Life's Future in the Cosmos | Martin Rees

I'm Alexander Rossum the executive director at the long now foundation welcome to our first Chabot Center talk here in the planetarium thank you guys for coming all the way up here as some of you know that that come to the lung now talks that before we do the talks we often do something called a long short which is a short film that exemplifies long term thinking and we were trying to figure out which one we should show here tonight and then it occurred to me that we were in a planetarium and for the very first time I could request a planetarium to do whatever I wanted and so one of the one of the things the clock of the long now tracks that actually the slowest cycle that it tracks if you can bring down the lights a little bit actually you can bring them all the way down you don't need to see me here in the center there is is the star field and all those pointers are pointing to the celestial pole Polaris which is currently at Polaris but the celestial pole is not always pointing to Polaris we the last few thousand years we happen to be in a very lucky position for navigation where we had a nice bright star there but that dome of stars underneath those pointers also turns once every twenty five thousand seven hundred and seventy one point five years in what's called the processional cycle the axial precession of the earth and so we actually have a demo of that from outside the planet we should kill our projector actually it's not gonna be possible excellent okay so this is the processional cycle happening you can see the North Pole they are nicely indicated by the arrow this is that one processional cycle 20 roughly 26,000 years happening in 30 seconds so it's that it's that 23-degree tilt of the earth doing a little wobble but then the thing that I've always wanted to see is what that looks like from one place on the planet now the computer was having some trouble with this earlier we'll see if it if it actually pulls it off I think it might have a deck of millennium bug in it we'll see okay so we're gonna swing around first to bring Polaris into view no one vomit okay so we're looking right now at celestial North that red dot which is Polaris and that's if you're looking at it that's the tail of Ursa Minor generally and now we're doing a one-minute full processional cycle this would be basically you know your shot at midnight once a night for twenty six thousand years condensed to one minute [Applause] Vegas coming around when the tail of Ursa Minor is up by that eighty roughly or about there's Vega right there swinging by the bright star so Vega will be our North Star in about thirteen thousand years if anyone's paying attention lovely thank you guys so much and I'll hand you off to Alex Whistler the director here at Chabot to tell you about our evening's activities thanks everyone our friends and family from Chabot that little moment exemplified I was watching that and I was just thinking this is exactly why I just love the long now foundation I had a chance to meet these folks several years ago in a previous life when I was the executive director at Fort Mason and we saw to it that they have their new home at Fort Mason center we hope might be a continuing partnership just a quick commercial on Chabot I know for some folks at your first time here or space and Science Center we see about 200,000 folks a year we're also the largest publicly accessible Observatory in the country and with us with the skies inspiring in our favor later tonight that the telescope's will be open for your pleasure 26,000 years is we like we started with 10,000 years and we're getting up to the 26,000 years we use the five digits for years as you know to get by the deck of millennium bug and about 8,000 years so you know this is zero 2010 but I realize that not too far out from that then there's going to be the whatever you call the bug when you need six digits if we stay with the same your numeration and then you can start wondering about what are the chances that will keep the same new year in numeration and how long will keep it you know out of the century I'm gonna hear a vertebra called star maker of course Martin Rees has I recommend it it has this context it is basically a guy out in a field looking up in the night sky and then he ascends into it and joins the life of the stars it is one of the great visionary texts and what Martin Rees brings is in a sense the star maker perspective and what else he brings is our context in that context overlapping which in a way is what the long now foundation is about we sort of use ten thousand years as a indicator of a time taking the long term very seriously a long time passed in a long time future Martin Rees lives there please welcome our speaker good evening ladies and gentlemen it's a great pleasure and privilege to be here my lecture is about the future but I'm going to start in an old-fashioned way with a text the famous closing words of the Origin of Species whilst this planet has been cycling on according to the fixed law of gravity from so simple a beginning forms most wonderful have been and are being evolved astronomers probe back before darwin's simple beginning which after all is quite a complicated situation in our young planet astronomers trace how starting from some mysterious beginning nearly 14 billion years ago atoms galaxies stars and planets emerged but in deference especially to Stuart brand I'd like to describe astronomy as the grandest environmental science and it really is