A conversation with the Arizona State University cosmologist and astrobiologist.

PaulrnDavies: My name is PaulrnCharles William Davies and I’m director of the BEYOND Center for FundamentalrnConcepts in Science at Arizona State University and author of “The EeriernSilence.”

Question: What first interested you about the search forrnalien life? 

PaulrnDavies: I suppose myrninterest in looking for life elsewhere in the universe really dates back to myrnteens.  What teenager doesn’t lookrnup at the sky at night and think am I alone in the universe?  Well most people get over it, but Irnnever did and though I made a career more in physics and cosmology thanrnastrobiology I’ve always had a soft spot for the subject of life because itrndoes seem so mysterious.  To arnphysicist life looks nothing short of a miracle.  It’s just amazing what living things can do and so thatrnsense of mystery, that sense of how did it all begin has always been there inrnthe background and then in the 1990s I began to take a more active part, beganrnto study the prospects that life could spread from Mars to Earth or maybe Earthrnto Mars and that maybe life began on Mars and came to Earth, and that idearnseemed to have a lot of traction and is now accepted as very plausible, and sornI was asked to help create the Australian Center for Astrobiology.  I was living at that time in Australiarnand we set this thing up in Sydney and I worked there for some years beforernmoving to Arizona.

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

PaulrnDavies: Well I firstrnsuggested the idea in the early 1990s that life could have come from Mars tornEarth inside rocks blasted off the red planet by comet and asteroidrnimpacts.  I think a lot of peoplernfelt that this was a pretty crackpot notion, but it became clear during thern1990s that not only that there is a large traffic of material exchanged betweenrnMars and Earth, but that microbes are hardy enough if protected by the rock,rncocooned inside, to survive the harsh conditions of outer space for a longrntime, many millions of years, and the evidence both theoretical and experimentalrnhas firmed up and I think many people now realize that if you get life onrneither Mars or Earth you’ll get it on both planets from this splashingrnphenomenon.  Now the case for itrnbeginning on Mars is not very strong. rnMars is a smaller planet, so it cooled quicker, so it was ready for lifernsooner.  Conditions there were morerncongenial for life to get going, but as we don’t know how life ever got goingrnthis is a bit of a leap in the dark—so we certainly can’t say that itrndefinitely started on Mars, but it seems very plausible that it did.  On Mars seems as good a place as Earthrnfor life to get started.

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

PaulrnDavies: I thinkrnastrobiologists are comfortable with the idea that it could have started onrnMars and come here.  As I’ve saidrnthe evidence is not compelling, but to really clinch this we would of coursernneed to either go to Mars and find life there and discover it is the same lifernas we have here on Earth or just possibly a sample return mission, which hasrnbeen long awaited by the astrobiology community.  This is a spacecraft that will be sent to Mars and pick up arnsort of grab bag of rocks and bring them back to Earth so they can bernstudied.  It’s just possible wernwill find traces of life in those rocks. rnIt’s equally possible we won’t, so it’s a bit of a long shot.  The only way to be really clear is tornhave some expedition to Mars and my feeling is that life on Mars today isrnalmost certainly, if there at all, deep under the ground, maybe a kilometer orrnso beneath the surface, and so that is going to be hard to get at.

Question: What is the SETI program?

