text: # this should go away, and be replaced everyhwere by astropy units
  
  '''Units, with everything in terms of cgs.'''
  import numpy as np
  
  # speeds
  c = 29979245800.0
  
  # times
  second = 1.0
  minute = 60.0*second
  hour = 60.0*minute
  day = 24.0*hour
  century = 36525.0*day
  year = century/100.0
  
  # angles
  radian = 1.0
  degree = np.pi/180.0
  arcmin = degree/60.0
  arcsec = arcmin/60.0
  
  
  # distances
  cm = 1.0
  m = 100.0*cm
  nm = 1e-9*m
  km = 1000.0*m
  Rsun = 695660*km
  Rearth = 6378.1366*km
  Rjupiter = 71492*km
  au = 149597870700.0*m
  pc = au/arcsec
  ly = c*year
  
  
  # masses
  g = 1.0
  kg = 1000.0
  Msun = 1.9884e30*kg
  Mjupiter = Msun/1.047348644e03
  Mearth = Msun/332946.0487
  mp = 1.66053892e-27*kg
  
  # energy
  erg = g*cm**2/second**2 # (should be 1!)
  Joule = 1e7*erg
  
  # power
  Lsun = 3.8270e33 # erg/s
  watt = 1e7
  
  # temperatures
  K = 1.0
  Tsun = 5771.8 # Mamajek
  k_B = 1.3806488e-23*m**2*kg/second**2/K
  sigma_SB = 5.6704e-5*erg/cm**2/second/K**4
  
  # other
  G = 6.67428e-11*m**3/kg/second**2
  