The Fibonacci sequence appears in sunflower seed patterns, pinecones, and galaxy spirals

Dark matter

Vera Rubin's galaxy rotation curves provided the strongest early evidence that most matter in the universe is invisible

Henrietta Swan Leavitt

Henrietta Leavitt discovered the period-luminosity relation of Cepheid variables

Chemistry: A Volatile History

52! ≈ 8 × 10^67 possible arrangements of a deck of cards

Barbara McClintock

Barbara McClintock discovered transposons in maize

Rosalind Franklin

Rosalind Franklin's X-ray diffraction image, known as Photo 51, was critical to discovering the structure of DNA

Keyboard layout

QWERTY was designed to prevent typewriter jamming