Life on the Edge: The Coming of Age of Quantum Biology by Johnjoe McFadden and Jim Al-Khalili (Crown, 2015), 368 pages.
This book, like last time, also forms a kind of bookend with a book I wrote about earlier about the discovery of DNA and RNA and the genetic “code”: Life’s Greatest Secret. The other book that is intimately related to the topics covered here are in a book I read a couple of years ago and which you can find here: Life’s Ratchet.
There seems to be something quantized about this book besides the subtitle. It appears to exist in two states at the same time, much like the particle and wave aspects of all quantum systems, which is why there are two images and links above. One book, with a light cover, was published in November of 2014 by Bantam and lists Jim Al-Khalili as the first author and has International Standard Book Number (ISBN) 978-0593069318. Sometimes you see this edition as the “International Edition” and that’s how I’ll talk about it here. The other book has a dark cover and was published in July of 2015 by Crown and lists Johnjoe McFadden as the first author and has ISBN 978-0307986818.
However, the two books (?) seem to be identical in terms of content and page number and even description. In fact, the content of the 2015 book is copyrighted 2014. (One reviewer on Amazon moaned that they expected a new book from July 2015 and got this “old” book from last year instead.) I have to admit this is the first time I have noticed something like this. Welcome to publishing in today’s world.
Once you get into the particle or wave version of the book, you’ll find a wild ride, as promised, on the leading edge of research into how quantum physical effects influence otherwise puzzling features of life such as bird navigation, the sense of smell, and the speed and accuracy of DNA reproduction and protein folding. The authors tackle head-on the issue of whether there is anything distinct about “quantum biology” as related to “regular biology” in the first place. That is, because everything small enough (and quiet enough, as the book points out) is better understood as a quantum system governed by probabilities, there are many people who see a separate category for quantum effects on biological systems as silly (page 19). But to me, this is a bit like saying because there is life on earth, the universe is alive. Is there life in outer space? Of course, because we’re in outer space! It’s undoubtedly true, but not particularly helpful.
I was attracted to this book because of one thing I knew was true: the fact that protein folding in a cell takes place much too quickly during protein synthesis to be explained by classical physics. Classical physics is what you use if you don’t use quantum physics, and classical rules usually apply to the objects we can see or deal with in everyday life. But at the other end of the microscope, quantum rules must apply to make these activities sensible—or so this book claims, correctly in my thinking.
After exploring how classical physics cannot explain how a migrating European robin can sense a weak magnetic field of the earth with an internal inclination compass (page 6 and 14), the book goes through a kind of crash-intro to quantum effects. These effects include how quantum states can be “smeared out” between possible values until a “measurement” snaps the mathematical wave function to a definite value, how quantum tunneling allows quantum particles to “tunnel” through an energy barrier (think of this as a high hill) to the other slope without having to climb to the summit, and how quantum entities can be “correlated” or entangled so that actions that should be impossible can take place.
As I said, in some sense this quantum action is trivial. This is how reality works. The surprise to researchers that this book points out again and again is that without a “quantum beat” drumming in the background at the molecular level, cellular activities like enzyme snipping and photosynthesis make no sense energetically and could never proceed, or proceed much too slowly, under the rules of classical physics.
This is fairly esoteric stuff, and the authors do a good job of keeping you on board by recapitulating important effects and with very well-done figures (for example, those on pages 80 for DNA and page 150 for the sense of smell). One of the real revelations to modern researchers is that quantum effects, normally reproduced in the lab by a very small number of atoms (a near vacuum) in a very cold environment, can exist and drive cellular events in the hot, wet, crowded environment of the cell. This is because the thermal activities of the atoms in the cell are performing “measurements” that destroy the quantum effects all the time (page 116). In spite of it all, there seems to be enough isolation at the atomic level in the cell to allow “quantum walks” to enable things to happen and make life possible.
For example, cells must not only build things up, they must break them down, a process known as catalysis. The “scaffolding” of a cell is collagen, a really tough molecular strand that has to be broken down, for instance, when a tadpole’s tail disappears as it becomes frog. The enzymes used in the cell to perform this “snipping” are well understood; the problem is that, using classical rules (page 79-80), the process is much too slow for life to function. Even with very efficient catalysts, cellular functions should take about 8 hours to complete (page 84), but we can see an entire cell reproduce in about 20 minutes in some cases. Only quantum “shortcuts” can make life possible, the book says.
Which brings me back to the issue of protein synthesis and folding. As proteins are formed by chains of amino acids from RNA, they must fold correctly in order to function, and fold almost instantaneously as they roll off the RNA assembly line. But there are literally hundreds or thousands of ways they can fold (misfolded proteins are behind many brain diseases, and probably Alzheimer’s disease as well). How do they fold so correctly so fast? It has to be some quantum effect in action…
I was fascinating by how quantum effects can explain the robin’s magnetic abilities, which seem to be located in the bird’s eye (page 18 and 171), the role of chlorophyll in photosynthesis, how molecules shaped almost the same can smell very differently, and how DNA and RNA seem to obey quantum rules. However, at the end of the book, quantum effects become to explanation for everything we don’t yet understand, it seems. But to me, the extension of the research results earlier in the book to explain human consciousness (page 231), the origin of life (page 265), and the finality of death (page 289), although they may prove to be correct, is one step too far.
I can’t close without telling the only physics joke I know, which I invented with Irwin Weingarten at NYU around 1967. The quantum, which is indicated mathematically by the letter symbol h, was discovered or invented by Max Planck around 1900. So here’s the joke. Q: Who put the h in pysics? A: Phlanck (Flanck).
OK, you can groan now. 🙂