Big Think Interview With Paul Davies
Davies’s research focuses on the “big questions” of existence, ranging from the origin of the universe to the origin of life, and include the nature of time, the search for life in the universe, and foundational questions in quantum mechanics. He helped create the theory of quantum fields in curved spacetime, with which he provided explanations for how black holes can radiate energy, and what caused the ripples in the cosmic afterglow of the Big Bang. In astrobiology, he was a forerunner of the theory that life on Earth may have come from Mars. He is currently championing the theory that Earth may host a shadow biosphere of alternative life forms.
Davies has lectured on scientific topics at institutions as diverse as The World Economic Forum, the United Nations, the Commission of the European Union, Google, Windsor Castle, The Vatican and Westminster Abbey, as well as mainstream academic establishments such as The Royal Society, The Smithsonian Institution, and the New York Academy of Sciences. Davies devised and presented a series of 45 minute BBC Radio 3 science documentaries and a one-hour television documentary about his work in astrobiology, entitled "The Cradle of Life." Among his bestselling books are "The Mind of God," "How to Build a Time Machine," and "The Goldilocks Enigma." His latest book, "The Eerie Silence," was published by Houghton Mifflin Harcourt in 2010.
Paul\r\nDavies: My name is Paul\r\nCharles William Davies and I’m director of the BEYOND Center for Fundamental\r\nConcepts in Science at Arizona State University and author of “The Eerie\r\nSilence.”\r\n\r\n
Question: What first interested you about the search for\r\nalien life?\r\n\r\n
Paul\r\nDavies: I suppose my\r\ninterest in looking for life elsewhere in the universe really dates back to my\r\nteens. What teenager doesn’t look\r\nup at the sky at night and think am I alone in the universe? Well most people get over it, but I\r\nnever did and though I made a career more in physics and cosmology than\r\nastrobiology I’ve always had a soft spot for the subject of life because it\r\ndoes seem so mysterious. To a\r\nphysicist life looks nothing short of a miracle. It’s just amazing what living things can do and so that\r\nsense of mystery, that sense of how did it all begin has always been there in\r\nthe background and then in the 1990s I began to take a more active part, began\r\nto study the prospects that life could spread from Mars to Earth or maybe Earth\r\nto Mars and that maybe life began on Mars and came to Earth, and that idea\r\nseemed to have a lot of traction and is now accepted as very plausible, and so\r\nI was asked to help create the Australian Center for Astrobiology. I was living at that time in Australia\r\nand we set this thing up in Sydney and I worked there for some years before\r\nmoving to Arizona.\r\n\r\n
Question: How much credence has the theory that life began\r\non Mars gained?\r\n\r\n
Paul\r\nDavies: Well I first\r\nsuggested the idea in the early 1990s that life could have come from Mars to\r\nEarth inside rocks blasted off the red planet by comet and asteroid\r\nimpacts. I think a lot of people\r\nfelt that this was a pretty crackpot notion, but it became clear during the\r\n1990s that not only that there is a large traffic of material exchanged between\r\nMars and Earth, but that microbes are hardy enough if protected by the rock,\r\ncocooned inside, to survive the harsh conditions of outer space for a long\r\ntime, many millions of years, and the evidence both theoretical and experimental\r\nhas firmed up and I think many people now realize that if you get life on\r\neither Mars or Earth you’ll get it on both planets from this splashing\r\nphenomenon. Now the case for it\r\nbeginning on Mars is not very strong. \r\nMars is a smaller planet, so it cooled quicker, so it was ready for life\r\nsooner. Conditions there were more\r\ncongenial for life to get going, but as we don’t know how life ever got going\r\nthis is a bit of a leap in the dark—so we certainly can’t say that it\r\ndefinitely started on Mars, but it seems very plausible that it did. On Mars seems as good a place as Earth\r\nfor life to get started.\r\n\r\n
Question: Is this theory still controversial, and how could\r\nit be verified?\r\n\r\n
Paul\r\nDavies: I think\r\nastrobiologists are comfortable with the idea that it could have started on\r\nMars and come here. As I’ve said\r\nthe evidence is not compelling, but to really clinch this we would of course\r\nneed to either go to Mars and find life there and discover it is the same life\r\nas we have here on Earth or just possibly a sample return mission, which has\r\nbeen long awaited by the astrobiology community. This is a spacecraft that will be sent to Mars and pick up a\r\nsort of grab bag of rocks and bring them back to Earth so they can be\r\nstudied. It’s just possible we\r\nwill find traces of life in those rocks. \r\nIt’s equally possible we won’t, so it’s a bit of a long shot. The only way to be really clear is to\r\nhave some expedition to Mars and my feeling is that life on Mars today is\r\nalmost certainly, if there at all, deep under the ground, maybe a kilometer or\r\nso beneath the surface, and so that is going to be hard to get at.\r\n\r\n
Question: What is the SETI program?\r\n\r\n
