Monday, March 28, 2005

Albert Einstein

Physics is just an explanation or theorization of the natural phenomenon. There is nothing strange about it when explained. But when any theory in physics was first discovered, no one but the mad scientist himself knew what it was all about. Newton and Einstein were like that at their time. But their theories are understood by many today, and thus entered the university curricula.

Many physicists discovered something important from time to time. But some fantastic physicists would suddenly struck by lightning, or an Act of God, and discovered many wonderful things within a very short time. Annus mirabilis, the miracle year, was first used to describe Isaac Newton in 1665-66, when he developed the theory of Calculus, gravitation and the colour spectrum.

1905 was the annus mirabilis for Einstein, when he published five scientific papers, one as his doctoral thesis and four in Annalen Der Physik. All of them are important theories which have great impact to the development of physics. Now the name Einstein is synonymous to physics, and everyone talk about his theory of relativity and the atomic bomb. Actually his achievement goes much beyond that. Relativity, or rather the unified theory of relativity, is the thing he tried but could not accomplished.

It is now the year 2005. To celebrate the centennial of Einstein's miracle year, physics societies around the world have declared 2005 as the World Year of Physics. This is followed by the UN declaring 2005 as the International Year of Physics. The launching of the year took place at the UNESCO headquarters in Paris during 13-15 January.

These are the five papers published by Einstein in 1905.

On a new determination of molecular dimensions
This is his doctoral thesis. By considering a collection of sugar molecules dissolved in a glass of water, Einstein derived a mathematical term that measured the speed of diffusion. It was then possible to elicit the size of the sugar molecules by contemplating the diffusion coefficient and the viscosity of the solution.

On the Motion of Small Particles Suspended in a Stationary Liquid
Following his study of Brownian motion and using the then-controversial kinetic theory of fluids, he established that the phenomenon provided empirical evidence for the reality of atoms. It also led to the advance of statistical mechanics.

On a Heuristic Viewpoint Concerning the Production and Transformation of Light
This is the paper which led to the award of the Nobel Prize. He proposed the idea of photons and showed how it could be used to explain the photoelectric effect. The idea was motivated by the law of black-body radiation by assuming that luminous energy could only be absorbed or emitted in discrete amounts, called quanta. This led to the development of quantum mechanics.

On the Electrodynamics of Moving Bodies
This is the famous theory of Special relativity. The whole new thinking about moving bodies supplemented, but not overturned, Newton's laws of motion. The idea of time being a dimension triggered a good topic for many science fictions.

Does the Inertia of a Body Depend Upon Its Energy Content?
This paper showed a deduction from relativity's axioms and introduced the equation E=MCsquared. Einstein considered this equation to be of paramount importance because it showed that a massive particle possesses an energy, the "rest energy", distinct from its classical kinetic and potential energy. The mass-energy relation can be used to predict how much energy will be released or consumed by chemical and nuclear reactions.

Many people consider that Einstein had supernatural power, or was influenced by alien beings. Actually he was a normal human being, just more clever than us, and had his down time and mistakes. In 1916, he published the paper on general relativity which was an extension on relativity and took into account the effects of acceleration, including the most common acceleration, gravity. The achievement was so great and Einstein was so ambitious that he went on and spent the rest of his life on a unified theory of relativity which could explain all things. He was unsuccessful. However, the quest has motivated many physicists and there are now many who are still working in this direction. Seen in this light, his theory was not overturned, but supplemented and respected by those following.

Einstein was a skeptic of quantum mechanics. It is ironic that his paper on photon emission was a great step in this area. He could not accept the probabilistic, non-visualizable account of physical behavior which was the basis of quantum physics, but looked for a more complete and deterministic explanation.

In 1926, he made a remark that is now famous: "The theory says a lot, but does not really bring us any closer to the secret of the Old One. I, at any rate, am convinced that He does not throw dice." To this, Niels Bohr, who sparred with Einstein on quantum theory retorted, "Stop telling God what He must do!" The Bohr and Einstein debate on quantum mechanics, the exchange of letters between them, now became the greatest literature on scientific debate of the 20th century.

I subscribed Scientific American. Last year, it dedicated a whole issue to Einstein. There is a good article from the magazine. Those interested may ask me for a copy directly.

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