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>Like you said, what if "suddenly a black hole appeared?" > >Well, the answer of course is that that never happens, ever. Can't it, though? It would be extreme
by mistercow 13y ago
>Like you said, what if "suddenly a black hole appeared?"
>
>Well, the answer of course is that that never happens, ever.
Can't it, though? It would be extremely unlikely, but pairs of particles and antiparticles pop into existence constantly. Again, it would be so unlikely as to be of only academic concern, but as I understand, it is technically possible that ~10^57 of antiparticles could pop up all over the universe, while their corresponding trillions of particles all popped into existence right inside the sun.
Presumably, in that so-rare-that-it-definitely-won't-happened case, it would take 8 minutes for us to be able to detect that the sun had doubled in mass.
- aidenn0 13y agoThat can't happen without them annihilating very quickly. Otherwise it would be violating conservation of mass.
- mistercow 13y agoThe particles do annihilate, but they don't have to annihilate with each other. If an electron/positron pair appear, the positron can annihilate a different electron, in which case the electron appears to jump. So if the pairs appeared light years apart, the antiparticles would annihilate something nearby, leaving their partners in the sun, as if particles were spontaneously jumping from all over the universe into the sun. Preposterous, yes, but as far as I understand, not actually impossible.
- davedx 13y agoWhat about Hawking radiation? [1] Then one of the pair escapes and the other falls into a black hole. [1] http://en.wikipedia.org/wiki/Hawking_radiation http://en.wikipedia.org/wiki/Hawking_radiation
- Filligree 13y agoThat reduces the mass of the black hole. Effectively, you have a particle tunneling out of the hole, mass is still not appearing from nowhere.
- jheriko 13y agodoesn't the 'big bang' violate this completely? i feel any fundamental theory must violate the conservation of mass as we perceive it in order to explain existance (not to say that it isn't a very good approximation with a true underlying conservation law)
- mistercow 13y agoAs I understand, the main hypothesis for how the big bang does not violate energy conservation is the zero-energy universe hypothesis: http://en.wikipedia.org/wiki/Zero-energy_universe http://en.wikipedia.org/wiki/Zero-energy_universe The general idea is that negative energy due to gravity (this is hard to wrap one's head around) perfectly cancels out all of the energy in the universe (including energy in the form of mass).