Paul\r\nDavies: SETI is the Search\r\nfor Extraterrestrial Intelligence and it addresses the question, “Are we alone\r\nin the universe?” This is a\r\nquestion which goes back to the dawn of history, but for most of human history\r\nit has been in the province of religion and philosophy. Fifty years ago, however, it became\r\npart of science and the trailblazing work of a young astronomer named Frank\r\nDrake set the trend. Frank decided\r\nto start scanning the skies with a large radio telescope in the hope of\r\nstumbling across a message from ET. \r\nIt seemed a somewhat quixotic enterprise when he began, but over the\r\nyears it has grown and grown. It’s\r\nnow an international effort and I think it is taken seriously by many\r\nscientists and so it really consists of using radio telescopes, choosing target\r\nstars where it is conceivable there might be some sort of advanced alien\r\ncivilization and hoping that they might be beaming radio messages our way and\r\nso the 50th anniversary of this it seemed to me a good time to take stock\r\nbecause after all, we’ve had nothing but an eerie silence in 50 years, so these\r\nastronomers have been patiently pursuing this quest. I might say Frank Drake himself is still in the game 50\r\nyears on. Now this is heroism of\r\nan unusual sort. Who else do you\r\nknow who has devised a scientific experiment and has pursued it for 50 years,\r\ngot a null result and is still smiling and optimistic? So Frank Drake is a\r\ngreat hero of mine and I admire his zeal and positivism, but it is just an\r\neerie silence and so the question is are we doing the wrong thing. Should we be looking somewhere else or\r\nin some other way? Should we\r\nbroaden the search? And my\r\nconclusion is really that I think what the SETI people are doing is just great\r\nand I hope they go on doing it and doing it better, but meanwhile, we should\r\nstart thinking outside the proverbial box a bit to see if there are other ways\r\nin which we could try to track down ET.\r\n\r\n
Question: Is this silence more likely due to aliens’\r\nnonexistence or to flaws in our search methods?\r\n\r\n
Paul\r\nDavies: If you ask the\r\nastronomers of the sharp end of SETI why they think there has been an eerie\r\nsilence they’ll say, “Well we only have been doing it for 50 years. We’ve just\r\nstarted. What more do you expect? It’s a big universe out there.” And in fact, to put that into context\r\nthey look carefully. It’s just a\r\nfew thousand stars. There are 400\r\nbillion stars within our Milky Way galaxy alone, so it is a needle in a\r\nhaystack search. Of course it’s\r\neasy to conclude simply that they just haven’t been doing it long enough or\r\nhard enough—it’s no surprise they haven’t heard anything, but the alternative\r\nis that we are indeed alone in the universe, and it’s impossible to answer that\r\nquestion because there are so many unknown factors. If we’re looking for intelligence in the universe I think\r\neverybody assumes that this has to start with life and so the question is: "How\r\nlikely is it that there will be life elsewhere in the universe?"\r\n\r\n
Now when I was a student almost nobody thought there was any\r\nlife beyond Earth. Today it’s\r\nfashionable to say that there is life all over the place, that the universe is\r\nteeming with it, but the scientific facts on the ground haven’t really\r\nchanged. We’re still just as\r\nignorant as we were 40 or 50 years ago about how life began. We’ve got a very good theory of the\r\nevolution of life once it gets started, but how does it get going in the first\r\nplace. We don’t need a blow by\r\nblow account of exactly how it got going on Earth, but we would at least like to\r\nknow whether it was a very probable event or very improbable event and in our\r\npresent state of ignorance we can’t even pin that down. We can’t even bracket the odds. It could have been a stupendously\r\nimprobable fluke, a freak chemical accident that occurs just once in the\r\nuniverse or it could be that life emerges automatically and naturally as part\r\nof the underlying scheme of things. \r\nMaybe the universe has intrinsically bio-friendly laws that brings life\r\ninto being all over the place. We\r\ndon’t know. It’s only\r\nfashion that has said the pendulum has swung from extreme skepticism about\r\nextraterrestrial life to extreme credulity. The truth is somewhere in between, but to pin it down we’ve\r\nreally got to address that question, how likely is it that life will arise on\r\nan Earth-like planet. I should say\r\nwe know that there are many, many other Earths out there. We’re almost certain that there will be\r\nupwards of a billion Earth-like planets in our galaxy alone, so there is no lack\r\nof real estate where life might happen, but what we don’t know is how likely it\r\nis given the real estate, given a wonderful pristine planet like Earth how\r\nlikely is it that life will pop up inhabited? We don’t know the answer to that.\r\n\r\n
Question: What new kinds of evidence of alien life might we\r\nsearch for?\r\n\r\n
Paul\r\nDavies: It seems to me that\r\nthe most obvious thing that we can do to test this idea that life does form\r\nreadily on Earth-like conditions, an idea incidentally that Christian de Duve, who\r\nis a famous biologist, has called the cosmic imperative, this sort of wonderful\r\nphrase, 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\r\ntree of life at all. All life that\r\nwe’ve studied so far on Earth belongs to the same tree. We share genes, for example, with mushrooms\r\nand oak trees and fish and bacteria that live in volcanic vents and so on that\r\nit’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\r\nnecessarily in the sense of having come from space, like it might have done, but\r\nalien in the sense of belonging to a different tree altogether. That is what we’re looking for, "life\r\n2.0." And one place we can look is right here on our home planet. No planet is more Earth like than Earth\r\nitself, so if life really does pop out readily in Earth like conditions surely\r\nit 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\r\nnobody thought to look for a second sample of life on Earth. Everybody just naturally assumed that\r\nall life on Earth is the same life. \r\nWell as I’ve said all life so far studied is the same life, but we haven’t\r\nstudied all the life there is.\r\n\r\n
