Alana Lynes Science Vignette EDSE 452/453
Curriculum fit: Physics 30, Unit 4: Nature of Matter
Major
Concept: Nuclear fission and fusion are nature’s most powerful energy sources.
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The
importance of Einstein’s concept of mass-energy equivalence.
Albert Einstein, perhaps the most well known scientific name in society, is most commonly associated with the equation E=mc2. Einstein and his famous equation have forever changed the way we view our world. Einstein was born in southern Germany on March 14, 1879 to non-religious Jewish parents. A failed family business forced the Einsteins’ to move to Milan when Einstein was 16 years old. Einstein entered the teacher-training program at the Swiss Federal Polytechnic (ETH) to obtain certification as a math and physics teacher. For reasons that are unclear (some speculate anti-Semitism), Einstein worked only temporary teaching positions and the odd tutoring job for several years after graduation. In 1902 Einstein obtained a full-time position at the Federal Patent Office in the Swiss capital of Bern, working as an entry-level patent examiner. In the same year he married Mileva Maric, a fellow student at ETH and they had a son in 1904. It was during these years, working independent of a scientific laboratory and learning theoretical physics completely on his own, that Einstein accomplished some of his greatest achievements.
It was in 1905 when Einstein had his ‘annus mirabilis’ or year of miracles. In this year he produced three papers of tremendous significance. The first paper was on photons, which explains light as a stream of particles or bundles of discrete energy. The second paper on Brownian motion (the random motions of tiny particles) irrevocably proved that electrons did in fact exist, an idea that was still in scientific debate at the time. The third paper of the year, which Einstein is remembered most for, was on special relativity. This paper offered new conceptions regarding space, time and mass. This theory applies to objects moving at constant velocities and says that mass and energy are equivalent. In other words, mass can be converted (by a conversion factor of c) to energy and vise versa. The paper was released in June of 1905 and in September Einstein presented the equation E=mc2 (where E is energy, m is mass and c is the speed of light). Essentially this means that a small amount of energy can be transformed into huge amounts of energy, the secret behind the energy of the stars and nuclear bombs.
Ten years later Einstein developed his general theory of relativity, which applies to objects that are accelerating. Special relativity concerned only cases of uniform velocity whereas general relativity extended relativity to all forms of accelerated motion. Up until this time gravitational forces were seen as a puzzling action between two bodies. Einstein explained that massive objects curve space, so instead of being mysterious attracted to a massive object; a mass following the curvature of space will bring the two together. It is this theory that describes our universe as a whole and now forms the basis of our understanding of the structure of the universe.
Einstein’s theories arose from his desire to unify the worldviews prevalent in science at the turn of the century. Newton’s universal law of gravitation was described as an action at a distance and didn’t have a mechanical mechanism. Problems arose when physicists tried to apply these laws to electrostatics and magnetism, and as a result they didn’t treat them like gravity. Einstein realized that this method of science just wouldn’t work and decided that the worldviews needed to be radically reformed. Einstein attacked the problem from the top®down, characteristic of theoretical physics. He didn’t spend time doing experiments or examining every result from every experiment ever produced. Einstein began to think very hard about ideas that seemed obvious by comparing frames of reference in ‘thought experiments’. These ‘experiments’ were not those of a regular scientist, they contained no data and talked about hypothetical situations such as being on a train in comparison to being on the ground. Einstein’s work was off the wall and unorthodox for his time.
As such Einstein’s theories were not universally accepted and for every supporter there was a critic. Critics attacked Einstein and a pamphlet was published, entitled 100 Authors against Einstein. Einstein retorted, “If I were wrong, one would be enough”. In 1919 Einstein’s general theory of relativity was put to the test. During a total solar eclipse on November 6, 1919, a team of British astronomers reported that the positions of the stars near the sun appeared to have shifted from their proper positions. The apparent shift could be explained from the bending of light rays as they passed by the sun, just as predicted by Einstein’s general theory of relativity. Although there were still many opponents to Einstein’s work, he gained fame almost over night. An ‘ordinary’ man, presented to the public as larger than life, claimed to have changed the universe as the world saw it and became a ‘scientific superstar’.
Note:
Einstein’s theories have repeatedly been reinforced by celestial events, such
as the 1st recorded image of an unbroken ‘Einstein Ring’ in 1998.
Gravitational lenses, as predicted 80 years earlier by Einstein’s general
theory of relativity, produce a ring image of a distant object due to the
gravitational warping of space around a massive object.
Questions:
1. Was Einstein justified in believing that a radical reform in physics was needed to unify worldviews? Do you feel that all aspects of science must agree with each other to be correct?
2. Is accepting a mathematical formula that produces accurate information for certain phenomena reasonable even though the application ignores certain natural laws (as they are known)?
3. Do you think Einstein’s method of doing science (theoretical physics) is an appropriate method for scientists to gain an understanding of the laws of nature? Why or why not?
Extension:
The Cosmological Constant
“The biggest blunder of my life,” as Einstein later called it; the cosmological constant represented a negative reaction to gravity to balance the expansion of the universe. When Einstein developed his general theory of relativity in 1915, he realized that the original equations required the universe to be in motion (expanding). The fact that other galaxies even existed was still highly debatable during this time period. Einstein accepted the belief of his time that the universe was static and he invented the Cosmological Constant to balance the force of gravity, allowing galaxies to remain at fixed distances. In 1931 Einstein went to visit Edwin Hubble, who had recorded evidence that all galaxies are receding from one another, a phenomenon that Einstein might have predicted had he believed his original equations.
Questions:
4. Do you consider Einstein’s Cosmological Constant a scientific blunder or a reasonable solution to the problem, given the knowledge of the times?
References:
Browne, M. “‘Einstein Ring’ Caused by Space Warping Is Found.” The New York Times
March 31,1998.
Cassidy, D. “Control of Nature: Einstein and Our World.” Amherst, New York: Humanity
Books, 1998.
Cutnell, J. & Johnson, K. “Physics: 4th Edition.” Toronto, Ontario: John Wiley & Sons, Inc.,
1998.
PBS, Albert Einstein. Retrieved January 24, 2002, from
http://www.pbs.org/wnet/hawking/cosmostar/html/cstars_eins.html