Hacker News Reader

Comment by dekken_ | Hacker News Reader

Except electrons aren't matter.

"The electron is a subatomic particle, (denoted by the symbol e− or β− ), whose electric charge is negative one elementary charge.[9] Electrons belong to the first generation of the lepton particle family,[10] and are generally thought to be elementary particles because they have no known components or substructure.[1] The electron has a mass that is approximately 1/1836 that of the proton."

https://en.m.wikipedia.org/wiki/Electron

I am positive that electrons are matter. Never heard your claim before.

You are positive you were told that electrons are matter maybe. This is the standard (see: current) model, in QFT electrons are not particles, so are not leptons, so are not matter.

Wikipedia says "Even restricting the discussion to physics, scientists do not have a unique definition of what matter is." (in the sense of contrasting with antimatter), and then later says "In a wider sense, one can use the word matter simply to refer to fermions.". (Presumably this means, fermions and things comprised of fermions. One would not say that Helium-4 is not matter just because it is a boson (and is comprised of an even number of fermions).)

Electrons are fermions.

I am therefore comfortable saying that electrons are matter.

I don't know why you say that electrons are "not particles" in QFT. Sure, there's an electron field, and electrons are just, like, excitations in that field. There's also a quark field. What of it? If you are saying "because everything is fields, there are therefore no particles, and therefore no matter", you are using the word "matter" in a silly way.

Also, isn't a "particle" just a representation of a compact Lie group? What's the problem?

(edit : though, I admit that I'd be a little hesitant about calling a massless fermion "matter". But, seeing as there are no known massless fermions, meh.)

Is the mass measurement of electrons an abberation then in the QFT interpretation of the empirical data? Or is it that energy can have mass prior to being converted under some conditions?

> Is the mass measurement of electrons an abberation then in the QFT interpretation of the empirical data.

I'm not sure this is resolved. see: https://en.wikipedia.org/wiki/Quantum_electrodynamics#Conclu...

> Or is it that energy can have mass prior to being converted under some conditions?

Using https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalenc... you can (theoretically) convert between energy and mass, and then measure everything as https://en.wikipedia.org/wiki/Electronvolt. I have yet to see anything create protons from energy, so I am hesitant to do this.

> I have yet to see anything create protons from energy, so I am hesitant to do this.

Won't a proton/antiproton annihilation also create two photons? If so, wouldn't that also work in reverse?

> Won't a proton/antiproton annihilation also create two photons?

I expect it would make a lot more than just two photons. See: https://en.wikipedia.org/wiki/Annihilation#Proton%E2%80%93an...

> If so, wouldn't that also work in reverse?

It would have to be demonstrated.

Thanks, I didn't know proton/antiproton annihilation is so complex. But it makes sense.

How do you think we got matter from the big bang?

I don't pay much attention to big bang things, as far as I'm concerned it's as unprovable as an infinite universe theory. I'm not sure we can ever know either way.

Electrons are Fermions, and therefore matter. That's in contrast to Bosons, which are "energy" (more precisely force carriers).

This gives me a negative feeling.

Reply on news.ycombinator.com