2005 marks the 50th anniversary of Einstein’s death and the centenary of the theory of relativity. Fritzsch and Helge explain how Einstein revolutionised physics by reinterpreting space and time.
Towards the end of the 19th century the world of macrophysics with visible objects gave way to a world of microphysics with events that occurred at unimaginable speeds and in orders of magnitude that were beyond human comprehension. The door to the age of quantum physics was opening.
In 1905 a young man contributed five articles to the journal Annalen der Physik. The 26-year-old Albert Einstein was employed at the Swiss Patent Office in Berne. He was about to create a radically new concept of space, time, matter and energy. According to Bill Bryson, Einstein’s first article explained the nature of light and won him the Nobel Prize in 1921. The second article proved that atoms really do exist. And the third simply changed the whole world.
Einstein’s revolutionary new theory of space and time later became known as “the theory of relativity”, although he would have preferred the title “theory of absoluteness”. The treatise “On the Electrodynamics of Moving Bodies” is seen as one of the most outstanding scientific contributions of all times, and could well be the greatest idea that ever occurred to any human being. The article contains no footnotes or quotes, hardly any mathematics and no references to other works. In CP Snow’s view, it was as if Einstein had reached his conclusions through pure thought, without any help and without listening to the opinions of others.
Born in Ulm in 1879, his family moved to Munich when he was six weeks old. An unusually quiet child, he did not start speaking until he was three. At 12 he taught himself geometry by studying Euclid. However, his school career was by no means brilliant, as is often the case with highly gifted children. In 1900 he graduated from the Swiss Institute of Technology with a teaching diploma in maths. Then, while working at the patent office, he married Mileva Maric “his dearest Doxerl” who had studied with him.
Evan as a child Einstein had wondered what would happen if someone moved as fast as light and observed a light wave that moved with him. He questioned the foundations of space and time. Then he heard about the results of an experiment by Michelson and Morley in the USA. The aim of this experiment was to measure the speed of light in relation to the earth, which moved at a considerable speed around the sun. It was assumed that there would be differences in the speed of light due to changes in the motion of the earth. But no such effect was found. The speed of light turned out to be absolutely constant. In the end Einstein adopted the invariability of the speed of light as a principle. According to his hypothesis, light spreads throughout space at a constant speed “c”. Although this assumption contradicted the accepted rules of mechanics, this did not bother Einstein. As it turned out, he was right. The speed of light is the highest attainable speed in our space-time continuum. Light travels at 299,792.458 kilometres per second. But by fixing the speed of light, space and time become relative.
Saint Augustine once wrote: “Time is like a river full of events. Its current is strong. No sooner does something appear, it is swept away again.” However, Saint Augustine did not know that the current of time is not constant, but dependent on the observer’s own condition of movement.
Newton had introduced space and time into physics in a simple way. He said that time ticks regularly from moment to moment. But even in Newton’s day there were doubts. Leibniz, for instance, thought that time was nothing more than a language that enables us to relate events to each other. In a world without change, that is without events, there would be no time. Einstein came close to Leibniz’s concept without adopting it completely. But in Einstein’s new view, the flow of time was at least something dependent on the system. The slowing of time in moving systems is determined by the gamma factor. For modest speeds this factor is practically equal to one, and in this case Newton’s concept works well. But if the speed is around 30,000 km/s, that is 10 percent of the speed of light, the factor changes to about 1.005. At 99 percent of the speed of light the factor is 7. So, in this kind of system, time passes about seven times more slowly than in a resting system. The gamma factor increases when the speed approaches the speed of light. Once this is reached, the gamma factor is infinite in size. For this reason it is not possible for a body with mass to move at the speed of light or faster.
In an extension of his theory of relativity Einstein finally developed the most famous formula in physics: E=mc2 It states that energy and mass are different forms of the same substance, and that they are equivalent to each other. Or, to put it differently: energy is released matter, and matter is energy waiting for its release. As c2 is an enormous figure, the formula expresses that every thing that consists of matter contains an unimaginable amount of energy. At the time Einstein was only thinking about the transformation of a very small part of the mass, such as in the radioactive decay of an atomic nucleus. But now we know that the formula is much more extensive. A proton, or the nucleus of a hydrogen atom, is completely transformed into radioactive energy when it collides with its antiparticle, an antiproton. During the Weimar Republic Einstein, who was an ardent pacifist with strong social views, experienced an increasing amount of anti-Semitic hostility. While in the USA with his second wife, Elsa Loewenthal, his books were burned in Germany and then Hitler took over government in 1933. He was so shocked at the mass crimes committed by the Nazis that he never set foot in Germany again. He accepted an invitation from the Institute for Advanced Study in Princeton, where he remained until his death. While at Princeton he focused his work on a comprehensive description of gravitation and electromagnetism but he did not manage to find a satisfactory solution.
Einstein wrote to President Roosevelt in August 1939 expressing his concern that Germany might be able to produce atom bombs. This letter was crucial in the founding of the ‘Manhattan Project’ that led to the construction of the atom bomb. Einstein later saw it as a mistake. In 1950 he wrote that he had never participated in enterprises of a military technical nature, nor had he carried out any research that had anything to do with the production of atomic bombs. During the post-war years he was actively involved in creating a world order that banished the nuclear threat.
This enthusiastic sailor and music lover, pacifist and non-conformist died in Princeton on 18 April 1955. .
This article first appeared in The Word (April 2005), a Divine Word Missionary Publication.
