# Albert Einstein

### Scientist

• Born: March 14, 1879 in Ulm, Germany
• Died: April 18, 1955 in Princeton, New Jersey, United States
• Nationality: American
• Occupation: Physicist
• The German-born American physicist Albert Einstein (1879-1955) revolutionized the science of physics. He is best known for his theory of relativity.

## Achievements

One of greatest scientific intellects who formulated theories of relatively; won Nobel Prize, 1921.

One of the foundations of quantum theory is the uncertainty principle, which places limits on the accuracy of measurements on the atomic scale. According to the uncertainty principle, it is impossible to measure two complementary variables (such as momentum and position) of a particle with exact precision. Likewise, the components of a particle's spin cannot be all known simultaneously.

Suppose, for example, there are two particles that have some correlated property--such as momentum, spin, or polarization state--such that they have opposite values of that property. (In the case of spin, this could result from a spin 0 particle decaying into two spin 1/2 particles, one with +1/2 spin, the other with -1/2 spin.) The particles, designated A and B, are then allowed to travel a long distance from each other in order to rule out the possibility of an exchange or signal traveling between them during the course of later measurements. A measurement performed on A to determine its z-component spin, would fix A's z-component spin at the expense of uncertainty in other quantum properties. If particle B were separated from A by light-years of distance, then according to special relativity theory (wherein faster-than-light travel is not possible), the measurement of A cannot instantly affect the measurement of B.

The paradox is established because the particles are also bound by the law of conservation of angular momentum. Thus, if the measurement on A finds its z-component spin to be +1/2, then the z-component of B's spin must--at that instant--be -1/2. (Remember that if they originally had zero spin together, then their spins must still add up to zero). A person could now choose to measure some other component of the spin of particle B. If a measurement of the x-component is performed, and since the z-component is already known through the correlation of the spins, the result is that an observer would know values for both the x- and z-components of the spin simultaneously. This extra information would contradict the limitations of the uncertainty principle.

## Albert arrives in New York

Professor Albert Einstein is pictured on the S. S. Belgenland arriving in New York City for a four-day stay. Einstein and his wife continued to California, where they would spend their winter months (image circa 1930).

## The ''H'' Bomb

Albert Einstein played a critical role in the development of the first atomic bomb. As early as 1939, he and a small group of American physicists perceived that Nazi Germany was attempting to build a uranium bomb. In consultation with other physicists, Einstein sent a letter that year to President Franklin D. Roosevelt, warning him of the German threat and asking his help in creating and funding an American project to build a uranium bomb.

Roosevelt responded cautiously, establishing a committee to explore the feasibility of building a uranium bomb and securing for it a \$6,000 congressional appropriation. From this modest beginning emerged the Manhattan Project, the American program to build an atomic bomb. In July 1945, physicists and engineers tested a uranium bomb in the New Mexico desert. Then, in August, the United States dropped two atomic bombs on Japan—a uranium bomb on Hiroshima and a plutonium bomb on Nagasaki—effectively ending World War II.

After the war, the United States and the Soviet Union, allies against Nazi Germany, grew suspicious of each other's intentions. Joseph Stalin, the Soviet leader, determined that he needed an atomic bomb, and in 1949 the Soviets stunned Americans by testing one. The Soviet Union was now America's rival in the nuclear arms race, leading American politicians, scientists, and the public to debate how the United States should respond to the Soviets.

Significance

President Harry S. Truman pledged to surpass the Soviets by building a hydrogen bomb, several orders of magnitude more destructive than either a uranium or plutonium bomb. Although Einstein had endorsed the building of the first atomic bombs, he broke ranks with Truman in 1950. He called Truman's belief that the United States could secure peace by staying a step ahead of the Soviets in the arms race "a disastrous illusion." Einstein believed that if the United States built a hydrogen bomb, its use would poison the atmosphere with radioactive fallout, extinguishing life on Earth.

Einstein's rejection of the hydrogen bomb was courageous but ineffective, and in 1952 the United States tested its first hydrogen bomb. As Einstein fore-saw, the hydrogen bomb did not bring security. The following year the Soviet Union tested its first hydrogen bomb, further escalating the nuclear arms race. Each nation now had the power to cause massive destruction. Science, the source of so much good in human history, had fully demonstrated its capacity for destruction, and not even its most reasoned voice could halt the ensuing arms race.

Primary Source: The H Bomb [excerpt]

SYNOPSIS: In the introduction to The H Bomb, a collection of essays by various authors, Einstein condemns the belief that the United States can achieve peace by staying a step ahead of the Soviets in the arms race. Trying to do so, he says, would concentrate power in the military and police and create a society in which hysteria replaced rational discourse. Because the hydrogen bomb would give the United States the power to extinguish life on Earth, Einstein rejects its construction as folly.

The idea of achieving security through national armament is, at the present state of military technique, a disastrous illusion. On the part of the United States this illusion has been particularly fostered by the fact that this country succeeded first in producing an atomic bomb. The belief seemed to prevail that in the end it were possible to achieve decisive military superiority.

