This year is the centennial of Einstein's "Miracle Year," and this month is the fiftieth anniversary of his death. I am currently compiling a list of new books that have come out on Einstein and physics, but my Science Shelf book review archive already has a substantial number of reviews, including this one.
On the anniversary of Einstein's death, I'll be posting my review of Driving Mr. Albert: A Trip Across America With Einstein's Brain by Michael Paterniti here.
For now, here's a look at what David Bodanis properly calls "The World's Most Famous Equation."
Young Einstein, beneath his wild hair,
Hatched a theory beyond all compare.
Its foremost equation
For every occasion
Is E equals m times c-square.
Albert Einstein's most famous equation wasn't an "Aha!" moment. It was not even in the 29-year-old patent clerk's first publication of the theory of relativity. E=mc2, an equation that would transform the world, appeared to little notice in a brief addendum published a short time later.
To a friend, Einstein admitted, "The idea is amusing and enticing, but whether the Lord is laughing at it and has played a trick on me — that I cannot know." Looking back on the century since that equation was born, many people would rephrase Einstein's bemusement. Is the discovery of this five-symbol fruit of the Tree of Knowledge a divine gift or a devilish prank?
Mr. Bodanis' superbly researched "biography" of the equation leaves room for both interpretations. Physicists may quibble about the author's explanations of the famous theory and his neglect of Einstein's Nobel Prize-winning work on the photoelectric effect, but they will agree that he got the main idea right: "By the mid-1800s, scientists accepted the vision of energy and mass as being like two separate domed cities.... Each one was a wondrous, magically balanced world; each was guaranteed in some unfathomable way to keep its total quantity unchanged, even though the forms in which it appeared could vary tremendously." Then came the equation that showed that the two realms were one and the same — and interchangeable.