gravitational constant

is the attractive force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them.

The constant of proportionality is called , the gravitational constant, the universal gravitational constant, Newton's constant, and colloquially big G. The gravitational constant is a physical constant which appears in Newton's law of universal gravitation and in Einstein's theory of general relativity.

The gravitational constant is perhaps the most difficult physical constant to measure.

where: