Big Think Interview With Paul Davies

A conversation with the Arizona State University cosmologist and astrobiologist.
  • Transcript


Paul Davies:  My name is Paul Charles William Davies and I’m director of the BEYOND Center for Fundamental Concepts in Science at Arizona State University and author of “The Eerie Silence.”

Question: What first interested you about the search for alien life? 

Paul Davies:  I suppose my interest in looking for life elsewhere in the universe really dates back to my teens.  What teenager doesn’t look up at the sky at night and think am I alone in the universe?  Well most people get over it, but I never did and though I made a career more in physics and cosmology than astrobiology I’ve always had a soft spot for the subject of life because it does seem so mysterious.  To a physicist life looks nothing short of a miracle.  It’s just amazing what living things can do and so that sense of mystery, that sense of how did it all begin has always been there in the background and then in the 1990s I began to take a more active part, began to study the prospects that life could spread from Mars to Earth or maybe Earth to Mars and that maybe life began on Mars and came to Earth, and that idea seemed to have a lot of traction and is now accepted as very plausible, and so I was asked to help create the Australian Center for Astrobiology.  I was living at that time in Australia and we set this thing up in Sydney and I worked there for some years before moving to Arizona.

Question: How much credence has the theory that life began on Mars gained? 

Paul Davies:  Well I first suggested the idea in the early 1990s that life could have come from Mars to Earth inside rocks blasted off the red planet by comet and asteroid impacts.  I think a lot of people felt that this was a pretty crackpot notion, but it became clear during the 1990s that not only that there is a large traffic of material exchanged between Mars and Earth, but that microbes are hardy enough if protected by the rock, cocooned inside, to survive the harsh conditions of outer space for a long time, many millions of years, and the evidence both theoretical and experimental has firmed up and I think many people now realize that if you get life on either Mars or Earth you’ll get it on both planets from this splashing phenomenon.  Now the case for it beginning on Mars is not very strong.  Mars is a smaller planet, so it cooled quicker, so it was ready for life sooner.  Conditions there were more congenial for life to get going, but as we don’t know how life ever got going this is a bit of a leap in the dark—so we certainly can’t say that it definitely started on Mars, but it seems very plausible that it did.  On Mars seems as good a place as Earth for life to get started.

Question: Is this theory still controversial, and how could it be verified? 

Paul Davies:  I think astrobiologists are comfortable with the idea that it could have started on Mars and come here.  As I’ve said the evidence is not compelling, but to really clinch this we would of course need to either go to Mars and find life there and discover it is the same life as we have here on Earth or just possibly a sample return mission, which has been long awaited by the astrobiology community.  This is a spacecraft that will be sent to Mars and pick up a sort of grab bag of rocks and bring them back to Earth so they can be studied.  It’s just possible we will find traces of life in those rocks.  It’s equally possible we won’t, so it’s a bit of a long shot.  The only way to be really clear is to have some expedition to Mars and my feeling is that life on Mars today is almost certainly, if there at all, deep under the ground, maybe a kilometer or so beneath the surface, and so that is going to be hard to get at.

Question: What is the SETI program?

Paul Davies:  SETI is the Search for Extraterrestrial Intelligence and it addresses the question, “Are we alone in the universe?”  This is a question which goes back to the dawn of history, but for most of human history it has been in the province of religion and philosophy.  Fifty years ago, however, it became part of science and the trailblazing work of a young astronomer named Frank Drake set the trend.  Frank decided to start scanning the skies with a large radio telescope in the hope of stumbling across a message from ET.  It seemed a somewhat quixotic enterprise when he began, but over the years it has grown and grown.  It’s now an international effort and I think it is taken seriously by many scientists and so it really consists of using radio telescopes, choosing target stars where it is conceivable there might be some sort of advanced alien civilization and hoping that they might be beaming radio messages our way and so the 50th anniversary of this it seemed to me a good time to take stock because after all, we’ve had nothing but an eerie silence in 50 years, so these astronomers have been patiently pursuing this quest.  I might say Frank Drake himself is still in the game 50 years on.  Now this is heroism of an unusual sort.  Who else do you know who has devised a scientific experiment and has pursued it for 50 years, got a null result and is still smiling and optimistic? So Frank Drake is a great hero of mine and I admire his zeal and positivism, but it is just an eerie silence and so the question is are we doing the wrong thing.  Should we be looking somewhere else or in some other way?  Should we broaden the search?  And my conclusion is really that I think what the SETI people are doing is just great and I hope they go on doing it and doing it better, but meanwhile, we should start thinking outside the proverbial box a bit to see if there are other ways in which we could try to track down ET.

