Sep 29, 1803: French mathematician, Jacques Charles-François Sturm, was born. Among other things, he developed Sturm’s theorem, an important contribution to the theory of equations. Sturm worked as a tutor of the de Broglie family in Paris around 1823, where he met many leading scientists and mathematicians. In 1826, working with Swiss engineer, Daniel Colladon, he made the first accurate measurement of the speed of sound in water (roughly 1,500 meters per second or 4,900 feet per second). In 1827 he wrote a prize-winning paper on the compressibility of fluids.

Since the work of mathematician René Descartes (1596-1650), a problem existed in finding the number of solutions of a given second-order differential equation within a given range of the variable. Sturm provided a complete solution to the problem with his theorem which he published in 1829. Sturm’s theorem has since been applied to many problems including the solution to the Schrödinger equation and its boundary values, a fundamental part of quantum mechanics.

Sep 29, 1859: American physician, Hermann M. Biggs, was born. He pioneered the use of bacteriological studies in the field of public health for the prevention and control of contagious diseases. In 1892, he became the first director of a new Division of Pathology, Bacteriology and Disinfection within the New York City Department of Health, addressing the problem of cholera infected immigrants arriving at the harbor. He eventually became the chief medical officer of the City of New York and in 1914, commissioner of health for the State of New York. The methods he developed spread throughout the USA.

Sep 29, 1901: Italian-American physicist, Enrico Fermi, who was awarded the Nobel Prize for physics in 1938, was born. He was one of the chief architects of the nuclear age. He was the last of the double-threat physicists: a genius at creating esoteric theories and also designing elegant experiments.

He developed the theory of beta decay in 1933, postulating that the newly-discovered neutron decaying to a proton emits an electron and a particle he called a neutrino.

Fermi developed theory to explain this decay, which led him to find the weak interaction force. He developed the statistical methods required to clarify a large class of subatomic phenomena. He discovered neutron-induced radioactivity, and he directed the construction and operation of the first controlled chain reaction involving nuclear fission — the first atomic reactor.

Sep 29, 1903: John Heysham Gibbon, the American surgeon who invented the heart-lung machine, was born. As a Harvard research fellow in surgery in 1930, he saw a patient undergoing heart-lung surgery suffocate on his own blood.

This inspired what became his life work. On May 10, 1935, he had built his first external pump, and was able to maintain the cardiac and respiratory functions of a cat. In the late 1940’s, Gibbon received financial and technical assistance from the IBM Corporation to develop an oxygenator with sufficient capacity for a human. On May 6, 1953, with his improved machine he was able to perform the first successful open-heart operation. He repaired an atrial septal defect on 18-yr-old Cecelia Bavolek, maintaining the patient’s heart and lung functions on the machine for 26 minutes.

Sep 29, 1914: A patent, US #1111999, for a “Phonograph-Record” was granted to Thomas A. Edison.

Sep 29, 1920: British biochemist, Peter Dennis Mitchell, who won the 1978 Nobel Prize for Chemistry, was born. His work helped to clarify how ADP (adenosine diphosphate) is converted into the energy-carrying compound ATP (adenosine triphosphate) in the mitochondria of living cells.

Sep 29, 1925: American engineer and inventor, Paul Beattie MacCready, was born. His life work focused on the design and construction of ultra-efficient flying machines. He invented the first human-powered flying machines and the first solar-powered aircraft to make sustained flights. In 1977, his pedal-powered Gossamer Condor flew a 1.15 mile figure-eight course demonstrating sustained, controlled, human-powered flight. For this, he won the Kremer Prize. Dr. Peter Lissamen was co-designer with MacCready. In 1979, their human-powered Gossamer Albatross won the second Kremer Prize when it crossed the English Channel.

Sep 29, 1931: American particle physicist, James Watson Cronin, was born. He shared, with Val Logsdon Fitch, the 1980 Nobel Prize for Physics for the discovery of violations of fundamental symmetry principles in the decay of neutral K-mesons.

Their experiment proved that a reaction of subatomic particles run in reverse does not follow the path of the original reaction. This implies that time has an effect on subatomic particle interactions. The experiment demonstrated a break in particle-antiparticle symmetry for certain reactions.

Sep 29, 1954: The CERN (Centre Européenne de Recherche Nucléaire) convention was ratified by the 12 founding member states. As stated by CERN’s Director General Robert Aymar, “gave the new organization a mission to provide first class facilities, to coordinate fundamental research in particle physics, and to help reunite the countries of Europe after two world wars.” Geneva, Switzerland had been chosen as the site of the new laboratory.