ASU PSOC Workshop, Monday October 25th – Friday October 27th 2010
Quantum Mechanics and Cancer Biology
The conjecture that quantum mechanics plays a key role in life dates back to the 1940s, and Erwin Schrödinger’s famous book “What is Life?” However, decades later, most scientists still assume that classical ball and stick models suffice in the realm of molecular biology. Recently there have been claims that quantum effects are essential in at least two biological processes – photosynthesis and bird navigation.
Listen to Audio Interviews and Read Transcripts
If non-trivial quantum effects such as superposition and entanglement can enhance the efficiency of some biological processes, then one might expect life to have evolved to exploit it. Unfortunately, biosystems are so complex that isolating clear quantum effects is challenging. More seriously, quantum effects are notoriously delicate and are easily disrupted by interaction with the environment, a process known as decoherence. The rate at which decoherence obliterates quantum effects depends on the strength of the coupling to the environment, as well as the temperature of the environment. On the face of it, the warm and wet conditions of biological organisms does not favor quantum coherence, and simple calculations predict that decoherence times are generally much shorter than biochemically relevant time scales. The credibility of quantum biology therefore hinges on the extent to which decoherence evasion might be possible in real biological systems.
The workshop focused on the question of whether, and how, naïve decoherence models might lead us astray, and how quantum effects could have a bearing on the inception of cancer. A subsidiary theme was whether emerging quantum technologies can offer novel diagnostic or therapeutic techniques. Reviews were presented on up-to-date thinking about quantum effects in photosynthesis and the avian compass, of proton tunneling in DNA as a source of mutations, of Fröhlich condensates (an old speculation that phonon energy in biological membranes might be channeled into the lowest vibrational mode) and the possible relevance of quantum tunneling to protein folding and enzyme action. Several new ideas for decoherence evasion were discussed. Gerard Milburn presented a generic mathematical model that demonstrated how a quantum feedback system could maintain coherence in the face of environmental noise.
Libby Heany discussed how proton or electron pumping in mitochondria may depend on the conformation of a protein molecule. Elisabeth Rieper described a new mathematical model of quantum effects in the electronic structure of DNA in the longitudinal direction, and Johnjoe McFadden explained how phenomena related to the so-called watched-pot effect might permit an explanation for puzzling examples of adaptive mutations. Another novel idea to emerge at the workshop was “quantum epigenetics” – that quantum fine-tuning of small molecules serving as epigenetic markers could trigger biologically significant effects.
Yakir Aharonov presented a new thought experiment involving quantum weak measurements and post-selection, which provoked a discussion about whether the environment could somehow exert a selective effect on superpositions of different biological pathways. The experimental aspect included a presentation by Marlan Scully of how quantum optics could be harnessed for rapid DNA sequencing, and some controversial experimental results were described concerning electron transport through microtubules.
The workshop terminated with a consensus that there was accumulating and tantalizing evidence for non-trivial quantum effects in biology, with clear potential relevance to cancer, but that decoherence evasion remained a key issue. It was not yet possible to say with conviction whether quantum mechanics merely played an incidental role here and there in biological systems, or whether some very basic biological processes depend in a crucial way and quantum mechanics. It was recognized that quantum biology is a fast-moving and rapidly-expanding field of research that cancer biologists should not ignore.
Audio Interviews from the Workshop
- Interview with Vlatko Vedral, Ph.D., Professor of Quantum Information Theory, Universities of Oxford and Singapore.
Interview with Elisabeth Rieper, Ph.D. student, Center for Quantum Technologies, National University of Singapore.
More Info: http://www.quantumlah.org/people/elisabeth
- Interview with Gerard Milburn, Ph.D., Professor, University of Queensland.
- Interview with Donald S. Coffey, PhD. professor at the John’s Hopkins University School of Medicine in the department of urology, pharmacology, oncology, and pathology.
More Info: http://urology.jhu.edu/about/coffey.php
- Interview with Ping Ao, PhD. Shanghai Center for Systems Biomedicine at Shanghai JiaoTong University.
Audio Interview Transcripts
Interview with Vlatko Vedro, Ph.D.
Vlatko Vedro My name is Vlatko Vedro and I’m a theoretical physicist. I’m from the University of Oxford.
Pauline Davies What are you working on?