because the night sky is the one feature of our environment which has been shared by all cultures throughout all ages where humans have existed though each culture has interpreted it in distinctive ways and as I'll describe in his lecture our origins lie in the Stars and our remote descendants may roam among them my topic today life in the cosmos fascinates astronomers but it would fascinated Darwin as well I'm going to ask what's the future of life and what's the chance if we discover it elsewhere I can't claim to be much of a forecaster or visionary myself and I always have to say I'm not an astrologer I don't give horoscopes but my next picture shows women someone who was a visionary and many of you recognize him that's arthur c clarke he said that his greatest wish was to see the discovery of alien life sadly he didn't live to see that he died in 2007 aged 90 but he did live long enough of course to see human life venture beyond the earth to give a bit of history he wasn't the first person to think about space travel among his precursors was the great Newton I gave him a plug Bush his most distinguished alumnus of my college in Cambridge I have to say though he was an unattractive character compared to Darwin solitary and obsessive when young vain and vindictive in his old age so not a nice man but he was of course the first to understand how in Darwin's phrase planets go cycling on in their orbits and he must have thought about space travel indeed this picture from the English edition of his Principia is still a neatest way to explain to students the nature of orbital flight he calculated that for the cannonball to achieve an orbital trajectory for it to curve in its tragically no rather than the earth curves away under it its speed must be 18,000 miles an hour far beyond roughest an achievable of course and the first object to reach that orbital speed was of course Sputnik 1 only 12 years separated Sputnik and the first moon landing and the moon landing was only 66 years after the Wright brothers first flight and many of us who recall that expected a lunar base even an expedition to Mars within 30 years but 2001 didn't resemble arthur c clarke vision any more than 1984 fortunately resembled Orwell's the political impetus for manned spaceflight was lost and only the middle-aged can now remember seeing live the murky TV pictures of Neil Armstrong as one small step in fact my students in England know that the Americans landed on the moon just as they know that the Egyptians built the pyramids both enterprises seemed driven by equally arcane national goals but it was a heroic episode and I cherished this picture assigned for me by seven of the Apollo astronauts since Apollo hundreds of astronauts have circle the earth in low orbit activities that really seemed neither practical nor inspiring meanwhile of course unmanned probes to other planets have been back pictures of many varied and distinctive worlds I run through a picture of Mars you've all seen pictures like this showing the extraordinary terrain on Mars here's a big crater there and the next picture is going to show the place where those arrows are this is a close-up of Mars and this is the Phoenix spacecraft which landed there about two years ago and is going to dig up a sample though not of course yet return it to earth going further afield the spacecraft have been to Jupiter here it's four big moons Europa specially interesting there's his icy surface beneath which there is probably an ocean and there's a close-up of the extraordinary surface one of the most remarkable feats of space robotics was connected with Saturn's giant moon Titan the Cassini mission went to Saturn and then when it got there a small European probe called Huygens broke loose and was aimed to land on Titan the giant moon of Saturn if we're supposed to do this this is an artist's impression of what was supposed to do open a parachute and land on the surface and indeed that is what it did on the left pictures taken all the way down on the right where it landed now this may look like rivers and lakes etc but this is not a hospitable environment these rivers are rivers of liquid methane the temperature here is minus 170 degrees centigrade well I hope that during this century the entire solar system all the planets and the main moons will be explored and mapped by flotillas of tiny robotic craft far more sophisticated than the Huygens probe I think we can predict that but will people follow them the practical case for sending people into space gets in my view ever weaker with each advance in robotics and miniaturization indeed as a scientist or practical man I see no real case for sending people into space at all but as a human being I'm nonetheless in favor of manned missions and I hope some people now living will walk on Mars and that it will be a long-range adventure for at least a few humans but of course this goal is receding NASA's firm plans now don't even include a return to the surface of the Moon and I think one problem actually is that NASA is constrained by public and political opinion to be too risk-averse and therefore expensive the shuttle failed twice in 120 launches but each of those failures was presented as a national trauma causing extra delay and expense so actually I don't think that future expeditions to the moon and Beyond will be politically and economically feasible unless they are as it were cut-price ventures perhaps even privately funded spearheaded by individuals prepared to accept high risks perhaps even one-way