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Then there are neutrons that are like protons with just a little bit more. It's sort of like infinity + 1. Is it bigger or is it equal? (I know, infinity is n

Then there are neutrons that are like protons with just a little bit more. It's sort of like infinity + 1. Is it bigger or is it equal? (I know, infinity is not a number, really)

drdeca 3y ago
Huh? With a little bit more what? Complexity? I expected that they would be pretty much the same except with a different mix of the different quarks and such (and also, unstable without having a nucleus to be a part of, and with a neutral charge)
- Tagbert 3y ago
  I've heard neutrons described as a union of a proton and an electron based on masses. The reality is probably much more complex.
  - marsissippi 3y ago
    Certainly when a free neutron decays it releases a proton and an electron, but also (probably, hypothetically) an antineutrino. https://en.wikipedia.org/wiki/Free_neutron_decay https://en.wikipedia.org/wiki/Free_neutron_decay
  - exmadscientist 3y ago
    The neutron and the proton are pretty similar. Of course, there's that tiny little bit of extra mass, but other than that: Strong-force-wise, they are very hard to tell apart. Weak-force-wise, you have the obvious changes in allowed interactions, but it's all stuff that's plain once you understand the theory of the weak force. No surprises. Electromagnetism is actually the interesting one: just how neutral is this neutral garbage can? There are some interesting measurements to be made here. ILL in particular has done a lot with neutrons. And the there's gravity. Gravity, you ask? Really? Yeah! If neutrons are really neutral, they don't interact electromagnetically, it's hard to get the strong force to come out and play, and the weak force only really does its thing here on the predictable* timescales of neutron decay... so all that's left is gravity. And thus, neutrons get used (or, I guess, more commonly just proposed...) as probes for gravitational effects! Fun, huh? (* Mostly. See neutron lifetime controversy....)
    - floxy 3y ago
      https://en.wikipedia.org/wiki/Nucleon_magnetic_moment https://en.wikipedia.org/wiki/Nucleon_magnetic_moment
  - JumpCrisscross 3y ago
    > neutrons described as a union of a proton and an electron based on masses If you squish an electron and proton really hard, you'll get a neutron [1]. [1] https://en.wikipedia.org/wiki/Electron_degeneracy_pressure https://en.wikipedia.org/wiki/Electron_degeneracy_pressure
    - bigbillheck 3y ago
      And a neutrino: https://en.wikipedia.org/wiki/Electron_capture https://en.wikipedia.org/wiki/Electron_capture
      - JumpCrisscross 3y ago
        If I understand correctly, which I probably don't, this is what releases the final wave of neutrinos in a supernova.
hughesjj 3y ago
Wat? Neutrons are (primarily) UDD while protons are (primarily) UUD. Although I do wonder if this charm+anticharm ghost exists in other hadrons
- gus_massa 3y ago
  > Neutrons are (primarily) UDD while protons are (primarily) UUD. Yes, this is correct. > Although I do wonder if this charm+anticharm ghost exists in other hadrons Yes, neutrons and all the other hadrons have virtual pairs of char-anticharm quarks. (And some of them have actual charm or anticharm quarks.)
gweinberg 3y ago
Yes, just what I was thinking: a neutron is actually more complicated than a proton, it's like a proton with an electron stuck inside it.
- saalweachter 3y ago
  It makes me so angry that a neutron isn't a proton and an electron stuck together.
- gus_massa 3y ago
  No. you can'tput an elelctron inside a proton to get a neutron. If you make them colide and you are lucky, one of the up quarks of the proton changes to a down quark, and now you get a neutron. Both up and down quarks are elelmentary particles as far as we know.
  - scotty79 3y ago
    Isn't it weird how one elementary particle can become completely different elementary particle by "absorbing" (?) yet another elementary particle? How exactly does that happen? Doesn't each particle species have it's own separate quantum field? How does one convert into another? Electromagnetic field can convert into quantum electron field by spawning electron-positron pair from a single photon. But all those exchanges are just weird. It's really shocking that people managed to figure out the math that rules over this.
    - gus_massa 3y ago
      > Isn't it weird how one elementary particle can become completely different elementary particle by "absorbing" (?) yet another elementary particle? Yes, it's weird. Quarks and electrons are just points, they have no interior, so they can't absorb other thing. I'm not sure about the official explanation, but IIRC they old quark and the electron just disapears, and a new quark appear instead??? Actually, it's more complicated, because there appears also a new neutrino, it's something like: quark up + electron --> quark down + neutrino. But neutrinos are very difficult to see, so let's ignore it. Actually, it's more complicated, because there is an intermediate W+ or W- particle. The W particles live for a very short time, so you can ignore it unless you work in a particle ascelerator, but to get the correct results you must use the W+ or W- particle in the middel of the transformation. The correct equation are quark up + electron --> quark up + neutrino + W- --> quark down + neutrino quark up + electron --> quark down + electron + W+ --> quark down + neutrino Actually, it's more complicated, because sometimes you get a strange quark instead of a down quark. Ignoring the W+ or W- particles quark up + electron --> quark strange + neutrino (And perhaps there are a few more "actualies", but these are the most important weird cases.) > How exactly does that happen? Magic? Nobody knows, we only can make experiments and guess the equations. There is people that enjoy discusing the interpretation, but I think it's better to ignore it and enjoy the agreement of equations and experiments. > Doesn't each particle species have it's own separate quantum field? Yes > How does one convert into another? Magic? Sorry, not good answer. > Electromagnetic field can convert into quantum electron field by spawning electron-positron pair from a single photon. But all those exchanges are just weird. It's really shocking that people managed to figure out the math that rules over this. A lot of the rules can be understood using magic balls. You can learn the rules to combine particles and draw Feynman diagrams as if they were magic balls. It took a long time to discover them, including two or three Nobel prices. It was very difficult, but somehow it was possible to discover one rule at a time, and add another rule a few years later, that made the whole procces slightly easier. The equations are more difficult. I only learned a small part of them (and I had forgoten them). Also, they were discovered in small steps, sometimes as simplification or generalizations of previous equations, and had a few Nobels in the list of discoverers. Also, most particles have the same equations, for example all the quarks have the same equations so you just copy it 6 times, but photons have a different equations. And you have one big equation that combines all of them in a very long formula, but each part is simple.

