Comments by "seneca983" (@seneca983) on "What the Crookes Radiometer can teach us" video.

vbddfy euuyt What's worse, the architect (Viñoly) had already made the same mistake before in Las Vegas but he thought that London would be cloudy enough that it wouldn't matter.
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17:30 "It would be great if we could develop some sort of selectable Low-E window. Maybe the glass could be reversible so it reflects short and medium-wave IR only on one side." I think that kind of reversible window is impossible. The reflectivity has to be the same in both directions because physics is time-symmetric.
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@AsterInDis Mirrors can't function asymmetrically.
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@AsterInDis "I know we can't get turn-on-turn-off windows" Boeing 787 Dreamliner has electronically dimmable windows. "window films exist that make it so that heat is reflected off what kinda looks like a mirror but allows a sufficient amount of light in" Windows that reflect infrared but not visible light were talked about in this video. They're obviously possible and that's not what I was reacting to. The part I quoted wanted windows that reflect IR only on one side which is impossible because reflection on one side but not the other would violate very basic laws of physics. In short, one-way mirrors cannot exist. The "one-way mirrors" used in e.g. recognizing a perpetrator of a crime are just half-reflective mirrors and the "one-way" aspect is simply one side being lit much more brightly than the other.
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@Owen_loves_Butters It's definitely not possible. It would violate some very basic laws of physics. Bulletproof glass is a different thing because the process where either the bullet or the window breaks upon collision is not a reversible process.
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@Owen_loves_Butters I'm quite confident that it is impossible. Physics is (mostly) time-symmetric and a one-way mirror would break that. I think there isn't a reasonable argument that that could be overcome. Technically some particle physics phenomena exhibit T-symmetry breaking but those are not relevant to light being reflected off windows. Negative temperatures are possible in systems where the energy level is bounded from above such as a spin system.
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