Life on the Edge:
The Coming of Age of Quantum Biology, Johnjoe McFadden
“Dig deeper and you will always find quantum mechanics lurking at the heart of our familiar reality.”
Remember this.
This is probably the most intellectually challenging book I’ve ever read, but it was worth it, and I’m as excited to review it – intellectually – as I was while reading it in parts. I felt as engaged as when I read The Moral Animal before entering the military. Perhaps more surprisingly, I felt some connection to my childhood brain: a child that used the word “All” to describe something greater than his parentally-indoctrinated concept of God; a child that found joy in thinking; a child that felt that there must be physical ripples from every action to every other point in the universe. No other book has made me feel like this before…so the question is, of course, “What do I do about it?”
I am thirty-one. If I pursued a Ph.D., I would likely not complete it until around forty. Granted, I could aim high and apply to great schools; attempt to earn money before and on the side, start a family while earning the degree; and it’s helpful to remember that chronological age means nothing. Still, these thoughts say nothing in response to the pressing question, “Why the hell get a Ph.D.?”
I’ve come across the two-slit experiment perhaps ten times in my life, but I’ve never understood it so well. Lesson learned: books beat YouTube videos watched only once! The authors dedicated a substantial portion of a chapter to the experiment, and it’s worth reviewing for an excellent scientific lesson, which “according to Richard Feynman, “has in it the heart of quantum mechanics.””
“Asking what is really going on between observations is like asking whether your fridge light is on before you open the fridge door: you can never know because as soon as you peek you change the system.”
Two or three times, the authors call “bullshit” on quantum claims about telepathy or anything related.
However, in their final chapter they also mention that when the chaos of the classical world overwhelms the ability of cells and organisms to maintain this “link” to the quantum world, this might be a good way to look at or even define death. I think that’s as good a theory (or explanation) as I’ve ever heard elsewhere!
I still do not believe I truly understand oxidation. How I have a master’s and have read a dozen books in these areas is a testament to how ignorance only grows faster than does knowledge! To understand oxidation, the photosynthetic capture of exitons, and other details, this report is worth reviewing and revising in the future.
They bring up Feynman’s quote, “What I cannot create, I do not understand” several times. As such, they note, we haven’t made – and thus do not understand! – the following: a cell, an enzyme, or even a simple self-replicator. What more profound pillars of biology are there? We really have no clue about biology, and this field is going to change profoundly in the next century. We certainly understand basic physics and chemistry more than biology, but sadly, this likely means we also understand some of the “social” sciences more than biology, as well! Unbelievable, but likely true!
[Note: In the interests of not over-quoting or citing the text in this web post, I’ve eliminated the bulk of my highlights from the book here.]
To start, why is quantum anything important?
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“In fact, it has been estimated that over one-third of the gross domestic product of the developed world depends on applications that would simply not exist without our understanding of the mechanics of the quantum world.”
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“Still, the quantum world appears very strange to us and it is often claimed that this strangeness is a symptom of a fundamental split between the world we see around us and its quantum underpinnings. But in reality there is only a single set of laws that govern the way the world behaves: quantum laws.*8 The familiar statistical laws and Newtonian laws are, ultimately, quantum laws that have been filtered through a decoherence lens that screens out the weird stuff (which is why quantum phenomena appear weird to us). Dig deeper and you will always find quantum mechanics lurking at the heart of our familiar reality.”
Okay, but why, specifically, is quantum biology relevant?
(Why do we have to look to the quantum world for biological explanations, rather than simply using classical physics? Of course quantum mechanics underlies all physical processes, but can’t we ignore these strange and counter-intuitive effects at the biological level?)
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“So isn’t everything, including us and other living creatures, just physics when you really get down to the fundamentals? This is indeed the argument of many scientists who accept that quantum mechanics must, at a deep level, be involved in biology; but they insist that its role is trivial. What they mean by this is that since the rules of quantum mechanics govern the behavior of atoms, and biology ultimately involves the interaction of atoms, then the rules of the quantum world must also operate at the tiniest scales within biology—but only at those scales, with the result that they will have little or no effect on the scaled-up processes important to life.”