Vlatko Vedro Well my main activity is really quantum mechanics in large systems and I’ve investigated this in various physical systems and then at some stage it occurred to me that some of these phenomena that I have found in physics, could actually occur in chemistry and biology. That was my main motivation, actually, to come here.
Pauline Davies You’ve been at this workshop and we’re dealing quantum behavior and cancer, can you see a connection?
Vlatko Vedro Yes, indeed I think the processes I worked on were linked to detecting the magnetic field. It seems that some animals really use genuine quantum effects like quantum entanglement to detect these fields. Another promising direction is photosynthesis and actually if you think about photosynthesis, the main issue is really there to generate, to convert solar energy into some kind of chemical energy that then drives cells. If you think about another place where something similar could occur is in mitochondria and in fact the electron transport in mitochondria, which may or may not be coherent, is actually extremely relevant because that’s one of the mechanisms that go wrong when cancer occurs. I think that’s one place that I’m trying to investigate now because there could be a genuine quantum link and the quantum phenomenon behind cancer, but I think it’s very speculative at this stage.
Pauline Davies You’re talking about magnetism and light because these are the sort of things, the physical processes that physicists are so familiar with and can have quantum implications.
Vlatko Vedro Yes that was a big surprise to us because usually people say that biological systems are at high temperature, they are hot, they are wet, they are complicated so its very difficult to imagine that any quantum behavior would survive such harsh conditions, but actually they do. I think exactly the things you would expect biological systems to be good at such as sensing magnetic fields – it seems that the core explanation really has got to be quantum mechanical. There are effects that we cannot simply explain using classical physics. So that was a big surprise to me, maybe two or three years ago when I discovered that. In that sense, I think if you zoom in at the right length scales and time scales, so if the time scales are short enough, something like a billionth of a second, and quite a lot of important physics and chemistry takes place at those time scales, then maybe we discover that there are some genuine quantum effects in cancer as well then.
Pauline Davies Since we’ve learned at school that quantum effects should underlie everything, it does make sense.
Vlatko Vedro Yes, I think you are fully right. It is just a question of how do these biological systems manage to preserve this even in the limit when you have a large number of atoms or cells or whatever else are the units there. So this is surprising to a physicist, because if you take a large solid and if you heat it up to a high temperature then usually quantum mechanical behavior disappears and we talk about the classical transition and everything becomes non-Newtonian and so on. But it seems the biological systems are able to preserve coherence over surprisingly long intervals of time. That’s a genuine surprise to all of us.
Pauline Davies So what’s the next step? Can you do any experiments?
Vlatko Vedro I think that actually is really the most exciting question and this is what we’ve been discussing. To really genuinely test whether something is quantum mechanical, I think there are experiments that you can do at various levels. You can really try to experiment on biological entities themselves. So for example in this case you have birds, which are sensing the magnetic field and the question is, so now that understand that it’s quantum mechanical can you really tamper with its quantumness? Can you try to spoil it by some external classical theory, if you like, so that really you test the hypothesis that the ability to detect the magnetic field will now just go away if you played with that? Of course it would be much easier to extract those relevant molecules and play with them under much more controlled laboratory conditions and in fact chemists do this all the time. They take molecules that they think play the same role in birds for example, then they isolate and cool them down so you eliminate certain noisy effects and then you test this hypothesis. So all sorts of experiments like that would be interesting. Then the mitochondria connection that I mentioned, in terms of cancer, I think that would be hugely exciting to try to experiment with. So what exactly goes wrong with the electron transport there? I think there are some very basic issues you know – getting an x-ray picture, just x-ray crystallography of this, can we see what geometrically changes when we have a cancer there? Then on top of it we can say, “What are the consequences of this?” That’s something that becomes less quantum mechanical, less efficient and so on. I think to me this would be extremely exciting to look at.
Pauline Davies So this is really a whole new way of looking at things, isn’t it? I mean scientists have got a lot of work to do to understand life.
Vlatko Vedro I think you are right, this is, I think we can bring a new way of thinking that physicists have been using for the last three hundred years. But I think in biology, you know, a standard biologist would not normally think along those lines, would not normally try to include quantum mechanical effects and I agree with you. I think in this sense this is a completely new way of thinking, but there is of course a lot more work to do. You have to make much more sensitive measurements, controlled measurements, and there’s always a debate whether this is really possible or is it just a matter of technology and is it just very difficult and with enough time and enough investment we’ll be able to do that.
Pauline Davies What are you thinking about this meeting so far?