Question: Is this silence more likely due to aliens’ nonexistence or to flaws in our search methods?

Paul Davies:  If you ask the astronomers of the sharp end of SETI why they think there has been an eerie silence they’ll say, “Well we only have been doing it for 50 years. We’ve just started. What more do you expect? It’s a big universe out there.”  And in fact, to put that into context they look carefully.  It’s just a few thousand stars.  There are 400 billion stars within our Milky Way galaxy alone, so it is a needle in a haystack search.  Of course it’s easy to conclude simply that they just haven’t been doing it long enough or hard enough—it’s no surprise they haven’t heard anything, but the alternative is that we are indeed alone in the universe, and it’s impossible to answer that question because there are so many unknown factors.  If we’re looking for intelligence in the universe I think everybody assumes that this has to start with life and so the question is: "How likely is it that there will be life elsewhere in the universe?"

Now when I was a student almost nobody thought there was any life beyond Earth.  Today it’s fashionable to say that there is life all over the place, that the universe is teeming with it, but the scientific facts on the ground haven’t really changed.  We’re still just as ignorant as we were 40 or 50 years ago about how life began.  We’ve got a very good theory of the evolution of life once it gets started, but how does it get going in the first place.  We don’t need a blow by blow account of exactly how it got going on Earth, but we would at least like to know whether it was a very probable event or very improbable event and in our present state of ignorance we can’t even pin that down.  We can’t even bracket the odds.  It could have been a stupendously improbable fluke, a freak chemical accident that occurs just once in the universe or it could be that life emerges automatically and naturally as part of the underlying scheme of things.  Maybe the universe has intrinsically bio-friendly laws that brings life into being all over the place.  We don’t know.   It’s only fashion that has said the pendulum has swung from extreme skepticism about extraterrestrial life to extreme credulity.  The truth is somewhere in between, but to pin it down we’ve really got to address that question, how likely is it that life will arise on an Earth-like planet.  I should say we know that there are many, many other Earths out there.  We’re almost certain that there will be upwards of a billion Earth-like planets in our galaxy alone, so there is no lack of real estate where life might happen, but what we don’t know is how likely it is given the real estate, given a wonderful pristine planet like Earth how likely is it that life will pop up inhabited?  We don’t know the answer to that.

Question: What new kinds of evidence of alien life might we search for?

Paul Davies:  It seems to me that the most obvious thing that we can do to test this idea that life does form readily on Earth-like conditions, an idea incidentally that Christian de Duve, who is a famous biologist, has called the cosmic imperative, this sort of wonderful phrase, so how do we test the cosmic imperative?  What we want is to find a second sample of life.  What Chris McKay at NASA Ames calls "life 2.0."  We’ve got life 1.0.  Here it is.  What we want is another sample of life, which is not on our tree of life at all.  All life that we’ve studied so far on Earth belongs to the same tree.  We share genes, for example, with mushrooms and oak trees and fish and bacteria that live in volcanic vents and so on that it’s all the same life descended from a common origin.  What we want is a second tree of life.  We want alien life, alien not necessarily in the sense of having come from space, like it might have done, but alien in the sense of belonging to a different tree altogether.  That is what we’re looking for, "life 2.0." And one place we can look is right here on our home planet.  No planet is more Earth like than Earth itself, so if life really does pop out readily in Earth like conditions surely it should have arisen many times over right here on Earth.  How do we know it didn’t?  Has anybody looked?  Remarkably enough until a few years ago nobody thought to look for a second sample of life on Earth.  Everybody just naturally assumed that all life on Earth is the same life.  Well as I’ve said all life so far studied is the same life, but we haven’t studied all the life there is. 

