Image: Oil painting of Carl Friedrich Gauss, by C.A. Jensen.
Source: Wikimedia Commons.
From Wikipedia: "Johann Carl Friedrich Gauss (30 April 1777 – 23 February 1855) was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.
Sometimes referred to as the Princeps mathematicorum (Latin, "the Prince of Mathematicians" or "the foremost of mathematicians") and "greatest mathematician since antiquity," Gauss had a remarkable influence in many fields of mathematics and science and is ranked as one of history's most influential mathematicians."
1876 – Orso Mario Corbino, Italian physicist, is born (d. 1937).
Image: Orso Mario Corbino.
From Wikipedia: "Orso Mario Corbino (30 April 1876, Augusta – 23 January 1937, Rome) was an Italian physicist and politician. He served as the minister for education in 1921 and as the minister for economy in 1921. He also served as professor in Messina (1905) and in Rome (1908). Noted for his studies of the influence of external magnetic fields on the motion of electrons in metals and discovered the Corbino effect.
Corbino worked with Damiano Macaluso where they discovered the Macaluso-Corbino effect, a strong magneto-rotation of the plane of polarization observed at wavelengths close to an absorption line of the material through which the light is travelling."
1896 – Hans List, Austrian inventor, is born (d. 1996).
Image: Hans List.
Source: Technische Universitat Dresden.
"Hans List (April 30, 1896 in Graz, capital of Austria's federal province Styria – September 10, 1996 in Graz) was a technical scientist and inventor and entepreneur.
After earning a degree of doctor in engineering at the Technical University in Graz, Hans List was appointed to the Tongji University in China (1926-32), followed by teaching positions back home in Graz (1932-41) and Dresden, Germany (until 1945). His research work yielded sensational insights into functionality and improvement of Diesel motors, and of combustion engines in general." (Wikipedia)
1897 - The existence of electrons is first announced.
Cartoon Source: Web Elements.
In 1897, at the Royal Institution Friday Evening Discourse, Joseph John Thomson (1856-1940) first announced the existence of electrons. Thomson told his audience that earlier in the year, he had made a surprising discovery. He had found a particle of matter a thousand times smaller than the atom. He called it a corpuscle, meaning "small body." (Today in Science History)
1905 – Sergey Nikolsky, Russian mathematician, is born.
Image: Sergey Nikolsky delivers one of his last lectures on mathematical analysis for 4th term students of MIPT. Spring 1997, Moscow Institute of Physics and Technology, auditorium 202NK.
According to Wikipedia, "Sergey Mikhailovich Nikolsky is a Russian mathematician. He was born in the place named Plant Talitsa, Permskaya guberniya, Russia. He has been an Academician since November 28, 1972. He has won many scientific prizes. At the age of 92 was still giving lectures in Moscow Institute of Physics and Technology. As of 2005, he only gives talks at scientific conferences, but still works in MIPT.
Professor Nikolsky made fundamental contributions to functional analysis, approximation of functions, quadrature formulas, enclosed functional spaces and their applications to variational solutions of partial differential equations. He created a large scientific school of functions' theory and its applications. He authored over 100 scientific publications, including 3 monographs, 2 college textbooks and 7 school textbooks."
1916 – Claude Shannon, American engineer and mathematician, is born (d. 2001).
Image: Claude Shannon.
"Claude Elwood Shannon (April 30, 1916 – February 24, 2001), an American mathematician, electronic engineer and geneticist, is known as "the father of information theory".
Shannon is famous for having founded information theory with one landmark paper published in 1948. But he is also credited with founding both digital computer and digital circuit design theory in 1937, when, as a 21-year-old master's student at MIT, he wrote a thesis demonstrating that electrical application of Boolean algebra could construct and resolve any logical, numerical relationship. It has been claimed that this was the most important master's thesis of all time." (Wikipedia)
1939 - Cosmic rays generate electricity.
From Today in Science History: "In 1939, cosmic rays entering a Geiger-Mueller counter produced electrical impulses used to control electrical power. This first ever such event, was used for the illumination ceremony of the 1939 New York World's Fair. The counter, at the Hayden Planetarium, New York City, switched on an electrical circuit wired to a display at the Lagoon of Nations where relays activated local battery circuits ringing bells and flashing lights to signal each capture of a cosmic ray. Albert Einstein as guest speaker explained cosmic rays. Sadly his accent and faulty amplification made his words incomprehensible to the crowd. Upon the tenth ray's signal, a huge light was to be turned on to illuminate the 600-ft Trylon triangular spire, but the power source failed."
1955 - Mendelevium, Element 101, a new artificial element was announced.
Image: Electron shell diagram for Mendelevium, the 101st element in the periodic table of elements.
Source: Wikimedia Commons.
"In 1955, the element 101, a new artificial element was announced. It was synthesized by bombardment of Es-253 with helium nuclei using the cyclotron at the Radiation Laboratory of the University of California by Albert Ghiorso, Bernard G. Harvey, G.R. Choppin and S.G. Thompson, research chemists, headed by the Nobel laureate Glenn T. Seaborg. Being radioactive, with a half-life of between a half hour to several hours, this transuranic element cannot exist in nature since it decays so rapidly into lighter elements. It was named mendelevium, named in honour of Dmitry Mendeleev, the Russian chemist who worked on the periodic classification of the elements (Today in Science History)."
1974 - Kempten, West Germany, Autoban Bridge collapses.
Image: Bridge Collapse in West Germany.
Source: "Independent Press-Telegram", Page B-5, Long Beach, California, Tuesday, April 30, 1974.
Nine people were killed and eleven seriously injured when a bridge being built over a Bavarian mountain stream at Kempten, West Germany, collapsed. Police reported at least 27 construction workers fell 50 feet with tons of wet concrete and construction debris piling upon most of them.
1983 - Joel Henry Hildebrand, American chemist and educator, died.
Image: Joel Henry Hildebrand.
"Hildebrand was an American chemist and educator. As an educator, he was involved with the University of California, Berkeley's College of Chemistry from 1907 to 1953. UC Berkeley became one of the top producers of chemists and their laboratories produced five Nobel Prizes and major innovations in chemistry and physics.
As a chemist, his work was primarily with liquids and nonelectrolyte solutions. He wrote several textbooks and monographs, one of which, the monograph Solubility was a standard reference for 50 years." (chemistry.about.com)
2009 - Building Collapse in New York