Neutron stars are so dense that a teaspoon of their material would weigh about 6 billion tons

Your body has about 37.2 trillion cells

"Your body contains approximately 37.2 trillion cells, surpassing the Milky Way's stars."

Subrahmanyan Chandrasekhar calculated the mass limit for white dwarfs at age 19 on a boat to England

Subrahmanyan Chandrasekhar calculated the mass limit for white dwarfs at age 19 on a boat to England

A single teaspoon of soil contains more microorganisms than people on Earth

A teaspoon of soil harbors more microorganisms than Earth's human population

Pi

Pi has been calculated to over 100 trillion digits

Observable universe

There are more stars in the universe than grains of sand on all of Earth's beaches

Stellar black hole

Schwarzschild radius ≈ 3 km for solar-mass black holes