Day in Engineering History Archive - March 20

March 20

Einstein Publishes General Theory of Relativity - RF Cafe1800: Alessandro Volta announced his invention of the electric battery. 1856: American inventor and engineer Frederick Taylor, known as the father of scientific management, was born. 1886: America's first demonstration of the AC power system provided lighting along Main Street at Great Barrington, MA. 1900: Nikola Tesla received a patent for the wireless transmission of electric power. 1916: Albert Einstein's Theory of General Relativity was published in Annalen der Physik. 1925: David Ronald de Mey Warren, the Australian scientist who invented the flight data recorder (or "black box"), was born. 1934: The first test of a practical radar apparatus was made by Rudolf Kuhnold in Kiel Harbour, Germany. 1993: Nobel physicist Polykarp Kusch, who determined that the magnetic moment of the electron is greater than its theoretical value, died. 1954: Newspaper vending machines became big news as the first one was introduced in Columbia, Pennsylvania. 1995: In Tokyo, 12 people were killed, more than 5,500 others sickened when terrorists released packages containing the poisonous gas Sarin into five separate subway trains. 2003: The Iraq war began.

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Note: These historical tidbits have been collected from various sources, mostly on the Internet. As detailed in this article, there is a lot of wrong information that is repeated hundreds of times because most websites do not validate with authoritative sources. On RF Cafe, events with hyperlinks have been verified. Many years ago, I began commemorating the birthdays of notable people and events with special RF Cafe logos. Where available, I like to use images from postage stamps from the country where the person or event occurred. Images used in the logos are often from open source websites like Wikipedia, and are specifically credited with a hyperlink back to the source where possible. Fair Use laws permit small samples of copyrighted content.