if the universe is so big and so cold (close to the absolute 0) how can it be that inside it there are small (compared to it) things like stars and planets that are way hotter than its temperature? how can Earth climate get hotter and hotter if it’s surrounded by such a cold environment?

Question

if everything that is surrounding us and everything else (the sun, other stars, planets etc) is cold to the point of beeing at absolute zero, how can things be at such a higher temperature? how can, for example, a spaceship keep a confortable temperature in the inside if outside there is such a massive temperature drop?

sorry for the many questions, but they all are part of the same big one 😀

In: 10

Answer 1

Vacuum is a great insulator.

It’s less that the universe is at absolute zero, and more that there is nothing to facilitate the transfer of heat energy. Space isn’t cold, it’s nothing, you can’t touch it.

Now the suns rays travel through space, pretty much uninterrupted and hit the earth heating it up. A good amount of that heat should be reflected back out into space.

Global warming is a build up of material in the atmosphere that is holding onto that heat and not letting it escape. A good example is being in a car on a hot day. The greenhouse gases are the car windows, they let the light in but keep the heat from getting out.