As much Physics as I studied, and as much as I have studied and pondered Relativity, both the Special and General theories, I realized I had never read more than a few lines by Einstein himself. When I saw Ideas and Opinions, a collection of essays and letters by Albert Einstein, I just had to snatch it up. The book is based on Mein Weltbild (My Worldview), edited by Carl Seelig, with a great deal of other material Einstein wrote after that book was published in 1934. Most of the material written before 1935 was in German and appears here in translation, mostly by Sonja Bargmann.
The greatest number of portions of My Worldview are found in the first two sections, about 2/5 of the book, titled "Ideas and Opinions" and "On Politics, Government, and Pacifism". The first section shows him to be a rather typical European intellectual, viewing America from a European standpoint. For example, he observes that an American is more goal-directed but a little less rigidly individualistic than a typical European. That is something with which some Americans might take issue! In his day he might have been the most visible proponent of total intellectual freedom among scientists, only modifying this view somewhat under threat from the possibility that the Nazis might develop atomic power and atomic weapons.
But I found most fascinating his extreme pacifism. In the second section he argues, strongly and repeatedly, for total disarmament, for all nations to eschew the use of force, most particularly armed warfare, and this to be enforced by a global authority which alone would be tasked to enforce the security of all. Here we find the highly brilliant Einstein as the poster child for Ivory Tower idealism. My answer to pacifism is, "As long as there exists the possibility for evil persons to attain coercive power, at any level, all others must be sufficiently armed and have the will to effectively resist, at any level." This demolishes pacifism in all its forms. You can quote me on that, and on this: Human nature must change dramatically before pacifism is practicable.
The third section, "On the Jewish People," contains ten items from My Worldview and four that were written or delivered between 1938 and 1950. Only the last item, "The Jews of Israel", was written (and delivered by radio broadcast) after the formation of Israel in the former territory of Palestine. Better than anyone else I have read from, he makes a clear case that the Jews cannot assimilate into any nation, because they are a nation already, though they were a nation without territory from 70 AD until 1948 AD; and that this fact is the singular source of Antisemitism.
The fourth and shortest section, "On Germany", primarily consists of letters between Einstein and the scientific academies from which he resigned after 1933, but concludes with a paean, "To the Heroes of the Battle of the Warsaw Ghetto." These sentences, written in 1944, make his standing clear:
"The Germans as an entire people are responsible for these mass murders and must be punished as a people if there is justice in the world and if the consciousness of collective responsibility in the nations is not to perish from the earth entirely. Behind the Nazi party stands the German people, who elected Hitler after he had in his book and in his speeches made his shameful intentions clear beyond the possibility of misunderstanding."The fifth and longest section, about 45% of the whole, is "Contributions to Science." Here he explained his work to a variety of audiences, primarily his Special and General Theories of Relativity, but also his later work toward a Unified Field Theory. Here his fundamental approach is most clearly displayed, encapsulated in the proverb (not found in this book, because it is a paraphrase), "Make everything as simple as possible, but no simpler."
Here we find Einstein as a master explainer. He shows that Newton felt compelled to introduce, almost against his will, the concepts of absolute space and absolute time, to make his mechanics and his gravitational theory work. Later physicists—Einstein mentions Faraday, Maxwell, Hertz and Mach, among others—labored to resolve inconsistencies in subtle experiments that test the limits of classical mechanics, as the Newtonian system has come to be called. Lorentz formulated a transformation based on the constancy of the speed of light, implied in the equations of Maxwell and observed by Michelson and Morley. Upon all this work did Einstein erect first Special Relativity, and a decade later, General Relativity.
I note that he gives rather short shrift to Quantum Theory. Indeed, it is well known that his view was quite at odds with that of Niels Bohr and what is now called the Copenhagen Interpretation. Now, since Einstein's death, three of the four known fundamental forces—Electromagnetism, Strong, and Weak—have been unified into one quantum-based theory, but Gravitation remains stubbornly on its own. Theories abound aimed at reconciling Quantum Mechanics with General Relativity, so far to no avail. The situation is analogous, but more confused, than the seemingly irreconcilable conflict between Newton and Lorentz, but so far no super-Einstein has arisen to resolve it.
It takes a lot of study and deep thinking to become comfortable with the fact that light is both a wave and a particle stream. I became used to working with photon streams long ago. (Here is my favorite illustration: In whichever way light arrives at your eye, it is refracted in the cornea and lens as a wave, but stimulates the cells in the retina as a particle stream.) Photons mediate the electromagnetic field and electromagnetic forces. So is there a Graviton that mediates gravity? Will physics students one day labor to become comfortable with both gravitational waves that obey General Relativity, and gravity as streams of gravitons according to a highly amped-up Quantum Theory?
To those working on this conundrum, I ask these things, for they truly puzzle me:
If gravity is mediated by gravitons, what emits them and where are they absorbed? Specifically, if black holes are real, from what are the gravitons that "reach out" to surrounding bodies emitted? Do gravitons indeed travel at the same speed as light, which implies that they have no "rest mass"? Or are they massive, and if so, how much "slower" than light do they travel (we know that neutrinos with their tiny masses seldom travel slower than about 0.999c)? And if gravitons are massive and thus sub-c, is there a possible violation of conservation of energy or of momentum in orbital motions, particularly on gravitational (or larger) scales? Could this account for the "cosmological constant" that is currently attributed to "dark energy"?Back to Einstein. Reading his writings about science, one feels one can almost follow in his footsteps. Yet his subtlety and extreme power as a scientific thinker are shown when, upon looking away from the page, we find that we must take many, many tiny steps just to cross from one of his footprints to the next.
No comments:
Post a Comment