Einstein and the Universe

Part I: The Special Theory of Relativity

It's been nearly a century since Einstein changed the universe with his Special Theory of Relativity. His ideas rocked the physics world and now we rank him alongside such great luminaries as Aristotle and Newton. Who was this genius and how did he come upon his revolutionary ideas?

Albert Einstein was born in Ulm, Germany in 1879. His father, Hermann Einstein, had shown an aptitude for mathematics as a boy, but became a businessman because, as a Jew, he would not be provided a public university education. Albert's mother, Pauline, had a passion for music, something she would pass on to her son, through her insistence on violin lessons. Young Albert resisted these, but as an adult, often took to playing the fiddle as a way to relax as he pondered the most difficult scientific problems.

It is said that as a boy Albert's teachers found him slow, perhaps because he seemed to have difficulty with learning by rote. He never gave his teachers a quick answer, but hesitated, as if he was thinking about it. After giving an answer, he would always repeat it softly to himself. This made some of his teachers wonder if he was mentally retarded. Classmates avoided him because he showed no interest in sports.

In Gymnasium, the German equivalent of high-school, he had a terrible time with Greek. His teacher was so frustrated with him he told young Albert "your mere presence here undermines the class's respect for me." He never graduated from that Gymnasium but left to join his family when they moved to Italy.

As a high-school dropout, Einstein had difficulty being accepted into college. His desire was to study and teach philosophy,but no university would accept him. His father, concerned about his son's financial future, pushed Albert to go to a technical college. Iin 1895 he applied to the Polytechnic Institute of Zurich, but he failed the entrance exam. The college principal, noting that Einstein was almost two years younger than most of the other candidates, decided to admit him the following semester without making him retake the test.

At the Polytecnikum, Albert was not considered the best of students. One professor told him, "You're enthusiastic, but hopeless at physics. For your own good you should switch to something else, medicine or maybe literature or law." His math professor referred to him as a "lazy dog." Another professor was antagonized by him because he did not address him as "Herr Professor." He barely passed the exit exam and was not offered a position at the Institute as an assistant professor as he had hoped. Instead, he had to settle for a job as a clerk at the Swiss patent office.

So how did this young man with such an unpromising future in physics revolutionize the science? As a boy he was a deep thinker. He had the ability to picture a complex problem in simple terms. When he was sixteen he wondered what a beam of light would look like if you rode a bicycle next to it at the speed of light, or what his own image would look like in the mirror at the speed of light. As he grew up, starting with these seemingly simple questions and with a drive to understand what he would later call "theories of principle", Einstein found the answers that would overturn the physics world.

Scientists that worked with Einstein noted he was neither a fast thinker nor the best of mathematicians. What he had, though, was a passion to understand nature and little interest in temporal goals. "I have never looked upon ease and happiness as ends in themselves...The ordinary objects of human endeaveor - property, outward success, luxury - have always seemed to me contemptible," he wrote in 1934.

Einstein's "theories of principle" were general rules that all phenomena must satisfy. Throughout his work he persuaded these theories with almost a moral fervor. He really cared, perhaps more than his colleagues, that physics should explain nature consistently and without contradiction.

The 19th Century: Physics in Crisis

Increasingly throughout the 19th century, scientists found themselves in a dilemma as long-held principals came in conflict with new experimental data. In the 1400's Sir Isaac Newton had come up with a series of rules that described the motion of bodies. Newton's Three Laws of Dynamics were, by anybody's measure, a great success. Scientists could use them to predict the motion of the planets in the sky as well as the movement of more mundane objects back on Earth. One of the rules that comes out of Newton's Laws, though, is that everything is in motion relative to something else. Nothing in the universe is absolutely still.

In the 19th century a brilliant Scottish physicist named James Maxwell started studying electromagnetism. His theories explained much that was observed in relation to the movement of radiant energy waves such as light and x-rays.

Some of Maxwell's theories directly contradicted Newton's Laws, however, and it seemed that either Newton's Laws were wrong or Maxwell's theories. Einstein likened the situation to a house built in two parts. The newly-added wing was causing tensions in the whole structure and fissures to appear in the masonry.

Maxwell had observed that light, and other forms of radiant energy, moved like a wave, not like a particle of matter. Waves, however, need a medium to move through. Ocean waves move through water. Sound waves move through air. What possible medium did light waves move through? Maxwell called this supposed medium "ether." Since light travels everywhere in the universe, it follows that the ether must extend everywhere. Maxwell also stated that it had to be absolutely motionless. This theory brought Maxwell's work into direct conflict with Newton's Laws.

Another conflict in physics was the problem of continuity. It was supposed (and later proven by Einstein) that all matter was made of tiny particles. No object is really solid but is composed of atoms separated by empty space. This means that matter is not continuous, but discontinuous. Maxwell's waves, however, appeared to be continuous. Since it was well known that matter could produce light (for example, a burning candle) physicists had a hard time explaining how discontinuous matter could produce waves of continuous light.

