Sunday, June 7, 2009

The God Effect: Quantum Entanglement, Science’s Strangest Phenomenon, by Brian Clegg.

Anton Chekhov once said that if you say in the first chapter of your book that there is a rifle hanging on the wall, in the second or third chapter it absolutely must go off. In other words, if the gun is not going to be fired, it shouldn't be hanging prominently on the wall.

With that in mind, I looked forward to the author’s discussion of how quantum entanglement could be seen as evidence of an invisible space deity, and was seriously disappointed that he dedicated but a single sentence to the topic, saying in the preface that entanglement is “a physical phenomenon so strange and all pervasive that this book calls it “the God Effect.””

I found his use of the third person here quite odd. Why does “the book” call entanglement “the God Effect?” Did the book write itself? What does the author think? We never find out, and I suspect that the word was added to the title to be sensationalistic.

Much of the rest of the book was similarly unsatisfying. Some parts were clever and thorough and I was fascinated to learn that mirrors do not really “reflect” photons of light. Rather, each time a photon of light hits the surface of a mirror it is absorbed by an electron. Nearly instantaneously, the electron make a quantum leap to a higher energy state where it becomes unstable and emits a new (different) photon of light to stabilize itself.

That said, I got the feeling that the book was dictated to a research assistant while the author sat before a fireplace with a glass of wine: Many of the chapters started on one topic and then devolved into anecdotes or historical explanations only tangentially related to the concept at hand.

Other ideas were explained in a way that I can only describe as lazy in their reasoning. One example concerns the concept of whether light is a wave or particle, and the concept of superposition, which says that photons fly through the air not as a single particles but rather as a clouds of possibility that coalesce into physical states only when they are forced to, by third-party observation/interaction.

The author describes an experiment in which 45-degree-polarized photons are fired through three slots in different orientations and claims that the fact of some particles getting through the obstacle course proves the concept of superposition.

He may be right that superposition is why it happens but his explanation is incomplete at best. The way he describes the experiment, the answer to what happens could be as simple as “anytime a photon goes through a slot it become oriented such that it can only go through another slot oriented within 45 degrees of the previous slot.”

To make my point let’s imagine high speed racecars instead of photons going 200 mph traveling north through a pair of cones and then trying to make a quick 90 degree turn. They are unable to do it because they are going too fast. Then, we change the 90 degree turn into two 45 degree angle turns, spaced out. Does the fact that some cars are now able to make those two turns mean that they entered a superposition and were simultaneously heading north and east? No, of course not.

The point here is not that the experiment was wrong (I’ve read much better descriptions of this experiment and I’m grudgingly willing to accept its conclusion) but rather that the author does a poor job of explaining how he (or anyone) knows that probabilities in quantum physics are real.

Also frustrating is the fact that the author give no effort to explaining what he (or anyone) thinks is the actual, factual, physical cause of quantum entanglement and spooky action at a distance. How can someone write a book called “Quantum Entanglement, Science’s Strangest Phenomenon” and not discuss the how and why of two particles being separated by great distance, impacting each other simultaneously, seemingly faster than the speed of light?

My layman’s research into this topic is in its infancy, but even I have my wild guesses about what is going on with entanglement (more on that in another post). Unfortunately, this author was more interested in telling stories of the CERN laboratory, the history of the telegraph and typewriter, and explaining how entanglement impacts cryptography than he was in diving in to the meat of how spooky action at a distance works.

In the end I don’t recommend this book to anyone, other than perhaps to those seriously into cryptography. “The God Particle” isn’t a good first introduction to the concept of quantum entanglement and it isn’t a book that dives deeper into any particular concepts. It rants and rambles and tries to mesmerize but in the end failed to interest, intrigue or inspire me much at all, other than to look for more and better books on the subject.

Tuesday, June 2, 2009

The Age of Entanglement : When Quantum Physics was Reborn, by Louisa Gilder


“This quantum question is so uncommonly important and difficult that it should concern everyone.”

-- Albert Einstein, 1908.

The concepts of quantum mechanics have fascinated me for a great many years. I’ve read dozens of books on the subject but am no closer to grasping the concepts underlying a mystery that perplexed Einstein himself until the day he died.

Einstein spent his entire life wrestling with the issues raised by the initial discovery of quantum mechanics in the year 1900. He was never really able to move past his initial frustration with the fact that under certain physical circumstances, two individual subatomic particles, far apart from each other, act in concert with each other in a way that violates all known explanations.

These two particles seem to influence each other simultaneously and remotely; communicating with each other by an unknown mechanism that would far exceed the speed of light.

Einstein ridiculed this phenomenon as “spooky action-at-a-distance” and called it “a sort of telepathic coupling” in his initial efforts to argue that someone must have had a few too many drinks down at the lab.

The phenomenon has since been proven to exist and this book is the true story of the people who spent (and are spending) their lives studying quantum mechanics, spooky action-at-a-distance, and are trying to make sense of it all. I really hope they figure it out in our lifetime because it is 100% guaranteed to be a jaw dropping revision to our sense of reality. [For a (relatively) quick overview of quantum entanglement, this entry in the Stanford Encyclopedia of Philosophy does as good a job of any on the web: http://plato.stanford.edu/entries/qt-entangle/]

What may be in store for us is a shock as big as the one that came to the citizens of Flatland in one of my absolute favorite books: The very brief (less than 50 pages) story of Flatland: A Romance of Many Dimensions, by Edwin Abbott.

In Flatland, Abbott describes a world of people who live in a two dimensional world – a flat plane -- where men are polygons and women are line segments. They have no concept of up or down. And then, one day, a three dimensional sphere visits them and it rocks their world as it demonstrates how what they see in two dimensions is proof of a third dimension.

Such a world-rocking is likely somewhere in our future, and some very smart folks (string theorists) think that many additional dimensions exist and that all matter (and especially those spooky particles) is connected through one of those other dimensions.

At first, The Age of Entanglement was not at all what I wanted, because I was hoping for an account of the latest breakthroughs in the field and a description of new quantum theories. Instead I found myself reading a historical account of the characters, featuring a fictionalized recreation of their conversations. (The author drew on actual letters and speeches by the scientists in her effort to recreate various conversations.)

After the initial frustration at this artifice I found myself captivated by the story of how Einstein, Schrödinger, Oppenheimer, von Neumann, Bohm, Feynman, and of course Bell devoted much of their lives to thinking about and discussing the phenomenon of quantum entanglement.

Put another way, I did not want to learn about the historical context of their respective efforts and how they overlapped and interacted with each other. But I’m glad I did.

I recommend this book only to people who have a strong interest not only in quantum mechanics but in the stories of the scientists whose lives were and are tangled up in its concepts. Those folks will likely enjoy it a great deal.