Math & science · 1887

Radio waves detected

Hertz makes and detects electromagnetic waves in his lab, confirming Maxwell.

Sparks across a gap produced waves that jumped to a receiver loop metres away. Within a decade Marconi turned the effect into wireless telegraphy.

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

The dashed line marks when it first worked.

US households with a radio Latest: 99 % of households (2005) Source: Our World in Data