tickets and the involvement of people like Elon Musk Jeff Bezos and others in the high tech community in launcher development is surely a positive step and it's surely not unrealistic to envisage multi-million dollar projects with private sponsorship even individuals could do it as another calibration is that Formula One car racing involved leading teams Ferrari and McLaren which each have sponsorship budgets of three or four hundred million dollars annually so in that perspective a ten billion dollar privately funded or sponsored project doesn't seem crazy although that of course is very cheap compared to what NASA would presently be doing and of course it's very important to realize that space travel is dangerous you must have killed ourselves this lovely routine and that's the worry I have with things like Richard Branson's scheme presented is space tourism which there again the first disaster will be a real trauma it's got to be approached in the same spirit that drives test pilots Mountaineers round-the-world sailors and the like and remember that no way in our solar system offers an environment even as clément as the Antarctic or the top of Everest space doesn't offer an escape from the world's problems as some people claim but they could I suppose in future centuries be self-sufficient groups of pioneers living away from the earth they would surely use all the resources of genetic technology to modify themselves to adapt to alien environments and the posthuman era will then have begun and thereafter evolution would happen on a technological timescale far far shorter than a time scale of Darwinian evolution and of course these Posthumus could spread still further and machines of human intelligence could spread further still indeed whether the future lies with organic post-humans or with robots is a matter for real debate in space exploration there are of course issues of environmental ethics would it be appropriate to exploit Mars as happened when the Pioneers advanced westwards across the United States is it okay to send sieves for plows to deadly modified to grow in alien environments like Mars should terraforming is probably thought about seriously or should the Red Planet be preserved as a natural wilderness like we think the Antarctic should be this is an important debate and the answer I think will depend on what the pristine state of Mars actually is if there were any life already on Mars especially if it had different DNA testifying to a quite separate origin from any life on Earth then there would be widely voiced insistence that it should be preserved as unpolluted as possible whereas if there's nothing there it would seem to me that it would matter less if we exploited it and ditto for the moon it would matter less if we exploited it well so much for the planets let's now widen our horizons to the Stars widen our gaze beyond our solar system far beyond the reach of any probe that we can now conceive we can't foresee going to the stars but could to be life already among the stars we certainly learned enough about stars to understand them and we understand how they evolved but we see places where they're born and where they die here in the famous Eagle Nebula about 7,000 light years away there's hundreds of solar masses of dusty gas condensing into new stars and new solar systems just as our own solar system once did and we see stars dying some die elegantly like this as our Sun will in about 6 billion years some die in a less symmetric way this is another star like the Sun dying and other stars stars which are much heavier than Sun to start with die more explosively this isn't so many people know is the famous object the Crab Nebula which is expanding debris from an explosion witnessed and recorded by chinese astronomers in the year 1054 ad the precursor of this was a star about 10 times as heavy as the Sun why do these far away long ago phenomena affect us they're very crucial to our very existence that's because during the lifetime of the star that gave rise to the Crab Nebula it was fueled by fusion of hydrogen to helium helium into carbon oxygen and the rest of the periodic table and then when it exploded this process material was flung back into space and eventually in about 10,000 years it would all have merged into interstellar gas and our galaxy is a kind of ecosystem where gas is processed and recycled through successive generations of stars if this lecture was two hours long I would explain all this diagram in detail I won't do that but this just indicates the various routes where by pristine gas eventually condenses into stars and the low mass tiles have long lifetimes they tie up the gas for a long time but the high mass stars evolve quite quickly and then explode and throw the stuff out again so that new generations of stars can fall and indeed all the carbon oxygen and iron on earth and in our bodies is ash from long dead stars stars that died before our solar system formed indeed each of our bodies contains atoms that came from thousands of different stars all over the Milky Way we are the nuclear waste as it were from the fusion power that makes stars shine and if you look at it that way then the cosmos is part of our environment in the very intimate sense we wouldn't be here were it not for these stars which lived and died far away and long ago stars in themselves are fascinating as part of our diurnal for just that reason but if you've now learned something that makes the night sky even more interesting that it was to our forebears