Most life on Earth is microbes. We notice the big things. We notice the trees and the elephants and so on because\r\nthey’re big, but the vast majority of species on Earth are microbes and we’ve\r\nonly just scratched the surface of the microbial realm. Probably less than .1% of microbes have\r\nbeen classified let alone cultured or had their genes sequenced, so really that\r\nmicrobial realm is a mystery. We\r\ndon’t know what those little bugs are and it’s entirely possible that\r\nintermingled among the microbes that are related to you and me are some\r\nmicrobes 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\r\nor even up our noses, so I think the most important way we can advance this\r\nquest for ET is to look right on our home planet to see if we can find a second\r\nsample of life and I’m working with people to do just that.\r\n\r\n
Question: How hard are we looking for simple, as opposed to\r\nintelligent, alien life?\r\n\r\n
Paul\r\nDavies: Almost all the\r\neffort that is expended in astrobiology is towards looking for simple forms of\r\nlife. Usually just microbes and\r\nmicrobes on Mars would be our best hope. \r\nThen we know that within the solar system is very unlikely there will be\r\nanything more advanced than\r\nmicrobial life, but if we think outside the solar system and then the distances\r\nare of course immense then there could be Earth-like planets with more advanced\r\nform of life. For example, there\r\ncould be photosynthesis that’s going on that would leave a signature in the\r\nform of oxygen in the atmospheres of these planets. Now it’s the only the last few years we’ve discovered any\r\nplanets outside the solar system. \r\nThere is a list of about 450 now and there is a satellite called Kepler,\r\nwhich is going to find a lot more over the coming year or two. And then we’ll\r\nhave a shopping list of likely planets, maybe Earthlike planets, where future\r\ninstruments that will be very expensive and very technically very challenging,\r\nbut nevertheless, could be built in decades hence. These instruments could then scrutinize these planets that\r\nwe’ve found and see if it can get enough information about their composition of\r\ntheir 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,\r\njust its byproducts, say, in the form of oxygen.\r\n\r\n
So these are the best hopes, but of course I think from the\r\npublic’s point of view they’re less interested in microbes or plants. They’re much more interested in\r\nintelligent aliens and so the search for intelligent, extraterrestrial\r\nintelligence, intelligent aliens or advanced alien civilizations, something like\r\nthat is in the province of the SETI program and they look set to continue\r\ndoing more of the same for the coming years. They’ve got a better system. The Allen telescope array in Northern California has been\r\npaid for in part by Paul Allen, the co-founder of Microsoft and this is\r\ncurrently under construction and when it is finished it should have 350 dishes,\r\nwhich hooked together will form a telescope with a very large collecting area. It’s a radio telescope, so again, it’s\r\nlistening for radio waves from ET, but I think meanwhile we should broaden the\r\nsearch and start looking for other things. For example, even in radio we should be looking for beacons\r\nas well as so called narrow-band signals. \r\nThe way that SETI works so far is that they tune into the heavens a bit\r\nlike you tune into your local radio station, that is that there is a\r\nparticular… they’re looking for a particular frequency, a continuous transmission at\r\nsome 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\r\nthe bottle. It’s a one-way\r\nmessage. It’s a lighthouse is a\r\ngood example of that. It just\r\nsends out a flash for anybody who may or may not be out there, who is\r\nlooking. In the same way we can\r\nimagine that some alien civilization may be be long vanished, has made a beacon\r\nthat is sweeping the plane of the galaxy and it would just something that goes\r\nbleep in the night. You’d hear this\r\nbleep that is ET pinging us. You\r\nmaybe wait a few months or years and it would ping us again and if you hear\r\nenough of those pings you would sit up and pay attention.\r\n\r\n
The SETI program is not well geared up for the pings. They’re trying to diversify their\r\ntechnique so they can search for such things, but it really needs a more\r\nexpensive system of dedicated instruments, radio telescopes that stare at some\r\nparticular patch of sky for months or years on end just so that you see the\r\nrepeat of these pings, so at the moment if a radio telescope picks up a ping, a\r\ntransient pulse of some sort what can you do? You can shrug and say well it was some strange pulse came\r\nfrom over there. There is nothing\r\nyou can do about it. It has been\r\nand it’s gone. You can’t get\r\nsomebody else to observe it because it is all over and there have been many\r\nexamples of recorded transient events of that nature. Nobody knows what they are. They could have natural explanations or maybe these really\r\nare beacons. We shall have to wait\r\nand see.\r\n\r\n
Question: Why do you believe we’re unlikely to find aliens\r\ncloser than 1,000 light years away?\r\n\r\n
