| APRIL 23 - BIRTHS | |
| Edmund Brisco Ford | |
 Born 23
Apr 1901; died 22 Jan 1988.
British geneticist who made substantial contributions to the genetics of natural selection and defined and developed the science of ecological genetics. |
|
| Johannes Fibiger | |
| Born 23
Apr 1867; died 30 Jan 1928.
Johannes Andreas Grib Fibiger was a Danish pathologist who received the Nobel Prize for Physiology or Medicine in 1926 for achieving the first controlled induction of cancer in laboratory animals, a development of profound importance to cancer research. |
|
| Max Planck | |
(source) |
Born 23
Apr 1858; died 4 Oct 1947.
Max (Karl Ernst Ludwig) Planck was a German theoretical physicist. He studied at Munich and Berlin, where he studied under Helmholz, Clausius and Kirchoff and subsequently joined the faculty.he became professor of theoretical physics (1889-1926). His work on the law of thermodynamics and the distribution of radiation from a black body led him to abandon classical Newtonian principles and introduce the quantum theory (1900), for which he was awarded the Nobel Prize for Physics in 1918. This assumes that energy is not infinitely subdivisible, but ultimately exists as discrete amounts he called quanta (Latin, "how much"). Further, the energy carried by a quantum depends in direct proportion to the frequency of its source radiation. |
| Granville T. Woods | |
(source) |
Born 23
Apr 1856; died 30 Jan 1910.
American inventor who held numerous patents in diverse fields. As the most prolific black inventor by career of the late 19th and early 20th century in the U.S., he has been called the Black Edison. Wood's first patent (3 Jun 1884) was for a locomotive steam boiler. He started the Woods Electric Company, in Cincinnati, Ohio, to commercially develop a variety of electrical devices. In 1887 he patented his Synchronous Multiplex Railway Telegraph, which enabled moving railway trains to maintain communications links thus avoiding accidents. His other patents included a telephone transmitter, an electric railway, an electric incubator for hatching chickens (1900) and an important safety device - an automatic air-brake for railroad use (10 Jun 1902).«  Black
Inventors in the Age of Segregation, by Rayvon Fouche. |
| Alphonse Bertillon | |
(source) |
Born 23
Apr 1853; died 13 Feb 1914
Chief of criminal identification for the Paris police (from 1880) who developed an identification system known as anthropometry, or the Bertillon system, that came into wide use in France and other countries. The system records physical characteristics (eye colour, scars, deformities, etc.) and specified measurements (height, fingertip reach, head length and width, ear, foot, arm and finger length, etc) These are recorded on cards and classified according to the length of the head. After two decades this system was replaced by fingerprinting in the early 1900s because Bertillon measurements were difficult to take with uniform exactness, and could change later due to growth or surgery. |
| Pierre-Louis-Georges Du Buat | |
| Born 23
Apr 1734; died 17 Oct 1809.
French hydraulic engineer who derived formulas for computing the discharge of fluids from pipes and open channels. |
|
| Johan van Waveren Hudde | |
| Born 23
Apr 1628; died 15 Apr 1704.
Dutch mathematician and statesman who promoted Cartesian geometry and philosophy in Holland and contributed to the theory of equations. |
|
| APRIL 23 - DEATHS | |
| Max von Laue | |
 Died
23 Apr 1960 (born 9 Oct 1879)
German recipient of the Nobel Prize for Physics in 1914 for his discovery of the diffraction of X rays in crystals. This enabled scientists to study the structure of crystals and hence marked the origin of solid-state physics, an important field in the development of modern electronics. |
|
| Edwin Ray Guthrie | |
(source) |
Died
23 Apr 1959 (born 9 Jan 1886)
American psychologist whose work dealt with the psychology of learning and the role association plays. In his Law of Contiguity, he held that "a combination of stimuli which has accompanied a movement, will on its recurrence tend to be followed by that movement." He said that all learning is based on a stimulus- response association. Movements are small stimulus- response combinations. These movements make up an act. A learned behavior is a series of movements. It takes time for the movements to develop into an act. He believed that learning is incremental. Some behavior involves repetition of movements and what is learned are movements, not behaviors. The
Psychology of Learning, by Edwin Ray Guthrie. |
| Pyotr Petrovich Lazarev | |
(source) |
Died
23 Apr 1942 (born 13 April 1878)
Soviet physicist and biophysicist known for his physicochemical theory of the movement of ions and the consequent theory of nerve excitation in living matter, which attempts to explain sensation, muscular contraction, and the functions of the central nervous system. He trained as a medical doctor in Moscow. In addition, he studied mathematics and physics on his own. His doctoral thesis (1912) at Moscow University was a fundamental investigation in prequantum photochemistry. He supported the October Revolution. Lazarev established prospecting surveys, which revealed enormous national reserves of iron ore (1919). |
