Day in Engineering History Archive - April 20


April 20

1862: The first test of pasteurization was completed by Louis Pasteur and Claude Bernard. 1902: Marie and Pierre Curie isolated the radioactive element radium. 1918: Ferdinand Braun, who shared a Nobel Prize with Guglielmo Marconi for the development of wireless telegraphy, died. 1928: English astronomer Gerald Hawkins, who first identified Stonehenge as an astronomical observatory, was born. 1961: FM stereo multiplex broadcasting was approved by the FCC. 1967: Surveyor 3 landed on the moon and began sending photos back to the U.S. 1978: Korean Air Flight 902 was shot down while in Russian airspace. 1989: The first successful testing of high-definition TV was announced. 1994: The WebCrawler search engine, brainchild of Brian Pinkerton, went online at the University of Washington. 1999: Eric Harris and Dylan Klebold shot and killed 12 classmates and 1 teacher before taking their own lives at Columbine High School in Littleton, CO.

| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |

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.