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“So the claim that delicately arranged quantum entangled states could survive in the warm and complex interior of living cells was thought by many to be an outlandish idea, verging on madness.”
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“Much of the skepticism Schrödinger’s claim attracted at the time was rooted in the general belief that delicate quantum states couldn’t possibly survive in the warm, wet and busy molecular environments inside living organisms.”
Why, then, do big objects do not have quantum properties?
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“This is why big objects, such as footballs, do not quantum tunnel: they are made up of trillions of atoms that cannot behave in a coordinated coherent wave-like fashion.”
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“The answer on one level is very simple: the bigger and more massive a body is, the smaller will its wave-like nature be, and something the size and mass of a human, or indeed anything large enough to be visible with the naked eye, will have a quantum wavelength so tiny as to have no measurable effect. But more deeply, you can think of each atom in your body as being observed, or measured, by all the other atoms around it, so that any delicate quantum properties it might have are very quickly destroyed.”
What areas of quantum biology are described?
- Enzymes.
- Essentially, quantum properties allow enzymes to perform reactions much faster than classical physics would predict. And as the authors note, since “About one-third of all enzyme reactions involve moving a hydrogen atom from one place to another,”(if this is true), quantum mechanics plays an enormously important role in all of biology, from the ground up!
- Respiration and the electron chain:
- Human systems to capture light are notoriously inefficient…yet plants successfully capture nearby 100% of the energy that hits their chlorophyll to the reaction center. How do they do this? Classical physics can’t explain it, a random walk would be terribly inefficient. They are capturing the wave-based nature of light, allowing the exitons to travel as a quantum wave, permitting nearly perfect efficiency of those that reach the reaction center! Amazing:
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“but the real action of photosynthesis takes place in the reaction center itself. Here the fragile energy of excitons is converted into the stable chemical energy of the electron carrier molecule that plants or microbes use to do lots of useful work, like building more plants and microbes.”
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“Photosystems, enzymes, respiratory chains and genes are structured right down to the position of individual particles, and their quantum motions do indeed make a difference to the respiration that keeps us alive, the enzymes that build our bodies or the photosynthesis that makes nearly all the biomass on our planet.”
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- Navigation by magnetic compasses:
- I agree with their decision to put this topic, with which they opened, in the middle of the book, as we needed to be convinced first about the quantum world. Then, the most substantial argument certainly belongs here. A block of granite over on its edge is a good analogy for how the ridiculously sensitive (and previously-thought-to-be-of-insignificant-importance) fast triplet reaction can influence the chemical products created in these reactions, their molecules created, and how ultimately the magnetic field could have an influence on the behavior of a bird (or other organism).
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“magnetoreception, particularly in robins, has become the poster child of quantum biology.”
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- (6) Smell:
- Here the authors describe the lock-in-key, conventional model, easy for anyone with introductory biological knowledge to understand; and also the various quantum models. It’s convincing that quantum mechanics is involved in smell reception, but they end by noting that the best theory is likely a combinatory model: both the physical shape of molecules/receptors, and the vibrations of odors likely play a role.
- (7) Quantum genes:
- This was a good chapter, but it took some time for me to accept, especially because they’re claiming something I’ve studied so much – MCB, Genetics, Central Dogma, etc. – is so intimately tied to the quantum world. But when I now think about how many decades ago these ideas were proposed, well… I am incredibly disappointed in my education for not bringing up these ideas to me! It makes sense in hindsight: since a quantum measurement is made of the hydrogen bonds (protons, acting quantum mechanically), each time a section of DNA is “read,” as it were, there is a chance the DNA will revert to its tautomeric form, causing a mutation. This chance is small of course, but it exists, and more importantly (surprise!), this makes mutations more likely in overly-expressed genes!
- (Here’s basically the base argument for periodically eating a ketogenic diet to prevent cancer! Overall, reading equally from diverse genes will minimize chances of cancer…)
- (8) Consciousness:
- This was an unimpressive chapter for me, gives an explanation of the “binding problem”, and discusses how the brain’s EM field may be equally important. I agree that it is from the E=mc2 perspective, but that doesn’t mean the EM field is equally as important as the physical reactions…
- (9) The primordial replicator:
- Here, they summarize an absolutely beautiful theory for how this first replicator might have been born. I’d heard of the RNA hypothesis, of course, which makes sense because of the higher variability and properties of RNA, but they shut the idea down quickly that this could happen with classical physics alone. It simply isn’t likely given the numbers we know – there aren’t enough particles or time in the universe to create even a simple self replicator by chance. But if quantum physics is invoked (search for “64” within the highlights below), it could happen. However, I’m disappointed they didn’t provide theoretical information on the time required. I’d love to see this hypothesis tested in the lab!
