Authors clarify quantum mechanics

Robert Starr

The last word a physicist wants to hear at a cocktail party is “quantum.” The science of quantum mechanics has been so badly butchered and misrepresented by well-meaning writers, that others have taken the oversimplifications and run with them. As a result, New Age mystics and alternative medicine proponents have used their misunderstandings of quantum mechanics (which they, more often than not, refer to as “quantum physics”) to add credence to their pseudoscientific ideas and products.

“The Quantum Universe,” by Brian Cox and Jeff Forshaw, both particle physicists at the University of Manchester, attempts to clear up some of the misconceptions by starting at the basics of quantum mechanics, covering the same material that many physics students will see in their introductory classes. Unfortunately, this means that they don't delve into some of the more elaborate and hotter topics, such as string theory.

However, what they lack in addressing newer ideas, they more than make up by writing what very well may be the definitive introduction to quantum mechanics. “The Quantum Universe” is written for the layman, who will likely enjoy it, but it would also be a superb supplement for physics students struggling through early quantum mechanics classes.

The fundamental difficulty of quantum mechanics arises from the discovery that things on a very small scale (the size of an electron, for instance) don't behave the same way as things do in our normal macroscopic world. On the macroscopic scale, if somebody places a block on a table and blinks, it will be in the same place when they opens their eyes again. On the quantum scale, however, if a person does the same experiment, the electron could be anywhere else in the universe after the blink.

Still, there are very specific rules for the possibilities of where else the electron could be that usually involve quite a bit of math.

Cox and Forshaw get around this by trading in abstract mathematical concepts and using images instead. Specifically, the authors use clock faces to represent complex numbers (“real” numbers added to “imaginary” ones). While not always easy to follow, this works better than requiring the reader to have a background in complex analysis.

Most readers will need to make their way through the book somewhat slowly, carefully rereading paragraphs to ensure understanding, but quantum mechanics is a tricky subject matter and this is not nearly as baffling as most textbooks that cover the same material are. Those who take the time to read the book properly will come away from it with a profound knowledge of what quantum mechanics is and how it works.

Some ideas are simply not easy to convey, but Cox and Forshaw are patient writers and really take the extra effort to spell everything out. Readers will need to meet them halfway, but this is likely to be as accessible as quantum mechanics will ever be, at least in book form.

And those who want to have a genuine understanding of how it works owe it to themselves to buy a copy of “The Quantum Universe” and keep it in their personal libraries. Many books have been written on the subject of quantum mechanics. For those looking for an understanding of exactly how it works, with no hand waving or beating around the bush, this may be the best.

Printed on Monday, February 13, 2012 as: Book uses images to explain quantum mechanics concepts