Sep 21, 1756: John Loudon McAdam was born in Ayr, Scotland. He was the inventor of macadam (McAdam) road construction, which consists of three layers of progressively finer crushed stone. Unlike loose gravel, crushed stone tends to lock together and stay in place. He developed methods for road construction where the road surface was slightly above ground level and drainage was considered. He also invented tarmac, where a layer of hot asphalt is used to bind the top layer. (Tar plus mac, tarmac.)
Sep 21, 1832: French physicist and iron master Louis-Paul Cailletet was born. He is noted for his work on the liquefaction of gases. He worked at his father’s metallurgy business and discovered the permeability of iron to hydrogen and other gases, which accounts for the unpredictable behavior of some irons and steels due to dissolved gases. Every professional welder today is conscious of “hydrogen embrittlement”, which is the reason high strength and critical welds are made using low-hydrogen welding rods like 7018.
Later he became interested in liquefaction of gases and measuring if gases deviated from the Ideal Gas Law. He used the Joule-Thomson effect to liquefy gases by compressing them while at the same time cooling them, then allowing expansion again to cause additional cooling. In this way, he was the first to produce droplets of liquid hydrogen, oxygen, nitrogen, CO, NO2, and acetylene.
He also invented the high-pressure manometer and the altimeter.
Sep 21, 1853: Dutch physicist Heike Kamerlingh Onnes was born today. He received the 1913 Nobel Prize for Physics for his work in low-temperature physics. He managed to liquefy hydrogen and helium. He obtained his first sample of liquid helium, the substantial amount of 60 cc, in 1908.
He also studied the resistance of metals at low temperatures and discovered superconductivity.
Sep 21, 1866: French physician and bacteriologist Charles-Jules-Henri Nicolle was born. He received the 1928 Nobel Prize for Medicine for his discovery that typhus was transmitted by the body louse. The clue was that typhus patients continued to spread the disease until they were bathed and issued new clothing. Further investigation led to the body louse as the disease vector.
Sep 21, 1895: Spanish aeronautical engineer, Juan de la Cierva (Codorniu) was born today. He invented the autogiro (autogyro) in 1923. The autogyro can land and take off in much shorter distances than a fixed-wing aircraft. While it cannot hover because the rotor is not powered, it can still spin safety to the ground (autorotation) if the engine fails. Ironically, he died in a fixed-wing plane accident.
Sep 21, 1895: The Duryea Motor Wagon Company became the first American auto manufacturer to open for business. In 1893, Frank Duryea and his brother, Charles, designed the first gasoline-powered automobile built in the U.S. Since it didn’t need a horse, it was called a “horseless carriage”. It was first test driven in Springfield, Massachusetts.
Sep 21, 1901: American physicist Lee Alvin DuBridge was born. He was best known as the president of Caltech (California Institute of Technology) from 1946 to 1969. He had a long career as an academic administrator, advisor to three presidents, and served on the boards of the RAND Corporation and numerous great institutions like the Huntington Library.
Sep 21, 1907: English marine geophysicist Sir Edward (Crisp) Bullard was born. His work with geomagnetism produced the first satisfactory measurements of geothermal heat flow through the earth’s crust beneath the oceans. Bullard made early measurements of gravitational variations in the East African Rift Valley. He helped develop the theory of continental drift. He used computers to analyze the fit of the rifted continents on each side of the Atlantic Ocean.
Most importantly, perhaps, he developed the dynamo theory of geomagnetism, which explains that Earth’s magnetic field is generated by the convection of molten material in the Earth’s core.
Sep 21, 1909: Canadian-American oceanographer Richard Howell Fleming was born. He researched ocean currents, chemistry and biochemistry. He applied oceanography for military uses and studied the disposal of atomic wastes in the ocean. Fleming worked with the first comprehensive synoptic two-year survey of the Northern Pacific Ocean, charting currents, tides, winds, depths, and temperatures and observing plant and animal life.
Sep 21, 1921: A huge explosion at a fertilizer factory at Oppau, Germany, caused 500 deaths. Destruction at the site included hundreds of neighboring houses. The fertilizer made was a 50/50 mix of ammonium nitrate and ammonium sulphate. Storage silos reached up to a hundred feet high. This fertilizer had a tendency to form solid clumps and it was routine to break it up with bulldozers and dynamite. The mixed fertilizer was not regarded as explosive because it was difficult to initiate and no explosion had ever happened before in such circumstances. However, this time, dynamite caused 4,500 tons of fertilizer to explode, creating a crater 250 feet diameter and 50 feet deep.
Sep 21, 1926: American physicist Donald Arthur Glaser was born. He received the 1960 Nobel Prize for Physics for his invention of the bubble chamber, which is used to observe and photograph the tracks left by subatomic particles.
Sep 21, 1971: American medical patient known as The Bubble Boy, David Vetter was born. He was born with the genetic disease, severe combined deficiency syndrome (SCID) in which the immune system is non-functional. This disease is quickly fatal but modern technology allowed the design of a sterile plastic bubble in which he could live. He lived for twelve years. He was publically identified only as David or The Bubble Boy. He died after a bone marrow transplant from his sister that was hoped would save him. It might have saved him, but despite careful screening, the marrow contained the Epstein-Barr virus. This resulted in Burkitt’s lymphoma, which killed him.
The media was never fully informed of the truth about The Bubble Boy, and were fed benign information. In fact, the young man suffered terrible emotional turmoil from the loneliness and confinement. The movie made about this is also inaccurate.
With the diagnosis of lymphoma, he was released and lived his final 15 days outside the bubble. The most important thing learned for the first time here was that a virus can cause cancer.
Sep 21, 2003: The NASA Galileo space probe ended its eight-year mission to Jupiter as planned. The Jet Propulsion Laboratory in Pasadena, California directed the craft into Jupiter’s atmosphere to burn up, completely vaporizing its structure. This prevented the possibility of any later uncontrolled fall onto a moon causing contamination with bacterial life from Earth.
Contact was lost with the spacecraft slightly after 3:40 p.m. EDT. More than 1,000 people who worked on the Galileo program gathered at the Laboratory to celebrate the end of the mission. Galileo was first conceived in 1976 as a mission to Jupiter and its moons, Ganymede, Callisto, Io, and Europa.