Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: William McCartney on 09/02/2011 16:30:03

Title: Is there is a matter/anti-matter bias in Hawking Radiation?
Post by: William McCartney on 09/02/2011 16:30:03

William McCartney  asked the Naked Scientists:
   
Hawking radiation was explained on The Naked Scientists recently as the result of the anti-matter particle of an anti-matter/matter pair falling into the black hole, while the matter particle escapes the event horizon.

But, half of the time, wouldn't the matter particle fall into the black hole, and the anti-matter particle escape, resulting in zero net radiation?

What do you think?

Title: Is there is a matter/anti-matter bias in Hawking Radiation?
Post by: yor_on on 09/02/2011 19:27:40

No, but it is weird. We discussed it before and there are different views on it. Read http://www.thenakedscientists.com/forum/index.php?topic=36395.0 the discussion there and tank home the PDF:s etc. Then if you have more ideas or questions use that thread as it's a good trampoline for the question, I think :)

But to give you the answer as I see it. It's a question about if a black hole is a singularity, or not, to me. And I think it is.

Title: Is there is a matter/anti-matter bias in Hawking Radiation?
Post by: Soul Surfer on 09/02/2011 19:42:07

There is no reason to believe that there would be an imbalance.  In fact most of the radiation will be electromagnetic.  An evaporating black hole only get hot enough to start emitting electrons and positrons in the last couple of million years of its life when it is about the size of a large atomic nucleus and weighs around 8 billion tons a minute fraction of the mass of the earth say around the weight of an asteroid one Km across.

Title: Is there is a matter/anti-matter bias in Hawking Radiation?
Post by: yor_on on 09/02/2011 21:34:22

Yes the reason we expect a Black hole to 're-emit' its 'radiation' is that we have the concept of the universe as a 'system' obeying laws of conservation. That means that the universe never loses anything. The reason why we think so goes back to one Frenchman experimenting with 'transformations' "In 1789 Frenchman Antoine Lavoisier discovered the law of conservation of mass and defined an element. In 1803 John Dalton  used the concept of atoms to explain why elements always react in ratios of small whole numbers(law of multiple proportions). He proposed that each element consists of atoms of a single, unique type, and that these atoms can join together to form chemical compounds. This is the basis of modern atomic theory."

So do we have proof or that? Well, it works on Earth at least? Does it mean that we actually can prove it 'universally'. I don't now, what we can do is to build on what we know, that in itself is no guarantee for it being correct though. People accepting the theory of relativity seem all to fast to forget that it did 'universally same, unchanging time' in, once and for all.

So, I don't know?
==

You can look at it this way too. Assuming that 'time' is a illusion a black hole is constricted by its event horizon. As we can't know its own 'frame of reference' everything becomes guesswork there. But assuming that with a near infinite gravity for matter comes a very quick time relative the universe at large. So any in-falling matter into a singularity, no matter when we see it start to 'move' towards the Black hole, are from their own point of view equal. That means that no matter when they started, they will all see the universe die before reaching the 'center' of the singularity. If you assume anything else you're giving this center of a singularity 'an arrow of time', meaning that you now introduced 'times arrow' to a 'infinity'.