Jim Al-Khalili is a theoretical physicist, author and broadcaster, Professor of Theoretical Physics and Chair in the Public Engagement in Science at the University of Surrey. He has hosted several BBC productions about science and is a frequent commentator about science in other British media.
I asked him some questions about Life and Quantum Physics.
Francesco Albanese: For years it has been said that the Newtonian and Quantum worlds are held to be irreducibly separate. Is it really true?
Jim Al-Khalili: Well, we know how to go between them. That is, mathematically we know how the quantum rule tend towards Newtonian (classical) mechanics in the limit when objects become large or complex. But what we don’t know is exactly where the dividing line is. That is, we still don’t properly understand where the Newtonian world ends and the quantum world begins.
F.A.: Your last book is titled: “Life on the Edge. The Coming Age of Quantum Biology.” What has Biology to do with Quantum Physics? And what is Quantum Biology?
J.A.K.: This is a new field of science. Physicists and chemists are familiar with quantum mechanics, but so far biologists have not had to worry too much about the strange behaviour of subatomic particles. But quantum biology is all about uncovering and understanding those mechanisms, processes and phenomena inside living cells that only work thanks to the quantum mechanics. Examples include enzymes using quantum tunnelling of particles to speed up reactions, or in photosynthesis where it seems the efficient transfer of energy from sunlight within cells is thanks to quantum coherence (things travelling along multiple pathways at the same time).
F.A.: What is life? And what makes something alive?
J.A.K.: This is a question science has yet to really answer. There are many definitions, such the ability of something to replicate itself, or to metabolise, or simply to maintain a special highly organised state (what physicists call a state of low entropy). We are not saying that quantum mechanics is the answer, but are proposing that it might be that life can uniquely reach down to the quantum domain and make use of its tricks in a way that we do not see in inanimate matter.
F.A.: Nobody really knows what consciousness is and where it comes from. Has Quantum Physics something to do with consciousness?
J.A.K.: It’s possible. But we are still along way from being able to know for sure.
F.A.: Roger Penrose said that consciousness needs to be based on a non-computable process of a quantum computer brain to manifest. Which is your opinion on it?
J.A.K.: Penrose’s idea is interesting, but I think it is too ambitious. Quantum biology doesn’t go that far. Rather, it demands careful experimental testing of ideas in the laboratory. That’s how science progresses. The link between quantum mechanics and consciousness is too speculative at the moment.
F.A.: Does the electromagnetic field of the brain play a role in the creation of consciousness?
J.A.K.: Ah, now this is possible. Indeed, my co-author, Johnjoe McFadden has some very interesting proposals on this topic.
F.A.: Will we ever be able to build self-aware quantum computers? Which is your opinion on it?
J.A.K.: If you mean do I subscribe to the idea of strong AI, then yes, I see no reason why a computer couldn’t be scaled up in complexity in the future to the extent that it becomes self-aware or conscious. This of course would be something Penrose would not agree with because of his insistence on non-computability of the processes of consciousness.
Life is the most extraordinary phenomenon in the known universe; but how does it work? Even in this age of cloning and synthetic biology, the remarkable truth remains: nobody has ever made anything living entirely out of dead material. Life remains the only way to make life. Are we missing a vital ingredient in its creation? Like Richard Dawkins’ The Selfish Gene, which provided a new perspective on evolution, Life on the Edge alters our understanding of life’s dynamics as Jim Al-Khalili and Johnjoe Macfadden reveal the hitherto missing ingredient to be quantum mechanics. Drawing on recent ground-breaking experiments around the world, they show how photosynthesis relies on subatomic particles existing in many places at once, while inside enzymes, those workhorses of life that make every molecule within our cells, particles vanish from one point in space and instantly materialize in another. Each chapter in Life on the Edge opens with an engaging example that illustrates one of life’s puzzles – How do migrating birds know where to go? How do we really smell the scent of a rose? How do our genes manage to copy themselves with such precision? – and then reveals how quantum mechanics delivers its answer. Guiding the reader through the maze of rapidly unfolding discovery, Al-Khalili and McFadden communicate vividly the excitement of this explosive new field of quantum biology, with its potentially revolutionary applications, and also offer insights into the biggest puzzle of all: what is life?