How hot is space

[Bob The Great]

I was working another 10 hour day and suddenly 2 hours in a thought popped into my head. I'm thirsty. So I drank some water, and that must have gotten my brain running cause I suddenly thought "How hot is space". I did a search when I got home, and couldn't find out.

My guess was that it doesn't actually get hot nor cold, but it transfers energy that then becomes heat when it hits something such as my neck and ears giving me sun burn. But where does the cold come from? Perhaps I slept through to many science classes. Could you guy's help me out so tommorow when I'm working another 10 hours I can work in peace! Thanks.

[OuTpaTienT]

It's but a smidgen above 0°K. So it's just about as cold as it can physically get. At least this is what I recall reading...somewhere.

[OuTpaTienT]

Here ya go. It's 2.7° Kelvin.

[caddmannq]

Only matter gets hot.

Space is nothing. The absence of matter.

Cold is nothing. The absence of energy.

The question is "where does heat come from."

Empty space is only nearly empty: the tiny bits of matter in it keep it just above absolute zero, by absorbing light from the stars. But the heat is re-radiated, keeping things cold.

When enough matter collects in one spot, however, (say a planet) more heat can collect in one spot. It can stay warmer.

Once enough matter collects to make a star, it undergoes fusion, and radiates heat like crazy.

[Bob The Great]

So it's cold?

[Bob The Great]

cool! Thanks! I thought space was nothing, but then I thought how does it get cold then? That really makes sense! Thanks! My mind will be at rest tommorow!

[vass0922]

If we put a thermometer in darkest space, with absolutely nothing around, it would first have to cool off. This might take a very very long time. Once it cooled off, it would read 2.7 Kelvin

Hmm but that is only in "the darkest space with absolutely nothing around it". Here we have the sun and other planets... I mean is that really possible (I'm thinking we don't know )?

How about the temperature out near a standard orbit of the earth?

[Gomer]

2.7K vass... once you escape the earths atmosphere there is nothing out there to have any heat associated with it. (in space that is)

[PartsMan]

Well in terms of a former teacher of mine:

There is no such thing as "cold."
There is heat, and there is lack of heat.

[fritz the cat]

Originally posted by PartsMan


There is no such thing as "cold."
There is heat, and there is lack of heat.

But we have to call it something, hence the "name" cold. And most people can't understand "cold" as being the absence of heat, so they create a definition/idea to go with the word.