Asked my college biology professor this and the only answer she was able to give me was “that’s just how it works” but I’m not satisfied with that. Why do molecules vibrate?
In: Biology
It doesn’t, heat *is* the movement of the molecules. What we measure as heat is the energy of that movement.
Vibrating molecules are heat so as they vibrate they bump into other molecules they pass on that heat/energy.
A molecule can have kinetic energy, just like anything else can. When that kinetic energy comes from uncoordinated movement (the molecules are all moving chaotically, not together) then we call it heat. That’s simply the word we’ve chosen to describe that thing.
Now, why is this chaotic motion the ‘natural’ result of energy being released? Why do friction, chemistry, and radiation all create this chaotic heat? What happens to the uniform motion of a thrown ball that turns into chaotic microscopic motion (heat) when it lands?
This has to do with statistics. When we allow the moving ball to bounce off of molecules, the ball in more likely to give some of its energy to them than they are to give energy back, and this is because a single moving ball has a lot more energy than a single molecule. The ball will slow down until it has energy similar to a single molecule – not enough energy to notice.
A much smaller ‘ball’, like pollen, will visibly jiggle too. It’s small enough that the energy of a single molecule is significant, but large enough that we can see it.
Because our current understanding of the universe says that entropy (chaos) is the natural state of everything. Given enough time, everything breaks down. Buildings will fall, mountains turn to dust, big rocks turn into little rocks, etc.
Kinetic Energy (movement energy) is transferred in one of three ways. 1) light waves. 2) Sound waves. 3) Heat waves. All of these involve molecules running into each other just at different sizes, speeds, and the amount of energy they transfer each time.
Molecules vibrating causes heat because energy is being transfered. This happens until all molecules that are similiar reach the same energy level/temperature. Heat spreads because of entropy. It is not natural to have an area with a high concentration of excess energy. In order to spread the energy as far as they can, the molecules vibrate. When the Molecules vibrate enough, they start running into other molecules, and those collisions give off what we refer to as heat (also light and sound).
The heat gun or whatever you are using to “heat” and object is just causing small particles with lots of energy to run into stationary(relatively) molecules. These collisions are causing them to start vibrating, causing more collisions, thus causing nearby Molecules to vibrate, on and on, and on.
Heat is a result of vibrations, but vibrations also spread heat.
Think measuring temperature as a measure of speed like miles per hour or KM per hours but instead of measuring the speed of cars you are measuring the speed of molecules.
Hot = molecules are moving fast
Cold = molecules are moving slow
When something melts the heat (molecule speed) is going up and the molecules start moving so fast they are not standing still and flowing like water
When something like water freezes the molecules slow down to the point where they basically stop.
The movement and vibration of molecules is heat.
So they move/vibrate, and then you point at it and say “look, heat”.
In other words, by definition.
If they all stopped moving, there would be no heat. And you wouldn’t be able to be there to observe it, because you being alive and performing observations alao by definition involves moving particles.
So you just have two definitions. One is that heat is moving particles. Second that if you’re thinking about it, there are moving particles enabling it, and therefore heat.
heat makes molecules move cause they’re like tiny bouncers at a club. more heat equals more energy and they start dancing around. it’s just their vibe you know
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