robsharp14 said:one more question. if god exists what is he made of,and how can he survive the big crunch?
From Stephen Hawking, of course :tongue:robsharp14 said:question, where does hawking radiation come from?
Naty1 said:there are different views about the precise origin or Hawking radiation, but I think there is general agreement that quantum fluctuations are the ultimate source.
Extremal black holes, at absolute zero, apparently do not radiate...these are as far as I understand theoretical constructs...in fact I don't believe we have absolute observational evidence for any black holes yet...
Black holes could be detected by observing their gravitational effect on their surroundings. Gravitational lensing, in which the black hole's gravity distorts the light from sources behind it, is one way. Also, by measuring the energy of the radiation from accretion discs, one can infer the existence (and mass) of the black hole. This second method is more indirect than the former, however, just because we can't use light to 'see' a black hole, this does not mean that they are undetectable in principle.TubbaBlubba said:Wouldn't black holes BE unobservable by definition? The fact that we have things that act as theories on black holes predict, including unobservability, makes it, at least to me, seem rather convincing.
bapowell said:I see little difference between those words. But this is no place for a semantic argument. Since this is a common question asked by forum goers, I think it's important to make the point that even though black holes are not visible, they are still observable.
George Jones said:There is a good chance that, within a decade or so, we should be able to "image" the astrophysical black hole at the centre of our galaxy. See
http://www.scientificamerican.com/article.cfm?id=portrait-of-a-black-hole
http://arxiv.org/abs/astro-ph/0607279.
andya said:and hawking radiation comes from a particle and an antiparticle formed just aboive the event horizon
Yes, and it has not been taken seriously.taxman said:Black Hole evaporation. Hawkins radiation. and dark matter. I think are the remains of proton distruction. It would explain why the universe is expanding as the charge would be positive and would repel all mater comming close to it. It would also account for the mismatch of strong and weak forces. Has anybody looked at this as a solution. Only areas where negative charges are abundant (electrons) would be able to accumulate and form stars and element solids.
Black hole evaporation is a theoretical process proposed by physicist Stephen Hawking in which black holes gradually lose mass over time and eventually disappear. This is due to the emission of particles from the black hole's event horizon, known as Hawking radiation.
Black hole evaporation occurs through a process known as Hawking radiation, where particles are emitted from the black hole's event horizon. This is caused by quantum effects near the event horizon, where particles are created in pairs and one falls into the black hole while the other escapes as radiation.
According to current theories, black holes can completely evaporate if they are small enough. This is because smaller black holes have a stronger gravitational pull, causing them to emit more Hawking radiation and lose mass at a faster rate. However, larger black holes may take trillions of years to completely evaporate.
This is still a topic of debate among scientists, but the currently accepted theory is that information is not destroyed when it falls into a black hole. Instead, it is encoded in the Hawking radiation that is emitted by the black hole. This is known as the "information paradox" and is still being studied by physicists.
As black holes lose mass through evaporation, they also release energy in the form of Hawking radiation. This energy can have an impact on the surrounding space, potentially heating up any nearby matter and causing changes in the black hole's environment. However, the effects of black hole evaporation on the surrounding space are still not fully understood.