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 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 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 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