PaulrnDavies: SETI is the Searchrnfor Extraterrestrial Intelligence and it addresses the question, “Are we alonernin the universe?”  This is arnquestion which goes back to the dawn of history, but for most of human historyrnit has been in the province of religion and philosophy.  Fifty years ago, however, it becamernpart of science and the trailblazing work of a young astronomer named FrankrnDrake set the trend.  Frank decidedrnto start scanning the skies with a large radio telescope in the hope ofrnstumbling across a message from ET. rnIt seemed a somewhat quixotic enterprise when he began, but over thernyears it has grown and grown.  It’srnnow an international effort and I think it is taken seriously by manyrnscientists and so it really consists of using radio telescopes, choosing targetrnstars where it is conceivable there might be some sort of advanced alienrncivilization and hoping that they might be beaming radio messages our way andrnso the 50th anniversary of this it seemed to me a good time to take stockrnbecause after all, we’ve had nothing but an eerie silence in 50 years, so thesernastronomers have been patiently pursuing this quest.  I might say Frank Drake himself is still in the game 50rnyears on.  Now this is heroism ofrnan unusual sort.  Who else do yournknow who has devised a scientific experiment and has pursued it for 50 years,rngot a null result and is still smiling and optimistic? So Frank Drake is arngreat hero of mine and I admire his zeal and positivism, but it is just anrneerie silence and so the question is are we doing the wrong thing.  Should we be looking somewhere else orrnin some other way?  Should wernbroaden the search?  And myrnconclusion is really that I think what the SETI people are doing is just greatrnand I hope they go on doing it and doing it better, but meanwhile, we shouldrnstart thinking outside the proverbial box a bit to see if there are other waysrnin which we could try to track down ET.

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

PaulrnDavies: If you ask thernastronomers of the sharp end of SETI why they think there has been an eeriernsilence they’ll say, “Well we only have been doing it for 50 years. We’ve justrnstarted. What more do you expect? It’s a big universe out there.”  And in fact, to put that into contextrnthey look carefully.  It’s just arnfew thousand stars.  There are 400rnbillion stars within our Milky Way galaxy alone, so it is a needle in arnhaystack search.  Of course it’srneasy to conclude simply that they just haven’t been doing it long enough orrnhard enough—it’s no surprise they haven’t heard anything, but the alternativernis that we are indeed alone in the universe, and it’s impossible to answer thatrnquestion because there are so many unknown factors.  If we’re looking for intelligence in the universe I thinkrneverybody assumes that this has to start with life and so the question is: "Howrnlikely is it that there will be life elsewhere in the universe?"

Now when I was a student almost nobody thought there was anyrnlife beyond Earth.  Today it’srnfashionable to say that there is life all over the place, that the universe isrnteeming with it, but the scientific facts on the ground haven’t reallyrnchanged.  We’re still just asrnignorant as we were 40 or 50 years ago about how life began.  We’ve got a very good theory of thernevolution of life once it gets started, but how does it get going in the firstrnplace.  We don’t need a blow byrnblow account of exactly how it got going on Earth, but we would at least like tornknow whether it was a very probable event or very improbable event and in ourrnpresent state of ignorance we can’t even pin that down.  We can’t even bracket the odds.  It could have been a stupendouslyrnimprobable fluke, a freak chemical accident that occurs just once in thernuniverse or it could be that life emerges automatically and naturally as partrnof the underlying scheme of things. rnMaybe the universe has intrinsically bio-friendly laws that brings liferninto being all over the place.  Werndon’t know.   It’s onlyrnfashion that has said the pendulum has swung from extreme skepticism aboutrnextraterrestrial life to extreme credulity.  The truth is somewhere in between, but to pin it down we’vernreally got to address that question, how likely is it that life will arise onrnan Earth-like planet.  I should sayrnwe know that there are many, many other Earths out there.  We’re almost certain that there will bernupwards of a billion Earth-like planets in our galaxy alone, so there is no lackrnof real estate where life might happen, but what we don’t know is how likely itrnis given the real estate, given a wonderful pristine planet like Earth howrnlikely 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 wernsearch for?

