Earth radiates heat to what? 3

[BrianE22]

I keep reading that the earth gets rid of its energy by radiation. But to what? Don't you need 2 masses at different temperatures for radiation to occur?

 

[TugboatEng]

Radiation occurs independently of outside factors. Any nearby bodies may reflect some radiation back or emit their own.

Supposedly, if you pour a thin layer of water on a well insulated black surface, protect it from and air movement, and have a very dark sky at night, you can freeze the water even if the ambient temperature is above freezing. I think some ancient Middle Eastern cultures used to do this.

 

[SuperSalad]

I believe it is mostly infrared radiation; which can travel through vacuum, as far as I know.

- Andrew

 

[btrueblood]

"to what"

Well, before Penzias and Wilson, the answer would be "to infinity", or 0 K - deep space. Today, we know the big bang left a cosmic background, so about 3 K (still deep space). If you need mass to support your theory (not sure about that), there is plenty of mass in interstellar space to radiate to.

 

[dik]

...and the CO[sub]2[/sub] reduces the amount of heat radiated back into space...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[BrianE22]

If you need mass to support your theory...

Ahh-yes. I'm mixing up radiation with gravity - thanks.

 

[enginesrus]

Heat radiates to cold, space is cold.

 

[btrueblood]

Sigh.

 

[SuperSalad]

Sigh.

In space, no one can hear you sigh.

- Andrew

 

[dik]

pardon?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[btrueblood]

Andrew: I'm LOL in vacuo.

 

[ACtrafficengr]

Heat radiates to cold, space is cold.

I had a hard time explaining to a banker friend how frost can form when it's 33F. Her car was stuck in some mud, and she thought she needed to wait until the air dropped below freezing for the mud to stiffen up. I told her to try it, it might work. It did, and she was quite confused. She couldn't grok the idea of a clear night sky being effectively close to absolute zero.

My understanding is space isn't so much cold as empty. If temperature is the average energy of atoms, and there are almost no atoms, and nothing to radiate or reflect heat, then temperature loses its meaning.



My glass has a v/c ratio of 0.5

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[Compositepro]

Grok . Temperature is defined as the kinetic energy of a molecule, including all vibrational modes. Radiation does not require that there be any matter with which to interact. A photon (a quantum of energy) can just travel off into space and not reflect back. In that case space would appear to be at absolute zero. However, there is enough matter in the universe that you cannot "see" through it, and it is at the microwave background temperature.