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Probably a stupid question, but will we ever have something like a microwave to make things cold? Is there a reason this can't exist?
(lemmy.dbzer0.com)
this post was submitted on 14 Sep 2023
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if you see a dark area you can turn on a flashlight to emit light towards the area and make it not-dark.
If you see a lit area and you want it unlit, there is no anti-flashlight you can point towards it to suck the light out.
Similar kind of thing, heat can only be given, not taken. heating stuff up is easy, but for cooling the best you can do in most cases is to make it easier for the thing to give you its heat (ex by the atmosphere colder), but you can't force it.
This is fundamentally not true.
Light is made of electromagnetic waves. If you can control the timing of those waves precisely enough, you can add another light with the opposite phase (an inverted wave) that will cancel out the other light.
This is what happens in the famous "double slit experiment". It's also the same principal as noise cancelling headphones albeit with sound pressure waves instead of EM waves.
Scientists have actually cooled atoms very close to absolute zero by shining a laser at them
I said "in most cases". I am aware that it is possible. We're looking at a macroscopic system here though. A microwave, not a couple of atoms in a lab. good luck cooling a couple of atoms in the center of an opaque blob of food with a laser
I completely agree with your third point where you said "in most cases".
It was your first two points trying to create an analogy with light that I was responding to