The Aztec Triple Alliance rapidly expanded from 1428 — within 90 years it controlled much of Mesoamerica.

The Olympic Games are held every four years.

Fact #923 · Human Body

The first successful kidney transplant occurred in 1954.

Fact #1221 · Human Body

Your stomach replaces itself every few days.

Fact #1696 · Human Body

The human eye can adapt to low-light conditions.

Fact #279 · Human Body

The brain consumes a significant portion of the body's energy.

Fact #967 · Human Body

In 1953, Watson and Crick described the double-helix structure of DNA.

Fact #1022 · Human Body

Some birds have hollow bones to reduce body weight for flight.

Fact #889 · Human Body

The fangtooth fish has some of the largest teeth relative to body size in the ocean.

Fact #1392 · Human Body