In this way, any potential opponent would be intimidated, and security, so ardently desired by all of us, would be brought to us and all of humanity. The maxim which we have been following during these

## A direct ''Photoelectric'' determination of Plank's H'''

In the early twentieth century, physicists were discovering the fundamental nature of the building blocks of matter and energy. There was much scientific debate concerning whether matter, such as atoms and subatomic particles, possessed wavelike characteristics and whether energy, such as electromagnetic radiation, possessed particle-like characteristics. That matter and energy could consist of both wave-and particle-like characteristics (the wave-particle duality) was not compatible with classical, or Newtonian physics, which was sacrosanct at the time.

Millikan's 1916 article was significant in that it provided experimental evidence for Planck's constant and the photoelectric effect, both of which were important in the development of the wave-particle duality and eventually to quantum mechanics. Quantum mechanics is the physical science that applies to the interaction of energy and matter on the scale of atoms and subatomic particles. On this infinitely small scale, the classical physics that rule the macromolecular world break down. The cornerstone of quantum mechanics is Planck's quantum theory, expressed as E = h.

In the equation, Max Planck's h plays a central role. This constant (h = 6.626 × 10 34 joule-second) is one of the most important in all of physics. Einstein used Planck's quantization-of-energy principle to explain the photoelectric effect, which involves the emission of electrons from certain materials when exposed to light, a phenomenon that could not be explained by classical models. "A Direct Photoelectric Determination of Planck's' h '" provided the most accurate measurement of h at the time. Additionally, it was part of a set of experiments in which Millikan proved the validity of the photoelectric effect.

Wave-length compared
with 5,461Slope in volt-frequencies

3,1264.11 × 10−16

3,6504.14 × 10−16

3,1264.10 × 10−16

3,6504.12 × 10−16

3,1264.24 × 10−16

4,0473.98 × 10−16

2,5354.04 × 10−16

3,1264.24 × 10−16

4,0474.21 × 10−16

Mean 4.131 × 10−16

## Legacy

• Died: April 18, 1955 in Princeton, New Jersey, United States

• In the history of the exact sciences, only a handful of men--men like Nicolaus Copernicus and Isaac Newton--share the honor that was Albert Einstein's: the initiation of a revolution in scientific thought. His insights into the nature of the physical world made it impossible for physicists and philosophers to view that world as they had before. When describing the achievements of other physicists, the tendency is to enumerate their major discoveries; when describing the achievements of Einstein, it is possible to say, simply, that he revolutionized physics.

• ''The difference between stupidity and genius is that genius has it's limits.''

• ''Put your hand on a hot stove for a minute it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute.''

## Annotated Bibliography

"About Albert Einstein": "Albert Einstein." Scientists: Their Lives and Works. Detroit: UXL, 2006. Research in Context. Web. 11 May 2016.

This source helped me with my research with Albert Einstien because it helped me find out when he was born and where he lived.

"Achievements": "Albert Einstein." Scientists: Their Lives and Works. Detroit: UXL, 2006. Research in Context. Web. 11 May 2016.

"A direct ''Photoelectric'' determination of Plank's H": "Albert Einstein." Scientists: Their Lives and Works. Detroit: UXL, 2006. Research in Context. Web. 11 May 2016.

"Albert arrives in New York": "Einstein, Albert." The Columbia Electronic Encyclopedia™. New York: Columbia University Press, 2016. Research in Context. Web. 11 May 2016.

"The ''H'' Bomb": "Albert Einstein." DISCovering Authors. Detroit: Gale, 2003. Research in Context. Web. 11 May 2016.

"Legacy": "Albert Einstein." UXL Encyclopedia of Science. Ed. Amy Hackney Blackwell and Elizabeth Manar. 3rd ed. Farmington Hills, MI: UXL, 2015. Research in Context. Web. 11 May 2016.

"Albert Einstein." Encyclopedia of World Biography. Detroit: Gale, 1998. Research in Context. Web. 11 May 2016.

"Pictures": "Albert Einstein Statue In Washington." UPI Photo Collection. 2009. Research in Context. Web. 11 May 2016.

"Einstein"Albert Einstein Arrives in New York." Gale Biography in Context. Detroit: Gale, 2016.

Biography in Context. Web. 11 May 2016., Albert." UXL Biographies. Detroit: UXL, 2011. Research in Context. Web. 11 May 2016.

"Albert Einstein Arrives in New York." Gale Biography in Context. Detroit: Gale, 2016. Biography in Context. Web. 11 May 2016

"Albert Einstein and friends." Science and Its Times. Ed. Neil Schlager and Josh Lauer. Detroit: Gale, 2001. Biography in Context. Web. 11 May 2016.

"Albert Einstein at His New Jersey Home, Circa 1950." Gale Biography in Context. Detroit: Gale, 2010."Albert Einstein." Gale Biography in Context. Detroit: Gale, 2010. Biography in Context. Web. 11 May 2016. Biography in Context. Web. 11 May 2016.

These sources helped me complete my smore flyer because they tell me where Albert was born and what he did and his achievements. They also tell me where he died and how his death and work effected modern scientist.