PaulrnDavies: It seems to me thatrnthe most obvious thing that we can do to test this idea that life does formrnreadily on Earth-like conditions, an idea incidentally that Christian de Duve, whornis a famous biologist, has called the cosmic imperative, this sort of wonderfulrnphrase, 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 ourrntree of life at all.  All life thatrnwe’ve studied so far on Earth belongs to the same tree.  We share genes, for example, with mushroomsrnand oak trees and fish and bacteria that live in volcanic vents and so on thatrnit’s all the same life descended from a common origin.  What we want is a second tree of life.  We want alien life, alien notrnnecessarily in the sense of having come from space, like it might have done, butrnalien in the sense of belonging to a different tree altogether.  That is what we’re looking for, "lifern2.0." And one place we can look is right here on our home planet.  No planet is more Earth like than Earthrnitself, so if life really does pop out readily in Earth like conditions surelyrnit 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 agornnobody thought to look for a second sample of life on Earth.  Everybody just naturally assumed thatrnall life on Earth is the same life. rnWell as I’ve said all life so far studied is the same life, but we haven’trnstudied 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 becausernthey’re big, but the vast majority of species on Earth are microbes and we’vernonly just scratched the surface of the microbial realm.  Probably less than .1% of microbes havernbeen classified let alone cultured or had their genes sequenced, so really thatrnmicrobial realm is a mystery.  Werndon’t know what those little bugs are and it’s entirely possible thatrnintermingled among the microbes that are related to you and me are somernmicrobes which are not on our tree of life at all.  They would be genuinely alien life.  Life 2.0 could be right under our nosesrnor even up our noses, so I think the most important way we can advance thisrnquest for ET is to look right on our home planet to see if we can find a secondrnsample of life and I’m working with people to do just that.

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

PaulrnDavies:  Almost all therneffort that is expended in astrobiology is towards looking for simple forms ofrnlife.  Usually just microbes andrnmicrobes on Mars would be our best hope. rnThen we know that within the solar system is very unlikely there will bernanything  more advanced thanrnmicrobial life, but if we think outside the solar system and then the distancesrnare of course immense then there could be Earth-like planets with more advancedrnform of life.  For example, thererncould be photosynthesis that’s going on that would leave a signature in thernform of oxygen in the atmospheres of these planets.  Now it’s the only the last few years we’ve discovered anyrnplanets outside the solar system. rnThere is a list of about 450 now and there is a satellite called Kepler,rnwhich is going to find a lot more over the coming year or two. And then we’llrnhave a shopping list of likely planets, maybe Earthlike planets, where futurerninstruments that will be very expensive and very technically very challenging,rnbut nevertheless, could be built in decades hence.  These instruments could then scrutinize these planets thatrnwe’ve found and see if it can get enough information about their composition ofrntheir 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,rnjust its byproducts, say, in the form of oxygen.

So these are the best hopes, but of course I think from thernpublic’s point of view they’re less interested in microbes or plants.  They’re much more interested inrnintelligent aliens and so the search for intelligent, extraterrestrialrnintelligence, intelligent aliens or advanced alien civilizations, something likernthat is in the province of the SETI program and they look set to continuerndoing more of the same for the coming years.  They’ve got a better system.  The Allen telescope array in Northern California has beenrnpaid for in part by Paul Allen, the co-founder of Microsoft and this isrncurrently under construction and when it is finished it should have 350 dishes,rnwhich hooked together will form a telescope with a very large collecting area.  It’s a radio telescope, so again, it’srnlistening for radio waves from ET, but I think meanwhile we should broaden thernsearch and start looking for other things.  For example, even in radio we should be looking for beaconsrnas well as so called narrow-band signals. rnThe way that SETI works so far is that they tune into the heavens a bitrnlike you tune into your local radio station, that is that there is arnparticular… they’re looking for a particular frequency, a continuous transmission atrnsome 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 inrnthe bottle.  It’s a one-wayrnmessage.  It’s a lighthouse is arngood example of that.  It justrnsends out a flash for anybody who may or may not be out there, who isrnlooking.  In the same way we canrnimagine that some alien civilization may be be long vanished, has made a beaconrnthat is sweeping the plane of the galaxy and it would just something that goesrnbleep in the night.  You’d hear thisrnbleep that is ET pinging us.  Yournmaybe wait a few months or years and it would ping us again and if you hearrnenough 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 theirrntechnique so they can search for such things, but it really needs a morernexpensive system of dedicated instruments, radio telescopes that stare at somernparticular patch of sky for months or years on end just so that you see thernrepeat of these pings, so at the moment if a radio telescope picks up a ping, arntransient pulse of some sort what can you do?  You can shrug and say well it was some strange pulse camernfrom over there.  There is nothingrnyou can do about it.  It has beenrnand it’s gone.  You can’t getrnsomebody else to observe it because it is all over and there have been manyrnexamples of recorded transient events of that nature.  Nobody knows what they are.  They could have natural explanations or maybe these reallyrnare beacons.  We shall have to waitrnand see.

