Electron lifetime is at least 66,000 yottayears | Hacker News Reader

Electron lifetime is at least 66,000 yottayears

physicsworld.com

83 pointsjonbaer25 comments

Note that this lifetime is ONLY for this one specific decay route!

If the electron decayed some other way then this research is silent on that.

This comment needs higher visibility. This paper doesn't set a lower bounds for all possible interactions.

The electron seems to very much be point-like[0], and its lack of decay, now with an extraordinary bound on its lifetime--these observations seem to suggest the electron really is the fundamental particle the standard model says it is.

It's interesting, as time goes on and more data comes in, the standard model is verified again and again, much to the chagrin of theoretical particle physicists who hope for more beyond the standard model.

I once saw a talk by Fabiola Gianotti, the leader of the ATLAS detector when the Higgs was discovered, and she said that the lack of evidence for supersymmetry might lead to a "crisis" in particle physics. It was surprising, because up till that point, she spoke matter-of-factly, but it's possible what she's saying is true.

[0] https://en.wikipedia.org/wiki/Electron_electric_dipole_momen...

the electron really is the fundamental particle

The curious thing is it has an electric charge of -1. But quarks, constituents of protons and neutrons, have +2/3 and -1/3 charge. So how is it that internally a proton has fractional charges but there's nothing analogous for the electron?

How is it that there's such weird asymmetry there? Why have we only observed -1, +2/3, and -1/3 for electric charge?

Somehow that just doesn't seem "fundamental" to me as a lay person.

That's good, because we've only got the one. ;) https://en.wikipedia.org/wiki/One-electron_universe

This is such a beautiful idea. Are there people developing this theory? How could this be experimentally verified? What are the philosophical/time-travel implications of the one-electron universe theory being true, distinct from classical QM?

I can't find a good reference, but as far as I know, this theory is no longer seriously considered. One problem right from the start was the observed difference between the quantity of electrons and anti-electrons in the universe.

Previous discussion: https://news.ycombinator.com/item?id=9007308

I'll repeat a quote of skywhopper in that thread, from Wikipedia:

Wikipedia> Feynman was struck by Wheeler's insight that antiparticles could be represented by reversed world lines, and credits this to Wheeler, saying in his Nobel speech:

Feynman>> I did not take the idea that all the electrons were the same one from [Wheeler] as seriously as I took the observation that positrons could simply be represented as electrons going from the future to the past in a back section of their world lines. That, I stole!

I should know better than to play armchair physicist, but isn't this the perfect mechanism for symmetry breaking? If antimatter is just matter travelling back in time, then naturally all the antimatter created in the big bang isn't here because it went the opposite way! This is probably dumb, but I'd love to hear more about it.

Good question. The answer is that the dimension of time is something that exists within our universe. Within the standard model of cosmology there is no notion of anything before the big bang - that would imply the there is a meta-time that exists outside our universe.

This might be slightly difficult to digest, so let me give an analogy. A few of centures/millinia ago it was valid to ask, "What is beyond the end of earth?". Now that we know that the earth is a sphere and spheres don't have ends, it is nonsensical to ask "What is beyond the end of earth?". Similarly, at the big bang time just stops, there is brick wall beyond which you can't go. And it is nonsensical to consider what happens before the big bang.

That might be the best analogy, but it's unsatisfying to me. The earth doesn't have an edge because it is round. When you go far enough in one direction you end up where you were.

If that was how they thought time worked, I could deal with that. But it's not. If they thought it was infinite in extent in both directions. I could deal with that. But the idea of a dimension just ending... That's a mind boggler.

That makes sense, but in a model where time doesn't have a privileged sign, would it have expanded in both directions then? So our universe inflates forwards, and the antimatter universe inflates backwards, both sides creating time from the same zero point.

[not-a-physicist]So why can't time be a ball, just like the earth, neither beginning nor ending? At some point we meet all the anti-matter going the other way...[/not-a-physicist]

Under the One Electron Theory, positrons are created some time in the future when an electron decays, and destroyed at some point in the past when the positron decays back into an electron. So the lifetime of a positron is bounded on both ends, and never crosses the "big bang" singularity.

It's not that antimatter 'created' in the big bang is traveling back in time, and only exists 'before' the big bang. It's that the big bang is when the antimatter is 'destroyed', turning into matter in the process.

Moreover, you cannot exactly measure the actual mass of the electron. A 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000001 difference is not measurable, which echoes the fact that you cannot verify the claim from the start.

> The electron is the least-massive carrier of negative electrical charge known to physicists.

I thought it was the only carrier of negative electric charge.

Muons also carry a negative charge, although they're unstable. (and of course there are antiprotons, if you count those)

207 time more massive than an electron - so if you could replace electrons with muons the resulting atom would me much smaller, so nuclei would be closer and therefore fusion easier. Possibly...

https://en.wikipedia.org/wiki/Muon-catalyzed_fusion

The Tau[1] as well.

[1] https://en.wikipedia.org/wiki/Tau_%28particle%29

Many things carry negative charge in particle physics, as others have pointed out. It is the lightest and, as we now to extreme scales, most stable.

The down/strange/top quarks have negative 1/3 charge.

Quarks have fractional electric charge.

66,000?! That's a yotta years!

If it were designed in base 2, the lifetime would be 65536 years.

6.6 * 1028 seems immortal to me.

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