Most life on Earth is microbes.  We notice the big things.  We notice the trees and the elephants and so on because they’re big, but the vast majority of species on Earth are microbes and we’ve only just scratched the surface of the microbial realm.  Probably less than .1% of microbes have been classified let alone cultured or had their genes sequenced, so really that microbial realm is a mystery.  We don’t know what those little bugs are and it’s entirely possible that intermingled among the microbes that are related to you and me are some microbes which are not on our tree of life at all.  They would be genuinely alien life.  Life 2.0 could be right under our noses or even up our noses, so I think the most important way we can advance this quest for ET is to look right on our home planet to see if we can find a second sample of life and I’m working with people to do just that.

Question: How hard are we looking for simple, as opposed to intelligent, alien life?

Paul Davies:  Almost all the effort that is expended in astrobiology is towards looking for simple forms of life.  Usually just microbes and microbes on Mars would be our best hope.  Then we know that within the solar system is very unlikely there will be anything  more advanced than microbial life, but if we think outside the solar system and then the distances are of course immense then there could be Earth-like planets with more advanced form of life.  For example, there could be photosynthesis that’s going on that would leave a signature in the form of oxygen in the atmospheres of these planets.  Now it’s the only the last few years we’ve discovered any planets outside the solar system.  There is a list of about 450 now and there is a satellite called Kepler, which is going to find a lot more over the coming year or two. And then we’ll have a shopping list of likely planets, maybe Earthlike planets, where future instruments that will be very expensive and very technically very challenging, but nevertheless, could be built in decades hence.  These instruments could then scrutinize these planets that we’ve found and see if it can get enough information about their composition of their atmospheres to say they may have life.  Of course again it would be an indirect signature of life.  We wouldn’t be seeing the life itself, just its byproducts, say, in the form of oxygen.

So these are the best hopes, but of course I think from the public’s point of view they’re less interested in microbes or plants.  They’re much more interested in intelligent aliens and so the search for intelligent, extraterrestrial intelligence, intelligent aliens or advanced alien civilizations, something like that is in the province of the SETI program and they look set to continue doing more of the same for the coming years.  They’ve got a better system.  The Allen telescope array in Northern California has been paid for in part by Paul Allen, the co-founder of Microsoft and this is currently under construction and when it is finished it should have 350 dishes, which hooked together will form a telescope with a very large collecting area.  It’s a radio telescope, so again, it’s listening for radio waves from ET, but I think meanwhile we should broaden the search and start looking for other things.  For example, even in radio we should be looking for beacons as well as so called narrow-band signals.  The way that SETI works so far is that they tune into the heavens a bit like you tune into your local radio station, that is that there is a particular… they’re looking for a particular frequency, a continuous transmission at some sharp frequency, which is the way we do it, we’re sending messages here. But there is another type of message which is in a way it’s like the message in the bottle.  It’s a one-way message.  It’s a lighthouse is a good example of that.  It just sends out a flash for anybody who may or may not be out there, who is looking.  In the same way we can imagine that some alien civilization may be be long vanished, has made a beacon that is sweeping the plane of the galaxy and it would just something that goes bleep in the night.  You’d hear this bleep that is ET pinging us.  You maybe wait a few months or years and it would ping us again and if you hear enough of those pings you would sit up and pay attention. 

The SETI program is not well geared up for the pings.  They’re trying to diversify their technique so they can search for such things, but it really needs a more expensive system of dedicated instruments, radio telescopes that stare at some particular patch of sky for months or years on end just so that you see the repeat of these pings, so at the moment if a radio telescope picks up a ping, a transient pulse of some sort what can you do?  You can shrug and say well it was some strange pulse came from over there.  There is nothing you can do about it.  It has been and it’s gone.  You can’t get somebody else to observe it because it is all over and there have been many examples of recorded transient events of that nature.  Nobody knows what they are.  They could have natural explanations or maybe these really are beacons.  We shall have to wait and see.

Question: Why do you believe we’re unlikely to find aliens closer than 1,000 light years away?

