The CT scan was invented by Godfrey Hounsfield in 1972 — enabling 3D internal imaging for the first time.

QWERTY keyboard layout was designed in 1873 partly to separate commonly used letter pairs and reduce mechanical jamming.

3D printing (additive manufacturing) was invented in the 1980s — early machines cost hundreds of thousands of dollars.

Fiber optic cables transmit data as pulses of light and can carry thousands of simultaneous communications.

The electric motor converts electrical energy into motion.

The printing press was invented around 1440 by Gutenberg — within 50 years, over 20 million books had been printed.

The Pentagon has plans prepared for zombie outbreaks as training scenarios.

The first emoji was created in 1999 by Japanese designer Shigetaka Kurita for a mobile internet platform.

There are classified inventions that have never been revealed publicly.