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

PaulrnDavies:  It’s almostrnimpossible to guess the number of communicating civilizations that are outrnthere because as I’ve described the fraction of planets on which life emergesrnis not known.  It could be anythingrnfrom zero to one and so the uncertainties in that number really mean that it isrna fool’s errand trying to estimate the further consequences of there beingrnintelligent life and communicating civilizations, but you can of course go tornan optimist and I guess there is no one more optimistic than Frank Drakernhimself and say, “How many do you think are out there in the galaxy?”  And he reckons 10,000.  That is his currently best guess whatrnthere is.  So you can then ask wellrnthen how close is the nearest one likely to be to us and it’s going to be a fewrnhundred light years, so let’s take 1,000 light years as the round figure.  Now the problem here is that arncivilization that is 1,000 light years away doesn’t know we exist.  They don’t know that we have radiorntelescopes here on Earth because they see Earth as it was 1,000 years ago.  Nothing can travel faster than light,rnso however good their instruments they can’t see in affect the future.  They can only see Earth as it was 1,000rnyears ago, so there is no particular reason they should be sending us messagesrnat this time and if you put yourself in the position of a SETI enthusiast onrnthis hypothetical distant planet going to a granting agency and saying, “Therernis a really interesting planet over there, Earth, that we’ve studied it veryrncarefully and we can see they’ve built huge structures like the pyramids andrnthis great wall in China and we think some millennium soon they may have radiorntelescopes, could we have some money to start broadcasting?”  And I can tell you what the grantrnagency would say.  It would say,rn“That is a great idea. You come back in a few thousand years when, you know,rnthey are actually on the air and we’ll give you the money to send them somernmessages.”  And that is thernsituation we’re in, so I think it’s a bit of a fool’s errand to be looking forrndeliberately beamed messages.  Wernmight stumble across a message intended for somebody else or it may be that wernsee a beacon or something like that. rnThese things are long shots and so my feeling is, well, we should carryrnon trying because who knows what is out there, but meanwhile we should bernfinding other ways of looking for ET.

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

PaulrnDavies: The history of therngalaxy is pretty well understood and the stars started forming towards therncenter first.  The age of therngalaxy is a little over 13 billion years. rnEarth is only 4 ½ billion years. rnThe very earliest stars didn’t have the sort of heavier elements likerncarbon and oxygen and so on that are necessary for life, but after a shortrnperiod of time these elements were manufactured when the first stars made themrnand then blew up and spread them around and so in the early days the mainrnaction 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 heavyrnelements and so every time what has happened is that this Goldilocks zone whichrncould support life has expanded out and we’re some way in the middle suburbs ofrnour Milky Way galaxy.  ThernGoldilocks zone is now moved out to here and but that is because of coursernwe’ve… we’re Earth and the solar system is only about half or a third as old asrnthe galaxy, so if we’re thinking about old civilizations, those that formed arnlong time ago and there were stars and planets around long before Earth evenrnexisted, then these are going to be towards the center of the galaxy.  That is the place to look if you thinkrnthere are ancient civilizations that have made beacons or some other way ofrnattracting our attention.

Question: What future technologies might enhance the searchrnfor extraterrestrials?