Paul Davies:  It’s almost impossible to guess the number of communicating civilizations that are out there because as I’ve described the fraction of planets on which life emerges is not known.  It could be anything from zero to one and so the uncertainties in that number really mean that it is a fool’s errand trying to estimate the further consequences of there being intelligent life and communicating civilizations, but you can of course go to an optimist and I guess there is no one more optimistic than Frank Drake himself and say, “How many do you think are out there in the galaxy?”  And he reckons 10,000.  That is his currently best guess what there is.  So you can then ask well then how close is the nearest one likely to be to us and it’s going to be a few hundred light years, so let’s take 1,000 light years as the round figure.  Now the problem here is that a civilization that is 1,000 light years away doesn’t know we exist.  They don’t know that we have radio telescopes here on Earth because they see Earth as it was 1,000 years ago.  Nothing can travel faster than light, so however good their instruments they can’t see in affect the future.  They can only see Earth as it was 1,000 years ago, so there is no particular reason they should be sending us messages at this time and if you put yourself in the position of a SETI enthusiast on this hypothetical distant planet going to a granting agency and saying, “There is a really interesting planet over there, Earth, that we’ve studied it very carefully and we can see they’ve built huge structures like the pyramids and this great wall in China and we think some millennium soon they may have radio telescopes, could we have some money to start broadcasting?”  And I can tell you what the grant agency would say.  It would say, “That is a great idea. You come back in a few thousand years when, you know, they are actually on the air and we’ll give you the money to send them some messages.”  And that is the situation we’re in, so I think it’s a bit of a fool’s errand to be looking for deliberately beamed messages.  We might stumble across a message intended for somebody else or it may be that we see a beacon or something like that.  These things are long shots and so my feeling is, well, we should carry on trying because who knows what is out there, but meanwhile we should be finding other ways of looking for ET.

Question: Why would  “older, wealthier” alien civilizations be found closer to the center of the galaxy? 

Paul Davies:  The history of the galaxy is pretty well understood and the stars started forming towards the center first.  The age of the galaxy is a little over 13 billion years.  Earth is only 4 ½ billion years.  The very earliest stars didn’t have the sort of heavier elements like carbon and oxygen and so on that are necessary for life, but after a short period of time these elements were manufactured when the first stars made them and then blew up and spread them around and so in the early days the main action was towards the center of the galaxy where the superstars had exploded, and then right out on the edges of the galaxy there was a paucity of these heavy elements and so every time what has happened is that this Goldilocks zone which could support life has expanded out and we’re some way in the middle suburbs of our Milky Way galaxy.  The Goldilocks zone is now moved out to here and but that is because of course we’ve… we’re Earth and the solar system is only about half or a third as old as the galaxy, so if we’re thinking about old civilizations, those that formed a long time ago and there were stars and planets around long before Earth even existed, then these are going to be towards the center of the galaxy.  That is the place to look if you think there are ancient civilizations that have made beacons or some other way of attracting our attention.

Question: What future technologies might enhance the search for extraterrestrials?

Paul Davies:  I think we need to get away from the idea of leaving this to a small and heroic band of radio astronomers and try and spread the burden across the entire scientific community.  I think all the sciences can contribute, and I’ll give you some examples.  One of the things that is baffling about ET, and this is an idea that goes back to Enrico Fermi at the end of the Second World War is, why haven’t the alien civilizations spread across the galaxy and colonized it or at the very least visited? “Where is everybody?” is the way Fermi put it, and so he took that as evidence that there is nobody out there, the fact that Earth has not been visited or colonized, that the aliens haven’t come here a long time ago is evidence that they’re not out there either, but I think one can put a spin on this particular story and say, well how do we know that the aliens didn’t come and it doesn’t have to be flesh and blood aliens literally stepping out of a spacecraft.  It could be their machines or their probes or robots or something of that sort that they could well have come a very long time ago, and in this game you’ve got to think not in thousands or even millions of years, but hundreds of millions or billions of years, so it's that sort of timescale we have to think on, and the question is, would any trace remain of alien activity, say in our solar system, after—let's pluck a figure out of midair—100 million years? If you came back in another 100 million years from now would any trace of human activity remain?  The answer is not very much, but there are some things that we could look for.  If ET did pass through the solar system obviously didn’t stop for 100 million years what would we find?  Well there are some things like nuclear waste.  If you dumped nuclear waste that will certainly survive for that length of time.  We could go look for that.  Any sort of large scale mining or quarrying activities would leave scars although they might be buried beneath rock strata would still be discernible to a geologist doing a survey.  We could look for that too. 

