The Dewey Decimal System, devised in 1876, organized books by subject — still used in libraries worldwide.

Economist Arthur Laffer famously sketched the Laffer Curve on a napkin during a dinner meeting in the 1970s.

Mozart composed his first symphony at age eight.

The mathematical constant tau (τ = 2π) is championed by some as more natural than pi for describing circles.

High jumpers use the Fosbury Flop — jumping backwards over the bar — introduced by Dick Fosbury at the 1968 Olympics.

The Olympic rings represent the five continents of the world — but no particular ring is tied to a specific continent.

Particles can exist in multiple states until observed.

Hip-hop culture originated in the South Bronx in the early 1970s and encompasses DJing, MCing, breakdancing, and graffiti art.

Particles can exist in multiple states until observed.