Would it be possible to detect change in charge?

minio

I was trying to think about charge and I am curious. It seems that there is unitary charge - +1 for protons and -1 for electrons. But is it possible to say that it is constant in time? I mean would it be possible to detect changes in unitary charge value? size?

Let us say that all charges are interconnected. So if charge of one proton will change from +1 to +1,5 this will gradualy change all other charges at speed of light, so every electron will change its charge to -1,5, proton to +1,5 and so on over time, would it be possible to detect that such event happened?

ZapperZ

You might want to look up "Fractional Quantum Hall Effect". In such experiments, the many-body effects caused the flow of charge to appear as if they are in units of e/3.

So yes, if the unit charge changes, we CAN detect it. There is no reason that we can't.

Zz.

mfb

The force between charged objects would increase, this can be detected.

If you weaken the electromagnetic force and increase the charge everywhere at the same time by a corresponding amount (and somehow fix the influence of all photons flying around in a similar way), you would not measure any change.

DaleSpam

As long as the fine structure constant changes, yes, we could detect a change. What we could not do is definitely say that the change in the fine structure constant is due to a change in the elementary charge instead of Planck's constant.

minio

So if I understand it correctly unitary charge is either constant or we would detect changes in fine structure constant, thus we could assume that unitary charge is constant whaterver charge actually is?

mfb

The fundamental quantity here is the fine-structure constant. And yes, it would be possible to measure a deviation if it is large enough.
"Large enough" is something like a relative change 10^-17/year with current precision (Reference).

DaleSpam

Yes. The same is true of all dimensionful physical constants. What we would actually be able to measure would be changes to the dimensionless physical constants, and then we could arbitrarily assign that change to one or more of the dimensionful physical constants that make up the dimensionless constant.