🔭 Hubble's Law

Hubble's Law is an observation in physical cosmology that galaxies are moving away from the Earth at a speed (v) proportional to their distance (d).
In other words, the farther they are, the faster they move away from the Earth.

v = H d

where
v is the speed at which the galaxy is receding,
d - distance to the galaxy,
H is the Hubble constant,
H = 22 (km/s) / (million light-years)