Paul\r\nDavies: It’s almost\r\nimpossible to guess the number of communicating civilizations that are out\r\nthere because as I’ve described the fraction of planets on which life emerges\r\nis not known. It could be anything\r\nfrom zero to one and so the uncertainties in that number really mean that it is\r\na fool’s errand trying to estimate the further consequences of there being\r\nintelligent life and communicating civilizations, but you can of course go to\r\nan optimist and I guess there is no one more optimistic than Frank Drake\r\nhimself 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\r\nthere is. So you can then ask well\r\nthen how close is the nearest one likely to be to us and it’s going to be a few\r\nhundred light years, so let’s take 1,000 light years as the round figure. Now the problem here is that a\r\ncivilization that is 1,000 light years away doesn’t know we exist. They don’t know that we have radio\r\ntelescopes here on Earth because they see Earth as it was 1,000 years ago. Nothing can travel faster than light,\r\nso however good their instruments they can’t see in affect the future. They can only see Earth as it was 1,000\r\nyears ago, so there is no particular reason they should be sending us messages\r\nat this time and if you put yourself in the position of a SETI enthusiast on\r\nthis hypothetical distant planet going to a granting agency and saying, “There\r\nis a really interesting planet over there, Earth, that we’ve studied it very\r\ncarefully and we can see they’ve built huge structures like the pyramids and\r\nthis great wall in China and we think some millennium soon they may have radio\r\ntelescopes, could we have some money to start broadcasting?” And I can tell you what the grant\r\nagency would say. It would say,\r\n“That is a great idea. You come back in a few thousand years when, you know,\r\nthey are actually on the air and we’ll give you the money to send them some\r\nmessages.” And that is the\r\nsituation we’re in, so I think it’s a bit of a fool’s errand to be looking for\r\ndeliberately beamed messages. We\r\nmight stumble across a message intended for somebody else or it may be that we\r\nsee a beacon or something like that. \r\nThese things are long shots and so my feeling is, well, we should carry\r\non trying because who knows what is out there, but meanwhile we should be\r\nfinding other ways of looking for ET.\r\n\r\n
Question: Why would \r\n“older, wealthier” alien civilizations be found closer to the center of\r\nthe galaxy?\r\n\r\n
Paul\r\nDavies: The history of the\r\ngalaxy is pretty well understood and the stars started forming towards the\r\ncenter first. The age of the\r\ngalaxy is a little over 13 billion years. \r\nEarth is only 4 ½ billion years. \r\nThe very earliest stars didn’t have the sort of heavier elements like\r\ncarbon and oxygen and so on that are necessary for life, but after a short\r\nperiod of time these elements were manufactured when the first stars made them\r\nand then blew up and spread them around and so in the early days the main\r\naction 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\r\nelements and so every time what has happened is that this Goldilocks zone which\r\ncould support life has expanded out and we’re some way in the middle suburbs of\r\nour Milky Way galaxy. The\r\nGoldilocks zone is now moved out to here and but that is because of course\r\nwe’ve… we’re Earth and the solar system is only about half or a third as old as\r\nthe galaxy, so if we’re thinking about old civilizations, those that formed a\r\nlong time ago and there were stars and planets around long before Earth even\r\nexisted, then these are going to be towards the center of the galaxy. That is the place to look if you think\r\nthere are ancient civilizations that have made beacons or some other way of\r\nattracting our attention.\r\n\r\n
Question: What future technologies might enhance the search\r\nfor extraterrestrials?\r\n\r\n
Paul\r\nDavies: I think we need to\r\nget away from the idea of leaving this to a small and heroic band of radio\r\nastronomers and try and spread the burden across the entire scientific\r\ncommunity. I think all the\r\nsciences can contribute, and I’ll give you some examples. One of the things that is baffling\r\nabout ET, and this is an idea that goes back to Enrico Fermi at the end of the\r\nSecond World War is, why haven’t the alien civilizations spread across the\r\ngalaxy and colonized it or at the very least visited? “Where is everybody?” is\r\nthe way Fermi put it, and so he took that as evidence that there is nobody out\r\nthere, the fact that Earth has not been visited or colonized, that the aliens\r\nhaven’t come here a long time ago is evidence that they’re not out there\r\neither, but I think one can put a spin on this particular story and say, well\r\nhow do we know that the aliens didn’t come and it doesn’t have to be flesh and\r\nblood aliens literally stepping out of a spacecraft. It could be their machines or their probes or robots or\r\nsomething of that sort that they could well have come a very long time ago, and\r\nin 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\r\nyears from now would any trace of human activity remain? The answer is not very much, but there\r\nare some things that we could look for. \r\nIf ET did pass through the solar system obviously didn’t stop for 100\r\nmillion years what would we find? \r\nWell there are some things like nuclear waste. If you dumped nuclear waste that will certainly survive for\r\nthat length of time. We could go\r\nlook for that. Any sort of large\r\nscale mining or quarrying activities would leave scars although they might be\r\nburied beneath rock strata would still be discernible to a geologist doing a\r\nsurvey. We could look for that\r\ntoo.\r\n\r\n
