[yt-users] Physical constants list

[Sam Patrick]

Hi,

I'm relatively new to yt and was wondering if there was any resource 
outlining the names of all physical constants programed into yt and how 
to access them i.e:

Newton's constant: G
Boltzmann constant; kboltz
Speed of light: c
etc.

specifically I need the name for the mass of hydrogen used within the 
program but I can foresee such a list being very useful in the future.

many thanks,
Sam P