Albert Einstein And His Theories Essay, Research Paper

Albert Einstein and His Theories

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.

Einstein hated the dull regimentation and unimaginative spirit of school

in Munich. When repeated business failure led the family to leave Germany for

Milan, Italy, Einstein, who was then 15 years old, used the opportunity to

withdraw from the school. He spent a year with his parents in Milan, and when it

became clear that he would have to make his own way in the world, he finished

secondary school in Arrau, Switzerland, and entered the Swiss National

Polytechnic in Z?rich. Einstein did not enjoy the methods of instruction there.

He often cut classes and used the time to study physics on his own or to play

his beloved violin. He passed his examinations and graduated in 1900 by studying

the notes of a classmate. His professors did not think highly of him and would

not recommend him for a university position.

For two years Einstein worked as a tutor and substitute teacher. In 1902

he secured a position as an examiner in the Swiss patent office in Bern. In 1903

he married Mileva Mari?, who had been his classmate at the polytechnic. They had

two sons but eventually divorced. Einstein later remarried.

Early Scientific Publications

In 1905 Einstein received his doctorate from the University of Z?rich

for a theoretical dissertation on the dimensions of molecules, and he also

published three theoretical papers of central importance to the development of

20th-century physics. In the first of these papers, on Brownian motion, he made

significant predictions about the motion of particles that are randomly

distributed in a fluid. These predictions were later confirmed by experiment.

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.

Einstein’s Special Theory of Relativity

Einstein’s third major paper in 1905, “On the Electrodynamics of Moving

Bodies,” contained what became known as the special theory of relativity. Since

the time of the English mathematician and physicist Sir Isaac Newton, natural

philosophers (as physicists and chemists were known) had been trying to

understand the nature of matter and radiation, and how they interacted in some

unified world picture. The position that mechanical laws are fundamental has

become known as the mechanical world view, and the position that electrical laws

are fundamental has become known as the electromagnetic world view. Neither

approach, however, is capable of providing a consistent explanation for the way

radiation (light, for example) and matter interact when viewed from different

inertial frames of reference, that is, an interaction viewed simultaneously by

an observer at rest and an observer moving at uniform speed.

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.

Early Reactions to Einstein

The difficulty that others had with Einstein’s work was not because it

was too mathematically complex or technically obscure; the problem resulted,

rather, from Einstein’s beliefs about the nature of good theories and the

relationship between experiment and theory. Although he maintained that the only

source of knowledge is experience, he also believed that scientific theories are

the free creations of a finely tuned physical intuition and that the premises on

which theories are based cannot be connected logically to experiment. A good

theory, therefore, is one in which a minimum number of postulates is required to

account for the physical evidence. This sparseness of postulates, a feature of

all Einstein’s work, was what made his work so difficult for colleagues to

comprehend, let alone support.

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 Z?rich. In 1911 he moved to the

German-speaking university at Prague, and in 1912 he returned to the Swiss

National Polytechnic in Z?rich. Finally, in 1913, he was appointed director of

the Kaiser Wilhelm Institute for Physics in Berlin.

The General Theory of Relativity

Even before he left the patent office in 1907, Einstein began work on

extending and generalizing the theory of relativity to all coordinate systems.

He began by enunciating the principle of equivalence, a postulate that

gravitational fields are equivalent to accelerations of the frame of reference.

For example, people in a moving elevator cannot, in principle, decide whether

the force that acts on them is caused by gravitation or by a constant

acceleration of the elevator. The full general theory of relativity was not

published until 1916. In this theory the interactions of bodies, which

heretofore had been ascribed to gravitational forces, are explained as the

influence of bodies on the geometry of space-time (four-dimensional space, a

mathematical abstraction, having the three dimensions from Euclidean space and

time as the fourth dimension).

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.

For the rest of his life Einstein devoted considerable time to

generalizing his theory even more. His last effort, the unified field theory,

which was not entirely successful, was an attempt to understand all physical

interactions-including electromagnetic interactions and weak and strong

interactions-in terms of the modification of the geometry of space-time between

interacting entities.

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.”

World Citizen

After 1919, Einstein became internationally renowned. He accrued honors

and awards, including the Nobel Prize in physics in 1921, from various world

scientific societies. His visit to any part of the world became a national

event; photographers and reporters followed him everywhere. While regretting his

loss of privacy, Einstein capitalized on his fame to further his own political

and social views.

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.

When Hitler came to power, Einstein immediately decided to leave Germany

for the United States. He took a position at the Institute for Advanced Study at

Princeton, New Jersey. While continuing his efforts on behalf of world Zionism,

Einstein renounced his former pacifist stand in the face of the awesome threat

to humankind posed by the Nazi regime in Germany.

In 1939 Einstein collaborated with several other physicists in writing a

letter to President Franklin D. Roosevelt, pointing out the possibility of

making an atomic bomb and the likelihood that the German government was

embarking on such a course. The letter, which bore only Einstein’s signature,

helped lend urgency to efforts in the U.S. to build the atomic bomb, but

Einstein himself played no role in the work and knew nothing about it at the

time.

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.