Then there are neutrons that are like protons with just a little bit more. It's sort of like infinity + 1. Is it bigger or is it equal? (I know, infinity is not a number, really)

drdeca 3y ago

Huh? With a little bit more what? Complexity? I expected that they would be pretty much the same except with a different mix of the different quarks and such (and also, unstable without having a nucleus to be a part of, and with a neutral charge)

Tagbert 3y ago
I've heard neutrons described as a union of a proton and an electron based on masses. The reality is probably much more complex.
- marsissippi 3y ago
  Certainly when a free neutron decays it releases a proton and an electron, but also (probably, hypothetically) an antineutrino. https://en.wikipedia.org/wiki/Free_neutron_decay https://en.wikipedia.org/wiki/Free_neutron_decay
- exmadscientist 3y ago
  The neutron and the proton are pretty similar. Of course, there's that tiny little bit of extra mass, but other than that: Strong-force-wise, they are very hard to tell apart. Weak-force-wise, you have the obvious changes in allowed interactions, but it's all stuff that's plain once you understand the theory of the weak force. No surprises. Electromagnetism is actually the interesting one: just how neutral is this neutral garbage can? There are some interesting measurements to be made here. ILL in particular has done a lot with neutrons. And the there's gravity. Gravity, you ask? Really? Yeah! If neutrons are really neutral, they don't interact electromagnetically, it's hard to get the strong force to come out and play, and the weak force only really does its thing here on the predictable* timescales of neutron decay... so all that's left is gravity. And thus, neutrons get used (or, I guess, more commonly just proposed...) as probes for gravitational effects! Fun, huh? (* Mostly. See neutron lifetime controversy....)
  - floxy 3y ago
    https://en.wikipedia.org/wiki/Nucleon_magnetic_moment https://en.wikipedia.org/wiki/Nucleon_magnetic_moment
- JumpCrisscross 3y ago
  > neutrons described as a union of a proton and an electron based on masses If you squish an electron and proton really hard, you'll get a neutron [1]. [1] https://en.wikipedia.org/wiki/Electron_degeneracy_pressure https://en.wikipedia.org/wiki/Electron_degeneracy_pressure
  - bigbillheck 3y ago
    And a neutrino: https://en.wikipedia.org/wiki/Electron_capture https://en.wikipedia.org/wiki/Electron_capture
    - JumpCrisscross 3y ago
      If I understand correctly, which I probably don't, this is what releases the final wave of neutrinos in a supernova.