many stars perhaps even most are orbited by retinues of planets just like the Sun is most are the planets that we know about aren't directly detected but they're inferred and the prime technique is illustrated in this picture here if a star is orbited by a planet then what actually happens is the star and the planet both orbits their center of mass what's called the barycenter if the planets going around in a large circular orbit then the star goes around in a much smaller circular orbit the radius being inversely proportional to the mass and the star being much more massive moves more slowly but the small amplitude periodic changes in the Doppler effect can be detected by amazingly precise spectroscopy of the star you can detect an orbital motion of the star at any speed down to walking pace that's about one in 10 to the 8th of the speed of light very precise spectroscopy indeed and by this technique by looking for the periodic wobbles in Stars induced by the pull of panitch orbiting them several hundred planets have been found and of course Jeff Marcy just down the road in Harvey in Berkeley is one of the leaders in this search and this is a slightly old slide this just shows a list of stars which are known to have at least two planets by this technique and indeed one star that's been found to have at least five planets by this technique now the evidence about planets around other stars pertains mainly so far to giant planets planets roughly the size of Jupiter or Saturn the chance of our solar system detecting an earth-like planet is much harder because they're put in induced motions of only few centimeters per second in its parent star too small to be detected by this technique of looking for the Doppler effect but we'd be especially interested in possible twins of our earth planets the same size as ours orbiting other sun-like stars on orbit with temperatures such that water neither freezes all the time nor boils and detecting these earth-like planets hundreds of times less massive than Jupiter is a real challenge as I said it can't be done yet by the same technique as the big ones are but there is another technique which can detect less massive planets we can as we look for their shadow and that's being done by the NASA Kepler mission if a planet moved across in front of a star and we were looking at the star then the star would get slightly fainter because the planet in front of it blocks out a bit of its light and so if you're looking at star that it's brightness would behave as in this diagram here if a planet was in orbit in the plane of our line of sight so it moved across it and so this technique allows you to detect planets by looking for regular periodic dips in the light curve of a star now the Kepler spacecraft which was launched back in March last year is already finding dozens of planets not much bigger than the earth by this technique what Kepler does is it looks at a patch of sky about seven degrees across and measures the brightness of up to a hundred thousand stars in that field to a position of about one part in 100,000 and does that every half hour and accumulating that data it looks the cases where you see this slight dimming by a few parts in 10,000 when an earth-like planet moves across and the hope is that in a year or two the Kepler team will announce a number of planets found by this technique now of course for every one they find on an earth-like orbit around a sun-like star you can expect at least 50 times more simple geometry because clearly you've got to be fairly accurately in the plane of the orbit in order to see this effect at all so in a couple of years time we will have fairly clear evidence on how many earth-like planets that are around a typical field of stars but we'd really of course like to see these planets directly not just their shadows as it were and that's hard to realize how hard let's suppose that an alien astronomer with a powerful telescope and say 30 light years away the distance of a nearby star was looking at our solar system when the Sun from that distance would look an ordinary star and our planet the earth would seem in Karl savior's nice phrase a pale blue dot very close to its star our Sun which would outshine it by many millions so you are looking for a firefly next to a searchlight as it were and that's a big challenge but if you could detect this pale blue dot then you could learn quite a bit about it by watching it because the shade of blue seen by the aliens if they looked at the earth would be slightly different depending on whether the Pacific Ocean or the landmass of Asia was facing them so by watching this dot the aliens could infer that there were continents the length of the day something of the seasons and the climate they might even be able to infer something about the atmosphere and it had oxygen and ozone in it well within 20 years we will be making inferences like that about earth-like planets around the nearest stars and that will involve either large arrays in space this is a proposed European project called Darwin as a miracle project called the terrestrial planet finder which is rather similar or maybe even by John telescopes on the ground this is a design for European giant telescopes really the truck to give the scale something like this would be able to resolve the image of a pale blue dot near to a much brighter star well this is what we can expect twenty years from now to detect planets like the earth but will there be life on them we still know very little about this question I would