And then there is one other idea that is crazy, but it’s\r\ndear to my heart and this comes back to the message in the bottle concept, so\r\nup to now SETI has been involved in looking for messages that are being\r\ndeliberately beamed at us and as I’ve explained that’s pretty unlikely, but\r\nthere 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\r\nthrow 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\r\ngoing to find it and certainly don’t know who is going to find it, so it’s just\r\nsort of left to its own devices. \r\nWell in the same way we might imagine that an alien civilization might\r\nhave put a message in a bottle for anyone who might find it and that anyone\r\ncould be us, could be human beings, so where is the bottle and where is the\r\nmessage? I’m open to\r\nsuggestions. One idea I’ve had is\r\nthat maybe the bottles are living cells, terrestrial organisms and that the\r\nmessage is encoded in DNA. Viruses\r\nare continually infecting organisms on Earth and uploading their DNA into the\r\ngenomes of those organisms, so there is a well understood pathway for getting\r\ninformation into DNA. We’re\r\nlittered with it. Our own genomes\r\nhave got huge amounts of this junk that has climbed onboard from viruses over\r\nevolutionary history, so if viruses can to it ET can do it and it seems to me\r\nthat we could in addition to scouring the skies for radio waves with a message\r\nencoded we could scour terrestrial genomes, which are being sequenced anyway, to\r\nsee if there is a message from ET encoded in it. You know, it could be some striking string of nucleotide\r\nbases, the famous four letter alphabet that is the language of life, the A’s,\r\nG’s, C’s and T’s in the DNA. It\r\nmight just spell out some sort of message that would attract our\r\nattention. Now of course this is a\r\ncrazy idea. I’m not actually\r\nsuggesting that there really is a message from ET in genomes. What I’m saying is that is the type of\r\nthinking we need. Maybe it is no\r\nmore crazy than expecting it to be etched into radio waves coming from the sky.\r\n\r\n
Question: What major issues would we confront if we\r\ndiscovered life elsewhere in the universe?\r\n\r\n
Paul\r\nDavies: People are amazed\r\nthat there is something called the SETI Post-Detection Task Group and I chair\r\nthis, and it’s an awesome responsibility. \r\nI say if ET calls on my watch I’ll be among the first to know and not\r\nonly the fate of the earth, but the fate of the entire galaxy may rest in my\r\nhands, so it’s not something to be undertaken lightly. Of course the people on this committee\r\nthink 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\r\nare a number of issues because I think if we suddenly did discover we’re not\r\nalone in the universe the ramifications for that could be very profound\r\nindeed. Now I like to make a\r\ndistinction between two extremes. \r\nOne is that we just stumble across some sort of evidence that there is\r\nsomebody out there, that there is alien technology. We can’t say anything more than that. It might be some distant star that has\r\ngot some signs of tampering or the planets around that star, some signs of\r\ntampering. It’s worth remembering\r\nthat all technology leaves a footprint. \r\nFor example, our own technology is leaving a footprint in terms of\r\nglobal warming, which could be detected from a long way away. One assumes that a very advanced\r\ncivilization that has been around maybe millions and millions of years would\r\nhave an even bigger footprint that might extend beyond its planet to its\r\nimmediate astronomical environment. \r\nIt might even be large-scale astro-engineering. We could look for that.\r\n\r\n
Supposing we found something like that, it wouldn’t be a\r\nmessage. It wouldn’t be contact\r\nwith aliens, but it would mean we could say definitely that there is or was\r\nsomebody out there, that these are the fruits of their intelligent activity. Now that would be in my view the most\r\nprofound scientific discovery in the history of mankind, and its impacts would\r\nbe a little bit like when Copernicus announced that the Earth is going around\r\nthe sun. There was no change in\r\nthe price of beer, no rioting in the streets, nothing of that sort, and yet\r\nover the centuries it has enormously colored the way we see ourselves and our\r\nplace in the universe, same thing with Darwin’s theory of evolution. Again, no rioting, no dramatic changes\r\nin society, but over the decades very definitely it has changed the way we\r\nthink... think about ourselves. And in the same way, if we knew we were not alone\r\nin the universe it would have a very, very deep impact on our worldview, on our\r\nunderstanding of our place in the universe, but I think it could be announced\r\nin the same way—well not quite in the same way as Copernicus. He waited until he died before he\r\npublished it because he was afraid of being killed by the church, but we don’t\r\nhave that fear I don’t think—but I think it could be announced in the same way\r\nas a major astronomical discovery with a published paper and a press conference\r\nand all the rest of it.\r\n\r\n
Now that is one extreme and that’s the most likely thing\r\nthat we’re going to find, but the other extreme is the Holy Grail of SETI,\r\nwhich is the message. You know, a\r\nmessage from ET for mankind: “Earthlings, have I got news for you.” That sort of thing, and then all bets\r\nare off because the effect of such a message could be enormously\r\ndisruptive. If it is a message\r\nwith content we have to think, what is that content. We can imagine all sorts of things ranging from, “Stop\r\nburning fossil fuels, you silly people. You’re heating your planet.” To, “There is a comet coming your way.\r\nYou’re going to be wiped out in 100 years.” Or it could be a more helpful thing along the lines of,\r\n“Here is a way of gaining control over nuclear fusion to give yourself a cheap\r\nenergy source.” Now these things\r\nwill all have enormous impacts on society, even just some helpful tips about\r\ntechnology would change the economic and technological balance of the planet\r\nand could be very, very disruptive, so we would need to think very carefully\r\nabout how that sort of information was handled. We’d also need to think very carefully about whether we\r\nshould reply and if so what should we say and who speaks for Earth. And that gets\r\nus into all sorts of difficult territory, but the one thing I think we’re all\r\nagreed with this task group is we should not disclose the coordinates in the\r\nsky of any transmitting source.\r\n\r\n