And then there is one other idea that is crazy, but it’s dear to my heart and this comes back to the message in the bottle concept, so up to now SETI has been involved in looking for messages that are being deliberately beamed at us and as I’ve explained that’s pretty unlikely, but there is another type of messaging of which the beacon is an example.  It’s a one way message.  When you put a message in a bottle and throw it into the sea you don’t think to yourself "Well, I expect a reply."  It’s you don’t know if anybody is ever going to find it and certainly don’t know who is going to find it, so it’s just sort of left to its own devices.  Well in the same way we might imagine that an alien civilization might have put a message in a bottle for anyone who might find it and that anyone could be us, could be human beings, so where is the bottle and where is the message?  I’m open to suggestions.  One idea I’ve had is that maybe the bottles are living cells, terrestrial organisms and that the message is encoded in DNA.  Viruses are continually infecting organisms on Earth and uploading their DNA into the genomes of those organisms, so there is a well understood pathway for getting information into DNA.  We’re littered with it.  Our own genomes have got huge amounts of this junk that has climbed onboard from viruses over evolutionary history, so if viruses can to it ET can do it and it seems to me that we could in addition to scouring the skies for radio waves with a message encoded we could scour terrestrial genomes, which are being sequenced anyway, to see if there is a message from ET encoded in it.  You know, it could be some striking string of nucleotide bases, the famous four letter alphabet that is the language of life, the A’s, G’s, C’s and T’s in the DNA.  It might just spell out some sort of message that would attract our attention.  Now of course this is a crazy idea.  I’m not actually suggesting that there really is a message from ET in genomes.  What I’m saying is that is the type of thinking we need.  Maybe it is no more crazy than expecting it to be etched into radio waves coming from the sky.

Question: What major issues would we confront if we discovered life elsewhere in the universe? 

Paul Davies:  People are amazed that there is something called the SETI Post-Detection Task Group and I chair this, and it’s an awesome responsibility.  I say if ET calls on my watch I’ll be among the first to know and not only the fate of the earth, but the fate of the entire galaxy may rest in my hands, so it’s not something to be undertaken lightly.  Of course the people on this committee think it’s very hypothetical, that it’s a tiny, tiny chance that this is ever going to happen, but it is as well that we think through the issues, and there are a number of issues because I think if we suddenly did discover we’re not alone in the universe the ramifications for that could be very profound indeed.  Now I like to make a distinction between two extremes.  One is that we just stumble across some sort of evidence that there is somebody out there, that there is alien technology.  We can’t say anything more than that.  It might be some distant star that has got some signs of tampering or the planets around that star, some signs of tampering.  It’s worth remembering that all technology leaves a footprint.  For example, our own technology is leaving a footprint in terms of global warming, which could be detected from a long way away.  One assumes that a very advanced civilization that has been around maybe millions and millions of years would have an even bigger footprint that might extend beyond its planet to its immediate astronomical environment.  It might even be large-scale astro-engineering.  We could look for that. 

Supposing we found something like that, it wouldn’t be a message.  It wouldn’t be contact with aliens, but it would mean we could say definitely that there is or was somebody out there, that these are the fruits of their intelligent activity.  Now that would be in my view the most profound scientific discovery in the history of mankind, and its impacts would be a little bit like when Copernicus announced that the Earth is going around the sun.  There was no change in the price of beer, no rioting in the streets, nothing of that sort, and yet over the centuries it has enormously colored the way we see ourselves and our place in the universe, same thing with Darwin’s theory of evolution.  Again, no rioting, no dramatic changes in society, but over the decades very definitely it has changed the way we think... think about ourselves. And in the same way, if we knew we were not alone in the universe it would have a very, very deep impact on our worldview, on our understanding of our place in the universe, but I think it could be announced in the same way—well not quite in the same way as Copernicus.  He waited until he died before he published it because he was afraid of being killed by the church, but we don’t have that fear I don’t think—but I think it could be announced in the same way as a major astronomical discovery with a published paper and a press conference and all the rest of it.

