Niels Bohr

Science / Great Scientists

Danish physicist, philosopher, teacher, and humanist, known for atomic structure with electrons orbiting nucleus  

Brief biography of Niels Bohr, best known for his 'solar system' model of atomic structure, the foundation of quantum mechanics.    

  

Niels Bohr (1885-1962), Danish physicist, was one of the greatest physical chemists of the 20^th century, famous for his contribution to quantum physics and atomic structure that won him Nobel Prize in Physics in 1922. He proposed the 'Solar System' model of atomic structure in which electrons orbit the central nucleus.  He married Margrette Norlind in 1912. They had six sons, the fourth, Aage Bohr, followed in his footsteps and won his own Nobel Prize in 1975.  

Early Life

Niels Henrik David Bohr was born on October 7, 1885, in a mansion owned by his maternal grandmother of influential Jewish banking family. His father, Christian Bohr, was a professor of physiology at Copenhagen University. The children grew up in an atmosphere in which pursuit of knowledge, intellectual discussions and culture were greatly encouraged. He loved football.

A Hopeful Beginning

Bohr studied at Copenhagen University and did experimental work by using his father's physiology laboratory since there was no physics laboratory at that time. In 1906, he won the Gold Medal from the Royal Danish Academy of the Sciences for his measurement of the surface tension of water.

On 1911, Bohr completed his PhD and went to England the same year. In Cambridge he met Ernest Rutherford, who just published his discovery that most of the mass of an atom is in its center, the nucleus. Bohr joined Rutherford's team in Manchester working on the structure of the atom. Rutherford became his role model and lifelong friend. 

John Bardeen

Science / Scientist Datebook: May 23 

Physicist and electrical engineer.  Nobel Laureate in Physics twice. 

John Bardeen (May 23, 1908 – January 30, 1991), was born in Madison,  Wisconsin. An electrical engineer and physicist, he was the only person to have won the Nobel Prize in Physics twice: first in 1956 with William Shockley and Walter Brattain, for their researches on semiconductors and their discovery of the transistor effect,  and in 1972 with Leon N Cooper and John Robert Schrieffer, for a fundamental theory of conventional superconductivity known as the BCS Theory. 

The transistor revolutionized the electronics industry, and made possible the development of almost every modern electronic device, from telephones to computers to missiles.

Ernest Rutherford: Nuclear Physics Pioneer

Science Datebook: March 11

Baron Ernest Rutherford, Father of Nuclear Physics

Baron Ernest Rutherford (b. August 30, 1871-d. October 19, 1937), was a New-Zealand born British physicist. 

This day on March 11, 1911, Ernest Rutherford is considered the father of nuclear physics, as he published his atomic theory describing the structure of the atom for the first time at the Manchester Literary and Philosophical Society.

He described the atom as having a central positive nucleus surrounded by negative orbiting electrons. His model suggested that most of the mass of the atom was contained in the small nucleus, with the rest of the atom mostly empty space. His conclusion followed what we now know as Rutherford's "gold foil experiment" especially amongst science students and other advocates.

Albert Einstein

Science / Scientists Datebook: 14 March

 

 

A brief biography of Albert Einstein, German-born American physicist, Famous for Theory of Relativity, E=MC².

 

 

 

 

 

Once again, we remember the birthday of Albert Einstein (March 14, 1879 - April 18, 1955), German-born American, born on March 14, 1879, in Ulm, Germany. Theoretical physicist and mathematician, Einstein is best known for his Theory of Relativity, with formula insignia E=MC².  He received the 1921 Nobel Prize in Physics, especially for his discovery of the law of photoelectric effect, and "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect", a pivotal step in the development of quantum theory . He was highly influential on the Manhattan Project, which led to the first atomic bomb. Like Wolfgang Amadeus Mozart, his musical idol, in the scientific world, Einstein's name has become synonymous with genius. 

 

Having made important contributions to quantum mechanics, Einstein was therefore a central figure in the revolutionary reshaping of the scientific understanding of nature that modern physics accomplished in the first decades of the twentieth century. His mass–energy equivalence formula E = mc², which arises from relativity theory, has been called "the world's most famous equation". His work is also known for its influence on the philosophy of science.

Christiaan Huygens: Discovered Saturn’s Rings

Dutch astronomer, mathematician and physicist Christiaan Huygens is famous for his invention of the first accurate pendulum clock, as well as his discovery of the rings of Saturn and its largest moon, Titan. He also founded the wave theory of light known as “Huygens Construction,” which he outlined in his Treatise on Light. 
 

Early Life of Christiaan Huygens, the ‘Little Archimedes’

Christiaan Huygens, (1629-1695), was born on April 14 in The Hague. He grew up in a wealthy environment, rich in both culture and intellectual pursuits. His father, Constantin Huygens, was a diplomat of the Dutch Republic, patron of the arts, composer and poet. Christiaan grew up exposed to distinguished visitors at home, such as the painter Rembrandt, English poet John Donne, and significantly for him, the great philosopher and mathematician René Descartes.
The influence of these men on young Christiaan was instrumental in the development of his lifelong love for art, music, law, engineering, and above all, mathematics. His father called him “mon Archimede” (“my Archimedes”).  Christiaan was also an excellent card and billiard player, anda top-class rider.
At the young age of 16, he entered the university and intensely focused on mathematics and law. He also  started writing his treatises on major mathematical problems at this time.

Huygens The Stargazer

Not long after he joined the university, Huygens became interested in the skies. In order to get a clear view of the surrounding planetary bodies, he developed one of the best lenses for telescopes of the time. Using his lenses, he discovered Saturn’s largest moon, Titan. The following year he made another astronomical discovery; the rings of Saturn. Galileo actually observed Saturn’s rings in his telescopic discoveries prior to Huygens’ discovery, but could not tell what they were. Huygens had a better telescope, however, and was the first to identify them as rings.
Working in astronomy demanded accurate timekeeping, and in that year, Huygens developed the pendulum clock with increased accuracy of time measurement. This is described in his famous book Horologium.

Celebrity Status, Scientists’ Scientist

Huygens’ reputation spread fast, and when he went to Paris in 1660, he was instantly a celebrity. He became a member of the circle of the best thinkers of the day, including the great French mathematician Blaise Pascal, then Sorbiere and Carcavi. The following year, he went to London and showed the English scientists his telescopes. Two years later, Huygens was invited to join the prestigious Royal Society. He then became a founding member of the Académie Royale des Sciences, the equivalent of the Royal Society. He became the president of the Académie in 1672, an extraordinary honor for a Dutchman at the time.

Ill Health in Last Years

Perhaps from overwork, Huygens was constantly ill. From Paris, he returned to Holland in 1670. Some years later, he had to give up his position in the French Académie. He also made a return visit to London and met Isaac Newton there. The scientists admired one another, and held one another in high esteem.
Cosmotheoros, published posthumously, was his last work. It was the first serious scientific book on the idea of a gigantic universe populated with ‘so many Suns, so many Earths…’ More startling at that point in time were his discussions of the possibility of extraterrestrial life, something that took more than three centuries for scientists to seriously investigate, although he was much admired in his day.

Video Credit:

Christiaan Huygens. en.wikipedia.org. / Public Domain

Resources:

1. Ellyard, David. Who Disovered What When. Sydney: New Holland (2005)
2. Farndon, John and Alex Woolf, Anne Rooney and Liz Gogerly.  The Great Scientist. Capella (2005)
3. McGovern, Una, Editor. Chambers Biographical Dictionary. Chambers Publishers (2002)


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