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“Haldane and Oparin proposed that the emergence of this primordial replicator was the key event that led to the origin of life as we know it.”
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- 10, How cells keep decoherance at bay to use quantum effects:
- The final analogy of “a ship whose narrow keel…” helps us understand how the cell navigates the rough waters of classical physics in such a warm, wet environment while maintaining its ability to use quantum mechanical laws. The ship with a good captain (the cell) is compared to an engineer who wants to sail the ship in a cold environment depleted of air or water and their associated randomly-driven molecular movements. This chapter also describes how the authors propose to test the effects of the quantum world on life: we’d need to build a cell (or at least a replicator) using only classical physical properties, and one using the quantum world…
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“The noise essentially acts as a kind of continuous measurement.”
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- The final analogy of “a ship whose narrow keel…” helps us understand how the cell navigates the rough waters of classical physics in such a warm, wet environment while maintaining its ability to use quantum mechanical laws. The ship with a good captain (the cell) is compared to an engineer who wants to sail the ship in a cold environment depleted of air or water and their associated randomly-driven molecular movements. This chapter also describes how the authors propose to test the effects of the quantum world on life: we’d need to build a cell (or at least a replicator) using only classical physical properties, and one using the quantum world…
- Here, they summarize an absolutely beautiful theory for how this first replicator might have been born. I’d heard of the RNA hypothesis, of course, which makes sense because of the higher variability and properties of RNA, but they shut the idea down quickly that this could happen with classical physics alone. It simply isn’t likely given the numbers we know – there aren’t enough particles or time in the universe to create even a simple self replicator by chance. But if quantum physics is invoked (search for “64” within the highlights below), it could happen. However, I’m disappointed they didn’t provide theoretical information on the time required. I’d love to see this hypothesis tested in the lab!
- I agree with their decision to put this topic, with which they opened, in the middle of the book, as we needed to be convinced first about the quantum world. Then, the most substantial argument certainly belongs here. A block of granite over on its edge is a good analogy for how the ridiculously sensitive (and previously-thought-to-be-of-insignificant-importance) fast triplet reaction can influence the chemical products created in these reactions, their molecules created, and how ultimately the magnetic field could have an influence on the behavior of a bird (or other organism).
- Human systems to capture light are notoriously inefficient…yet plants successfully capture nearby 100% of the energy that hits their chlorophyll to the reaction center. How do they do this? Classical physics can’t explain it, a random walk would be terribly inefficient. They are capturing the wave-based nature of light, allowing the exitons to travel as a quantum wave, permitting nearly perfect efficiency of those that reach the reaction center! Amazing:
Great quotes about science in general:
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“Mysteries, however small, are fascinating because there’s always the possibility that their solution may lead to a fundamental shift in our understanding of the world.”
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“And no one has yet found a way of determining the structure of proteins while they remain embedded in cell membranes.”
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“As he talked freely about his idea, Schulten developed a reputation at the Max Planck Institute for being regarded as somewhat crazy. His problem was that he was a theoretical physicist who worked with paper, pen and computers, not a chemist; and certainly not an experimental chemist capable of donning a lab coat and performing the kind of experiment that would prove his ideas. Thus he was in the position of many theoreticians who come up with a neat idea but have then to find a friendly experimentalist willing to take time out of their busy lab schedule to test a theory that, more often than not, will prove to be wrong.”
Themes and analogies to help understand them, highlighted throughout my file in green:
- Measurement, ocean waves
- Billiard table
- Violin as a classical, warm wet biological instrument, guitar as a quantum incremental instrument
- Behavior of a tiny balloon will be quantum, and unpredictable — gas laws can’t help us.
- Decoherance (search)
- The oxidation of water
- Cycling postmen to illustrate …