Now that is one extreme and that’s the most likely thing that we’re going to find, but the other extreme is the Holy Grail of SETI, which is the message.  You know, a message from ET for mankind: “Earthlings, have I got news for you.”  That sort of thing, and then all bets are off because the effect of such a message could be enormously disruptive.  If it is a message with content we have to think, what is that content.  We can imagine all sorts of things ranging from, “Stop burning fossil fuels, you silly people. You’re heating your planet.”  To, “There is a comet coming your way. You’re going to be wiped out in 100 years.”  Or it could be a more helpful thing along the lines of, “Here is a way of gaining control over nuclear fusion to give yourself a cheap energy source.”  Now these things will all have enormous impacts on society, even just some helpful tips about technology would change the economic and technological balance of the planet and could be very, very disruptive, so we would need to think very carefully about how that sort of information was handled.  We’d also need to think very carefully about whether we should reply and if so what should we say and who speaks for Earth. And that gets us into all sorts of difficult territory, but the one thing I think we’re all agreed with this task group is we should not disclose the coordinates in the sky of any transmitting source.  

Supposing we knew that up there is some alien civilization and it’s sending radio signals our way we should not tell the public where that is.  We could say that we’ve got… we’ve picked up a signal, but we should not tell them where for the simple reason that anybody could commandeer a radio telescope, set themselves up as some self appointed spokesperson of mankind and start beaming all sorts of crazy messages back to the aliens.  I think if we’re going to send messages to the stars then it needs a great deal of thought that it’s something that should involve the entire not only scientific community, but the entire world community.  We need to think very carefully indeed.  So that should be prevented, but SETI is not a secret enterprise and this task group is itself completely public.  It’s completely open.  Our conclusions are available on the Internet.  It’s not anything we want to keep from the public, but the effects are very sobering.  We do really do have to think about what the affect on society would be and the effect on religion for example could be very profound and we know what an explosive issue religion is on planet Earth, so those are the sorts of things we deliberate on.

Question: If you were the first human to communicate with an alien civilization, what would you say?

Paul Davies:  Well first of all we have to understand that they’re unlikely to speak English unless they’ve been studying us for a long time and that it’s hard enough to communicate properly between different people on this planet, all part of the same species, the cultural gulfs of misunderstandings are of course notorious.  We’re now dealing with a completely separate species.  Then you have to think what on Earth have we got in common, so I feel that our communication will be… we will want to let ET know our finest achievements, the things we’re most proud of and if you just go out on the street and ask people well what do you think are our finest achievements, chances are that you’ll be told a Beethoven symphony or a Picasso painting or something like that and I have no quarrel with that, but the problem is that our appreciation of works of art and music are very much tied to our cognitive system and an alien whose brain is wired differently probably wouldn’t have any understanding of it and certainly wouldn’t have any understanding of politics or sport or anything of that sort, so there would be no point in sending those things.  Now there is one thing we’re all agreed that we must share and that is mathematics.  Mathematics is universal.  It’s discovered by human beings, but the rules of mathematics are the same throughout the universe and the laws of the universe.  Our mathematical relationships or the underlying laws of physics we can cast in mathematical form, so if they are communicating with us if they have technology they will understand the laws of physics and the nature of mathematics.  These are things that we can share, so it seems to me that our communication will begin in terms of mathematics and physics. 

So me, I’m a mathematical physicist, so you might say well you would say that wouldn’t you, but I really do think that this is the common currency of the cosmos and so we will want to communicate about our understanding of mathematical physics, so we could tell them things that we have discovered in the realm of mathematical physics, but there is stuff that I would like to know.   There are some famous problems like how to bring gravitation and quantum physics together, the long-sought-after theory of quantum gravity.  That’s one thing that I would like to know.  It may be hard to understand the answer that comes back.  There is something that is perhaps a little easier.  There is a quantity in the theory of quantum electrodynamics called the fine-structure constant.  I’m getting technical here.  It’s a particular quantity.  It’s a fundamental constant of nature.  It has a value of about 1 over 137.  Nobody knows why that number is as it is.  It’s a pure number.  It doesn’t matter what units you use and it’s long been an interest of mine as to how that number has arisen in nature, why that particular number and none other, so I would like ET to give me the explanation for that.  Of course the answer might be we don’t know either.  It’s not clear that ET will be all-knowing.

