Steel was a rare luxury material in the ancient world — mass production became possible only in the 19th century.

The electric motor converts electrical energy into motion.

The Brooklyn Bridge was one of the first steel-wire suspension bridges.

The Internet weighs approximately 50 grams — the mass of the electrons in motion that carry its data at any given moment.

The invention of the compass improved long-distance navigation.

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

The mechanical clock improved timekeeping accuracy.

The credit card simplified cashless transactions.

Bluetooth is named after Harald Bluetooth, a 10th-century Danish king — the logo combines his initials in runic letters.