Formulas & Data:
- Electronics
- Mathematics
- Physics
- RF & Microwaves

Parts Vendors:
- all hand-selected

- Amateur Radio
- Vintage Articles:
- Electronics World
- Popular Electronics
- QST
- Radio & TV News
- Radio Craft
- Short Wave Craft
- Wireless World

- Events Calendar
RF Cafe Homepage
Copyright 1999-2015   •−•  ••−•    −•−•  •−  ••−•  •   "RF Cafe" in Morse Code  >> Listen to It <<
- EW & Radar Handbook
- Quizzes       - Software
- App Notes
- Calculators
- Advertise on RF Cafe
- About RF Cafe™
- RF Cafe Shirts & Mugs
- RF Cafe Archives
RF Cafe Book Contest
- RF Cafe on Visit RF Cafe on Facebook Visit RF Cafe on Twitter Visit RF Cafe on LinkedIn
- Tech Humor
- Forums Archive
- Job Board
- Donate to RF Cafe
- Kirt's Cogitations
Custom Search
More than 10,000 searchable pages indexed.
Greetings: There is so much good stuff on RF Cafe that there is no way to list or link to all of it here. Please use the Search box or the Site Map to find what you want - there is a good chance I have it here. Thanks!

Day in Engineering History Archive February 20

| 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.
Please submit significant historical events and dates for inclusion in these lists. I will be glad to include your name and birthday. Please do not submit your death date ;-) A couple 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.

February 20

Ludwig Boltzmann's Birthday - Please click here to visit RF Cafe.

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.


Your RF Cafe
Progenitor & Webmaster

Click here to read about RF CafeKirt Blattenberger… single-handedly redefining what an engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem!
(Seize the Day!)

5th MOB: My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website