PaulrnDavies: I think we need tornget away from the idea of leaving this to a small and heroic band of radiornastronomers and try and spread the burden across the entire scientificrncommunity.  I think all thernsciences can contribute, and I’ll give you some examples.  One of the things that is bafflingrnabout ET, and this is an idea that goes back to Enrico Fermi at the end of thernSecond World War is, why haven’t the alien civilizations spread across therngalaxy and colonized it or at the very least visited? “Where is everybody?” isrnthe way Fermi put it, and so he took that as evidence that there is nobody outrnthere, the fact that Earth has not been visited or colonized, that the aliensrnhaven’t come here a long time ago is evidence that they’re not out thererneither, but I think one can put a spin on this particular story and say, wellrnhow do we know that the aliens didn’t come and it doesn’t have to be flesh andrnblood aliens literally stepping out of a spacecraft.  It could be their machines or their probes or robots orrnsomething of that sort that they could well have come a very long time ago, andrnin 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 millionrnyears from now would any trace of human activity remain?  The answer is not very much, but therernare some things that we could look for. rnIf ET did pass through the solar system obviously didn’t stop for 100rnmillion years what would we find? rnWell there are some things like nuclear waste.  If you dumped nuclear waste that will certainly survive forrnthat length of time.  We could gornlook for that.  Any sort of largernscale mining or quarrying activities would leave scars although they might bernburied beneath rock strata would still be discernible to a geologist doing arnsurvey.  We could look for thatrntoo. 

And then there is one other idea that is crazy, but it’srndear to my heart and this comes back to the message in the bottle concept, sornup to now SETI has been involved in looking for messages that are beingrndeliberately beamed at us and as I’ve explained that’s pretty unlikely, butrnthere 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 andrnthrow it into the sea you don’t think to yourself "Well, I expect a reply."  It’s you don’t know if anybody is everrngoing to find it and certainly don’t know who is going to find it, so it’s justrnsort of left to its own devices. rnWell in the same way we might imagine that an alien civilization mightrnhave put a message in a bottle for anyone who might find it and that anyonerncould be us, could be human beings, so where is the bottle and where is thernmessage?  I’m open tornsuggestions.  One idea I’ve had isrnthat maybe the bottles are living cells, terrestrial organisms and that thernmessage is encoded in DNA.  Virusesrnare continually infecting organisms on Earth and uploading their DNA into therngenomes of those organisms, so there is a well understood pathway for gettingrninformation into DNA.  We’rernlittered with it.  Our own genomesrnhave got huge amounts of this junk that has climbed onboard from viruses overrnevolutionary history, so if viruses can to it ET can do it and it seems to mernthat we could in addition to scouring the skies for radio waves with a messagernencoded we could scour terrestrial genomes, which are being sequenced anyway, tornsee if there is a message from ET encoded in it.  You know, it could be some striking string of nucleotidernbases, the famous four letter alphabet that is the language of life, the A’s,rnG’s, C’s and T’s in the DNA.  Itrnmight just spell out some sort of message that would attract ourrnattention.  Now of course this is arncrazy idea.  I’m not actuallyrnsuggesting that there really is a message from ET in genomes.  What I’m saying is that is the type ofrnthinking we need.  Maybe it is nornmore crazy than expecting it to be etched into radio waves coming from the sky.

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

PaulrnDavies: People are amazedrnthat there is something called the SETI Post-Detection Task Group and I chairrnthis, and it’s an awesome responsibility. rnI say if ET calls on my watch I’ll be among the first to know and notrnonly the fate of the earth, but the fate of the entire galaxy may rest in myrnhands, so it’s not something to be undertaken lightly.  Of course the people on this committeernthink 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 therernare a number of issues because I think if we suddenly did discover we’re notrnalone in the universe the ramifications for that could be very profoundrnindeed.  Now I like to make arndistinction between two extremes. rnOne is that we just stumble across some sort of evidence that there isrnsomebody out there, that there is alien technology.  We can’t say anything more than that.  It might be some distant star that hasrngot some signs of tampering or the planets around that star, some signs ofrntampering.  It’s worth rememberingrnthat all technology leaves a footprint. rnFor example, our own technology is leaving a footprint in terms ofrnglobal warming, which could be detected from a long way away.  One assumes that a very advancedrncivilization that has been around maybe millions and millions of years wouldrnhave an even bigger footprint that might extend beyond its planet to itsrnimmediate astronomical environment. rnIt might even be large-scale astro-engineering.  We could look for that. 

