Here are some facts about the World War 2 blackout: During World War 2, the blackout was a nationwide effort to turn off all lights in towns and cities. It was devised as a defence against German bombers, so they could not be guided by the lights.
Explanation:
A blackout during war, or in preparation for an expected war, is the practice of collectively minimizing outdoor light, including upwardly directed light. This was done in the 20th century to prevent crews of enemy aircraft from being able to identify their targets by sight, for example during the London Blitz of 1940. In coastal regions a shore-side blackout of city lights also helped protect ships from being seen in silhouette against the shore by enemy submarines farther out at sea.
