How does cold transfer if it’s just the absence of heat?


How does cold transfer if it’s just the absence of heat?

In: Physics

Cold doesn’t transfer, as in cold moving from one object to another. As you said cold is the absence of heat, so a colder space tends to attract heat. The cold isn’t moving into a new area, heat is being sucked away from said area into the colder space. Think of it like oxygen in a vacuum where the barrier between the two gets broken (window in space ship breaks. The vacuum isn’t moving into the oxygenated area, the oxygen is being pulled into the vacuum.

It was explained to me this way. There is no such thing as cold, it’s simply less heat, not necessarily the absence of heat. We can’t measure cold, we can measure heat. So even though something feels cold to the touch, it’s simply far less hot than your hand and therefore it transfers the heat from your hand faster than your hand can transfer the heat from the “cold” item. I’m no scientist and I’m sure others can explain better, but it helped me when explained that way.

Cold doesn’t really transfer. The second law of thermodynamics states that heat transfer only occurs from hot to cold. In other words, heat will never move from a cold to a hot object. Heat will be transferred from a hot region to a cold region until there is no temperature difference.

Cold doesn’t transfer but the difference in temperature between a cold substance and a hot one increases the rate at which the hot substance loses heat to the cold substance.

Cold do not travel as it is not a thing. It is heat that travel in the other direction. It is heat that travel from the warmer object to the colder object. The result that the warmer object the a colder and the colder object get warmer.

The transfer is exact the same as when heat is transferred. There is not fundamental difference between when it is warmer outside and it hear up a house compared to when it is colder outside and it cool down your house.

There is a practical difference and that is that you can generate heat by burning fuel or using electricity. Covering heat to other energy is a lot harder hand you need a temperature difference to do that. So it is a lot easier to warm stuff upp then to cool then down.

Cold sucks the heat out of other things. If you have a cold thing and a hot thing and put them together the heat will transfer to the cooler part until they both reach the same temperature as their surroundings.

Others have covered thermodynamics. There is a slight/not-really-exception to this which is convection. Warm gasses rise causing cooler gasses to fall, meaning in a tall room, the cold comes down. Also if you open a door on a windy day, physically cold air may blow in and replace your warm air. In a closed system the warm air would give its heat to the cold air in time, but this is why it annoys me that “smart” people poke fun at the commonly said “you’re letting the cold in”. You can absolutely let cold air in.

/end rant.

Think of heat as a bunch of super bouncy balls. If you have big box and you pour a lot of these balls in one end of it, then they are going to be bouncing into each other and on the walls. This is the hot end of the box.

In the other end of the box there are no balls. This is the cold end of the box.

Now, every time a ball bounces towards the hot end it’s more likely to bounce of another ball, because there’s loads of them.

But if it bounces towards the cold end it’s got more free space and is less likely to bounce of another ball.

This way balls migrate over towards the cold end until the balls are pretty much evened out across the box. The cold end has become hotter and the hot end has become colder.

But the emptyness(cold) hasn’t moved to the hot end, it’s just that some bouncyness has moved from the hot end to the cold side so now the hot end is less hot (or less full of bouncy balls)

Heat transfers when particles that are moving/vibrating fast collide with slower moving/vibrating particles, which have lower temperature. This results in the faster particles slowing down and the slower particles speeding up until a balance is restored and the temperature evens out. So the particles transferring their kinetic energy is basically them transferring heat.A microwave uses this while heating our food, the microwaves vibrate the water molecules, speeding them up, thus heating our food.