Question: What do you hope to accomplish by applying physics to cancer research? 

Paul Davies:  A couple of years ago I had a call from the deputy director at the National Cancer Institute, Anna Barker, with an amazing proposal.  She said "Well, we’re spending billions of dollars worth of taxpayer’s money on the famous war on cancer and most of this is going to cancer biologists, oncologists, geneticists following sort of the well trodden path that those very brilliant people have trodden and they’ve accumulated a vast, vast amount of information. Here is a subject about which an enormous amount is known, but unfortunately very little is understood." And so she had this very bold proposal that maybe physicists and physical scientists generally, including mathematicians and chemists and so on might be able to lend a hand, not by giving the cancer biologists a new death ray, but by lending some of the concepts in, say, fundamental physics to the problem of cancer.  Physicists think about the world in a very particular way.  They go about solving problems in a certain manner.  The whole culture of physics is really very different from that, biology, so maybe physicists have got something to contribute.  Now this is obviously a bold venture, but as a consequence of two or three workshops exploring that possibility the National Cancer Institute announced about a year ago that they will be funding 12 centers around the country and Arizona State University has one and I’m principle investigator.  There are about 12 people on my team, a similar number in the other centers, and it is early days yet, but it’s an experimental as well as a theoretical program. 

Because I’m completely new to the field I’m having to learn very fast.  My own contribution is in running workshops, brainstorming workshops questioning the hidden assumptions that go into our current folklore understanding of cancer.  If you open a textbook or talk to an oncologist you will be taught all sorts of things about the nature of cancer, stuff which may be true, but it may not be true, and it’s always good in science to say "Well how do you know that?" and "Are you really sure?" and "Could there be an exceptional case?" And so my job really is, I call it grandly a "cancer forum."  I run a cancer forum in which I bring together from time to time about 20 people from different disciplines and we’ll pick a particular subject.  The next one is applying evolutionary mathematics to cancer and we’ll focus on that and we’ll really try and come up with a totally new way of thinking and hopefully with a new research agenda.  It’s all about coming up with new ideas, but we’ve got to be able to test those ideas in the lab or at least with computational models to see if we can move forward, so what we’re aiming for is the big breakthrough, the penicillin moment, which cancer research has never had.  If you look at the mortality rate from cancer it has largely unchanged in 40 years whereas almost all other diseases have had enormous success and so there hasn’t been that really major breakthrough, that now we’ve nailed it type of moment where the cancer can be tackled to make a really dramatic difference in the mortality rate.  There are one or two cancers that have been cleared up.  Childhood leukemia, has been huge success there, but you know it’s odds and ends.  The overall picture of the major killers, breast cancer, lung cancer, stomach cancer, and so on, the statistics there are really pretty dreadful and I think all of us working in this field feel that if we can make a contribution by coming up with a genuinely new idea, tackle the problem in a completely different way, then this could be what we have really waited a long time for, which is that big breakthrough that is going to maybe halve that mortality rate.  That’s my ambition. 

Question: What are the most promising ideas you’ve encountered in your cancer research?

Paul Davies:  Well there is something that interests me and it does look quite promising, and maybe I’m inflating its importance because I can understand it, but for most of the history of biology the stuff of life well it used to be thought of some sort of magic matter, but then about 100 years ago the cell became seen as a sort of bag of complex chemicals and so the chemical approach to cancer is of course well known, chemotherapy.  About 60 years ago the informational side of life became apparent with the discovery of DNA and the genetic code and so on and so now we have genetics and bioinformatics and the whole sort of informational approach, genomics, proteomics and so on that follows from that, so we got two views of cancer cells, bag of chemicals and an information processing system, but there is a third view.  A cancer cell is a physical object.  It’s got properties like everything else.  It’s got viscoelastic properties.  It’s got a mass.  It’s got a size and a shape and an internal organization and it’s full of pumps and levers and chains and other paraphernalia that engineers and physicists are very familiar with, so it’s a physical system and we would like is to integrate all of these three points of view, but the physical part has been very much neglected, so for example, healthy cells and cancer cells respond very dramatically to things like forces and stresses in their immediate vicinity.  The micro-environment in which a cell grows can dramatically affect its gene expression, how it behaves, what it does, and also its physical properties.  It can greatly change its elasticity, for example.  Cancer cells become usually much softer than healthy cells and they get all bent out of shape and part of the reason we can diagnose cancer is because they become deformed, swollen and funny shapes and funny shaped nuclei and so trying to understand the relationship between the forces that act on these cells, and I’m talking about good old push and pull Newtonian forces, nothing mysterious here and their chemical and genetic response.  Trying to map those correlates I think is a really important way forward, so maybe we can control cancer by controlling or manipulating the micro-environment.  

