a = s 360/2 p d
Force and energy
E= 1/2 mv2
E= mc2
F = GM1M2/d2
vesc = (2GM/r)1/2
density
D= M/ (4/3) p R3
Kepler
P2 =a3
(M1 +M2) p2 = (4p2/G) a3
Light
c = lf
E = h f
E = sT4
lmax = .003m K/T
D l/l0 = v/c