Vlatko Vedro I’m learning a lot. I think the main reason being probably that I really came here with very little knowledge of cancer and there are some hugely surprising actually facts that I’m now learning about. So I think I have a very steep learning curve on the biological and medical side of things.
Interview with Don Coffey, Ph.D.
Donald S. Coffey I’m a professor at the John’s Hopkins University School of Medicine in the department of urology, pharmacology, oncology, and pathology those are four departments.
Pauline Davies What have you made of meeting so far?
Donald S. Coffey Well what happens is that life the mystery of life in the advanced part of our life, we age and with aging we develop cancer and not everyone develops cancer. One out of three do, and one out of four people will die from it. So this is the big major disease with heart and strokes that affects people around the world. So we are at logger heads in trying to understand what the issues are here in both life and cancer. Now many years ago a famous physicist wrote an article his name was Schrödinger and he called it, What is Life? He is the man who figured out there’s a field called quantum mechanics. Quantum mechanics is so mysterious in itself that its almost mind boggling. What he had observed is that when a particle comes up to a slit and goes through the slit, like it’s going to make a dot on your television screen, what it does it actually goes two ways at the same time so the actual particle appears in two different places and its wavelengths. So how can something that’s solid be a wavelength, and how can you be at two places at the same time and how do they interact, and this is called entanglement. So from entanglement it means that each of these particles are somehow aware of themselves and they respond in some similar ways. Now is that a bunch of physics that just highfalutin, that is just for the people up stairs to think about? Well it turns out they’re trying to figure out how birds migrate from Europe down into South Africa and when they look at that, it turns out to be a quantum mechanic mechanism – that is, that the birds have the ability when they migrate to visually see the magnetic field. Now they are going by a whole new system here that we hadn’t even thought about for cancer and life. Many years ago Paul Davies had a meeting called the quantum mechanics of biology. Well that was on the real cutting edge, but now its turned out that it reaches into some things that evaporates some mysteries. The second one is that when the sun comes down and hits the tree, it is so efficient in capturing that energy and converting it into chlorophyll and using chlorophyll to convert this into foods that we eat, sugars and things like this, that no one can understand how it’s that efficient. We talk about solar collectors but nothing we do here, I mean most the engines and things we make run at ten or twenty percent efficiency, but this solar collector, made by nature, over the years, is just way up there around ninety-some percent. Well now they found out, in several important papers that have been published within the last two years, that this too uses a quantum mechanics method of transferring this information. Now that was controversial but everyday it looks clearer and clearer that this truly is how the sun works how birds migrate.
Now let’s come back to cancer. We’re here to look at quantum mechanics of cancer. It’s apparent that all of the forces of gravity, light, energy, all these things are a part of life and cancer is an aberration in the life process. So what’s come out of this meeting is dozens of important concepts being developed here in the department of Beyond here at Arizona State, in which they’re looking at how does quantum mechanics actually have a role to play in the cancer. Now I have never been to a meeting on that issue. I’ve spent my life in this field, fifty years, and this is the first time these types of things have been discussed.
So almost everyone at this table I did not know before, I’d never seen them, I’m in the cancer field, they had never seen me, they’re in the quantum mechanics field of physics, and together its was just electrifying.
Pauline Davies Can you just tell me, why is it that biologists have not got together with the quantum physicists before now?
Donald S. Coffey Why haven’t you talked to an oyster?
Pauline Davies I never thought of talking to an oyster.
strong>Donald S. Coffey That’s right, we never thought of talking to a physicist. In other words, you talk to people you interact with, you talk to people that you know. So if I move down your block five blocks, there are people everywhere you don’t talk to. And you don’t talk to them cause you don’t have a common interest, you don’t go to the same meetings. In any field it breaks up into specialists, I mean if you go to any university, the people in one department hardly know what the other departments doing. Even in art, I mean people who are into choreography, they don’t understand sculpturing and they might appreciate it , okay, but they don’t understand the issues that are afloat there. So that’s the way it is in science, physicists, chemists, biologists, cancer people. You go to a hospital, our plate is full of trying to take care of people and figure out what we can do for Mr. Jones or Ms. Smith who’s sitting there with an advanced cancer and there are families involved and all sorts of things involved and we hardly even have time to talk to the cell biologists much less the physicists.
Pauline Davies Yes well hopefully something productive will come out of this because new ideas seem to be badly needed.
