I read on an article that electrons are “all the same.” Why is that and what does that mean? How can electrons be identical? Does that apply to other elementary particles?
In: 9
The question of “all the same” goes back to the [fundamental math](https://en.wikipedia.org/wiki/Dirac_equation) that describes how electrons behave.
The word “same” can mean a lot of things in the general English language. But in terms of the physics description linked above, the word “same” has more precise meanings.
In 1950, the physicist Schrodinger wrote his own ELI5 about that, using analogies:
The older defunct classical notion of a particle would allow you to make an analogy where 2 electrons are represented by 2 coins. Then you could say: ‘I’m putting the first coin in this first box, and the second coin in this second box.’ Or ‘I’m putting both coins in the first box’ That’d make perfect sense.
But it turns out that the [math description makes that analogy fail](https://en.wikipedia.org/wiki/Fermi%E2%80%93Dirac_statistics) when talking about electrons.
Instead, as Schrodinger wrote, the correct modern analogy for the behavior of electrons would say that two electrons are analogous to two vacancies in a group. That changes everything. Now it doesn’t make sense to say “the first vacancy” is somehow “filled twice” while the second vacancy is somehow unfilled. It also makes no sense to attach *objective* labels to two equivalent vacancies.
And that represents the aspect of “sameness” that people refer to when talking about electrons.
As Schrodinger further wrote:
> The implication, far from obvious, is that the unsuspected epithet ‘this’ is not quite properly applicable to, say, an electron, except with caution, in a restricted sense, and sometimes not at all
Latest Answers