say we know far too little to say whether alien life is likely or unlikely that's basically because we don't know how life began on earth we know from Darwin how it evolved once it got started we didn't know whether life on Earth arose by some natural process or whether it was a rare fluke like shuffling a deck of cards into perfect order you just don't know we would of course like to find out if there is any life in our solar system before looking further and here are possible places to look no one expects any very advanced life but it would be very important to see if there is any vestiges of life here and if there is as I said early in the case of Mars we'd like to be sure whether this life has an independent origin or whether the life safe from Mars had gone to the earth or vice versa and that can be done by seeing if it has similar DNA but clearly if there's any life in any of these locations it's not going to be very exciting or very advanced life and so we do have to look further afield to can it's around all the stars it makes sense I suppose to focus on other planets which are like the earth because we know that life did start at least once in that sort of environment and so it's sensible to look at earth-like planets orbitting long-lived solar-type stars but I think we shouldn't exclusively focus on that there is an argument that there are lots of special features of our earth which were required some of them are listed here I've been booked called rare earth which has given a list of these things I tend to feel that that maybe being too prescriptive as it were because it's not clear these are prerequisites for life although we have clearly evolved in symbiosis with our environment but to say that life can only exist when all these conditions are fulfilled is rather misguided perhaps like saying is that amazement our legs are just long enough to reach the ground it's not amazing at all and so we've evolved to fit in with this environment but that doesn't mean that life could not evolve in other environments so I think we should be entirely open-minded about where we look and less parochial indeed we realized that life is found under fairly extreme nations on earth in hot springs and deep underground and of course science fiction writers have other ideas balloon like creatures floating in the dense atmospheres of jupiter-like planets swarms of intelligent insects nano scale robots and all kinds of things and incidentally about science fiction I tell my students it's better to read first rate science fiction like arthur c clarke than second rate science second rate science may not be true either and is far less entertaining and to follow up is your planet i would put in a plug for the classic science fiction writer oh that Stapleton who wrote not only star maker but the book called last and first men these were two classics and actually last and first men was one of the books that inspired arthur c clarke when he was a child well even if simple life is common and exists on many times around other stars it's of course a separate question whether it is likely to evolve into anything we might recognize as intelligent or complex that's a separate question of course some people read you know those who've seen UFOs were being abducted and in the UK we have the title of a storm a royal I get quite a lot of letters from these people and I tell them isn't it a pity that these aliens came here and all they did was despoiled a few corn fields making corn circles met a few well-known cranks and went away again and I tend to get these people to write to each other rather than to write to me but perhaps someday we will have real evidence perhaps one day the SETI searches again being spearheaded near here will succeed I think it's very very important that these are being done because even if the signal that is detected is very boring a list of prime numbers or the digits of pi it would carry the mementos message that concepts of logic and physics weren't limited to the hard way human skulls it wouldn't prove there was consciousness out there but it would prove that there was some kind of intelligence either organic or some sort of computer now if there is anything out there which is sending such signals would we have a common culture with them well we would not just mathematics but even if these aliens live on Planet Zog and have seven tentacles they'd be made of the same kind of atoms as we are they'd gaze out if they had eyes at the same cosmos as us they trace their origins back to the same Big Bang so we would have a lot in common but of course as you know even if they are around and miss by star signals will take many years to reach us so we would have plenty of time to compose a measured response if we wished but no scope for snappy repartee as it were on the other hand perhaps these searches will fail earth intricate biosphere may be unique and that may be disappointing but it would have its upside because it would entitle us to be less cosmically modest with our tiny planets could then be the most important place in the galaxy perhaps even a seed from which life could spread through the entire galaxy eventually but it's an old saying that absence of evidence isn't evidence of absence and of course even if the SETI search is a V or nothing there could be intelligences out there that are leading contemplative lives and not trying to communicate whether they could be some that we couldn't recognize because they're so different from anything we can conceive there might