# The Constants of Mathematics

Science is full of constants. Probably the best known such constant is the velocity of light (c), made famous by Einstein’s Special Theory of Relativity. (He postulated that all observers measuring the velocity of light in vacuum would obtain the same figure, regardless of their own velocity.) Other such constants, slightly less famous, are Planck’s constant (h), the gravitational constant (G) which occurs in Newton’s law of universal gravitation, the charge of the electron (e), the mass of the electron (m e ) and the mass of the proton (m p ). All these constants have units (so their values depend on the system of measurement), but there are also constants which are ‘dimensionless’.