Comment by mianos
2 years ago
Imagine you have a bunch of fulcrums in the air and items droping down. If the things that land on the fulcrums don't balance each other out the fulcrum tips and the items keep dropping. Eventually all the fulcrums are balanced.
A lot of these things coalesce until they are stable enough they don't fall apart. If there is a stable form and you have enough of them, eventually you get a lot of stable forms.
It is not some magical thing that makes all this balance, it is more of a settling thing where things eventually drop to a stable state. There is lots of matter that is still unstable.
This explains why atoms have 0 charge, but not why protons, which are stable even without electrons, have a charge of 1.
Put in terms of elementary particles, why is it that the ratio of electric charge between a quark and an electron is either 1:3 or 2:3?
a proton, in the simplist version, is made of 3 quarks. two up quarks one down quark.
down qwark is -1/3 e ; up quark is +2/3 e.
they sum up to +1 e.
neutrons are the opposite made of 3 quarks. two down quarks one up quark. and sum to 0e
the unitary quantity is a conveinience.
1 e = 1.602176634×10−19 coulombs,
Yes, yes, I also understand this.
But why are they in units of 1/3(e).
Why are down quarks not -0.398390847895...(e) and up quarks not +0.6234098129034809234...(e). Why do they add up so damn neatly?
53 replies →
>the unitary quantity is a conveinience.
Ah right, so basically its just a convenience notation? We could as well say that proton has 3 and electron is -3 charge?
2 replies →
> a proton, in the simplist version, is made of 3 quarks. two up quarks one down quark.
OP's article has a full paragraph dedicated saying that "The proton is much more than three quarks"
How does 2/3 - 1/3 not sum to 1/3? 2-1 is 1, right? What am I missing?
3 replies →
If the universe is old, then how do you expect atoms to exist if this was not the case?
Couldn't there be a different physics where protons had a charge of 0.5 and, therefore, every atomic nucleus would have twice as many protons as electrons? Or pick any other ratio you like.
Or course, I don't mean to hand-wave away the potential implications of this. Maybe there would be no atomic nuclei in such a universe, for all I know. But if not, why not?
6 replies →
A proton, electron, and a neutron walk into a bar…
After about 15 minutes, the neutron has changed into another proton and electron, so bar now has a bigger party on its hands.
2 replies →
I like your explanation.
> There is lots of matter that is still unstable.
What are you referring to with this?
https://en.m.wikipedia.org/wiki/Proton_decay
I need to read the article, but yeah protons might not be stable, we just need to wait a long time to find out.
And free quarks within stars in conditions where they are not confined. They can exist unconfined for a real short time. At the start of the big bang there were a lot of them.
1 reply →