The United Nations has declared 2015 the International Year of Light, to showcase “to the citizens of the world the importance of light and optical technologies in their lives, for their futures, and for the development of society.”

Light is absolutely fundamental to theoretical physics, from Einstein’s general relativity to the quantum computers of the not-too-distant future. It literally and figuratively lights up our lives in ways too numerous to list, so we stuck with just 20.

Scroll down and let the trillions of photons stimulate your optic nerves to perceive colours and shapes and pithy factoids, and enjoy.

MORE BITES OF PI: