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Electrons (mander.xyz)

submitted 5 months ago by fossilesque@mander.xyz to c/science_memes@mander.xyz

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[-] marcos@lemmy.world 42 points 5 months ago

Up and down in what direction, electron?!?

Up and down on what direction?!?

[-] AngryCommieKender@lemmy.world 18 points 5 months ago

Relative to A'Tuin

[-] smeg@feddit.uk 2 points 5 months ago

My favourite quark is the hubwise quark, closely followed by the widdershins quark

[-] Chrobin@discuss.tchncs.de 12 points 5 months ago

Actually a good point, tho. And also a good thought: If there is no special direction, what would be up? And that's where quantum mechanics gets even weirder: It's either up or down in the direction you measure.

[-] i_love_FFT@lemmy.ml 8 points 5 months ago* (last edited 5 months ago)

It's either up or down whatever the direction.

If you measure 100%up-0%down then you rotate your frame of reference by 90°, you automatically get 50%up-50%down... (iirc)

It's weirdly teasing us like that!

[-] Ziglin@lemmy.world 8 points 5 months ago* (last edited 5 months ago)

Just in case it wasn't clear you can't measure anything other than "100%" up or down spin. The quantum state of it being 50/50 is described by 1/sqrt{2} times the up and down vector, when you measure it you have a probability of getting either result calculated by the square of the absolute (||psi||^2) that way you avoid getting a complex probability.

btw I was too scared to try in case it doesn't but can I use LaTeX in Lemmy comments? $\psi$ Edit: No LaTeX doesn't seem to work and btw I didn't study this so it might be taught differently at uni. This was explained to me in/for the context of quantum computing.

[-] i_love_FFT@lemmy.ml 3 points 5 months ago

True! Thanks for the clarification, it's been a while since i played with the maths of quantum physics!

After you measure a spin as 100% up, the state will be close to that for a while, si the next measurement has higher chance of being up, with this probability slowly decreasing with time.

[-] Ziglin@lemmy.world 1 points 5 months ago

I think that assuming the particle has no (extra?) energy it's state does stay the same. That is of course not possible in real life though but the <20 millikelvin in some quantum computers get pretty close.

Also I think nobody says they measure it as 0/100% up, They just say up or down in my limited experience.

Does anyone have any good resources on quantum mechanics? (Most of my information comes from a few professors) There's some useful stuff on chem libretexts (I think that's what it's called) for simple wave functions, but it doesn't seem perfect.