Racemic is probably not the correct word here. I’m just wondering if the EM radiation that we can see from earth has any net polarization in any direction. If yes, how does that occur?
Back in the 40’s, Albert Hiltner discovered that starlight coming from the milky way is slightly polarized by the galaxy’s magnetic field. In fact that polarization is a big factor in mapping the field. I think the polarization comes about through the field imposing structure on interstellar dust, hence a preferred angle of reflection, but there are likely other factors in play as well.
The cosmic microwave background radiation (CMB) is also mildly polarized, although properly speaking we can’t “see” it since it’s not visible light. Roughly speaking, its polarization arises from the very early universe cooling slightly faster in some regions than in others; more info than you ever wanted to know about it can be found here. These temperature fluctuations are in turn thought to be caused by inflation.
Last I heard, Gamma Ray Bursts are highly polarized, possibly because they are generated by electrons interacting with a strong magnetic field (i.e. synchrotron radiation).
There’s a bit on polarization in this New Scientist piece:
Space Radiation May Select Amino Acids For Life
Also, light reflected from large surfaces is polarized. This can be a non-trivial amount of the radiation near an ocean or other body of water.
Funny that you should bring that up. This is why I was asking about polarization. I was reading up on dynamic kinetic resolution the other day, and one of the review article I read mentioned that CPL will decompose one enantiomer preferentially. I then wondered if this could be the original cause of a high ee of molecules that eventually led to life on earth. I see that my thoughts were not terribly original :D. Oh well. Thanks all who posted relevant info.