tangentially: is it consensus at this point that the proton decays -- it just does so on a really large timescale?
What Is a Particle? (2020)
11–20 of 196 posts
Re: What Is a Particle? (2020)
#12I'm reading "The Big Picture" (Sean Carroll) right now. I'd love to have a real physicist explain this, but: When we think of what a particle IS, we often think as though it were dirt, or a billiard ball, or something. As though there were some other substance of which it's made. At least I do. But the definition is as low as you can go. It's hard to wrap your head around that. Unless you're trained to do so, I guess…
The same is true about the terms "waves" and "fields" when it comes to quantum mechanics.
They're analogies. The concepts need names, but I think they do more harm than good because people then start with a mental model of a membrane or a surface - something they have experience seeing waves in. And then after 1 or 2 steps where the analogy helps, it breaks down, and people start being confused.
Of course the alternative isn't any better. If they had named it a "Wazoo function" and a "Quantum Flarg" everyone would've just kept asking "OK but what IS a Wazoo? What IS a Flarg" and not been satisfied with a "Yeah, it's a fundamental own thing".
Feynman, of course, has a pretty definitive response on the difficulty of this problem: https://www.youtube.com/watch?v=Dp4dpeJVDxs
Re: What Is a Particle? (2020)
#13A particle is a thing you can "look" at, and say "that's a particle". It is whatever one says it is. They're not exactly discovered, they're invented. Fundamental in this context is not so much a word as it is an analogy. And, don't get me wrong, that doesn't mean particles don't exist. They do. But, a particle is whatever we say it is.
We're not asking questions about human constructs like what is moral or what is the ideal form of government. We're trying to understand what the most fundamental building block of reality is, which is something objective. Something independent of whether of not people ever existed. So no, countless people around the world aren't wasting their lives researching particles when the answer is simply, it's whatever we sa…
I'll go even further and point out that in 2003, it was proven that particles are not, in fact, the friends we made along the way.
Re: What Is a Particle? (2020)
#14tangentially: is it consensus at this point that the proton decays -- it just does so on a really large timescale?
No it would be very hard to actually have a consensus on proton decay. If it decays then according to the measurements (or the limits on the lack of the measurement) lifetime of such decay will be more than the universe age (Even without all the puzzle about Hubble constant tension and age of universe measurement disagreements). It was predicted first time by SU(5) theory and many other theories since then but the experiments rules out some of them (including original SU(5)) [1]
I would be personally interested in proton decay as it could be indirect indication for magnetic monopoles [2].
[1] https://en.wikipedia.org/wiki/Proton_decay?useskin=vector#Pr...
[2] https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.52...
Re: What Is a Particle? (2020)
#15A particle is a thing you can "look" at, and say "that's a particle". It is whatever one says it is. They're not exactly discovered, they're invented. Fundamental in this context is not so much a word as it is an analogy. And, don't get me wrong, that doesn't mean particles don't exist. They do. But, a particle is whatever we say it is.
"Things are named before they are understood." -- Matt Strassler
Re: What Is a Particle? (2020)
#16I have another definition, or at least this is how I think of it. I’m not sure many people would buy into it. In the standard model, the fermions are particles, like the electrons, quarks, neutrinos. Electroweak, strong force, gravity are fields. This means the photon is not a particle, but just a field excitation. I know people can think of fermions as fields, I just think of them as particles.
Aren't you describing quantum field theory (QFT)?
Anyway, what exactly is a field besides a mathematical object? What is it made of?
Re: What Is a Particle? (2020)
#17A particle is a node in the universal interaction graph.
“Space”, however, is a derivative attribute emerging as the “distance” between particles in the graph; there is no “space”, only metrics.
Reality does not exist between measurements/interactions; the outcome is calculated on demand.
Re: What Is a Particle? (2020)
#18A particle is a node in the universal interaction graph. “Space”, however, is a derivative attribute emerging as the “distance” between particles in the graph; there is no “space”, only metrics. Reality does not exist between measurements/interactions; the outcome is calculated on demand.
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Re: What Is a Particle? (2020)
#19(2020)
Some discussion then: https://news.ycombinator.com/item?id=25091742
Re: What Is a Particle? (2020)
#20[deleted]