Wednesday, 29 December 2010

Einstein, by Jeremy Bernstein

This book is part of the Fontana ‘Modern Masters’ series, published in 1973, which I purchased in 1979, whilst at Oxford. I picked it off my dusty shelves to read again, after a recent discussion with my nephew, who is studying Physics at University. This series was a high-minded (and largely successful) attempt to profile some of the most prominent thinkers of the 20th century, and to explain succinctly their contribution to their field.

For a layman who recognises the importance of science, this is a book I recommend you read – if you can still find it! It covers a wide range of science in an engaging way.

This volume gives us a good idea of Einstein the man, and valiantly explicates his contributions to the big ideas of relativity, gravitation, cosmology, electro-magnetism and quantum theory. Bernstein (a well-known American researcher, teacher and writer of physics) avoids the mathematics, but I had to realise that one cannot truly understand these concepts without the mathematics. I do not have the inclination, the time or possibly the sheet intelligence to understand the mathematics, so a volume like this is as close as I am ever going to come to understanding these difficult, counter-intuitive concepts.

It is interesting to learn that Einstein was relatively weak on mathematics (pun intended), and Bernstein spends time trying to understand how Einstein came up with his ideas – his thought processes. In common with many of the great physicists of that era, Einstein employed thought experiments and logic to arrive at many of his theories. His paper on the special theory of relativity (1905) has virtually no equations in it. Ultimately, Bernstein says that Einstein had a deep intuition about the truth, ahead of the empirical evidence, which strikes one as essentially unscientific in method:

“Results seemed to materialise out of ‘thin air’ rather than out of long chains of elaborate calculation. Moreover, Einstein was continuously ahead of the experimental confirmations that eventually established his predictions, or, perhaps more accurately, he was able, because of his intuition about general principles, to sort out experimental results he felt must be correct from the rest, which he more or less ignored.”

This is a lucid exposition of the great advances in science, and I was able to grasp the ideas as they came by on the page, but I have to confess they slipped from my grasp, like slippery eels slithering back into the murky water. I lost the chain of logic, and found it difficult to accept the conclusions that seem to militate against our everyday common-sense understanding of the world. The same happened with my multiple readings of ‘A brief history of time’ by Stephen Hawkings.

For instance, in Newton’s laws a force applied to an object without resistance (such as ion propulsion on a space ship) will continue to accelerate infinitely. However that would mean it would eventually exceed the speed of light. Why the speed of light is a constant, and an apparently impassable barrier, is one of those concepts that somehow still eludes me – something to do with the ever-increasing mass of the object. I tend to think of the Einsteinian universe as curved: the acceleration of the spaceship is curved, light curves around the sun, even space itself is curved. One has to abandon the idea of a Platonic, fixed reality.

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