This is what I was wondering: How is heat different from sound? - Factual Questions - Straight Dope Message Board we have anti-sound; is anti-heat possible? Or is it fundamentally impossible by the laws of physics?
Every Metroid game, Crysis, Diablo and multiple Zelda games if we include frost magic. See http://tvtropes.org/pmwiki/pmwiki.php/Main/FreezeRay . Warning: not responsible for time wasted clicking links in TV Tropes.
Sound is pressure waves, so ‘anti-sound’ is really just another sound wave but at the opposite phase and perfectly in wync, so the 2 pressure waves cancel eqch other out as they reach your ears. AIf either sound changes frequency, or even if you move relative to either sound source, the cancelling effect will diminish or end. In reality, the environment is louder (more sound waves).
Heat isn’t like that – it isn’t waves on a background medium (like sound waves in air) – it’s more like the background medium itself. It’s random motion of the molecules making up the background. Being mainly random, it can’t be ‘cancelled’ by opposite motion.
So yes, our current understanding the laws of physics doesn’t allow for ‘anti-heat’.
All we can do with heat is to move it elsewhere. Thus a cool wet washcloth on your neck msakes you feel cooler, by transferring body heat to the washcloth. after a few minutes, you have to turn it over, or re-cool it in cold water. And swamp coolers or air conditioners work the same way – they transfer heat out of the air and exhaust it outside, so then the cooler air absorbs heat from your body, thus cooling you. Basically, just moving the heat from you to the outdoors.
Not really, we can already use lasers to cool things, which could be interpreted as a “cold ray”, meaning something that can lower the temperature of a target remotely, preferably through a vacuum, without projecting cold matter onto it. Now we just have to figure out how to do it to more than a few gas atoms.
Although my preference for cold rays would be something that projects negative energy. i.e. transfers heat to the source instead of dissipating it randomly.