets sucked into them.

Originally Posted by Xei

They appear bigger than points, as black circles, because light gets sucked into them.

wow really?

although im probably misunderstanding what you said (as usual), and its probably not as amazing as im interpreting it.

Originally Posted by slash112

although im probably misunderstanding what you said (as usual), and its probably not as amazing as im interpreting it.

It is pretty amazing... According to general relativity the gravity is so strong that it bends spacetime in such a way that once you've entered the black holes, there are no way out. This is, from within a black hole no direction is outwards.

Yes there is a way out. Via hawking radiation. The way I understand it, annihilation between anti-particles and the particles inside the hole. Due to the creation of virtual particles in quantum vacuum.

Originally Posted by slash112

wow really?

although im probably misunderstanding what you said (as usual), and its probably not as amazing as im interpreting it.

Well it's obvious since the strength the force gravity increases gradually (into infinity). There must come a point between 0 and infinite newtons (?) where there is enough strength to stop the light from escaping - it is the fastest thing according to relativity. So there is an event horizon or a black sphere of doom around the point of infinite power .

Originally Posted by Bonsay

Yes there is a way out. Via hawking radiation. The way I understand it, annihilation between anti-particles and the particles inside the hole. Due to the creation of virtual particles in quantum vacuum.

That's not a way out, really. That's antiparticles going into the black hole, decreasing it's mass, until there's not enough mass left for it to continue to be a black hole, at which point it explodes (I think).

Originally Posted by khh

That's not a way out, really. That's antiparticles going into the black hole, decreasing it's mass, until there's not enough mass left for it to continue to be a black hole, at which point it explodes (I think).

Well it's the only way out. You must remember that at a point before you even reach the event horizon you cease to be. You die. Your body is stripped atom by atom.

So, asking if there was a way out is, in a way, the wrong question, because you cannot get in.

I haven't heard of it exploding, don't see why it would though. But I don't know.

Originally Posted by Bonsay

Well it's the only way out. You must remember that at a point before you even reach the event horizon you cease to be. You die. Your body is stripped atom by atom.

Yes, I'm certainly aware of that fact :p
But my point is that it's awesome, and that this is why light gets trapped in it. Because there's physically no way out.

Originally Posted by Bonsay

So, asking if there was a way out is, in a way, the wrong question, because you cannot get in.

No, no, you can get in. You just wouldn't survive the experience. But you - every particle in you, that is - could get in.

Originally Posted by Bonsay

I haven't heard of it exploding, don't see why it would though. But I don't know.

Well, when the gravity no longer is sufficient to keep the remaining mass in a singularity, it's got to expand, doesn't it?

how can light be effected by it? i thought electromagnetic radiation (in this case visible light) isnt effected by magnetic fields

Originally Posted by slash112

how can light be effected by it? i thought electromagnetic radiation (in this case visible light) isnt effected by magnetic fields

Magnetic? We're talking about gravitational fields... That's something else entirely.

Originally Posted by khh

Magnetic? We're talking about gravitational fields... That's something else entirely.

oh wait, woops, i dont think i meant to say that. infact i was talking a load of crap either way, i was thinking about something else, but that turns out to be the same thing as i said basically.

but put that aside, how can light be effected by gravitational fields?

You'd die before you even got near a black hole.

I watched a really cool documentary on black holes a long time ago. They said your body would stretch out, and for a while it would feel good, then you'd get pulled apart limb by limb...

But this would only happen I think if you were still on earth because of conflicting gravitational pulls.


Black holes are awesome...I want to touch one.

Originally Posted by slash112

but put that aside, how can light be effected by gravitational fields?

The idea is that gravity warps space (or timespace, that is) itself. So that the shortest way for the light to travel no-longer is in a straight line. But when there is as much gravity as a black hole, then timespace is warped back in on itself, in a way, which traps the electromagetic waves inside.

Originally Posted by khh

No, no, you can get in. You just wouldn't survive the experience. But you - every particle in you, that is - could get in.

I... as in my soul has nothing to do with my atoms. Rather it's the interaction between them which creates me. If I get close, at a certain point I will cease to exist, before I even reach the event horizon. So I stick by my claim - you can't escape, because you can't get in. What does it mean for existence of matter/energy inside the singularity, who knows? It must be something awesomely incomprehensible.

Originally Posted by khh

Well, when the gravity no longer is sufficient to keep the remaining mass in a singularity, it's got to expand, doesn't it?

Why? it's infinitely strong. If you take a chunk away, it will still stay infinitely strong.

Originally Posted by Bonsay

I... as in my soul has nothing to do with my atoms. Rather it's the interaction between them which creates me. If I get close, at a certain point I will cease to exist, before I even reach the event horizon. So I stick by my claim - you can't escape, because you can't get in. What does it mean for existence of matter/energy inside the singularity, who knows? It must be something awesomely incomprehensible.

No, no, I quite agree that your self would cease to exist before you got there.

Originally Posted by Bonsay

Why? it's infinitely strong. If you take a chunk away, it will still stay infinitely strong.

No, it's not infinitely song. Every black whole varies in diameter, after how much mass it has. It's just a lot of mass in one place, not an infinite amount.

he said infinitely strong not infinite mass

Originally Posted by slash112

he said infinitely strong not infinite mass

Well, yes, but the gravitational force is determined by the mass, and therefore it cannot be infinitively strong without infinite mass, which it doesn't have.

Originally Posted by khh

Well, yes, but the gravitational force is determined by the mass, and therefore it cannot be infinitively strong without infinite mass, which it doesn't have.

but it is also determined by the weight aswell, so say you were to have infinite gravitational feild strenght and infinite weight, you would get a mass of 1.

Originally Posted by khh

Well, yes, but the gravitational force is determined by the mass, and therefore it cannot be infinitively strong without infinite mass, which it doesn't have.

Then how is it that a singularity is infinitely small and infinitely dense?

Originally Posted by slash112

but it is also determined by the weight aswell, so say you were to have infinite gravitational feild strenght and infinite weight, you would get a mass of 1.

Uh... mass = weight. And you don't have infinite weight.

Originally Posted by Bonsay

Then how is it that a singularity is infinitely small and infinitely dense?

Uh, there's a certain point at which the forces inwards (gravity) gets bigger than the forces outwards, and a mass implodes. Beyond that I don't know. I'm not a physicist :p