Day in Engineering History Archive February 19

February 19

1473: Polish astronomer Nicolaus Copernicus, who published proof of a sun-centered solar system, was born. 1834: Dutch ophthalmologist Herman Snellen, developer of the visual acuity Snellen Chart seen in all opticians' offices, was born. 1859: Svante Arrhenius, whose famous equation relating temperature change to chemical reactions and is applied to semiconductor lifetime acceleration, was born. 1878: Thomas Edison received a patent for his phonograph. 1916: Ernst Mach, of speed of sound unit defining fame, died. 1945: During World War II, 30,000 U.S. Marines landed on the island of Iwo Jima, where they encountered ferocious resistance from Japanese forces, and took control of the strategically important island after a month-long battle.  1986: The Soviet Union launched the Mir space station.

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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.