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Friday, April 24, 2026
Open today 4 PM - 11 PM
Kind of vacuum tube used for the Franck-Hertz experiment of 1914, contemporary with the one actually used by James Franck; C is the cathode, G the wire-mesh grid, and A the anode; electron flow is upward (Wikimedia commons)
On Apr. 24, 1914, James Franck, a 32-year-0ld German physicist, read a paper to the Physical Society of Berlin, reporting the results of...
John Tradescant the Younger, an English traveler, gardener and collector, died Apr. 22, 1662, at age 53. His father, John the Elder, was also an...
Mark Twain, an American writer, humorist, and champion of science and technology, died on Apr. 21, 1910, having been born as Samuel L. Clemens, on...
On Apr. 20, 1884, Pope Leo XIII issued a papal encyclical known as Humanum genus. Its purpose was to denounce Freemasonry, the members of which he...
Giovanni Battista Riccioli, an Italian Jesuit astronomer, was born on Apr. 17, 1598, in Ferrara. After joining the Jesuit order, he studied...
Henry Augustus Rowland, an American physicist, died Apr. 16, 1901, at the age of 52. He was born on Nov. 27, 1848, in Honesdale, Pennsylvania, in...
Charles Robert Knight, an American wildlife painter, paleo-artist, and sculptor, died Apr. 15, 1953, at the age of 78. He was born in Brooklyn on...
Amalie Emmy Noether, a German mathematician, died Apr. 14, 1935, at the age of 53. She is often called the greatest woman mathematician of the...
Alexander Mitchell, an Irish engineer, was born in Dublin on Apr. 13, 1780. He was brought up in Belfast, where he attended the Academy and...
Robert Burns Woodward, an American organic chemist, was born Apr. 10, 1917, in Boston. His father died when he was only 1 year old (in the flu...
Gaius Plinius Secundus, better known as Pliny the Elder, was a Roman statesman, military officer, and encyclopedist in the early Roman Empire. He...
Karl Hencke, a German amateur astronomer, was born Apr. 8, 1793. In 1845, Hencke discovered the 5th known asteroid, Astraea, at his private...
The Law for the Restoration of the Professional Civil Service was enacted by the Nazi regime in Germany, led by newly appointed Chancellor Adolf...
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