| Carl F.W. Ludwig | |
(source) |
Died
23 Apr 1895 (born 29 Dec 1816)
Carl Friedrich Wilhelm Ludwig, one of the creators of modern physiology, applied the experimental approach of chemistry and physics to explain the way the body functions. He investigated the structure of the kidneys and cardiac activity. The kymograph he invented (1847) continuously recorded blood pressure on a rotating drum. He explained blood circulation in terms of conventional forces, repudiating any mysterious "vital force." With his mercurial blood-gas pump (1859) he extracted gases from blood for study. In 1856, he was the first to keep an organ alive after removal from an animal (a frog heart), using perfusion (pumping blood plasma through them.) He was also first to study the nitrogen content of urine as a measure of protein metabolism.« |
| Auguste Laurent | |
| Died
23 Apr 1853 (born 14 Nov 1807)
French chemist who advanced knowledge of the structure of organic compounds. |
|
| APRIL 23 - EVENTS | |
| Top quark | |
In 1994, physicists at the Department of Energy's Fermi National Accelerator
Laboratory discovered the subatomic particle called the top quark. |
|
| Artificial skin | |
|
In 1981, artificial skin was first transplanted in the U.S. on patients
at Massachussetts General Hospital, Boston. The combination of cowhide,
shark cartilage and plastic was developed by Ioannis V. Yannas and a research
team at MIT. This material makes possible the treatment of burn patients
whose injuries might otherwise be fatal. |
|
| Electrical anesthesia | |
|
In 1970, electrical anesthesia was first used in obstetrics. The inventor,
Prof. Aime Limoge applied the technique at the Rothschild Hospital in Paris. |
|
| US moon satellite | |
|
In 1962, the first American satellite to reach the moon surface, the
Ranger
IV, was launched at 3:50pm from Cape Canaveral, Florida. As intended,
it impacted on the moon three days later at 7:50pm on 26 Apr, travelling
at 5,963 mph. The launch vehicle was an Atlas-Agena B rocket, 102 feet
high, 16 feet in diameter at the base. The distance the satellite would
travel was about 229,541 miles. |
|
| Teletypesetting | |
|
In 1951, the Associated Press started using their new "teletypesetting"
service in Charlotte, NC. The news article information was transmitted
using a perforated, paper tape. At the receiving end of the circuit, a
punch produced a copy of the perforated tape. This tape could then be used
by typesetting machines. The first message sent was "Greetings. This is
the opening of the first teletypesetter circuit," for they were the first
news agency in the U.S. to begin such operation. |
|
| Battery | |
1939 (source) |
In 1940, a leak-proof flashlight battery (Ray-o-Vac) was patented in the
U.S. by Herman Anthony (No. 2,198,423). |
| Paying movie audience | |
|
In 1896, the first movie shown to a paying theatre audience in the U.S.
was presented using Thomas Edison's
Vitascope. The movie had a series of short scenes, and were part of a program
with other acts at Koster and Bial's Music Hall, 34th St, New York City.
Included in the film shorts were a ballet scene, a burlesque boxing match,
waves on a sea shore, and a comic allegory The Monroe Doctrine, all
of which were projected at about half life size. |
|
| Patents by black American inventors | |
|
In 1895, a "photographic print wash" was patented by a black American inventor,
C.J. Dorticus (No. 537,968). Another black American invention was patented
this same day, issued to Purdy and Peters for a "design for spoons" (No.
524,228). Other black American inventions were patented on this day in
other years. In 1889, a "passenger register" was patented by A. Romain.
(No. 402,035). In 1878, B.H. Taylor patented a "rotary engine" (No. 202,888).
The
Inventive Spirit of African Americans: Patented Ingenuity,
by Patricia Carter Sluby. |
|
| Zoetrope | |
|
In 1867, the Zoetrope was patented by William E. Lincoln of Providence,
R.I. (No. 64,117). The device was the first animated picture machine. It
provided an animation sequence of pictures lining the inside wall of a
shallow cylinder, with vertical slits between the images. By spinning the
cylinder and looking through the slits, a repeating loop of a moving image
could be viewed. |
|
| Light theory | |
|
In 1827, William Rowan Hamilton presented his Theory of Systems of Rays
at the Royal Irish Academy in Dublin. Although he was still an undergraduate,
only 21 years old, his work is one of the important works in optics, for
it provided a single function that brings together mechanics, optics and
mathematics. It led to establishing the wave theory of light, which gives
that light is a form of energy that travels in waves. |
|
