Mar 14, 1879:
Albert Einstein born
On March 14, 1879, Albert Einstein is born, the son of a Jewish
electrical engineer in Ulm, Germany. Einstein's theories of special and
general relativity drastically altered man's view of the universe, and
his work in particle and energy theory helped make possible quantum
mechanics and, ultimately, the atomic bomb.
After a childhood in
Germany and Italy, Einstein studied physics and mathematics at the
Federal Polytechnic Academy in Zurich, Switzerland. He became a Swiss
citizen and in 1905 was awarded a Ph.D. from the University of Zurich
while working at the Swiss patent office in Bern. That year, which
historians of Einstein's career call the annus mirabilis--the "miracle
year"--he published five theoretical papers that were to have a profound
effect on the development of modern physics.
In the first of
these, titled "On a Heuristic Viewpoint Concerning the Production and
Transformation of Light," Einstein theorized that light is made up of
individual quanta (photons) that demonstrate particle-like properties
while collectively behaving like a wave. The hypothesis, an important
step in the development of quantum theory, was arrived at through
Einstein's examination of the photoelectric effect, a phenomenon in
which some solids emit electrically charged particles when struck by
light. This work would later earn him the 1921 Nobel Prize in Physics.
In
the second paper, he devised a new method of counting and determining
the size of the atoms and molecules in a given space, and in the third
he offered a mathematical explanation for the constant erratic movement
of particles suspended in a fluid, known as Brownian motion. These two
papers provided indisputable evidence of the existence of atoms, which
at the time was still disputed by a few scientists.
Einstein's
fourth groundbreaking scientific work of 1905 addressed what he termed
his special theory of relativity. In special relativity, time and space
are not absolute, but relative to the motion of the observer. Thus, two
observers traveling at great speeds in regard to each other would not
necessarily observe simultaneous events in time at the same moment, nor
necessarily agree in their measurements of space. In Einstein's theory,
the speed of light, which is the limiting speed of any body having mass,
is constant in all frames of reference. In the fifth paper that year,
an exploration of the mathematics of special relativity, Einstein
announced that mass and energy were equivalent and could be calculated
with an equation, E=mc2.
Although the public was not quick to
embrace his revolutionary science, Einstein was welcomed into the circle
of Europe's most eminent physicists and given professorships in Zýrich,
Prague, and Berlin. In 1916, he published "The Foundation of the
General Theory of Relativity," which proposed that gravity, as well as
motion, can affect the intervals of time and of space. According to
Einstein, gravitation is not a force, as Isaac Newton had argued, but a
curved field in the space-time continuum, created by the presence of
mass. An object of very large gravitational mass, such as the sun, would
therefore appear to warp space and time around it, which could be
demonstrated by observing starlight as it skirted the sun on its way to
earth. In 1919, astronomers studying a solar eclipse verified
predictions Einstein made in the general theory of relativity, and he
became an overnight celebrity. Later, other predictions of general
relativity, such as a shift in the orbit of the planet Mercury and the
probable existence of black holes, were confirmed by scientists.
During
the next decade, Einstein made continued contributions to quantum
theory and began work on a unified field theory, which he hoped would
encompass quantum mechanics and his own relativity theory as a grand
explanation of the workings of the universe. As a world-renowned public
figure, he became increasingly political, taking up the cause of Zionism
and speaking out against militarism and rearmament. In his native
Germany, this made him an unpopular figure, and after Nazi leader Adolf
Hitler became chancellor of Germany in 1933 Einstein renounced his
German citizenship and left the country.
He later settled in the
United States, where he accepted a post at the Institute for Advanced
Study in Princeton, New Jersey. He would remain there for the rest of
his life, working on his unified field theory and relaxing by sailing on
a local lake or playing his violin. He became an American citizen in
1940.
In 1939, despite his lifelong pacifist beliefs, he agreed
to write to President Franklin D. Roosevelt on behalf of a group of
scientists who were concerned with American inaction in the field of
atomic-weapons research. Like the other scientists, he feared sole
German possession of such a weapon. He played no role, however, in the
subsequent Manhattan Project and later deplored the use of atomic bombs
against Japan. After the war, he called for the establishment of a world
government that would control nuclear technology and prevent future
armed conflict.
In 1950, he published his unified field theory,
which was quietly criticized as a failure. A unified explanation of
gravitation, subatomic phenomena, and electromagnetism remains elusive
today. Albert Einstein, one of the most creative minds in human history,
died in Princeton in 1955.
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