How does a reflective material such as a space blanket reflect heat as well as light? Like, I knew light was reflected off of mirror like surfaces but I can’t comprehend the heat part. Can someone please, explain this to me. How do space blankets work?
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One of the key ways for a hot object to affect a cold one is by glowing at it: having light and light-like radiation fall on you makes you gain heat. In the range of temperatures we’re familiar with on earth, even very hot objects don’t glow very brightly in *visible* light, but they put off a lot of infra-red (this is basically the opposite of ultra-violet) ~~light~~ radiation.
If your body is warm, and your environment is cold, your body is busy glowing in infrared, losing heat with every photon. But if you’re wrapped in a space blanket, which is basically a crinkly mirror, a lot of those photons get bounced back, re-heating you.
You still lose heat through other mechanisms, though, mainly touching-things-that-are-colder-than-you, including air and the ground.
Visible light and heat (technically known as infrared) both exist on the electromagnet spectrum and are waves of energy; thus heat can be reflected like light in a mirror.
One of the ways heat is transferred is by radiation. All objects emit a thermal spectrum, that peaks at a wavelength dependent on their temperature. You are glowing bright in infrared right now. Those blankets reflect that light back at the object (you) emitting it. Incidentally you can experience this by enjoying a warm sunny day. When you’re out in the sun you feel more warmth. This is partly because, well, the sun’s light. It’s the same principle. It’s just that the sun has a very high temperature. This is actually how we know the temperature of stars that are far away, we measure their thermal spectrum.
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