old_contents: """
  
  Physical constants in cgs.
  
  Copyright 2012, Casey W. Stark. See LICENSE.txt for more information.
  
  """
  
  import numpy as np
  
  from dimensionful.common_units import *
  from dimensionful.quantity import Quantity
  
  # speed of light
  c = Quantity(2.99792458e10, cm / s)
  
  # Gravitational constant
  G = Quantity(6.673e-8, cm**3 * g**-1 * s**-2)
  
  # Boltzmann constant
  k = Quantity(1.38064e-16, erg / K)
  
  # Planck constant
  h = Quantity(6.626070e-27, erg * s)
  hbar = h / (2 * np.pi)
  
  # atomic constants
  e = Quantity(4.8032068e-10, esu)
  m_p = Quantity(1.672623e-24, g)
  m_e = Quantity(9.109389e-28, g)
  amu = Quantity(1.6605402e-24, g)
  
  # radiation
  sigma_T = Quantity(6.6524588e-25, cm**2)
  sigma_SB = Quantity(5.67e-5, g * K**(-4) * s**(-3))
  a = Quantity(7.5657e-15, g * K**(-4) * cm**(-1) * s**(-2))
  
new_contents: """
  
  Physical constants in cgs.
  
  Copyright 2012, Casey W. Stark. See LICENSE.txt for more information.
  
  """
  
  from dimensionful.common_units import *
  from dimensionful.quantity import Quantity
  
  pi = 3.141592653589793
  
  # speed of light
  c = Quantity(2.99792458e10, cm / s)
  
  # Gravitational constant
  G = Quantity(6.673e-8, cm**3 * g**-1 * s**-2)
  
  # Boltzmann constant
  k = Quantity(1.38064e-16, erg / K)
  
  # Planck constant
  h = Quantity(6.626070e-27, erg * s)
  hbar = h / (2 * pi)
  
  # atomic constants
  e = Quantity(4.8032068e-10, esu)
  m_p = Quantity(1.672623e-24, g)
  m_e = Quantity(9.109389e-28, g)
  amu = Quantity(1.6605402e-24, g)
  
  # radiation
  sigma_T = Quantity(6.6524588e-25, cm**2)
  sigma_SB = Quantity(5.67e-5, g * K**(-4) * s**(-3))
  a = Quantity(7.5657e-15, g * K**(-4) * cm**(-1) * s**(-2))
  
subject: Remove unnecessary numpy import