Day in Engineering History Archive February 20

February 20

1844: Ludwig Boltzmann, after whom the Boltzmann constant (1.3806505 × 10^-23 J/K) was named, was born. 1877: The first cantilever bridge in the U.S. was completed in Harrodsburg, KY. 1931: John Milnor, who proved that a 7-dimensional sphere can have 28 different differential structures - important work to be sure - was born. 1948: The first B-50 Superfortress bomber was delivered to the Air Force. 1956: German physicist Heinrich Barkhausen, who discovered the effect named after him regarding changes in the magnetic domain properties of metal, died. 1962: Astronaut John Glenn became the first American to orbit Earth as he flew 3 times around the earth aboard the Friendship 7 Mercury capsule. 1965: The Ranger 8 spacecraft crashed on the moon after sending back thousands of pictures of the lunar surface. 1986: The Soviet Union launched the Mir space station into orbit. 1993: Ferruccio Lamborghini, of sports car fame, died. 2005: Spain became the first country to vote in a referendum on ratification of the proposed Constitution of the European Union.

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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.