Supposing we knew that up there is some alien civilization\r\nand it’s sending radio signals our way we should not tell the public where that\r\nis. We could say that we’ve got…\r\nwe’ve picked up a signal, but we should not tell them where for the simple\r\nreason that anybody could commandeer a radio telescope, set themselves up as\r\nsome self appointed spokesperson of mankind and start beaming all sorts of\r\ncrazy messages back to the aliens. \r\nI think if we’re going to send messages to the stars then it needs a\r\ngreat deal of thought that it’s something that should involve the entire not\r\nonly scientific community, but the entire world community. We need to think very carefully\r\nindeed. So that should be\r\nprevented, but SETI is not a secret enterprise and this task group is itself\r\ncompletely public. It’s completely\r\nopen. Our conclusions are\r\navailable on the Internet. It’s\r\nnot anything we want to keep from the public, but the effects are very\r\nsobering. We do really do have to\r\nthink about what the affect on society would be and the effect on religion for\r\nexample could be very profound and we know what an explosive issue religion is on\r\nplanet Earth, so those are the sorts of things we deliberate on.\r\n\r\n
Question: If you were the first human to communicate with an\r\nalien civilization, what would you say?\r\n\r\n
Paul\r\nDavies: Well first of all\r\nwe have to understand that they’re unlikely to speak English unless they’ve\r\nbeen studying us for a long time and that it’s hard enough to communicate\r\nproperly between different people on this planet, all part of the same species,\r\nthe cultural gulfs of misunderstandings are of course notorious. We’re now dealing with a completely\r\nseparate species. Then you have to\r\nthink what on Earth have we got in common, so I feel that our communication\r\nwill be… we will want to let ET know our finest achievements, the things we’re\r\nmost proud of and if you just go out on the street and ask people well what do\r\nyou think are our finest achievements, chances are that you’ll be told a\r\nBeethoven symphony or a Picasso painting or something like that and I have no\r\nquarrel with that, but the problem is that our appreciation of works of art and\r\nmusic are very much tied to our cognitive system and an alien whose brain is\r\nwired differently probably wouldn’t have any understanding of it and certainly\r\nwouldn’t have any understanding of politics or sport or anything of that sort,\r\nso there would be no point in sending those things. Now there is one thing we’re all agreed that we must share\r\nand that is mathematics. \r\nMathematics is universal. \r\nIt’s discovered by human beings, but the rules of mathematics are the\r\nsame throughout the universe and the laws of the universe. Our mathematical relationships or the\r\nunderlying laws of physics we can cast in mathematical form, so if they are\r\ncommunicating with us if they have technology they will understand the laws of\r\nphysics and the nature of mathematics. \r\nThese are things that we can share, so it seems to me that our\r\ncommunication will begin in terms of mathematics and physics.\r\n\r\n
So me, I’m a mathematical physicist, so you might say well\r\nyou would say that wouldn’t you, but I really do think that this is the common\r\ncurrency of the cosmos and so we will want to communicate about our\r\nunderstanding of mathematical physics, so we could tell them things that we\r\nhave discovered in the realm of mathematical physics, but there is stuff that I\r\nwould like to know. There\r\nare some famous problems like how to bring gravitation and quantum physics\r\ntogether, the long-sought-after theory of quantum gravity. That’s one thing that I would like to\r\nknow. It may be hard to understand\r\nthe answer that comes back. There\r\nis something that is perhaps a little easier. There is a quantity in the theory of quantum electrodynamics\r\ncalled the fine-structure constant. \r\nI’m getting technical here. \r\nIt’s a particular quantity. \r\nIt’s a fundamental constant of nature. It has a value of about 1 over 137. Nobody knows why that number is as it\r\nis. It’s a pure number. It doesn’t matter what units you use\r\nand it’s long been an interest of mine as to how that number has arisen in\r\nnature, why that particular number and none other, so I would like ET to give\r\nme the explanation for that. Of\r\ncourse the answer might be we don’t know either. It’s not clear that ET will be all-knowing.\r\n\r\n
Question: What do you hope to accomplish by applying physics\r\nto cancer research?\r\n\r\n
