Naked Universe of Ana

Wave function and spin of ē

Added 2025-09-28 18:12:10 +0000 UTC

Now let’s dig a bit deeper into the structure of particles.

Spin is basically like a built-in quantum magnet.

In the Stern-Gerlach experiment(on the pic), electrons are sent through a magnetic field.
Before the experiment, the logic was: if each electron has its own little arrow, the beam should smear into a stripe. Arrows could point in any direction, full 360°.

But in reality the beam always split into just 2 spots. Everyone freaked out, again physics didn’t match the expectation, lol. Turns out electrons only ever give two outcomes: spin up or spin down. No “in between.”

And here’s the crazy part: before you measure, the electron sits in a superposition - both up and down at the same time.

So its wave function actually holds both possibilities:

Ψ = ( ψ_up )
ψ_down

You put up a magnet, and it decides right there where to go. You never can know before, only probability, remember last Post?:)

Of course, spin is not the only property of a particle. Its position in space is described by other parts of the wave function too.

Pic credit
physicus-minimus.com