Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: DoctorBeaver on 11/05/2005 17:25:42
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If energy & mass are the same thing in different forms & mass is just energy "locked up", is it theoretically possible for a black hole to form from energy alone? Or how about a photonic black hole? I believe it's possible for a photon to produce gravity, so if there were enough could they produce a block hole?
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No thoughts on this, then?
It wasn't me - a big boy did it & ran away
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Possibly, although I would have thought that at the energy densities in a black hole you would start forming particles when the photons interacted with the virtual particles of the vacuum.
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There *are* suspicions about micro black holes formed in the upper layers of our atmosphere under the impact of high-energy cosmic particles:
http://www.absoluteastronomy.com/encyclopedia/m/mi/micro_black_hole.htm
here's a bit more serious one:
http://www.shef.ac.uk/content/1/c6/01/38/17/researchsummary.pdf
mind you that virtual particles from vacuum decay interacting with normal photons would IMO lack the necessary energy requirements, for that you'd have to upscale to either accelerator or upper atmosphere, which is no picnick area either.
The living are the dead on holiday. -- Maurice de Maeterlinck (1862-1949)
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This is an area of current research, so stay tuned for further developments. 4-D Q-M predicted the microscopic black holes were too massive to be formed by accelerators or any process in the universe today. Primordial microscopic black holes would have evaporated long ago, although one class of black hole may be evaporating in this epoch, and may be responisble for some cosmic ray bursts.
Now 11-D string theory predicts that as the size of the black hole gets as small as the size of the "curled-up" dimensions, the gravity grows with an inverse-9 law instead of an inverse-square law. Then the mass/energy required to form the black hole is many orders of magnitude less than traditionally thought. It is nearly within the reach of the Fermilab accelerator. Soon experimenters will attempt to produce black holes.
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Interesting. The reason I asked this question is that I got to wondering if someone produced an unimaginably large atom bomb (many millions of stellar masses), could the explosion of energy create a black hole that would keep the explosion in? I realise that the creation of such a bomb would be impossible, but what does theory say about it?
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Interesting idea but you would have to compress matter loads to make a light black hole? I think the only way you are likely to do this is by equal and opposite reaction, throw stuff outwards so that the stuff in the middle moves inwards. So most of the explosion is going to escape anyway.
Also unless your bomb is of a mass similar to a star I think the black hole is going to be so light that it will evaporate due to hawking radiation pretty quickly - giving a result a bit like an explosion...
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quote:
Originally posted by DoctorBeaver
Interesting. The reason I asked this question is that I got to wondering if someone produced an unimaginably large atom bomb (many millions of stellar masses), could the explosion of energy create a black hole that would keep the explosion in? I realise that the creation of such a bomb would be impossible, but what does theory say about it?
I think theory says creation of such a bomb is impossible. Stars don't get much larger than 10 stellar masses. The compression of the material due to gravity starts nuclear reactions. A million-stellar mass of hydrogen would collapse into a black hole under its own weight.