Amazon.co.uk Review
Who would have thought a mathematical constant would make such an engaging character?
God's Equation: Einstein, Relativity and the Expanding Universe, mathematician Amir Aczel's tale of the search for a scientific explanation of the universe, features the cosmological constant in a role as complex as Einstein's. The great genius referred to it as his "greatest blunder" but recent events in the world of astrophysics have brought the prodigal term back into the fold as an important part of his field equation. Aczel is a powerful storyteller and makes no secret of his admiration for Einstein; much of the book revolves around his conquest of general relativity. Integrating relativity with gravitation was no easy task (even for Einstein) but the author deftly steers the reader away from the sticky stuff and focuses attention on concepts of importance.
Aczel shows Einstein's aesthetic troubles with the cosmological constant, which preceded theoretical and experimental problems leading to its abandonment. The universe was caught in the act of expansion by Edwin Hubble and the constant, originally invoked to maintain a steady-state universe, was unnecessary. Fortunately, though, the mathematics underlying the constant had become important tools for physicists; observations in 1997 and 1998 by Saul Perlmutter, Neta Bahcall and others showed that the universe will continue expanding indefinitely and sent theorists back to the drawing board to revise their equations. The cosmological constant returned triumphant and, while its inventor might never have approved of it, today's scientific community gives it an honoured role in God's Equation. --Rob Lightner, Amazon.com
Review
In 1912, Albert Einstein wrote down an equation that describes the structure of the universe. But even he didn't recognize its full meaning. Aczel (Probability 1, 1998, etc.) has made a career of explaining the frontiers of mathematics. Here he tackles Einstein's field equation of general relativity not only in the context of modern physics, but in the history of mathematics. When Einstein began to incorporate gravity into his theories, he realized that it must have certain effects on light, ha particular, light leaving a massive object would he red-shifted; its frequency would become longer, as if the object were moving away. Space was curved, and that curvature could be described in terms of non-Euclidean geometry - built on alterations of Euclid's fifth postulate, which after trying unsuccessfully to prove for two millennia, mathematicians decided to treat as an arbitrary and unprovable assumption. The curvature of space and its effect on light made possible experimental verifications of relativity: for example, the positions of stars seen near the sun in an eclipse should differ from their positions when the sun was in another part of the sky. In 1919, a British expedition led by Arthur Eddington measured those star positions and proved Einstein's theories correct. Meanwhile, Einstein had been exploring the cosmological implications of his theory, in particular the question of whether the universe expands, contracts, or remains the same size. Here, for the first time, he did not believe his own calculations and felt it necessary to add a "cosmological constant" to his field equation - a fudge factor he later described as his greatest blunder when astronomers demonstrated that the universe was in fact expanding. More recent theorists suspect that the cosmological constant was needed, after all - but until another Einstein comes along, the field equation remains the closest thing we have to a divine blueprint for the universe. While the actual math is heavy going, Aczel gives a very readable account of the science and the scientists involved. (Kirkus Reviews)
See all Product Description