Physical Constants
Speed of light	c	=	3.00 × 10	cm s
Gravitational constant	G	=	6.67 × 10	gm cm s
Planck's constant	h	=	6.63 × 10	erg s
		=	h / (2 × )
Mass of proton	m	=	1.67 × 10	gm
Mass of electron	m	=	9.11 × 10	gm
Charge of electron	e	=	4.80 × 10	gm cm s
Boltzmann's constant	k	=	1.38 × 10	egs K
Radiation constant	a	=	7.56 × 10	egs cm K
Stefan-Boltzmann constant		=	5.67 × 10	erg cm s K
Electron volt	eV	=	1.60 × 10	egs
Rydberg constant	R	=	2.18 × 10	erg	=	13.6 eV
Fine structure constant		=	7.30 × 10		=	1 / 137
Avagadro's number	N	=	6.023 × 10

year	=	× 10	s
parsec	=	3.26	light-year
m s	=	2.24	mile hour
kgm	=	2.20	pound
erg	=	1	gm cm s
erg	=	10	Joule
dyne	=	10	newton

Astronomical Constants
Radius of the Moon	R	=	1.74 × 10	cm	=	R / 4
Radius of Mars	R	=	3.40 × 10	cm	=	R / 2
Radius of the Earth	R	=	6.37 × 10	cm
Radius of Jupiter	R	=	7.14 × 10	cm	=	10 × R
Radius of the Sun	R	=	6.96 × 10	cm	=	100 × R
Astronomical Unit	AU	=	1.50 × 10	cm	=	200 × R
Parsec	pc	=	3.09 × 10	cm	=	3.26 light-years
Light-year	ly	=	9.46 × 10	cm
Earth mass	M	=	5.98 × 10	gm
Solar mass	M	=	1.99 × 10	gm
Solar luminosity	L	=	3.90 × 10	erg s
Solar temperature	T	=	5.78 × 10	K
Density of water		=	1	gm cm
Density of rock		=	3	gm cm
Density of steel		=	8	gm cm