**Ask a monkey a physics question thread**

[OngBonga]

Thanks for the article, bookmarked for later consumption.

it ejects an electron when the muon's magnetic moment is aligned with the external field, but it ejects a positron when it is anti-aligned.

This is super interesting. It kinda implies that natural processes result in 50% matter and 50% antimatter, which of course begs the question of why we only observe matter in our observable universe. Of course I understand the idea that a simple imbalance of 0.00000000000000000001% is enough over time to result in a universe of matter and photons, but that imbalance is still weird. This is a digression though.

I don't really want to get into g-factor

Matt on PBS did go into this, at least scratching the surface, and I got it enough to understand why they're excited. They were talking about G-2, which would be zero if SM predictions held, but it was a small fraction above zero. This involved Feynman diagrams, which are really cool in their own right and because I have a little knowledge of what they are, I could follow this line of thought. I know the most simple Feynman diagrams represent the highest probability, and that there are potentially infinite amounts of different configurations, but with more complexity they become ever more unlikely. I get what's happening here mathematically... we're converging like an infinite fraction that doesn't blow up to infinity. So I could understand how they got to this G-2 number mathematically using Feynman diagrams.

I'll read that article after dinner.

[MadMojoMonkey]

The weak interaction is the only hypothesis I know of that uses currently known physics to explain why there is an abundance of matter and not anti-matter in the universe. Basically, as bad-ass as you already imagine the Big Bang to be, it probably contained more than a billion times more energy than the mass energy left in the universe we observe. Nearly all of that annihilated in matter / anti-matter cancellation, but a tiny imbalance in the chaos of that event left one weak interaction process favored over its equal opposite. And there is matter left in the universe. All of this is pure speculation, AFAIK. I don't think I've seen a mathematical model that lays out that imbalance in the early universe.

Oh. Did PBS Spacetime already hit this? I'll check it out right away.

On the Feynmann diagrams... I know some people doing research into them and apparently the diverging pathways available in the diagrams begin to dominate the diminishing probabilities after about 20 iterations down. The total energy in the exponentiating pathways possible drops and drops out to about 20-ish steps... so the early speculation was that they'd keep diminishing and be convergent. But now we're finding that the total energy available in the really complicated pathways starts to rise again. So the initial assumption that the more complicated terms played ever less relevant roles seems to have some doubts attached to it.

However, this is one group of researchers, and they're all quite convincing, but time will tell.