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

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

Supposing we knew that up there is some alien civilizationrnand it’s sending radio signals our way we should not tell the public where thatrnis.  We could say that we’ve got…rnwe’ve picked up a signal, but we should not tell them where for the simplernreason that anybody could commandeer a radio telescope, set themselves up asrnsome self appointed spokesperson of mankind and start beaming all sorts ofrncrazy messages back to the aliens. rnI think if we’re going to send messages to the stars then it needs arngreat deal of thought that it’s something that should involve the entire notrnonly scientific community, but the entire world community.  We need to think very carefullyrnindeed.  So that should bernprevented, but SETI is not a secret enterprise and this task group is itselfrncompletely public.  It’s completelyrnopen.  Our conclusions arernavailable on the Internet.  It’srnnot anything we want to keep from the public, but the effects are veryrnsobering.  We do really do have tornthink about what the affect on society would be and the effect on religion forrnexample could be very profound and we know what an explosive issue religion is onrnplanet Earth, so those are the sorts of things we deliberate on.

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

PaulrnDavies:  Well first of allrnwe have to understand that they’re unlikely to speak English unless they’vernbeen studying us for a long time and that it’s hard enough to communicaternproperly between different people on this planet, all part of the same species,rnthe cultural gulfs of misunderstandings are of course notorious.  We’re now dealing with a completelyrnseparate species.  Then you have tornthink what on Earth have we got in common, so I feel that our communicationrnwill be… we will want to let ET know our finest achievements, the things we’rernmost proud of and if you just go out on the street and ask people well what dornyou think are our finest achievements, chances are that you’ll be told arnBeethoven symphony or a Picasso painting or something like that and I have nornquarrel with that, but the problem is that our appreciation of works of art andrnmusic are very much tied to our cognitive system and an alien whose brain isrnwired differently probably wouldn’t have any understanding of it and certainlyrnwouldn’t have any understanding of politics or sport or anything of that sort,rnso there would be no point in sending those things.  Now there is one thing we’re all agreed that we must sharernand that is mathematics. rnMathematics is universal. rnIt’s discovered by human beings, but the rules of mathematics are thernsame throughout the universe and the laws of the universe.  Our mathematical relationships or thernunderlying laws of physics we can cast in mathematical form, so if they arerncommunicating with us if they have technology they will understand the laws ofrnphysics and the nature of mathematics. rnThese are things that we can share, so it seems to me that ourrncommunication will begin in terms of mathematics and physics. 

So me, I’m a mathematical physicist, so you might say wellrnyou would say that wouldn’t you, but I really do think that this is the commonrncurrency of the cosmos and so we will want to communicate about ourrnunderstanding of mathematical physics, so we could tell them things that wernhave discovered in the realm of mathematical physics, but there is stuff that Irnwould like to know.   Therernare some famous problems like how to bring gravitation and quantum physicsrntogether, the long-sought-after theory of quantum gravity.  That’s one thing that I would like tornknow.  It may be hard to understandrnthe answer that comes back.  Therernis something that is perhaps a little easier.  There is a quantity in the theory of quantum electrodynamicsrncalled the fine-structure constant. rnI’m getting technical here. rnIt’s a particular quantity. rnIt’s a fundamental constant of nature.  It has a value of about 1 over 137.  Nobody knows why that number is as itrnis.  It’s a pure number.  It doesn’t matter what units you usernand it’s long been an interest of mine as to how that number has arisen inrnnature, why that particular number and none other, so I would like ET to givernme the explanation for that.  Ofrncourse 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 physicsrnto cancer research? 

PaulrnDavies: A couple of yearsrnago I had a call from the deputy director at the National Cancer Institute,rnAnna Barker, with an amazing proposal. rnShe said "Well, we’re spending billions of dollars worth of taxpayer’srnmoney on the famous war on cancer and most of this is going to cancerrnbiologists, oncologists, geneticists following sort of the well trodden pathrnthat those very brilliant people have trodden and they’ve accumulated a vast,rnvast amount of information.Herernis a subject about which an enormous amount is known, but unfortunately veryrnlittle is understood." And so she had this very bold proposal that maybernphysicists and physical scientists generally, including mathematicians andrnchemists and so on might be able to lend a hand, not by giving the cancerrnbiologists a new death ray, but by lending some of the concepts in, say,rnfundamental physics to the problem of cancer.  Physicists think about the world in a very particular way.  They go about solving problems in arncertain manner.  The whole culturernof physics is really very different from that, biology, so maybe physicistsrnhave got something to contribute. rnNow this is obviously a bold venture, but as a consequence of two orrnthree workshops exploring that possibility the National Cancer Instituternannounced about a year ago that they will be funding 12 centers around therncountry and Arizona State University has one and I’m principlerninvestigator.  There are about 12rnpeople on my team, a similar number in the other centers, and it is early daysrnyet, but it’s an experimental as well as a theoretical program. 

