Bekenstein–Hawking formula has been termed as one of the most beautiful equations in physics c

Bekenstein–Hawking formula has been termed as one of the most beautiful equations in physics connecting mathematically quantities from thermodynamics, gravitation and quantum mechanics, an expression for the entropy of a black hole in terms of the surface area of its event horizon;
S = kc³A/4Gℏ
Where;
S - Entropy
k - Boltzmann constant
A - Area of the event horizon
ℏ - Reduced Planck’s constant, h/2π
c - Speed of light
G - Gravitational constant
Today we mark the 4th death anniversary of one of, if not the greatest mind to ever grace the world of physics, theoretical physicist, cosmologist and author, Stephen Hawking who died on this day 14th March 2018 in Cambridge, United Kingdom.