Paul\r\nDavies: A couple of years\r\nago I had a call from the deputy director at the National Cancer Institute,\r\nAnna Barker, with an amazing proposal. \r\nShe said "Well, we’re spending billions of dollars worth of taxpayer’s\r\nmoney on the famous war on cancer and most of this is going to cancer\r\nbiologists, oncologists, geneticists following sort of the well trodden path\r\nthat those very brilliant people have trodden and they’ve accumulated a vast,\r\nvast amount of information. Here\r\nis a subject about which an enormous amount is known, but unfortunately very\r\nlittle is understood." And so she had this very bold proposal that maybe\r\nphysicists and physical scientists generally, including mathematicians and\r\nchemists and so on might be able to lend a hand, not by giving the cancer\r\nbiologists a new death ray, but by lending some of the concepts in, say,\r\nfundamental physics to the problem of cancer. Physicists think about the world in a very particular way. They go about solving problems in a\r\ncertain manner. The whole culture\r\nof physics is really very different from that, biology, so maybe physicists\r\nhave got something to contribute. \r\nNow this is obviously a bold venture, but as a consequence of two or\r\nthree workshops exploring that possibility the National Cancer Institute\r\nannounced about a year ago that they will be funding 12 centers around the\r\ncountry and Arizona State University has one and I’m principle\r\ninvestigator. There are about 12\r\npeople on my team, a similar number in the other centers, and it is early days\r\nyet, but it’s an experimental as well as a theoretical program.\r\n\r\n
Because I’m completely new to the field I’m having to learn\r\nvery fast. My own contribution is\r\nin running workshops, brainstorming workshops questioning the hidden\r\nassumptions that go into our current folklore understanding of cancer. If you open a textbook or talk to an\r\noncologist you will be taught all sorts of things about the nature of cancer,\r\nstuff which may be true, but it may not be true, and it’s always good in\r\nscience to say "Well how do you know that?" and "Are you really sure?" and "Could\r\nthere be an exceptional case?" And so my job really is, I call it grandly a "cancer\r\nforum." I run a cancer forum in\r\nwhich I bring together from time to time about 20 people from different disciplines\r\nand we’ll pick a particular subject. \r\nThe next one is applying evolutionary mathematics to cancer and we’ll\r\nfocus on that and we’ll really try and come up with a totally new way of\r\nthinking and hopefully with a new research agenda. It’s all about coming up with new ideas, but we’ve got to be\r\nable to test those ideas in the lab or at least with computational models to\r\nsee if we can move forward, so what we’re aiming for is the big breakthrough,\r\nthe penicillin moment, which cancer research has never had. If you look at the mortality rate from\r\ncancer it has largely unchanged in 40 years whereas almost all other diseases\r\nhave had enormous success and so there hasn’t been that really major\r\nbreakthrough, that now we’ve nailed it type of moment where the cancer can be\r\ntackled to make a really dramatic difference in the mortality rate. There are one or two cancers that have\r\nbeen cleared up. Childhood\r\nleukemia, has been huge success there, but you know it’s odds and ends. The overall picture of the major\r\nkillers, breast cancer, lung cancer, stomach cancer, and so on, the statistics\r\nthere are really pretty dreadful and I think all of us working in this field\r\nfeel that if we can make a contribution by coming up with a genuinely new idea,\r\ntackle the problem in a completely different way, then this could be what we\r\nhave really waited a long time for, which is that big breakthrough that is\r\ngoing to maybe halve that mortality rate. \r\nThat’s my ambition.\r\n\r\n
Question: What are the most promising ideas you’ve encountered\r\nin your cancer research?\r\n\r\n
Paul\r\nDavies: Well there is\r\nsomething that interests me and it does look quite promising, and maybe I’m\r\ninflating its importance because I can understand it, but for most of the\r\nhistory of biology the stuff of life well it used to be thought of some sort of\r\nmagic matter, but then about 100 years ago the cell became seen as a sort of\r\nbag of complex chemicals and so the chemical approach to cancer is of course\r\nwell known, chemotherapy. About 60\r\nyears ago the informational side of life became apparent with the discovery of\r\nDNA and the genetic code and so on and so now we have genetics and\r\nbioinformatics and the whole sort of informational approach, genomics,\r\nproteomics and so on that follows from that, so we got two views of cancer\r\ncells, bag of chemicals and an information processing system, but there is a\r\nthird view. A cancer cell is a\r\nphysical object. It’s got\r\nproperties like everything else. \r\nIt’s got viscoelastic properties. \r\nIt’s got a mass. It’s got a\r\nsize and a shape and an internal organization and it’s full of pumps and levers\r\nand chains and other paraphernalia that engineers and physicists are very\r\nfamiliar with, so it’s a physical system and we would like is to integrate all\r\nof these three points of view, but the physical part has been very much\r\nneglected, so for example, healthy cells and cancer cells respond very\r\ndramatically to things like forces and stresses in their immediate\r\nvicinity. The micro-environment in\r\nwhich a cell grows can dramatically affect its gene expression, how it behaves,\r\nwhat it does, and also its physical properties. It can greatly change its elasticity, for example. Cancer cells become usually much softer\r\nthan healthy cells and they get all bent out of shape and part of the reason we\r\ncan diagnose cancer is because they become deformed, swollen and funny shapes\r\nand funny shaped nuclei and so trying to understand the relationship between\r\nthe forces that act on these cells, and I’m talking about good old push and\r\npull Newtonian forces, nothing mysterious here and their chemical and genetic\r\nresponse. Trying to map those\r\ncorrelates I think is a really important way forward, so maybe we can control\r\ncancer by controlling or manipulating the micro-environment.\r\n\r\n
