Albert Einstein 

After formulating the theory of general relativity, Albert Einstein had shown that photons have momentum and that electrons and other subatomic particles display characteristics of both waves and particles. These discoveries helped form the quantum theories of Werner Heisenberg and Niels Bohr, who proposed that this wave-particle duality exhibited a randomness that is affected by the observer himself. Thereby, the more precisely the particle’s position is determined, the less precisely its momentum is known; the more precisely the momentum of the particle, the less precisely its position is known.

Einstein could never accept the random nature of quantum mechanics and conducted a series of thought experiments to disprove this theory. Bohr would counter and attempt to prove him wrong. Albert Einstein and Niels Bohr held a long-standing verbal jousting match about quantum theory during the 1920s and 30s. Bohr responded to Einstein’s famous quip, “God does not play dice,” by saying “Einstein, stop telling God what to do.”

NIELS BOHR

Niels Bohr was born on October 7, 1885 in Copenhagen, Denmark. Bohr made numerous contributions to our understanding of the structure of properties of atoms. He won the 1922 Nobel Prize for physics, chiefly for his work on atomic structure.

Bohr received his doctorate in physics from the University of Copenhagen in 1911. He then traveled to Manchester, England to study under Ernest Rutherford.

In 1913, Bohr published a theory about the structure of the atom based on an earlier theory of Rutherford’s. Rutherford had shown that the atom consisted of a positively charged nucleus, with negatively charged electrons in orbit around it. Bohr expanded upon this theory by proposing that electrons travel only in certain successively larger orbits. He suggested that the outer orbits could hold more electrons than the inner ones, and that these outer orbits determine the atom’s chemical properties.

Bohr also described the way atoms emit radiation by suggesting that when an electron jumps from an outer orbit to an inner one, that it emits light. Later other physicists expanded his theory into quantum mechanics. This theory explains the structure and actions of complex atoms.

Bohr became a professor of physics at the University of Copenhagen in 1916. In 1920, he was named director of the newly constructed Institute of Theoretical Physics at the University. Bohr became a Fellow of the Royal Society of London in 1926, receiving the Royal Society Copley Medal in 1938.

During World War II, Bohr fled Copenhagen to escape the Nazis. He traveled to Los Alamos, New Mexico to advise the scientists developing the first atomic bomb. He returned to Copenhagen after the war and later promoted the peaceful use of atomic energy.

 

ALBERT EINSTEIN

Albert Einstein was born on March 14, 1879 in Ulm, Wurttemberg, Germany. Einstein contributed more than any other scientist since Sir Isaac Newton to our understanding of physical reality.

Einstein was slow to learn to talk, not beginning to speak until sometime after his second birthday. His slow verbal development combined with a native rebelliousness toward authority, led one schoolmaster to say that young Albert would never amount to much.

Einstein’s mother, Pauline, was a talented pianist. She introduced Albert to music as a small child, beginning his violin lessons at age six. He labored under unimaginative instruction until discovering the joys of Mozart’s sonatas at age 13. From that point on, although he had no further lessons, his violin remained a constant companion. Einstein said later that, “I live my daydreams in music. I see my life in the form of music.”

When Einstein was 10, a poor student named Max Talmud began dining with the Einstein family once a week. Max would bring illustrated science books for Albert to study, and they would discuss what Albert learned. Max gave him a geometry textbook two years before Albert was to study the subject at school. Max later recalled, “Soon the flight of his mathematical genius was so high that I could no longer follow.”

In 1896, Einstein entered the Swiss Federal Polytechnic School in Zurich to be trained as a physics and mathematics instructor. He graduated in 1901, and unable to find a teaching position, accepted a job as technical assistant in the Swiss Patent Office in Bern. Einstein worked at the patent office from 1902 to 1909. During this period he completed an astonishing range of theoretical physics publications, written in his spare time, without the benefit of scientific literature or close contact with colleagues.

The most well known of these works is Einstein’s 1905 paper proposing ̴the special theory of relativity.” He based his new theory on the principle that the laws of physics are in the same form in any frame of reference. As a second fundamental hypothesis, Einstein assumed that the speed of light remained constant in all frames of reference.

Later in 1905 Einstein showed how mass and energy were equivalent expressing it in the famous equation: E=mc2 (energy equals mass times the velocity of light squared). This equation became a cornerstone in the development of nuclear energy.

Einstein received the Nobel Prize in 1921 but not for relativity, rather for his 1905 work on the photoelectric effect. He worked on at Princeton until the end of his life on an attempt to unify the laws of physics.

Via Lucid Cafe