ivi said:

Still, if you put a thermometer in space with no light or heat source around and absolutely no background radiation, you'd get the temperature reading of 2.7279K (0K =absolute zero=-273C) - the temperature of the space if you please. It was determined by the NASA COBE satellite in 1992. This is, however, not the temperature of space itself, but that of the primordial cosmic background radiation left over from the Big Bang. No matter where you go, you cannot escape it.

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dblaney18 said:

..in a vacuum, there are no molecules, and since there aren't any molecules, there cannot be a temperature...

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dblaney said:

Depends on where. Clearly the vast majority of outer space is vacuum. In a vacuum, there is no such thing as temperature. Temperature is a measure of kinetic molecular energy, but in a vacuum, there are no molecules, and since there aren't any molecules, there cannot be a temperature. However, planetary and celestial bodies aside, there are gases in outer space, and they can range in temperature from 2K to millions of degrees K.

An interesting question would be what temperature is a black hole.

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mca0824 said:

Well that's a good question.  The answer is not so simple.  Temperature is equal to a subjects vibration. like if water is rapidly vibrating it begins to boil and some of it is moving so quickly that some of it escapes as steam.  If water is vibrating very slowly it turns to ice.  So fast motion = hot  slow motion = cold.  In space their is no atmosphere to vibrate so no heat transfer.  If you are in view of the sun however you will be interacting with the suns rays and you will vibrate rapidly so you will get hot, very hot.  The further from the sun you are the less of the suns rays you will interact with so you would get cooler as you are further away.  If you are not in view of the sun then you would not have anything around moving so you would vibrate slower. So you would be cold.  very cold. Like minus 400 degrees f cold.  In short, it depends on your proximity to the nearest star, atmosphere, etc..

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imachavel said:

mca0824 said:

Well that's a good question.  The answer is not so simple.  Temperature is equal to a subjects vibration. like if water is rapidly vibrating it begins to boil and some of it is moving so quickly that some of it escapes as steam.  If water is vibrating very slowly it turns to ice.  So fast motion = hot  slow motion = cold.  In space their is no atmosphere to vibrate so no heat transfer.  If you are in view of the sun however you will be interacting with the suns rays and you will vibrate rapidly so you will get hot, very hot.  The further from the sun you are the less of the suns rays you will interact with so you would get cooler as you are further away.  If you are not in view of the sun then you would not have anything around moving so you would vibrate slower. So you would be cold.  very cold. Like minus 400 degrees f cold.  In short, it depends on your proximity to the nearest star, atmosphere, etc..

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Speaking of water there is no "water" in space. "Water" is held together by the pressure of the atmosphere. In space it's ice at 32 F and boils at 33 F. It's one of my favorite molecules, and of course a very critical one to my life function.

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krypto2000 said:

imachavel said:

mca0824 said:

Well that's a good question.  The answer is not so simple.  Temperature is equal to a subjects vibration. like if water is rapidly vibrating it begins to boil and some of it is moving so quickly that some of it escapes as steam.  If water is vibrating very slowly it turns to ice.  So fast motion = hot  slow motion = cold.  In space their is no atmosphere to vibrate so no heat transfer.  If you are in view of the sun however you will be interacting with the suns rays and you will vibrate rapidly so you will get hot, very hot.  The further from the sun you are the less of the suns rays you will interact with so you would get cooler as you are further away.  If you are not in view of the sun then you would not have anything around moving so you would vibrate slower. So you would be cold.  very cold. Like minus 400 degrees f cold.  In short, it depends on your proximity to the nearest star, atmosphere, etc..

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Speaking of water there is no "water" in space. "Water" is held together by the pressure of the atmosphere. In space it's ice at 32 F and boils at 33 F. It's one of my favorite molecules, and of course a very critical one to my life function.

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Are you saying the molecular bonds would break and it would become hydrogen and oxygen or are you saying that when water freezes or evaporates that it's no longer water?

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krypto2000 said:

There's no such thing as a true vacuum though, it can't physically exist, so it makes no sense to ask what the temperature would be. On the quantum level space itself fluctuates with energy and matter popping into and out of existence so even if somehow you could create a complete vacuum it would not last. If something were at absolute zero it would also expand to fill all of space itself which is obviously impossible. Absolute zero is just the theoretical bottom.

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