Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#276 2017-12-06 00:39:41

ganesh
Administrator
Registered: 2005-06-28
Posts: 23,445

Re: crème de la crème

243) Otto von Guericke

Otto von Guericke, (born Nov. 20, 1602, Magdeburg, Prussian Saxony [now in Germany]—died May 11, 1686, Hamburg), German physicist, engineer, and natural philosopher who invented the first air pump and used it to study the phenomenon of vacuum and the role of air in combustion and respiration.

Guericke was educated at the University of Leipzig and studied law at the University of Jena in 1621 and mathematics and mechanics at the University of Leyden in 1623. In 1631 he became an engineer in the army of Gustavus II Adolphus of Sweden, and from 1646 to 1681 he was bürgermeister (mayor) of Magdeburg and magistrate for Brandenburg.

In 1650 Guericke invented the air pump, which he used to create a partial vacuum. His studies revealed that light travels through a vacuum but sound does not. In 1654, in a famous series of experiments that were performed before Emperor Ferdinand III at Regensburg, Guericke placed two copper bowls (Magdeburg hemispheres) together to form a hollow sphere about 35.5 cm (14 inches) in diameter. After he had removed the air from the sphere, horses were unable to pull the bowls apart, even though they were held together only by the air around them. The tremendous force that air pressure exerts was thus first demonstrated.

In 1663 he invented the first electric generator, which produced static electricity by applying friction against a revolving ball of sulfur. In 1672 he discovered that the electricity thus produced could cause the surface of the sulfur ball to glow; hence, he became the first man to view electroluminescence. Guericke also studied astronomy and predicted that comets would return regularly from outer space.

Otto_Von_Guerickea.JPG


It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi. 

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#277 2017-12-08 00:42:03

ganesh
Administrator
Registered: 2005-06-28
Posts: 23,445

Re: crème de la crème

244) John Harrison

John Harrison, (born March 1693, Foulby, Yorkshire, Eng.—died March 24, 1776, London), English horologist who invented the first practical marine chronometer, which enabled navigators to compute accurately their longitude at sea.

Harrison, the son of a carpenter and a mechanic himself, became interested in constructing an accurate chronometer in 1728. Several unfortunate disasters at sea, caused ostensibly by poor navigation, prompted the British government to create a Board of Longitude empowered to award £20,000 to the first man who developed a chronometer with which longitude could be calculated within half a degree at the end of a voyage to the West Indies. Harrison completed his first chronometer in 1735 and submitted it for the prize. He then built three more instruments, each smaller and more accurate than its predecessor. In 1762 Harrison’s famous No. 4 marine chronometer was found to be in error by only five seconds (1 1/4′ longitude) after a voyage to Jamaica. Although his chronometers all met the standards set up by the Board of Longitude, he was not awarded any money until 1763, when he received £5,000, and not until 1773 was he paid in full. The only feature of his chronometers retained by later manufacturers was a device that keeps the clock running while it is being wound.

Harrison.jpg


It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi. 

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#278 2017-12-10 00:19:34

ganesh
Administrator
Registered: 2005-06-28
Posts: 23,445

Re: crème de la crème

245) Benjamin Spock

Benjamin Spock, in full Benjamin McLane Spock, byname Dr. Spock (born May 2, 1903, New Haven, Connecticut, U.S.—died March 15, 1998, La Jolla, California), American pediatrician whose books on child-rearing, especially his Common Sense Book of Baby and Child Care (1946; 6th ed., 1992), influenced generations of parents and made his name a household word.

Spock received his medical degree in 1929 from Columbia University’s College of Physicians and Surgeons and trained for six years at the New York Psychoanalytic Institute. He practiced pediatrics in New York City while teaching the subject at the Cornell University Medical College from 1933 to 1947. Spock wrote Baby and Child Care partly to counteract the rigid pediatric doctrines of his day, which emphasized strict feeding schedules for infants and discouraged open displays of affection between parent and child. Spock, by contrast, encouraged understanding and flexibility on the part of parents, and he stressed the importance of listening to children and appreciating their individual differences. From its first appearance in 1946, Baby and Child Care served as the definitive child-rearing manual for millions of American parents in the “baby boom” that followed World War II. Spock’s approach was criticized as overly permissive by a minority of physicians, and he was even blamed for having helped form the generation of young Americans that protested the Vietnam War and launched the youth counterculture movement of the 1960s.

Spock taught child development at Western Reserve University (now Case Western Reserve University) in Cleveland, Ohio, from 1955 to 1967, when he resigned in order to devote himself more fully to the antiwar movement. Spock’s bitter opposition to U.S. involvement in the Vietnam War during the 1960s led to his trial and conviction (1968) for counseling draft evasion—a conviction overturned on appeal. In 1972 he was the presidential candidate of the pacifist People’s Party.

Spock’s many other books on child care include Dr. Spock Talks with Mothers (1961), Raising Children in a Difficult Time (1974), and Dr. Spock on Parenting (1988). He also wrote Decent and Indecent: Our Personal and Political Behavior (1970). In 1989 Spock on Spock: A Memoir of Growing Up with the Century, edited by Spock’s second wife, Mary Morgan, was published. By the time Spock died in 1998, his Baby and Child Care had sold nearly 50 million copies worldwide and been translated into 39 languages.

SPOK_Bendzhamin3.jpg


It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi. 

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

Board footer

Powered by FluxBB