8 out of 10 cats prefer quantum mechanics! (In Search of Schrodinger's Cat - John Gribbin)

Member Name: markos9

Product:	In Search of Schrodinger's Cat - John Gribbin
Date:	01/07/09 (64 review reads)
Rating:

Advantages: Highly readable account of a fascinating story.

Disadvantages: Some maths is inevitable in a book of this type.

The theory of quantum mechanics is almost incomprehensible, almost unbelievable, and has taxed, perplexed and infuriated our greatest scientific minds for over 70 years. Einstein refused to believe the theory and spent most of his life trying (unsuccessfully) to disprove it.

The theory starts, however, with a simple premise. Energy can only be transferred in tiny discrete packets (called quanta), rather than continuously as would be expected. That's it, the basis of quantum theory!

The implications of this theory are so encompassing, so wide ranging, and so counter-intuitive, that scientists like Einstein fought against belief, despite mounting evidence to the contrary, for many years.

This book is the story of the development, testing, and implications of quantum mechanics. The story is told on several levels. Firstly, it's a detective story; we read how the scientists unravelled the theory, painstakingly piecing together evidence and intuition then taking two steps forward and one back.

The book is also, of course, a history book; giving the reader over 70 years of scientific development, conflict and resolution.

Finally, the book gently introduces the reader to the really weird world of the quantum!

A taste of things to come can be gleaned by reading the simple quotation at the front of the book:

"Nothing is real" John Lennon 1940 - 1980.

Now I suspect that, when John Lennon wrote "Strawberry Fields Forever" in 1966, quantum theory wasn't foremost in his mind, but the reader of this book will realise with each passing chapter how apt a quote this is.

The author, John Gribben is well placed to tell this story. He is an accomplished science writer who's written many popular science books, as well as writing for the Guardian and The Times. Gribben's writing style is chatty and humorous, but he manages to make complex subjects (and there's lots of them in quantum theory!) understandable.

There is a small amount of maths included in the book, where necessary to explain a concept, as well as a few graphs, but these are kept to a bare minimum.

The book tells the complete story of the development of the theory, from its conception to the present day. At the beginning of the 20th century, scientists were confused by research into light waves; whether they were due to waves, or were due to particles (called photons). The confusion arose because any test designed to show light as particles gave the result, particles, and any test designed to show light as waves gave the result, waves!

This wave/particle duality led the physicists towards the quantum theory. The development was made all the more difficult due to the bizarre implications that arose from each new revelation.

One implication of the theory is given by the two slit experiment. Here an electron is aimed at two slits in a wall. Common sense tells us that the electron will go through one or the other. Quantum theory shows that the electron goes through both!

"God does not play dice" Einstein is quoted as saying upon realisation that the quantum world prevents any events from being precisely predicted. The theory states that only the probability of an event happening can be calculated (for example, if I fall from an aeroplane, it's not CERTAIN that I'll die, only very probable!).

Another implication is that any measurement must affect the status of an experiment; it's not possible to know the exact position and momentum of an atom (any attempt to measure it, causes the state to change).

The consequences are bizarre. One test of quantum theory is Schrödinger's Cat. This famous 'thought experiment' (an experiment designed to be discussed rather than carried out) goes as follows. A cat is placed in a box with a radioactive atom linked to a vial of poison. The experiment is designed so that there's a 50/50 chance of the atom decaying and the vial breaking; therefore there's a 50/50 chance of the cat dying (cat lovers will be relieved that this was a thought experiment, no felines were harmed in the testing of this theory!).

Since the act of measurement alters the state of an experiment, it's the opening of the box that causes the event to occur; whilst the box is closed, the cat must be considered to be both alive and dead!

I think you can see from the above, why the scientists were so aghast as each new test showed the validity of quantum theory. Although the theory appears surreal, it has been proven to be correct. Many modern developments (computers, lasers, superconductors, and many others), would not be possible without an understanding of quantum mechanics.

Each chapter of the book gives the reader more and more insight into the strange world of the quantum. The author weaves the tale of history, science, and technology expertly; the very short, sharp chapters work like a soap opera, making the reader want to know what's revealed on the next page.

The latest developments in the theory give us the most bizarre consequences imaginable; the many worlds theory. This states that for every possible action with more than one outcome, TWO universes are created; one for each possible outcome. Imagine this, every possible change in an atom's state, over the past thirteen billion years has resulted in a new universe being created!

This theory has been used as a plot device in many science fiction films and books including Star Trek, Red Dwarf, and Sliders. The author explains that, the fact is more complicated than the fiction and the only way to go from one universe to another is to go back in time! This is apparently not impossible, and there's evidence that some subatomic particles do just that!

Phew! John Lennon was right!

As you can probably tell, this book is extremely readable and fascinating. I found it difficult to put down as each new revelation or argument led to another. The author explains the strange world of quantum mechanics in a way that's understandable, whilst still being decidedly weird. Anyone with an interest in learning about the world of the quantum should look here. Highly recommended.

The book is available from Amazon for £6.99 in paperback. A small price to pay to have your horizons expanded!

Summary: Learn all about the weird world of the quantum.