The American and British governments kept the research under wraps for years. But once World War 2, they found themselves needing the technology — radar, short for "radio detection and ranging" — to protect their soldiers. In this article, PopSci reported on how the British used radar, which they called a "radio locator," to determine when enemy planes were coming overhead and to help allied planes navigate at night. What now is used for tasks such air traffic control started off as a tool to save lives.
Read the full story in
How Warplanes Fight at Night.