even be such things in our solar system and of course if there are aliens out there some of them may have insights which are more advanced than anything we can pose they may have intelligence far ahead of us just as quantum theory would flummoxed a chimpanzee so there may be aspect of reality humans were never grasped but which would be grasped by remote descendants and may be grasped already by aliens if they are out there well so much for possible alien life around stars in our galaxy let's now enlarge our horizons further and I'm going to describe briefly the large-scale structure of our universe if it could get 2 million light years away from the earth and look back we'd see something like this this picture of course is you know as Andromeda the nearest big galaxy to ours it's a spinning disk viewed obliquely we're about 100 billion stars are orbiting around a central hub in the middle of which lurks a big black hole and this is a typical galaxy like ours and our Sun if we could look at our galaxy from great distance will be a fairly ordinary star located out towards the edge orbiting the central hub once every 200 million years long even by long now standards well here's another galaxy the Whirlpool now astronomers actually understand a lot about galaxies you might ask how can they do this because they can't do any experiments on galaxies they could just look at them and and it might be hard to believe that we can be confident we understand what they're made of and how they form but we can do experiments in computer we can't crash together particles like a particle visitors can in the Large Hadron Collider but we can crash galaxies together in our computers and here's the results of one such calculation two galaxies crashing together what's happening is that the gravity of each star in wrong acts on the others and they pull out these sort of tidal plumes and when these galaxies have settled down they will have merged into one single big amorphous bloated galaxy now we can then look up in the sky and we see things like that and it's fairly clear that what's happened here is rather like in that movie two galaxies have got dangerously close and each has pulled out a title plume on the other and by doing calculations with different assumptions about the masses the dark matter etc we can firm up our picture of galaxies by comparing the outcome of those calculations with things we see in the sky so that's why there is quite a substantial basis for our understanding of galaxies and of course there are huge numbers available for study this is a picture of the galaxies within about a few hundred million light years of ours they're grouped together in clusters one thing we know about galaxies is that they're moving away from us I mean we've known this ever since the work of Edwin Hubble here's a heavy smoker as you can see and he he discovered that distant galaxies moving away from us and further they are from us the faster they're moving indicated by the longer arrows further away now this doesn't imply we in a central position the best way to envisage the expanding universe is to think of a lattice like this supposing that you sit on one of the vertices and all the rods lengthen then the other vertices will move away from you with the speed depending on the number of intervening links the whole network will expand now that's a good picture for the expanding universe if you imagine galaxies or at least clusters of galaxies joined together by rods and all the rods lengthen in the same proportion and the galaxies get further away there's no preferred central position but there's one feature which isn't borne out by this picture and is better done by this other Escher picture angels and devils because when you look a very long way away at a galaxy you see it as it was a lot time ago because lights take a long time and so if the universe is expanding you see distant galaxies at a time when they were close together when the rods were shorter as it were so what we actually see if we look back along our past light cone is something better resembling this picture here where as you look further out towards your horizon you see things more closely packed together and we can't see very far back this picture shows a patch of sky only a few minutes across it would take more than a hundred patches like this to cover the full moon in the sky with the smallest telescope this would be a blank bit of sky but with the Hubble or the biggest ground-based telescope you see something like this and each of these smudges is a galaxy many of them fully the equal of our galaxy or Andromeda looking so small and faint because of the huge distance and many of these are so far away their light set out ten or eleven billion years ago long before earth formed and in fact these galaxies look different from nearby galaxies because they contain more unprocessed gas that hasn't yet turned into stars and a lower proportion of elements like carbon and oxygen which you can look for spectroscopically that's because 10 billion years ago there had been enough time to process much material through stars to build up the heavy elements and therefore even though the mite on Andromeda be alien life there may be astronomers under looking back at us with bigger telescopes and ours but you can save for sure that there aren't such astronomers on these very distant galaxies because at the time in the light from these galaxies set out there would not have been enough carbon oxygen and phosphorus to make a planet so we know