The Quantum Channel

On the one hand, my rule of thumb is that reading a popular book that explains the “how” of a scientific concept is a waste of time because you can learn it much faster and with much more depth from a good textbook. On the other hand, I always appreciate a popular book that tries to explain the “why,” and it is even more delightful that such a high-caliber writer as James Gleick chooses to explore the central theme of my scientific interest, information.

As for my opinion of it, I think one of the Amazon reviews is spot on. “A history” and “a flood”, from the book’s subtitle, are a bit boring for me, while “a theory” is excellent. For that reason, I recommend a preview of some of those boring parts How We Know, by Freeman Dyson. For me, the book starts to pick up from chapter 6 “New Wires, New Logic” when Shannon, Hartley, and Nyquist enter the scene. Following are a fraction of what everyone can learn from this book

• why we have the mantra “meaning is irrelevant” and the notion of coding and an abstract bit
• the relationship between Shannon and Turing and the parallel relationship between Shannon’s information theory and the Turing machine, which ultimately resulted in the Kolmogorov-Chaitin algorithmic entropy
• the role of chance and information in fundamental laws of physics

For further technical readings of specific topics, I recommend taking a look at

• Information theory, Evolution, and the Origin of Life by Hubert Yockey
• Maxwell’s Demon 2 by Harvey Leff and Andrew Rex
• Quantum Processes Systems, and Information by Benjamin Schumacher and Michael Westmoreland, especially the notion of an informationally isolated system that is tied to the ultimate physical limit of privacy, error correction, and duplication of information (copying)
• Quantum Mechanics as Quantum Information (and only a little more) by Christopher Fuchs
• From Classical to Quantum Shannon Theory by Mark Wilde for an official account of quantum Shannon theory
• for this one, the name alone might blow your mind–Quantum Darwinism, a research program by Wojciech Zurek et al.

Other related and interesting topics are probabilitistic paradoxes and Bayes’ theorem which are featured more in Hans Christian von Baeyer book’s Information, but that’s for another time.

My first thought when I saw the table of content was “Hey, this book could have initiated my whole scientific career!” I began to have serious interest in science in high school, where, unfortunately, the maths and physics were to me mere fun and games without any purpose. Biology was more like storytelling. I became interest in consciousness, evolution, and genetics and picked biology major in college, and was thoroughly disappointed by lack of clear thinking from most professors and fellow students. (The last class that I enjoyed was organic chemistry. Everything went downhill after that when all classes became purely “biology.”) That was when I discovered Schrödinger’s What is Life? and started to discuss with physics professors and friends about quantum mechanics (and not surprisingly, Schrödinger’s cat). Once I bit the apple, there was no turning back.

I really want to buy many copies of this book and send it to my cousins and friends, if only they are fluent in English, at least only to show the unity of science. It is such a sad state that most Thai students I have met never imagine that mathematics can be used in biology, that one can bring physics and biology together not in an ad hoc way, or that abstractly biology is about information. (It’s still a mystery to me why in high school the naive scientific methods–make a hypothesis, do experiment, analyze data, conclude–is exclusively belong to biology courses. I think it encourages the attitude “why think when we can do more experiments?”)