Donald S. Coffey Well, all new ideas are resisted. As soon as someone comes up with, the Galileo – he takes his telescope, he looks out there he says, “Wow,” nobody want to believe him, but then he didn’t even understand .1 percent of what’s out there and that’s the way we are right now. We’re looking at quantum mechanics we’re seeing some really strong signals that its more involved than we believed. It has something to do with life it has something to do with biology and with cancer and with aging. We don’t know as we make better telescopes here where this is going to go, but this is some of the early events to try to bring us together.
Interview with Elisabeth Rieper
Elisabeth Rieper My name is Elisabeth Rieper. I am a Ph.D. student at the National University of Singapore and for the last three years, in my thesis, I worked on quantum coherence and biological systems.
Pauline Davies So how do quantum effects play out in biological systems, in your experience?
Elisabeth Rieper In the beginning we thought that they would have no effect but now it seems that they play an important role almost everywhere. When you go down to a small level everything works with the laws of quantum mechanics. So it would be very surprising if biological systems were not due to the same constraints of using quantum mechanics. Now we have a couple of examples where quantum mechanics helps you improve transport probabilities, measurement of fields, just to name two of them.
Pauline Davies So you’ve been looking in individual cells for quantum effects have you?
Elisabeth Rieper Yes small parts inside the cell. For example, any sort of information flow or proton tunneling, how can a proton go in a controlled way from one end of a molecule to the other end. So the answer is, if there’s a coherent pathway, and coherence means suppressants of quantum corrolation, then it turns out that this coherence pass way makes this transport of a single proton far more easy and faster. Classical mechanics, a proton would need to hop from one side to the next and hope to arrive finally at the correct spot and this hopping is hopeless. Whereas quantum mechanically allows you to do direct and fast.
Pauline Davies You say quantum tunneling, now that’s an unusual concept to ordinary people. Explain.
Elisabeth Rieper Well quantum tunneling means that instead of going step by step you exploit a couple of simultaneous pathways all together. And one big problem, well one big challenge for biology, is overcoming barriers. So when you have a barrier you cannot move over it unless you give additional energy.
Pauline Davies This is that what you meant by the protons hopping?
Elisabeth Rieper Sort of. Now two concepts here are playing together, one is a coherence pathways, where you exploit many many paths simultaneously and the other one is tunneling. So tunneling allows you to go through that barrier, you do not have to wait for that extra amount of energy to arrive miraculously; you just go directly through the barrier.
Pauline Davies How does the proton know where to go?
Elisabeth Rieper Good question. Probably we do not know. It just seems that the energy surface is a landscape the proton sees, directs the proton to go to the correct spot.
Pauline Davies So something is actually drawing it towards itself.
Elisabeth Rieper Yes. I think we can say that.
Pauline Davies What have you learned from this conference?
Elisabeth Rieper Well it might sound stupid, but I learned that I don’t know anything. And I learned that all the other experts in the field ranging from physics over chemistry to biology don’t really know that much either. As a physicist I was shocked to find out how little is actually known about how cells work and that lacking, that ignorance might be due because we haven’t taken quantum mechanics into account.
Pauline Davies What about collaborations? Has this conference suggested any collaborations to you?
Elisabeth Rieper Now I have made a lot of contacts and I will have to read up on the fields my colleagues are working on. But it was definitely fantastic to get to know them and once I have an idea how my work will connect to theirs we will definitely start working. We agreed to keep on discussing each others idea, so this is the first stage of forming a collaboration, just to start talking to each other and given that the problem of understanding a cell ranges from computer science over physics to chemistry to biochemistry to biology, I think its very important to bring people from different fields to start discussing with each other.
Pauline Davies This hasn’t happened before in your experience?
Elisabeth Rieper Well you are asking a young scientist with the question. Probably it happened before, but as far as I know the quantum physicists were always left out of the discussion. And it’s a new trend starting like four years ago since all sorts of quantum physicists are invited to such cross-interdisciplinary workshops and I think we had a couple of very interesting talks. Quantum physics brings in new aspects of what’s possible and impossible.
Pauline Davies As you’ve mentioned you started off as a physicist and now you’re interested in biology. Was it a difficult thing to learn the biology that you needed?
