April 13 in Physics History
Physics history will help you to develop a better understanding of the physics world!
birthdays & deaths
Explore all birthdays & deaths of physicists occurred on this day with their short biography!
physics Events
Know all important discoveries made by physicists & events happened on this day with complete information!
April 13 in Physics History - Births – Physicists born on April 13
Robert Alexander Watson-Watt (13 Apr 1892 - 5 Dec 1973)
He was a Scottish physicist who helped to develop the radar location of aircraft in England. He got his degree from St Andrews University and taught at Dundee University. He designed devices to locate thunderstorms while working in the Meteorological Office. He invented the term ionosphere in 1926. Later, he became the head of the radio section of the National Physical Laboratory. The development of radar played a vital role in the defense of Britain against German air raids in 1940.
Bruno Rossi (13 Apr 1905 - 21 Nov 1993)
He was an Italian-American physicist who was an expert in the study of cosmic radiation. His experiments led to the foundation of high-energy particle physics. The atomic particles that enter earth from outer space are called cosmic rays. The cosmic rays at speeds approaching that of light, bombards atmospheric atoms and produce mesons and secondary particles. He used rockets to study cosmic rays above Earth’s atmosphere and found X-rays from space.
John Hays Hammond Jr. (13 Apr 1888 - 12 Feb 1965)
He was a US inventor who was the son of the US mining engineer John Hays Hammond. His works in the development of radio-controlled to the basis for modern missile guidance systems. He established subsequent radio control that was able to send an unmanned hatch from Gloucester to Boston successfully. During WWI he added an interference feature to prevent jamming. He had earned over 100 patents by 1916.
Paolo Frisi (13 Apr 1728 - 22 Nov 1784)
He was an Italian mathematician, physicist, and astronomer who designed a canal between Milan and Pavia. He mostly compiled, interpreted, and disseminated the work of other scientists, such as Sir Isaac Newton and Galileo Galilei. He tried to figure out the physical causes of the earth using the theory of gravity.
Pyotr Petrovich Lazarev (13 Apr 1878 - 23 Apr 1942)
He was a Soviet physicist and biophysicist who developed the theory of the movement of ions and successive theory of nerve excitation in living matter. It explained the reason behind sensation, muscular contraction, and also the functions of the central nervous system. He studied mathematics and physics on his own and his doctoral thesis was an elementary investigation in prequantum photochemistry.
April 13 in Physics History - Deaths – Physicists died on April 13
John Wheeler (9 Jul 1911 - 13 Apr 2008)
He was the first American physicist who was involved in the theoretical development of the atomic bomb. For his contribution to quantum gravity, black hole physics, and the theories of nuclear scattering and nuclear fission, he was awarded the Wolf Prize in 1997. He was the one who coined the term “black hole” in 1967.
Samuel Molyneux (18 Jul 1689 - 13 Apr 1728)
He was a British astronomer and politician who made measurements of the diversion of light from stars together with his assistant James Bradley. They used a vertical telescope to observe the star  Draconis. They noted its lowest declination in May and the highest point of its oscillation in September. He fell ill in 1728 and died shortly thereafter.
Annie Jump Cannon (11 Dec 1863 - 13 Apr 1941)
She was an American astronomer who was deaf but yet specialized in the classification of stellar spectra. She remained in the Harvard College Observatory for the rest of her career since 1896. She rationalized the classification of stars based on surface temperature in spectral classes O, B, A, F, G, K, M, and for the monumental Henry Draper Catalogue, she coordinated over 225,000 stars.
April 13 in Physics History - Events – Physics Events of April 13
Apollo 13 Rescue
On this day, when Apollo 13 mission was met with an explosion in 1970, a rescue mission was started in the US. Because of an oxygen leak, the astronauts were forced to leave the ship behind and return to the lunar module. The astronauts were Jack Swigert, Commander Jim Lovell, and Fred, all three of them came back to Earth safe and sound.
The First US Navigational Satellite
The Transit-1B, the first US navigational satellite was launched from Cape Canaveral, Florida in 1960. The first engine restart in space to refine the orbit was carried out by the rocket Thor-Ablestar. The payload included 2 ultrastable oscillators, batteries, 2 telemetry transmitters, and receivers and solar cells. It was at its full capacity in Oct 1968 and its navigation broadcasts were turned off on 31 Dec 1996. It retired after more than 32 years of successful service to the US Navy.