You’ve got to get away from the idea cancer is a disease to be cured.  It’s not a disease really.  It’s, the cancer cell is your own body, your own cells, just misbehaving and going a bit wrong, and you don’t have to cure cancer.  You don’t have to get rid of all those cells.  Most people have cancer cells swirling around inside them all the time and mostly they don’t do any harm, so what we want to do is prevent the cancer from gaining control.  We just want to keep it in check for long enough that people die of something else, to put it crudely, and maybe we can do that by controlling the microenvironment.  I should say that tumors, primary tumors very rarely kill people and of course if you have a tumor pressing on a nerve or something it could be problematic, but mostly tumors can be shrunk and they can be kept in check or they can be removed surgically.  It’s when the cancer spreads around the body, the metastatic process that things get grim.  If we can either prevent that metastatic process or prevent the cells that are circulating around the body making a home in organs where they don’t belong by controlling the physical properties of the tissues that surround them in some way to be worked out, then maybe this is a whole new approach.  It’s not…  You don’t zap the cancer with chemicals.  You don’t bombard them with rays to make them die and you don’t… We’re not talking about gene therapy where you try and insert some sort of gene to switch them off or something.  We’re talking about something much simpler, about controlling the physics of the cells and their immediate environment in a way that will change their behavior and their gene expression, so it’s really a whole new way of thinking about it and I’m really hopeful that we’re going to learn a lot of interesting things.  I might say that this cancer research I think it’s really important to inform cancer not just from subjects like physics and chemistry, but also from astrobiology. 

Astrobiologists have spent a longtime thinking about the nature of life and its evolutionary history, how it began, how it evolved over time.  I think they have a lot to contribute to the understanding of cancer, so earlier I was talking about the Holy Grail of astrobiology is to find life 2.0.  That is a second form of life right here on Earth.  I think cancer is life 1.1.  It’s like another form of life.  It’s closely related to healthy life.  A healthy body is one form of life.  Cancer is in a way nature’s experiment with life.  It’s life almost as we know it, but modified in a certain way and I think studying cancer it’s not a one way street.  Studying cancer could provide huge insights for astrobiologists into the nature of life itself.  Cancer biologists really are not, mostly are not very interested in evolution.  They’re not evolutionary biologists. They’re cancer biologists or cell biologists, but we really only understand the nature of life itself by looking at that long evolutionary history.  Cancer is not something confined to human beings.  It’s found in all multi cellular organisms where the adult cells proliferate, so it’s widespread in the biosphere.  It’s a phenomenon that is deeply related to the history of life itself, so by studying cancer I think we can illuminate the history of life itself and vice versa, so my thinking in running this cancer forum is to just get expertise from as many fields as we can, bring it to bear, hopefully some very well defined problems in cancer biology and really try and nail them and try and move the subject along.

Question: Could you explain the universe—past, present, and future—in one minute?

Paul Davies:  Okay, the universe is by definition everything there is, but of course we only see a small patch of it.  We see only out as far as the speed of light will let us and so we think it began, are sure it began with an explosive outburst called the Big Bang, which may have been the origin of space and time as well as matter and energy or it might just have been one bang among an infinite number scattered throughout space and time, but certainly our region in the universe had this dramatic hot explosive origin, and it’s expanding and cooling and it has become ever more enriched and complex over time, and so life and thinking beings like us have emerged who wonder what it all means, and as for its ultimate fate the best evidence at the moment is it is going to expand faster and faster and faster and become totally empty and utterly boring and it is a rather dismal fate for what is a rather glorious cosmos.

Recorded April 15, 2010
Interviewed by Austin Allen