You’ve got to get away from the idea cancer is a disease to\r\nbe cured. It’s not a disease\r\nreally. It’s, the cancer cell is\r\nyour own body, your own cells, just misbehaving and going a bit wrong, and you\r\ndon’t have to cure cancer. You\r\ndon’t have to get rid of all those cells. \r\nMost people have cancer cells swirling around inside them all the time\r\nand mostly they don’t do any harm, so what we want to do is prevent the cancer\r\nfrom gaining control. We just want\r\nto keep it in check for long enough that people die of something else, to put\r\nit crudely, and maybe we can do that by controlling the microenvironment. I should say that tumors, primary\r\ntumors very rarely kill people and of course if you have a tumor pressing on a\r\nnerve or something it could be problematic, but mostly tumors can be shrunk and\r\nthey can be kept in check or they can be removed surgically. It’s when the cancer spreads around the\r\nbody, the metastatic process that things get grim. If we can either prevent that metastatic process or prevent\r\nthe cells that are circulating around the body making a home in organs where\r\nthey don’t belong by controlling the physical properties of the tissues that\r\nsurround them in some way to be worked out, then maybe this is a whole new\r\napproach. It’s not… You don’t zap the cancer with\r\nchemicals. You don’t bombard them\r\nwith rays to make them die and you don’t… We’re not talking about gene therapy\r\nwhere you try and insert some sort of gene to switch them off or something. We’re talking about something much\r\nsimpler, about controlling the physics of the cells and their immediate\r\nenvironment in a way that will change their behavior and their gene expression,\r\nso it’s really a whole new way of thinking about it and I’m really hopeful that\r\nwe’re going to learn a lot of interesting things. I might say that this cancer research I think it’s really\r\nimportant to inform cancer not just from subjects like physics and chemistry,\r\nbut also from astrobiology.\r\n\r\n
Astrobiologists have spent a longtime thinking about the\r\nnature of life and its evolutionary history, how it began, how it evolved over\r\ntime. I think they have a lot to\r\ncontribute to the understanding of cancer, so earlier I was talking about the\r\nHoly 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\r\nlife. A healthy body is one form\r\nof life. Cancer is in a way\r\nnature’s experiment with life. \r\nIt’s life almost as we know it, but modified in a certain way and I\r\nthink studying cancer it’s not a one way street. Studying cancer could provide huge insights for\r\nastrobiologists into the nature of life itself. Cancer biologists really are not, mostly are not very\r\ninterested in evolution. They’re\r\nnot evolutionary biologists. They’re cancer biologists or cell biologists, but\r\nwe really only understand the nature of life itself by looking at that long\r\nevolutionary history. Cancer is\r\nnot something confined to human beings. \r\nIt’s found in all multi cellular organisms where the adult cells\r\nproliferate, so it’s widespread in the biosphere. It’s a phenomenon that is deeply related to the history of\r\nlife itself, so by studying cancer I think we can illuminate the history of\r\nlife itself and vice versa, so my thinking in running this cancer forum is to\r\njust get expertise from as many fields as we can, bring it to bear, hopefully\r\nsome very well defined problems in cancer biology and really try and nail them\r\nand try and move the subject along.\r\n\r\n
Question: Could you explain the universe—past, present, and\r\nfuture—in one minute?\r\n\r\n
Paul\r\nDavies: Okay, the universe\r\nis by definition everything there is, but of course we only see a small patch\r\nof it. We see only out as far as\r\nthe speed of light will let us and so we think it began, are sure it began with\r\nan explosive outburst called the Big Bang, which may have been the origin of\r\nspace and time as well as matter and energy or it might just have been one bang\r\namong an infinite number scattered throughout space and time, but certainly our\r\nregion in the universe had this dramatic hot explosive origin, and it’s\r\nexpanding and cooling and it has become ever more enriched and complex over\r\ntime, and so life and thinking beings like us have emerged who wonder what it\r\nall means, and as for its ultimate fate the best evidence at the moment is it\r\nis going to expand faster and faster and faster and become totally empty and\r\nutterly boring and it is a rather dismal fate for what is a rather glorious\r\ncosmos.Recorded April 15, 2010
\r\nInterviewed by Austin Allen
A conversation with the Arizona State University cosmologist and astrobiologist.
Political activism may get people invested in politics, and affect urgently needed change, but it comes at the expense of tolerance and healthy democratic norms.
- Polarization and extreme partisanships have been on the rise in the United States.
- Political psychologist Diana Mutz argues that we need more deliberation, not political activism, to keep our democracy robust.
- Despite increased polarization, Americans still have more in common than we appear to.
An amateur astronomer discovers an interstellar comet on its way to our Sun.
So much for rest in peace.
- Australian scientists found that bodies kept moving for 17 months after being pronounced dead.
- Researchers used photography capture technology in 30 minute intervals everyday to capture the movement.
- This study could help better identify time of death.