Elisabeth Rieper It is a challenge. One problem is that, for example the word entanglement is used completely differently in the two fields and there are a couple of more examples. And one problem of quantum biology is that biology is massively complex – large systems. You just have problems to understand the sheer amount of what’s going on, whereas quantum mechanics goes very deep its analytical; you need to learn a hell of a lot of mathematics, you can never solve your equations because its too deep, and now you want to combine these very two different fields and its just getting a mess. But it’s a fantastic mess, it’s a challenging mess and I enjoy working on it.
Interview with Gerard Milburn, Ph.D.
Gerard Milburn My name is Gerard Milburn; I’m a physicist, theoretical physicist at the University of Queensland in Australia.
Pauline Davies You specialize in quantum mechanisms, quantum computing in fact don’t you?
Gerard Milburn That’s correct. For the last ten years I’ve been part of the Australian Center for Quantum Computer Technology and I’m now about to begin leading a new center in engineered quantum systems.
Pauline Davies So what brought you to this meeting?
Gerard Milburn The connection between quantum physics and biophysics is something that’s intrigued me for a long time, largely going back to the meeting I attended at NASA about four years ago, organized by Paul as well. And only very recently have I become interested to the point of calculating something in studying quantum coherence in photosynthesis so this seemed to be a nice opportunity to come and see what else is happening in the area of quantum biology.
Pauline Davies Do you think this is more difficult that doing quantum computation?
Gerard Milburn Studying quantum effects in biology? It’s certainly at a much earlier stage of its development. Quantum computing has been around for well over twenty years now and it’s had hundreds of millions of dollars of investment and research, so it’s much further along.
Pauline Davies Probably not quite so complicated.
Gerard Milburn No its much more complicated. Biological systems are vastly more complicated than anything we can build in the lab.
Pauline Davies So are you enjoying your new field and looking at biological systems and the quantum world?
Gerard Milburn Absolutely. Yes I’ve co-supervised one PhD student over the last two years looking at quantum effects in photosynthesis and I’m now looking for a couple more new students. In fact just at this meeting I’ve got a nice new project on controlling quantum coherence with chemical kinetics. So I’m looking for a new student when I go back to Australia next year to work on that.
Pauline Davies Have you just developed that program here?
Gerard Milburn Yes, exactly yes, that’s true it’s a calculation I started about twenty-four hours ago and it’s to my surprise it’s actually working pretty well!
Pauline Davies Well that really is amazing and did you say you’ve got a collaboration going?
Gerard Milburn Yes there’s a couple of collaborations I think that will come out of this meeting. The work on chemical kinetic control of quantum coherence, I’m going to pursue with Professor Briegel in Innsbruck for example.
Pauline Davies So this has been a worthwhile experience for you?
Gerard Milburn Oh absolutely, yes its been incredibly productive and more particularly I’ve learned a huge amount of biophysics and biology and also everything I know about cancer, I’ve learned since Monday since I came to this meeting, so that’s been extremely useful!
Pauline Davies Someone said to me that they were shocked at their own ignorance and also shocked at the ignorance of everyone else because no one really knows very much about quantum mechanisms in biology.
Gerard Milburn Yes I think that’s true. This is a very, very young field. There seem to be some interesting problems – we’re not a hundred percent sure they’re real problems yet – but they’re so interesting that we have to spend a bit of trouble to try and find out.
Interview with Ping Ao, Ph.D.
Ping Ao My name is Ping Ao. I’m from Shanghai. I’m doing cancer research and then sometimes also physicist.
Pauline Davies So you’re one of the few people who are studying both physics and cancer?
Ping Ao Yes that’s correct.
Pauline Davies Had you ever thought before of quantum mechanisms and how they might impact cancer or life in general?
Ping Ao One should answer this in two ways: I think on the basic side of course quantum mechanics is important for life as well as for cancer, but on the other side there is higher level, before I came to this conference, I discounted cancer and quantum mechanics but now after this conference, I started to feel there probably is a connection.
Pauline Davies Right. So before you hadn’t thought there was a connection and now you do. Do you think it can have any practical significance?
Ping Ao Could be yeah. I think it might provide a key to understanding some important aspects of cancer. Yes.
Pauline Davies So what do you think is the next step? Is it experiment?
Ping Ao I think it’s both. I think actually probably the first one will be the very creative thinking – kind of a layout of the direction for experiments to go.
Pauline Davies So for this creative thinking to happen I guess you need to have more conferences with physicists talking to cancer biologists.
Ping Ao Oh yes. Both. We also want to know and the cancer biologists want to present their questions to physicists, yes.