hughesjj 3y ago

Wat? Neutrons are (primarily) UDD while protons are (primarily) UUD. Although I do wonder if this charm+anticharm ghost exists in other hadrons

gus_massa 3y ago
> Neutrons are (primarily) UDD while protons are (primarily) UUD. Yes, this is correct. > Although I do wonder if this charm+anticharm ghost exists in other hadrons Yes, neutrons and all the other hadrons have virtual pairs of char-anticharm quarks. (And some of them have actual charm or anticharm quarks.)

gweinberg 3y ago

Yes, just what I was thinking: a neutron is actually more complicated than a proton, it's like a proton with an electron stuck inside it.

saalweachter 3y ago
It makes me so angry that a neutron isn't a proton and an electron stuck together.
gus_massa 3y ago
No. you can'tput an elelctron inside a proton to get a neutron. If you make them colide and you are lucky, one of the up quarks of the proton changes to a down quark, and now you get a neutron. Both up and down quarks are elelmentary particles as far as we know.
- scotty79 3y ago
  Isn't it weird how one elementary particle can become completely different elementary particle by "absorbing" (?) yet another elementary particle? How exactly does that happen? Doesn't each particle species have it's own separate quantum field? How does one convert into another? Electromagnetic field can convert into quantum electron field by spawning electron-positron pair from a single photon. But all those exchanges are just weird. It's really shocking that people managed to figure out the math that rules over this.
  - gus_massa 3y ago
    > Isn't it weird how one elementary particle can become completely different elementary particle by "absorbing" (?) yet another elementary particle? Yes, it's weird. Quarks and electrons are just points, they have no interior, so they can't absorb other thing. I'm not sure about the official explanation, but IIRC they old quark and the electron just disapears, and a new quark appear instead??? Actually, it's more complicated, because there appears also a new neutrino, it's something like: quark up + electron --> quark down + neutrino. But neutrinos are very difficult to see, so let's ignore it. Actually, it's more complicated, because there is an intermediate W+ or W- particle. The W particles live for a very short time, so you can ignore it unless you work in a particle ascelerator, but to get the correct results you must use the W+ or W- particle in the middel of the transformation. The correct equation are quark up + electron --> quark up + neutrino + W- --> quark down + neutrino quark up + electron --> quark down + electron + W+ --> quark down + neutrino Actually, it's more complicated, because sometimes you get a strange quark instead of a down quark. Ignoring the W+ or W- particles quark up + electron --> quark strange + neutrino (And perhaps there are a few more "actualies", but these are the most important weird cases.) > How exactly does that happen? Magic? Nobody knows, we only can make experiments and guess the equations. There is people that enjoy discusing the interpretation, but I think it's better to ignore it and enjoy the agreement of equations and experiments. > Doesn't each particle species have it's own separate quantum field? Yes > How does one convert into another? Magic? Sorry, not good answer. > Electromagnetic field can convert into quantum electron field by spawning electron-positron pair from a single photon. But all those exchanges are just weird. It's really shocking that people managed to figure out the math that rules over this. A lot of the rules can be understood using magic balls. You can learn the rules to combine particles and draw Feynman diagrams as if they were magic balls. It took a long time to discover them, including two or three Nobel prices. It was very difficult, but somehow it was possible to discover one rule at a time, and add another rule a few years later, that made the whole procces slightly easier. The equations are more difficult. I only learned a small part of them (and I had forgoten them). Also, they were discovered in small steps, sometimes as simplification or generalizations of previous equations, and had a few Nobels in the list of discoverers. Also, most particles have the same equations, for example all the quarks have the same equations so you just copy it 6 times, but photons have a different equations. And you have one big equation that combines all of them in a very long formula, but each part is simple.