# Temperature of the universe

by Knightycloud
Tags: temperature, universe
 P: 83 Is there a temperature out there at the universe, outside earth's atmosphere? and if there is any, how can we feel it? The sun rays travel through the space and the green house gases absorbs and reflect it over and over again so there is a temperature down on earth. With having no gases or matter out there at the space, is there no temp?
 PF Patron P: 4,980 The average temperature in space is that of the CMB --- about 3 degrees Kelvin. This is what would be radiated to your body if you were in deep space, way away from any large concentrations of matter such as galaxies. Directly outside Earth's atmosphere is a whole different story and would depend on where you are in relation to the sun. EDIT: actually, even inside a galaxy, if you could be far away from the nearest sun so the temp would likely still be about 3 degrees K.
 P: 83 And is that a one reason for the space to have no gases? It's out of the question. Just popped into my mind! :D Because all the gases will have zero volume when it's 0 K, right?
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## Temperature of the universe

 Quote by Knightycloud And is that a one reason for the space to have no gases? It's out of the question. Just popped into my mind! :D Because all the gases will have zero volume when it's 0 K, right?
I don't understand this question --- not sure what you mean by "zero volumn". Intergalactic space DOES have "gas" it's just incredibly thin in most places outside of galaxies (and inside as well, but sometimes less so).
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 Quote by Knightycloud And is that a one reason for the space to have no gases? It's out of the question. Just popped into my mind! :D Because all the gases will have zero volume when it's 0 K, right?
No, at absolute zero the gas would be in a minimum energy state but still take up volume. It's important to understand that a system at a minimum energy state still has energy and momentum. You just can't remove any of it from the system.

Plus, as Phinds said, space still has gas in it. There is a smooth, continuous drop in density as you move away from large bodies such as planets and stars and into interplanetary, interstellar, and intergalactic space.
P: 83
 Quote by Drakkith No, at absolute zero the gas would be in a minimum energy state but still take up volume. It's important to understand that a system at a minimum energy state still has energy and momentum. You just can't remove any of it from the system.
Yea and when we extend the V-T curve (Volume to Temperature) it meets the X axis (Temperature) at some point (-273.17 oC). It's just a theory right? In the actual case there's still a volume. :D

Thank you for the wisdom people. My question is solved!!!
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 Quote by Knightycloud Yea and when we extend the V-T curve (Volume to Temperature) it meets the X axis (Temperature) at some point (-273.17 oC). It's just a theory right? In the actual case there's still a volume. :D Thank you for the wisdom people. My question is solved!!!
There is, but it's a little complicated and involves some quantum mechanical rules when you get near absolute zero. Whether the gas is a boson or fermion matters. It still has a volume, but it is very very very small and you almost can't consider it a gas any longer. Especially if its a boson and becomes a bose-einstein condensate, as I believe that is technically a different state of matter.
http://en.wikipedia.org/wiki/Bose-Einstein_condensate
 P: 4 I have a question. We know the coldest place in space is 0 K. In this temperature atoms don't move. Is there a maximum limit of temperature? If we assume that all the atoms move in light speed what would the temperature be? I'm not a physicist. So maybe my question is nonsensical but if you explain I'll be grateful.
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 Quote by sunay I have a question. We know the coldest place in space is 0 K.
Not true. Absolute zero is not reachable.

 Is there a maximum limit of temperature?
There is not.

 If we assume that all the atoms move in light speed what would the temperature be?
This is not possible. Atoms have mass and cannot move at light speed. Attempting to do the math would give you infinity as an answer. This doesn't actually mean their temperature would be infinity, it means that the math broke down because we used it incorrectly.
 PF Patron Sci Advisor P: 8,903 The maximum possible temperature in theory is 1.42×10^32 kelvin, otherwise known as the Planck temperature - which is very hot. You could grill a galactic mass turkey to golden perfection in a planck time at that temperature - which would be quite a feast.