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LIGHT YEAR

What Einstein Did in 1905

12:00 AM, Oct 5, 1998 • By JONATHAN V. LAST
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Einstein still held one constant, the speed of light, which he labeled "c." But he made it a stricter constant than the scientific world had ever seen. Unlike anything else, light has an absolutely constant velocity. If a man is standing on a train moving twenty miles per hour and throws a baseball forward at thirty miles per hour, the baseball is actually moving fifty miles per hour. But if that man turns on a flashlight, the light moves at the same speed that it would if he were standing still. The speed of light never varies.


The concept of multiple frames of reference was utterly revolutionary. And when combined with the absolute speed of light, it led to the paper on the special theory of relativity, which Einstein wrote in five weeks, and later to his formula E=mc<2> -- the famous expression of the relation between the mass of an object and its energy.


Knowing the most important characteristic of light, Einstein turned to its nature. One of the most vexing problems of physics in the early 1900s was the mystery of the photoelectric effect. When light shines on certain metals, electrons are emitted. And worse yet for the wave theory, the number of electrons emitted increases with the intensity of the light, and the energy of the emitted electrons increases with the frequency of the light.


Einstein determined that the photoelectric effect must be the result of the bombardment of the metal by discrete packets of energy, which he dubbed "photons." The photon is a particle of light whose energy is proportional to its frequency and whose propagation requires no intermediary medium. This theory of quantum light was so radical that it was immediately dismissed by most of the scientific community as folly until 1916, when Robert Millikan confirmed Einstein's calculations about the photoelectric effect. By the early 1920s, at long last, the photon was accepted and quantum theory predominated.


After hundreds of years of wrong thinking, Einstein had abolished the aether. He did for light what Newton had done for gravity: In five papers in 1905, he gave it a thorough, original, and mathematically complete explanation and changed all our conceptions of the world and the boundaries of science.


All that work in one year's time. The rest of his life saw other accomplishments. In 1916, for example, he published what would become his most famous work, The General Theory of Relativity. But mostly, his remaining days were spent chasing the one that got away: the unified field theory.


When Einstein finally published his Unified Field Theory in 1929, he created a media circus. After submitting the paper to the Prussian Academy of Sciences, he retired to his home in Berlin. The academy, not knowing what to make of the six dense pages of equations, simply released the long-awaited work to the public without commenting on it. The new theory, which tried to find a single set of laws to govern both electricity and gravity, mystified literally everyone in the world, and hordes of reporters from around the globe camped outside Einstein's house for weeks, waiting for the great man to explain himself. Finally, Einstein granted his only interview to a reporter from the New York Times -- as a favor to its managing editor, Carr Van Anda, who had once corrected one of Einstein's mathematical mistakes. (Like many theoretical physicists and mathematicians, Einstein found actual calculation tedious, and occasional errors crop up in the math in his letters and notebooks.)


Einstein emigrated to the United States in 1933 after the Nazis confiscated all his property for the crimes of "cultural intellectualism, intellectual treason, and pacifist excesses." He took a position at Princeton University's Institute for Advanced Study, where he requested as his only research equipment "a desk or table, a chair, paper, and pencils. Oh yes, and a large waste basket . . . so I can throw away all my mistakes."


In the early months of World War II, aware of German experiments with fission, Einstein signed a letter (prepared by other physicists) describing to President Roosevelt the possibility of creating an atomic bomb, and his prestige was sufficient to spark the birth of the Manhattan Project. He was offered the prime minister's post in the newly born nation of Israel, but he turned it down so that he could continue working on the unified field theory that would, he hoped, lay bare God's blueprint for the universe.


He never succeeded, but without knowing it he sketched the task for the next three generations: super-string theory. In Einstein's time, physicists were aware of only two fundamental forces of physics, while today there are four known forces: gravitational, electromagnetic, weak atomic, and strong atomic. And today every theoretical physicist worth his salt, from Stephen Hawking to John Wheeler, is obsessed with the quest for unification of the laws that govern these forces.


That quest has recently taken a fascinating and mind-bending twist into the world of fundamental particles. In the fifteen years following Einstein's death in 1955, a number of very, very small particles were discovered -- and the theory of quarks was developed to explain them. According to quark theory, the only elementary particles are leptons and quarks (although there are six flavors of quarks, each of which comes in six colors). Leptons and quarks combine in various ways and combinations to make different, bigger particles, much as electrons, neutrons, and protons combine to make different types of atoms.


Superstring theory postulates that there is only one truly elemental particle, which is a tiny loop of "string" that measures roughly 10<-35> meters and has an incredibly high level of energy. This string vibrates in different ways, and it is these different modes of vibration that cause the string to take on the forms of the different leptons and quarks, which in turn serve as the building blocks for all other particles. If superstring theory were proved, it would not only establish a fundamental particle, but also solve Einstein's problem of the unified field theory.


The problem is that for superstring theory to hold, the strings themselves must exist in anywhere from six to twenty-two dimensions beyond the four we see in everyday life.


More, the combining of these strings would take place on a scale that is many orders of magnitude smaller than is measurable by any sort of technology we can build. Finding a way to refine and prove superstring theory and finish Einstein's unification will require advances so revolutionary that no one can imagine what they might be.


No one, that is, but a giant.




Jonathan V. Last is a reporter at THE WEEKLY STANDARD.