# Decay of matter

I was watching Stephen Hawking's documentary and in there he explained how he realized why black holes eventually disintegrate:

There are ripples in space, an antiparticle and a particle get created for a brief time then annihilate each other. When this happens very close to a black hole sometimes an antiparticle will be sucked in, but normal particle will escape. Hence the black hole radiation is due to extra particles escaping and black hole disintegration is due to antimatter getting sucked in.

That made me think what happens around ordinary matter. If the antiparticle is close enough to a normal particle then it will annihilated. So is this what is responsible for Radioactive Decay? And how does it affect normal matter? For example a human being? Does it mean that all the atoms will eventually disintegrate?

I am not QM savy so if you can explain it in layman terms that would be very appreciated.

• You're asking about impact of annihilation? It's almost zero, but for ex. PET is useful. Apr 30, 2015 at 23:53
• Yes, eventually all matter will (most likely) disintegrate, but black holes and ripples in space have nothing to do with it. It's the electroweak force that causes radioactive decay (at least some of it) and proton-decay can be modeled in a number of ways. Ultimately matter has to be unstable, because it is not the lowest possible energy state of the universe. May 1, 2015 at 0:05
• Observation: if particle pairs are created as matter / anti-matter pairs, 50% of the time the matter particle will fall in adding to the mass rather than annihilating it, if that description of the situation is taken literally. May 1, 2015 at 1:24
• @XerenNarcy There is no such thing as negative mass. When a virtual proton/anti-proton pair is created, both particles have the same mass, 1. I am not a physicist, and I can not explain why this is not a violation of conservation laws, but I've heard of an explanation that has something to do with "uncertainty" and the extremely short time interval during which the particles exist. But, if one particle escapes the black hole, and the other does not, then conservation laws require that the black hole lose mass. I can't explain how that works either. Jun 17, 2015 at 19:58

At least for the radioactive decay that most people are familiar with, and that you're probably talking about, electroweak force is the cause.

I'm going to give this a shot, cause I think it's a fun question, but you probobly should work it out a bit more.

Virtual particles, or particle/anti-particle creation looks like 1 electron and 1 anti electron (for example) existing briefly then cancelling each other out. If it happens in the void of space, they interact with each other and - poof, gone. They (as I understand it) borrow energy from the future, are created and annihilate each other with no net energy created.

If they are created near an atom - it's perfectly reasonable to say that the anti-electron meets an electron around an atom - but all that happens in this scenario is that the "non virtual" electron is replaced by the virtual electron. - nothing really changes.

Same if you have a quark/antiquark, where if an anti-up quark meets an up quark in the nucleus, you have the virtual up quark ready to replace it - so it doesn't explain the Proton to Neutron or Neutron to proton change known as beta decay.

unless it's a virtual W or Z boson . . . not sure where to go with that, as that's a bit over my pay-grade, but there's a question about that here: Are W & Z bosons virtual or not?

Your idea, I think, works for electron capture. (Both Electron Capture and Beta decay described in the link below).

http://www.livescience.com/49254-weak-force.html

I'm, however, a layman who enjoys physics as a hobby, not a professor, so take my explanation with a grain or two of skepticism.

... is this what is responsible for Radioactive Decay?

Sort of ... radioactive decay occurs when the final state (result of the decay) has lower energy than the initial nucleus and the barrier is occasionally surmounted. This barrier penetration and the virtual pair at the black hole horizon are both quantum processes, so they have a little physics in common.

And how does it affect normal matter? For example a human being? Does it mean that all the atoms will eventually disintegrate?

Fortunately, Hawking's ideas do not affect normal matter. The pair creation can be used to understand why a black hole evaporates. Stable nuclei and atoms have an infinite lifetime - all the higher-order quantum loop corrections have been accounted for in calculating the stable (infinite) lifetime. So human beings, or at least the atoms they're made of, aren't going to go away any time soon. Our current best guess for the future of the universe (say 100 trillion years from now) is a cold, dark place, with nothing going on, but all the atoms are still there doing essentially nothing. There will be zero-point fluctuations, but there will be zero point in those - OK?!