Why are the charges of the proton and electron equal but opposite in size?

[kye]

Why (or what mathematical reason) is the charge of the electron being -1.60217733 x 10-19 C equal to the charge of the proton but opposite in size? Proton are composed of quarks and electrons don't have anything to do with quarks.

 

[ShayanJ]

That's what we see in nature,experimentally, and there is no explanation for it yet,at least non that is proved!

 

[Drakkith]

There is no underlying reason why fundamental properties exist. They just do. Perhaps our understanding will change in the future.

 

[kye]

There are 3 quarks in a proton. What is the value of each quark such that the composite proton has the value 1.60217733 x 10-19 C? Or how does each of the 3 quarks contribute to this value?

 

[ShayanJ]

There are 3 quarks in a proton. What is the value of each quark such that the composite proton has the value 1.60217733 x 10-19 C? Or how does each of the 3 quarks contribute to this value?

A proton has 2 up quarks and 1 down quark.Up quarks have electric charge equal to $+\frac{2}{3}e$ and down quarks have electric charge equal to $-\frac{1}{3}e$ where e is the charge on a proton.

 

[kye]

A proton has 2 up quarks and 1 down quark.Up quarks have electric charge equal to $+\frac{2}{3}e$ and down quarks have electric charge equal to $-\frac{1}{3}e$ where e is the charge on a proton.

It sounds like an up quark is composed of 2/3 of electron and down quark is composed of 1/3 of electron. Won't it sounds like an electron is composed of 3 units. I know we treat it as a point object. But the Landau problem says an electron can't be a point because its electric charge at infinite center would repel each other. So there is still hope an electron can be even composed of smaller objects bound together to form an electron?

 

[Drakkith]

It sounds like an up quark is composed of 2/3 of electron and down quark is composed of 1/3 of electron. Won't it sounds like an electron is composed of 3 units. I know we treat it as a point object. But the Landau problem says an electron can't be a point because its electric charge at infinite center would repel each other. So there is still hope an electron can be even composed of smaller objects bound together to form an electron?

Not much hope, no. Electrons are thought to be fundamental particles.

 

[dauto]

There is no explanation for that apparent "coincidence" between the charges of the quarks and the electron within the Standard model (except for the highly technical requirement of triangular anomaly canceleation requirements in order to preserve renormalizability). But with GUT theories that "coincidence" is actually a consequence of the symmetries imposed on the theory by the GUT gauge interaction.