Finally, confusing the issue even further was an experiment done by Albert Michelson and Edward Morley. They set out to prove the existence of ether by detecting tiny differences in the speed of light. Their clever experiment took a beam of light and split it two ways. One traveled along the direction the earth traveled through space. The other traveled across that same path. Later the two beams were allowed to combine and create an interference pattern. If the edges of the pattern were fuzzy, it meant that one of the split beams of light was arriving just a bit later than the other. Michelson and Morley expected that this would be the case as they thought one beam should be reduced by the same amount of speed as the earth's forward orbital movement.

The scientists were surprised at the result of the experiment. It seemed that the speed of light did not change even if one of the beams traveled the same direction as the movement of the earth. What could this mean?

Einstein Saves the Day

Perhaps mankind is lucky that Einstein got turned down for a teaching job at the Polytecnikum. As a professor his schedule would have been heavy. At the Swiss patent office he worked during the day, but had ample time during the night to ponder the problems of physics. In 1905 he submitted four articles to the German Annalen der Physik (Annals of Physics). They were published that year. Experts agree that probably each of them was worthy of a Nobel prize. Many people refer to 1905 as Einstein's "Miracle Year."

His first paper, which came out in March, attacked the problem of discontinuity. Einstein showed that light is actually made up of what he called "atoms of energy" or "quanta" (these"quanta" are now refered to as "photons.") Photons are the basic unit of all forms of electromagnetic radiation. Einstein also correctly hypothesized that photons have both properties of continuity and discontinuity. They behave like a wave in some cases and like a particle in others. This not only resolved a major problem in science, but gave rise to a whole new field dealing with activity in the world of particles smaller than the atom: quantum physics.

Special Relativity

In June of 1905 Einstein's second major paper was published which dealt with the nature of the speed of light. He started his paper by declaring the idea of an ether was "superfluous" and unnecessary to explain what experiments were showing. Since light was a particle with wave properties, it needed no medium. This is why Michelson and Morley's experiment had failed. Since light was not a wave traveling through a motionless "ether," the movement of the earth was not subtracted from its speed. What the experiment showed was that light is unique in that it always moves at the same speed (approximately 186,000 miles per second, sometimes referred to as the constant "c") no matter how fast the observer is moving.

This seemed to create a strange contradiction. If a rocket pilot was traveling near the speed of light - "c" - a motionless observer would see him almost keeping up with a light beam traveling in the same direction. Einstein said that if you asked the rocket pilot about the beam of light, however, he would say that no matter how fast he accelerated the beam was still traveling at speed "c" faster away from him.

Einstein realized that the only way this could happen was if time slowed down for the rocket pilot as he accelerated to near the speed of light. Since his clock would be running slower, when he measured the light beam traveling next to him it would seem to be still moving at "c." This idea that time did not have to be the same for all observers in all places but is "relative" differs radically from Newton's thinking and is the heart of the Special Theory.

Experiments have proven that Einstein was right about time dilation of accelerated objects. Today the GPS satellites that provide position information to receivers on Earth must correct their onboard clocks by a tiny amount to account for their speed as they orbit the planet. Time moves just slightly faster for the satellites than it does down here on Earth.

Not only does time change as the result of acceleration, but physical objects get distorted too. Yardsticks under Newton's laws were the same anywhere in the universe under all conditions, but according to Einstein they actually get shorter in the direction of travel as they are accelerated. This isn't noticeable to the traveler, as everything around him, including he and his spaceship, grows shorter also.

Since Einstein showed that no "ether" was necessary to explain light, the contradiction between Maxwell's work and Newton's Laws disappeared.

Almost as a postscript to his theory, Einstein noted that matter was just a "condensed" form of energy. The relationship is shown by his famous equation "E=mc^2." Energy is equal to mass times the speed of light squared. Since "c" is such a large number it follows that if even a small bit of matter is converted, the amount of energy released is enormous. This was demonstrated dramatically with the first atomic bomb blasts. Only a tiny amount (.01 percent) of the uranium in a bomb is converted to energy, but it accounts for all the power unleashed in the explosion.

Brownian Motion Explained

The other important paper Einstein produced in 1905 explained an effect called "Brownian Motion." Brownian motion is the random, jerky motions observed in floating microscopic particles. Einstein demonstrated that this was caused by atoms striking the particles in uneven amounts from different directions. This proved that atoms existed (something that some scientists continued to doubt even at the beginning of the 20th century). By analyzing the movement of the particles, he was also able to calculate the number of atoms in a particular mass of element and how much each atom weighed.

Einstein's success in 1905 would bring him fame. In 1908 he left the patent office for a university position first in Bern and later in Prague. In 1912 he was appointed a professor at the Polytecnikum, his alma mater. This success might seem to be enough for any man for any one lifetime, but Einstein had greater goals. In 1907 he would start thinking about how we could extend this theory of relativity not just to include motion, but the entire universe.

Continue on to Part II

Copyright Lee Krystek 2004. All Rights Reserved.