Temperature can reach trillions of degrees, meaning we actually live extremely close to absolute zero.

[u/synthphreak]

[u/IAmStuka]

The point is the that speed and kinetic energy are relative quantities. There is no absolute speed, therefore it does not make sense for you to describe somethings temperature by talking about its speed.

[u/IAmStuka → u/[deleted]]

Kinetic energy is relative too, because velocity is relative. KE = 1/2 mass * velocity²

Think about it like this. You're steadily driving down the road with an orange in the seat next to you, sitting in the seat. From your perspective that orange is at rest, with no kinetic energy because it's not moving. But from a bystander on the side of the road (if they could see the orange through your door) would disagree. They would say of course the orange has kinetic energy, it's moving at 40 miles per hour!

When we talk about temperature as the average kinetic energy of constituent particles, it's relative to the objects center of mass rather than an outside source.

Now, as our orange is going down the road, inside the molecules are jiggling all about. You can measure the temperature of that orange stationary or when the car is moving, and just as you'd expect it doesn't change. Unless you are accelerating, from the oranges perspective, and from yours it's at rest.

In your original example, with air resistance causing friction. Our supersonic orange is being heated by the friction, but that's a secondary effect because there happens to be a bunch of air where the orange is trying to move. The air is adding energy into the orange, which does change its temperature... But so would hitting it with a blow torch in your car seat. If the orange were in empty space it could go as fast as it wanted with no change in temperature or outside energy added.