Velocity of light c = 2.998x10^{10} cm/sec
Gravitational Constant G = 6.6742x10^{8} cm^{3}/sec^{2}gm
Hubble constant H_{o} = 71 km/secMpc = 1/13.7x10^{9} years
Hubble parameter (dimensionless) h = H_{o}/100
Luminosity of the Sun = 3.86x10^{33} erg/sec
Mass of the Sun = 2x10^{33} gm
Distance from Sun to Earth = 1 AU = 1.5x10^{13} cm
Flight time of light from Sun to Earth = 499 sec
Solar constant = 1.388x10^{6} erg/cm^{2}sec
Diameter of the Earth = 1.3x10^{9} cm
Mass of the Earth = 6x10^{27} gm
Mean radius of the Earth = 6371 km
Standard acceleration of gravity = 980.6 cm/sec^{2}
1^{o} of latitude = 110.5 km (at equator) = 111.7 km (at poles)
1^{o} of longitude at equator = 111.3 km

Planck's constant = 6.625x10^{27} ergsec = 4.136x10^{15} evsec
Avogadro's number = 6.023x10^{23} molecules/mole
Normal volume of perfect gas = 2.241x10^{4} cm^{3}/mole
kT = 0.0258 ev at T = 300^{o}K
Gas constant = 8.314x10^{7} erg/K^{o}mole = R = pV/nT
Boltzmann constant = 1.38x10^{16} erg/K^{o}
Speed of sound = 34000 cm/sec
Electronic charge = 1.602x10^{19} coul
Finestructure constant = e^{2}/c = 1/137
Hydrogen atom ground state energy = 13.6 ev = 2.18x10^{11} erg
Bohr radius = 5.29 nm
Mass of unit atomic weight = 1.6603x10^{24} gm
Nucleon rest mass = 1.67x10^{24} gm
Electron rest mass = 9.109x10^{28} gm
Nuclear Radius = (1.3x10^{13})A^{1/3} cm (A = mass number)