Because I’m completely new to the field I’m having to learnrnvery fast.  My own contribution isrnin running workshops, brainstorming workshops questioning the hiddenrnassumptions that go into our current folklore understanding of cancer.  If you open a textbook or talk to anrnoncologist you will be taught all sorts of things about the nature of cancer,rnstuff which may be true, but it may not be true, and it’s always good inrnscience to say "Well how do you know that?" and "Are you really sure?" and "Couldrnthere be an exceptional case?" And so my job really is, I call it grandly a "cancerrnforum."  I run a cancer forum inrnwhich I bring together from time to time about 20 people from different disciplinesrnand we’ll pick a particular subject. rnThe next one is applying evolutionary mathematics to cancer and we’llrnfocus on that and we’ll really try and come up with a totally new way ofrnthinking and hopefully with a new research agenda.  It’s all about coming up with new ideas, but we’ve got to bernable to test those ideas in the lab or at least with computational models tornsee if we can move forward, so what we’re aiming for is the big breakthrough,rnthe penicillin moment, which cancer research has never had.  If you look at the mortality rate fromrncancer it has largely unchanged in 40 years whereas almost all other diseasesrnhave had enormous success and so there hasn’t been that really majorrnbreakthrough, that now we’ve nailed it type of moment where the cancer can berntackled to make a really dramatic difference in the mortality rate.  There are one or two cancers that havernbeen cleared up.  Childhoodrnleukemia, has been huge success there, but you know it’s odds and ends.  The overall picture of the majorrnkillers, breast cancer, lung cancer, stomach cancer, and so on, the statisticsrnthere are really pretty dreadful and I think all of us working in this fieldrnfeel that if we can make a contribution by coming up with a genuinely new idea,rntackle the problem in a completely different way, then this could be what wernhave really waited a long time for, which is that big breakthrough that isrngoing to maybe halve that mortality rate. rnThat’s my ambition. 

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

PaulrnDavies:  Well there isrnsomething that interests me and it does look quite promising, and maybe I’mrninflating its importance because I can understand it, but for most of thernhistory of biology the stuff of life well it used to be thought of some sort ofrnmagic matter, but then about 100 years ago the cell became seen as a sort ofrnbag of complex chemicals and so the chemical approach to cancer is of coursernwell known, chemotherapy.  About 60rnyears ago the informational side of life became apparent with the discovery ofrnDNA and the genetic code and so on and so now we have genetics andrnbioinformatics and the whole sort of informational approach, genomics,rnproteomics and so on that follows from that, so we got two views of cancerrncells, bag of chemicals and an information processing system, but there is arnthird view.  A cancer cell is arnphysical object.  It’s gotrnproperties like everything else. rnIt’s got viscoelastic properties. rnIt’s got a mass.  It’s got arnsize and a shape and an internal organization and it’s full of pumps and leversrnand chains and other paraphernalia that engineers and physicists are veryrnfamiliar with, so it’s a physical system and we would like is to integrate allrnof these three points of view, but the physical part has been very muchrnneglected, so for example, healthy cells and cancer cells respond veryrndramatically to things like forces and stresses in their immediaternvicinity.  The micro-environment inrnwhich a cell grows can dramatically affect its gene expression, how it behaves,rnwhat it does, and also its physical properties.  It can greatly change its elasticity, for example.  Cancer cells become usually much softerrnthan healthy cells and they get all bent out of shape and part of the reason werncan diagnose cancer is because they become deformed, swollen and funny shapesrnand funny shaped nuclei and so trying to understand the relationship betweenrnthe forces that act on these cells, and I’m talking about good old push andrnpull Newtonian forces, nothing mysterious here and their chemical and geneticrnresponse.  Trying to map thoserncorrelates I think is a really important way forward, so maybe we can controlrncancer by controlling or manipulating the micro-environment.  

