Sep 24, 1501: Italian physician, mathematician and astrologer Girolamo Cardano (a.k.a. Geronimo, Gerolamo, or Anglicized as Jerome Cardan) was born. He was the first to give a clinical description of typhus fever. His book, Ars Magna (“Great Art,” 1545) is one of the great achievements in the history of algebra, in which he published the solutions to the cubic and quartic equations. His mechanical inventions included the combination lock, the compass gimbal consisting of three concentric rings, and the universal joint to transmit rotary motion at various angles, used in nearly every automobile today. He contributed to hydrodynamics and held that perpetual motion is impossible, except in celestial bodies. Cardano published two encyclopedias of natural science, introduced the Cardan grille, a cryptographic tool in 1550. He died by suicide.

Sep 24, 1852: A new invention, the dirigible, a semi-rigid airship, was demonstrated in a flight from Paris to Trappe. Henri Giffard (1825-82) installed a 3 horsepower steam engine of his own design in the gondola of a 147-foot-long spindle shaped coal-gas balloon. This engine turned an 11 foot propeller producing a speed of 5 mph over a distance of 17 miles on a 3 hour trip. This was the first powered and controlled flight ever achieved by humans.

In 1858 he patented a steam injector which became widely used in locomotives, making him rich. However, Giffard was depressive and died by suicide in 1882.

Sep 24, 1870: Georges Claude, French chemist, engineer and inventor was born. He invented the neon light, which was the forerunner of the fluorescent light. Claude was the first to apply an electrical discharge to a sealed tube of neon gas around 1902 and make a neon lamp. He first publicly displayed the neon lamp on Dec 11, 1910 in Paris. His French company Claude Neon, introduced neon signs to the U.S. with two “Packard” signs for a Packard car dealership in Los Angeles, purchased by Earle C. Anthony for $24,000.

Sep 24, 1889: Alexander Dey patented the dial time recorder or “punch clock” for employees to record their arrival and departure times from work.

Sep 24, 1891: William F. Friedman was born today. He was one of the world’s greatest cryptologists, who helped decipher enemy codes from World War I to World War II. He was born as Wolfe Friedman in Kishinev, Russia. He emigrated to the U.S. in 1893. Originally trained as an agricultural geneticist, he had become interested in cryptology. During World War I, with his wife Elizabeth, he set up a cryptology school for military personnel, which led to appointment by the U.S. as head of the Signal Intelligence Service in 1930. He broke the Japanese “Purple” code before 1940, thus allowing Americans to read much of Japan’s secret messages during World War II.

Sep 24, 1895: French-American physiologist and physician André Frederic Cournand was born today. He shared the 1956 Nobel Prize for Physiology and Medicine with two others “for their discoveries concerning heart catheterization and pathological changes in the circulatory system”. Cournand helped develop the technique by which a catheter could be threaded through a vein into the heart to withdraw blood samples to determine cardiac abnormalities. In addition, it permits the measurement of blood pressure, blood flow or gas concentrations in various parts of the cardiac circulatory system (atrium, ventricles, or artery).

Sep 24, 1898: American astrophysicist Charlotte Moore Sitterly was born today. She organized, analyzed, and published definitive books on the solar spectrum and spectral line multiplets. Starting in 1945 until the age of 90, she conducted her work at the U.S. National Bureau of Standards and the Naval Research Laboratory. She detected that technetium, an unstable element created by nuclear reactions in the laboratory, exists in nature. She made major contributions to the compilation of tables for atomic-energy levels associated with optical spectra, which are now standard reference material in astrophysics. She was awarded the Bruce Medal in 1990.

Sep 24, 1898: Sir Howard Walter Florey, Australian pathologist, was born today. He, with Ernst Boris Chain, researched, isolated and purified penicillin for general clinical use. From 1939, he worked with Chain on natural antibacterial agents produced by microorganisms, leading to their isolation and purification, and the determination of the chemical structure of penicillin. They performed the first clinical trials of the antibiotic. They shared the 1945 Nobel Prize for Physiology and Medicine with Sir Alexander Fleming, who had discovered antibiotic penicillin in 1928. Florey was knighted in 1944.

Sep 24, 1905: Spanish-American biochemist and molecular biologist, Severo Ochoa, was born. He shared the 1959 Nobel Prize for Physiology and Medicine with Arthur Kornberg for “for their discovery of the mechanisms in the biological synthesis of ribonucleic acid and deoxyribonucleic acid” Ochoa discovered an enzyme in bacteria that enabled him to synthesize ribonucleic acid (RNA), a substance of central importance to the synthesis of proteins by the cell.

