what about a black holes surface temperature (read details)?

for having an idea....
a black hole has a surface which must not necessarily be the same as the diameter of its event horizon.
This is (as far as i know) depending on the BH size and should make it possible for certain types of BH to have some Space between EH and surface.

So ok we can't observe the surface...
what will happen if this surface get heated up, lets say by infalling matter in hughe ammounts (neutron star or bigger).
Is it heating up ? will it do so ?
or not ?
and if so CAN it heat up endlessly ?

Mercury 20102007-07-12T15:15:58Z

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wow. you really like black holes don;t you?

the heat would be devoured like the rest of energy and matter.

all that light and matter inside a black hole beign compacted has to create some kind of massive levels of heat, it just can't escape into our universe

I'm sure it adds upon itself, but reality is so multilated and compacted, I don't know if heat could even still have a normal effect.

I think there are universes inside a black whole. and in those universes, matter and energy from the black hole are released to create big bangs.

quantumclaustrophobe2007-07-12T22:23:56Z

Well... from what *I* know about black holes - they're all essentially dimensionless points. They occupy zero space. God divided by zero, and got the black hole.

Now, the only indication to how massive a black hole really is can be seen by how big the diameter of the event horizon is. The event horizon is the border of 'normal' space, and the realm of the black hole.

Figure: if Earth were to collapse to a dimensionless point, a black hole would form, with an event horizon of about 1/2 the size of a golf ball. For Jupiter, again - the actual mass would be a single quantum point in space, but the event horizon would be about 30 feet in diameter.
The event horizon is the point out in space where the orbital velocity of the black hole is the speed of light. Doesn't matter how 'big' the black hole is (because none of 'em have a true size) but the location of the EH is directly dependend on how much mass the black hole contains.

As for heating... When a black hole forms, it's the core of a star, and it's super-hot - say, 60 million degrees. For one thing, electromagnetic energy can't escape the black hole. (At least, it can't escape the EH), and for another, the surface area of a black hole is nearly (or is) non-existent - meaning, heat **can't** escape.

After our sun finishes it's red giant phase while dying, and blows off it's outer layers, a super-hot white dwarf about the size of the Earth will remain; it'll gradually cool - but it's cooling will be MUCH slower because of it's small size. Now, imagine a black hole that has *no* size - it will be likely hot forever.

Anonymous2007-07-18T04:23:37Z

I am not sure to understand the BH theory but I believe that they are a point or a flat disk. I don't understand how a surface exist there. The temperature is the moving of particles, but as the BH have no volume, nothing can move there. Probably the matter irradiates most of the heat before reach the EH and the remaining heat becomes kinetic energy (the BH spin) .
The matter falling to a BH (but outside the EH can be heated to a high temperature so the radiation removes fast most of the heat.

johnandeileen20002007-07-16T16:37:34Z

This is a great question! I can't come up with any way to explain how a space could exist between the event horizon and the surface. To me the temperature of a black hole while in a state of not absorbing more matter must be close to absolute zero because there is no activity whithin it. However if it is impacted by a large mass of neutrons there has to be thermal activity, if none this radiation can escape it must be because it absorbed quickly by the tremendous mass of the black hole. There is no way that it can heat up endlessly. If a giant star in the neighbourhood of a black hole could, somehow, collapse into a mass of anti matter and be pulled into a black hole, that would be a very interesting thing to observe, it could be the mother all exlosions.

cosmo2007-07-12T23:06:31Z

The classical "black hole" solution to the equations of general relativity is a vacuum everywhere, except for the infinitely dense singularity at the center. If you fell in from a distance, you would never see any surface, or indeed anything nearby at all as you fell in, although if you looked back on the outside universe it would get faster and faster and brighter and brighter. There would be a flash due to external radiation as you passed the event horizon.

A star that collapses to form a black hole is a different matter. There is an inwardly-moving surface, and if the star still has some internal pressure you might be able to catch up to it. The surface will fall into the singularity, and you'll fall in after. The star will heat up as it is compressed, to the extent that it still has some internal pressure.

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