You’ve got to get away from the idea cancer is a disease tornbe cured.  It’s not a diseasernreally.  It’s, the cancer cell isrnyour own body, your own cells, just misbehaving and going a bit wrong, and yourndon’t have to cure cancer.  Yourndon’t have to get rid of all those cells. rnMost people have cancer cells swirling around inside them all the timernand mostly they don’t do any harm, so what we want to do is prevent the cancerrnfrom gaining control.  We just wantrnto keep it in check for long enough that people die of something else, to putrnit crudely, and maybe we can do that by controlling the microenvironment.  I should say that tumors, primaryrntumors very rarely kill people and of course if you have a tumor pressing on arnnerve or something it could be problematic, but mostly tumors can be shrunk andrnthey can be kept in check or they can be removed surgically.  It’s when the cancer spreads around thernbody, the metastatic process that things get grim.  If we can either prevent that metastatic process or preventrnthe cells that are circulating around the body making a home in organs wherernthey don’t belong by controlling the physical properties of the tissues thatrnsurround them in some way to be worked out, then maybe this is a whole newrnapproach.  It’s not…  You don’t zap the cancer withrnchemicals.  You don’t bombard themrnwith rays to make them die and you don’t… We’re not talking about gene therapyrnwhere you try and insert some sort of gene to switch them off or something.  We’re talking about something muchrnsimpler, about controlling the physics of the cells and their immediaternenvironment in a way that will change their behavior and their gene expression,rnso it’s really a whole new way of thinking about it and I’m really hopeful thatrnwe’re going to learn a lot of interesting things.  I might say that this cancer research I think it’s reallyrnimportant to inform cancer not just from subjects like physics and chemistry,rnbut also from astrobiology. 

Astrobiologists have spent a longtime thinking about thernnature of life and its evolutionary history, how it began, how it evolved overrntime.  I think they have a lot torncontribute to the understanding of cancer, so earlier I was talking about thernHoly 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 healthyrnlife.  A healthy body is one formrnof life.  Cancer is in a wayrnnature’s experiment with life. rnIt’s life almost as we know it, but modified in a certain way and Irnthink studying cancer it’s not a one way street.  Studying cancer could provide huge insights forrnastrobiologists into the nature of life itself.  Cancer biologists really are not, mostly are not veryrninterested in evolution.  They’rernnot evolutionary biologists. They’re cancer biologists or cell biologists, butrnwe really only understand the nature of life itself by looking at that longrnevolutionary history.  Cancer isrnnot something confined to human beings. rnIt’s found in all multi cellular organisms where the adult cellsrnproliferate, so it’s widespread in the biosphere.  It’s a phenomenon that is deeply related to the history ofrnlife itself, so by studying cancer I think we can illuminate the history ofrnlife itself and vice versa, so my thinking in running this cancer forum is tornjust get expertise from as many fields as we can, bring it to bear, hopefullyrnsome very well defined problems in cancer biology and really try and nail themrnand try and move the subject along.

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

PaulrnDavies:  Okay, the universernis by definition everything there is, but of course we only see a small patchrnof it.  We see only out as far asrnthe speed of light will let us and so we think it began, are sure it began withrnan explosive outburst called the Big Bang, which may have been the origin ofrnspace and time as well as matter and energy or it might just have been one bangrnamong an infinite number scattered throughout space and time, but certainly ourrnregion in the universe had this dramatic hot explosive origin, and it’srnexpanding and cooling and it has become ever more enriched and complex overrntime, and so life and thinking beings like us have emerged who wonder what itrnall means, and as for its ultimate fate the best evidence at the moment is itrnis going to expand faster and faster and faster and become totally empty andrnutterly boring and it is a rather dismal fate for what is a rather gloriousrncosmos.