Why does current flow the opposite way from the electrons?

Re:Why does current flow the opposite way from the electrons? by im3w1l on Saturday June 22, 2024 @10:43AM (#40759453)

I think there might be a difference. From our experience with air we know that blowing and sucking are not quite the same. Blown air has a much greater capacity for direction than sucked air. I would assume that this is because the when we blow we add additional molecules and we get to decide the inertia of those molecules, but when we suck we take away molecules and they have the inertia they have.

I would suspect that the same goes for electrons.

An electron gun would (as used in old CRT monitors), would be a very striking example of this - I doubt we could make an electron-hole gun (though shooting positive ions could work, but that's not quite the same thing) - but it may be possible to observe in more normal conditions too?

[ Parent | on HN ]

Re:Why does current flow the opposite way from the electrons? by denton-scratch on Saturday June 22, 2024 @11:58AM (#40759962)

Your hole-gun idea left me scratching my head.

An electron gun produces a beam that contains only electrons; there is no conductor, and I think holes can exist only in the presence of a conductor. So you can't shoot a beam of holes through a vacuum. But if the material between the gun and the screen were a semiconductor, maybe you could draw pictures on the screen using a beam of holes? I mean, I don't see why a beam of holes can't be focused just like a beam of electrons.

[ Parent | on HN ]

Re:Why does current flow the opposite way from the electrons? by im3w1l on Saturday June 22, 2024 @12:47PM (#40760339)

> I mean, I don't see why a beam of holes can't be focused just like a beam of electrons.

Wouldn't electrons rush in to fill the holes from every direction, rather than just the intended one? That's what my intuition says anyway. So yeah, my guess would be that it is in fact not possible.

[ Parent | on HN ]

Re:Why does current flow the opposite way from the electrons? by denton-scratch on Saturday June 22, 2024 @01:39PM (#40760700)

That blade cuts both ways; the electron beam in a CRT travels through a vacuum, there's nothing to "rush in". A hole beam would have to travel through a medium with no free electrons.

[ Parent | on HN ]

Re:Why does current flow the opposite way from the electrons? by dotnet00 on Saturday June 22, 2024 @07:26PM (#40763178)

I wouldn't consider the working of an electron gun to be an introductory physics context.

[ Parent | on HN ]