Sep 24, 1906: Polidore F. F. Swings, Belgian astrophysicist, was born. He made spectroscopic studies to identify elements and structure of stars and comets. He discovered the first interstellar molecule, the CH radical, called methylidyne or carbyne in 1937. In comet atmospheres he studied the “Swings bands”, which are carbon emission lines. In 1941, with a slit spectrograph he identified a “Swings effect” in the violet CN bands around 387 nm, a fluorescence partly due to solar radiation that shows excitation differences dependant on the Doppler shift caused by a comet’s motion relative to the Sun.

Sep 24, 1907: John Ray Dunning, American nuclear physicist, was born. His experiments in nuclear fission helped lay the groundwork for the development of the atomic bomb. Fission of the rare U235 uranium isotope was verified in an experiment using the microscopic quantity of 20 nanograms. But, great difficulty remained in separating U235 from the more abundant U238. Dunning led the research team at Columbia University which studied the gaseous diffusion method for uranium separation. This process was based on the slightly smaller size of the U235 isotope molecules. When pushed through a porous barrier, U235 would move through faster, and several repetitions would produce almost pure U235.

Sep 24, 1909: Thomas M. Flaherty filed for a U.S. patent for a “Signal for Crossings”. This was the first U.S. patent application for a traffic signal. Patent 991,964 issued on May 9, 1911. His signal used a large horizontal arrow pivoting on a post, which turned to indicate the right of way direction. It was activated by an electric solenoid by a policeman beside the road. Although filed first, it was not the first patent actually issued for a traffic signal. Ernest E. Sirrine filed a different design seven months after Flaherty, but his patent was issued earlier, and thus he held the first U.S. patent for a “Street Traffic System”, 976,939 Nov 29, 1910.

Sep 24, 1918: Michael J. S. Dewar was a Scottish organic chemist who was born in India and attended boarding school in England. His career included both industrial and academic positions in England and the United States. As a theoretician, he was an early master of molecular orbital theory and wrote The Electronic Theory of Organic Chemistry (1949), the first book applying molecular orbital theory to organic chemistry. His experimental work studied carbenium ions, boron chemistry, superconductors, liquid crystals, the biosynthesis of fatty acids, and phenyl radicals.

Sep 24, 1930: John Watts Young, American astronaut, was born. He was the commander of the first Space Shuttle mission, STS-1, April 12, 1981. He walked on the Moon during the Apollo 16 mission, April 21, 1972. He made the first manned flight of the Gemini spacecraft with Virgil Grissom. And he was on the aborted Apollo 13 flight. He became the first person to fly into space six times in a career that was one of the busiest of any NASA astronaut. He piloted four different classes of spacecraft: Gemini, Apollo Command and Service Module, Apollo Lunar Module and the Space Shuttle. Young worked for NASA for 42 years and retired on Dec 31, 2004.

Sep 24, 1945: Ian Stewart, English mathematician was born. He authored many books on mathematics for the lay reader, and others for academics, and textbooks. As a young teenager with a zeal for mathematics, he always read the “Mathematical Games” column in Scientific American. From this he not only expanded his knowledge of mathematics, but also acquired the skills needed to be an entertaining communicator. Now, he writes the “Mathematical Recreations” column in Scientific American.

In his career at the University of Warwick, he is a professor of mathematics with special responsibility for public understanding of science. He gave the 1997 Royal Institute Christmas Lectures. On June 8, 2009, he was presented with the award at the Science Museum in London as the first recipient of the Christopher Zeeman medal for public engagement in mathematics.

Sep 24, 1960: The first nuclear-powered aircraft carrier, the USS Enterprise, was launched in Newport, Virginia. It was the most astonishing vessel of its time and by far the largest warship in the world. It was powered by eight nuclear reactors. Since it doesn’t need to carry its own fuel oil it has much more room for aviation fuel and weapons. In 1963, the Enterprise and two similarly powered cruisers made a non-stop voyage around the world to demonstrate the viability of nuclear power. Length of the ship: 1120 ft, flight deck width: 250 ft, displacement: 93,970 tons, speed: 33 knots, range: 470,000 miles at 20 knots, air complement: 86 aircraft, crew: 5765.