Math & science · 1865
Maxwell's equations
Maxwell unifies electricity, magnetism and light in four equations.
His theory predicted electromagnetic waves moving at the speed of light. Radio, radar, television and wireless networks all follow from it.
What it built on 3
What it led to 8
Related measurements
The dashed line marks when it first worked.
US households with a radio Latest: 99 % of households (2005) Source: Our World in Data
Telegrams sent in the UK Latest: 5.7M telegrams per year (1983) Source: Our World in Data