eli5: Why is it temperatures can go up to the trillions but only down to -273?
In: Physics
Temperature is a measure of how much the particles of a thing are moving. You can keep pumping more and more energy into it and they’ll move more and more, but “absolute zero”, at -273C, means that they’re *not* moving. And that’s it – you can’t move less than “not moving to begin with”.
Temperature is a measure of how much the molecules are vibrating. When they stop, that is -273. You can always go faster, (up to light speed), but you cannot go slower than not moving at all.
People have given you the physics answer, but it’s worth acknowledging the linguistic one as well.
Most of our uses for temperature relate to either freezing or boiling of water. Cooking is the obvious one, but it’s also very important for our understanding of weather, and to some degree even practising medicine.
This is to say the average person benefits from understanding generally what temperature boiling and freezing are, so we decided to make freezing zero and boiling one hundred. This makes it easy for people to remember.
Ultimately though on the grand scheme of physics freezing of water is pretty far towards the cold end of the spectrum. So when you use these measurements for physics it can feel like we set some sort of arbitrary limit on how cold things can get.
Temperature is the measure of the *average kinetic energy* of a system. Kinetic energy can always go up, but it can’t go below zero. (The number -273 is just one we picked so zero lines up with where water freezes.)
In other words, it’s how hard you’re going to be hit by random stuff just bouncing around.
Note that *kinetic energy* is not speed. A heavy thing traveling at 60 mph has more kinetic energy than a light thing traveling at the same speed.
Note also that temperature can never be zero, because of quantum effects.
Temperature is a measure for the amount of one sort of energy in a system
It is the same as your piggy bank. The amount in it can go up as high as you can imagine, but it can never go lower than 0
Temperature is a measure of how much energy something has. 0 degrees Kelvin means zero energy (which also can not be reached).
-237 degrees Celsius is equal to 0 degrees Kelvin, it’s just that Celsius was zeroed at the freezing point of water.
Because there is no such thing as cold only the absence of heat and 0 degrees C or F are both slightly arbitrary. You can always add more energy and therefore more heat but you can’t take away what isn’t there.
Your exact answer is here:
The best explanation I’ve ever heard.
You can’t have negative energy of something. Absolute zero means that something has no more heat energy. Absolute zero with Celsius just happens to be -273.
Is -273 stopped, or just so slow we can’t detect movement of the molecule in our lifetime?
Is it a exponential slowdown between -272 and -273, if so, why not exponentially more to -274?
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