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Einstein, Albert (1879-1955), German-born
American physicist and Nobel laureate, best known as the creator of the
special and general theories of relativity and for his bold hypothesis
concerning the particle nature of light. He is perhaps the most well-known
scientist of the 20th century.
Einstein was born in Ulm on March 14, 1879, and spent his youth in Munich,
where his family owned a small shop that manufactured electric machinery.
He did not talk until the age of three, but even as a youth he showed a
brilliant curiosity about nature and an ability to understand difficult
mathematical concepts. At the age of 12 he taught himself Euclidean geometry.
The second paper, on the photoelectric effect, contained a revolutionary hypothesis concerning the nature of light. Einstein not only proposed that under certain circumstances light can be considered as consisting of particles, but he also hypothesized that the energy carried by any light particle, called a photon, is proportional to the frequency of the radiation. The formula for this is E = hu, where E is the energy of the radiation, h is a universal constant known as Planck's constant, and u is the frequency of the radiation. This proposal-that the energy contained within a light beam is transferred in individual units, or quanta-contradicted a hundred-year-old tradition of considering light energy a manifestation of continuous processes. Virtually no one accepted Einstein's proposal. In fact, when the American physicist Robert Andrews Millikan experimentally confirmed the theory almost a decade later, he was surprised and somewhat disquieted by the outcome. Einstein, whose prime concern was to understand the nature of electromagnetic radiation, subsequently urged the development of a theory that would be a fusion of the wave and particle models for light. Again, very few physicists understood or were sympathetic to these ideas. In the spring of 1905, after considering these problems for ten years, Einstein realized that the crux of the problem lay not in a theory of matter but in a theory of measurement. At the heart of his special theory of relativity was the realization that all measurements of time and space depend on judgments as to whether two distant events occur simultaneously. This led him to develop a theory based on two postulates: the principle of relativity, that physical laws are the same in all inertial reference systems, and the principle of the invariance of the speed of light, that the speed of light in a vacuum is a universal constant. He was thus able to provide a consistent and correct description of physical events in different inertial frames of reference without making special assumptions about the nature of matter or radiation, or how they interact. Virtually no one understood Einstein's argument.
Einstein did have important supporters, however. His chief early patron was the German physicist Max Planck. Einstein remained at the patent office for four years after his star began to rise within the physics community. He then moved rapidly upward in the German-speaking academic world; his first academic appointment was in 1909 at the University of Zürich. In 1911 he moved to the German-speaking university at Prague, and in 1912 he returned to the Swiss National Polytechnic in Zürich. Finally, in 1913, he was appointed director of the Kaiser Wilhelm Institute for Physics in Berlin.
On the basis of the general theory of relativity, Einstein accounted
for the previously unexplained variations in the orbital motion of the
planets and predicted the bending of starlight in the vicinity of a massive
body such as the sun. The confirmation of this latter phenomenon during
an eclipse of the sun in 1919 became a media event, and Einstein's fame
spread worldwide.
Most of Einstein's colleagues felt that these efforts were misguided. Between 1915 and 1930 the mainstream of physics was in developing a new conception of the fundamental character of matter, known as quantum theory. This theory contained the feature of wave-particle duality (light exhibits the properties of a particle, as well as of a wave) that Einstein had earlier urged as necessary, as well as the uncertainty principle, which states that precision in measuring processes is limited. Additionally, it contained a novel rejection, at a fundamental level, of the notion of strict causality. Einstein, however, would not accept such notions and remained a critic of these developments until the end of his life. "God," Einstein once said, "does not play dice with the world."
The two social movements that received his full support were pacifism
and Zionism. During World War I he was one of a handful of German academics
willing to publicly decry Germany's involvement in the war. After the war
his continued public support of pacifist and Zionist goals made him the
target of vicious attacks by anti-Semitic and right-wing elements in Germany.
Even his scientific theories were publicly ridiculed, especially the theory
of relativity.
After the war, Einstein was active in the cause of international disarmament and world government. He continued his active support of Zionism but declined the offer made by leaders of the state of Israel to become president of that country. In the U.S. during the late 1940s and early '50s he spoke out on the need for the nation's intellectuals to make any sacrifice necessary to preserve political freedom. Einstein died in Princeton on April 18, 1955. Einstein's efforts in behalf of social causes have sometimes been viewed as unrealistic. In fact, his proposals were always carefully thought out. Like his scientific theories, they were motivated by sound intuition based on a shrewd and careful assessment of evidence and observation. Although Einstein gave much of himself to political and social causes, science always came first, because, he often said, only the discovery of the nature of the universe would have lasting meaning. His writings include Relativity: The Special and General Theory (1916); About Zionism (1931); Builders of the Universe (1932); Why War? (1933), with Sigmund Freud; The World as I See It (1934); The Evolution of Physics (1938), with the Polish physicist Leopold Infeld; and Out of My Later Years (1950). Einstein's collected papers are being published in a multivolume work, beginning in 1987. |
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