1908 – A massive explosion erupted over the Podkamennaya Tunguska River in Siberia in far eastern Russia. Now believed to have been caused by a meteorite, the blast flattened some 850 square miles of forest and generated a shock wave that could be felt as far west as Great Britain.
1921 – The Radio Corporation of America (RCA) was formed.
1952 – The radio soap opera, The Guiding Light, appeared on television for the first time on CBS television. The show remains the longest running program in television and radio history, running from 1937 until 2009.
1985 – For the 13th time since 1972, the world’s official timekeeper atomic clock ticked off one extra second at 23:59 Greenwich Mean Time (also called UCT, Universal Coordinated Time) or 7:59:59 p.m. in New York City. The leap second was added to compensate for the gradual slowing of the Earth’s rotation.
1994 – The temperature at Death Valley, California reached 128 degrees (Fahrenheit). The only other time it has been that hot (since 1961 when weather data was first recorded) was on July 14, 1972.