planets and therefore scanted chance of life well we look at these distant galaxies we're looking back to when Universe was about of its present age and about five or more times more compressed but what about still earlier times I did have time to go through all the arguments but again as you probably know there is important evidence we've had for more than 40 years which is that intergalactic space isn't completely cold it's warm to about three degrees above absolute zero by very weak microwaves and these microwaves if you measure their spectrum at different frequencies have an almost exact so-called blackbody spectrum indicating this is radiation that was once in equilibrium and so this radiation filling all of space is a relic of when the entire universe was squeezed hot and dense hotter and denser the center of the Sun and as universe expanded this radiation cooled the wavelength stretched but it's still around it had nowhere else to go and it's this weak background radiation and we have this evidence and others which give us confidence in extrapolating back to the time when universe was a few seconds old astronomers are often accused of being often in error but never in doubts so you may say how confident can be about this but actually the evidence for the universe at one second is in my view as compelling as anything a geologist could tell you about the early history of the earth we've got various fossils which could be measured very exactly and so we do have this time chart for the evolution of the universe and back to one second or at least a modest fraction of a second it's fairly well understood but right back still earlier on it's a rather mysterious what we know is that at one second everything was in his very hot dense gas now when you are told that the early universe was very hot and dense at a morphism structureless there's a tendency to be rather puzzled about how from something like that can our present complex and structured cosmos have because most people have heard of a so-called second law of thermodynamics which says that structure tends to wash out structure tends to be eliminated rather than the form whereas our present universe is clearly far more structured than the hypothetical early stage which was almost smooth how can we reconcile this emergence of structure with this law of thermodynamics when the answer is a crucial role is played by gravity gravity enhances density contrasts as universe expands a region slightly denser than average would lag behind as the universe expands because of the extra gravity and eventually condensed out and I'm going to show you a movie which shows a volume of the universe starting at the beginning and ending up now where the expansion is subtracted out so it's a patch big enough to make several hundred galaxies it looks the same size all the way and on the bottom left you see the time measured in gigahertz billions of years and you see that it started off amorphis but density contrast grow because gravity is enhancing them and eventually after 30 points 7 million years we get something which actually is rather like the structures in our universe and we have put in to the initial conditions here fluctuations which are known to exist in the background radiation and models of this kind which are shown 16 powers of 10,000 in real time of course they show that galaxies can have emerged from an amorphous early universe and of course each of these galaxies is then an arena within which stars planets and perhaps life can emerge we'd like to understand in full of detail how from these amorphous beginnings the cosmos evolved to its present complexities with the life and planets and there have to be quite a few requirements in order for this to happen and I let me give a list of them first we've got had particles at the beginning protons and neutrons you think could have stars and planets and then we've got to have the synthesis of the periodic table in Stars and then can its forming around later generation stars and then of course on at least one planet around at least one star life has to form and undergo Darwinian evolution and that evolution has led on at least one planets to creatures able to ponder the wonder and mystery of their origins well what are the key prerequisites in the universe in order that all these things can happen I'm going to give you a list the first thing is that we need to have gravity if there wasn't any gravity then structures wouldn't condense out as universe expands stars wouldn't pull themselves together but gravity is very weak force gravity is negligible between individual atoms it's negative on where you have say a sugar cube or something like that it's negative for an asteroid when you get something as big as a planet it makes it round and when it's bigger it crushes it to make a star so this picture here shows the various structures and it's because gravity is so weak that stars are so big compared to atoms so gravity is crucial but we also need the parts of third-ranked equilibrium if the universe expanded but then collapsed almost straight away then nothing complicated will ever happen we need matter/antimatter asymmetry we need more matter than antimatter because if through equal amounts then as universe expanded and cooled you put all the na relate and to be lots of radiation but no atoms left behind we need a non-trivial chemistry we need to have a periodic table and that requires some other tuning between the nuclear force that holds the nuclei together and the electric forces disrupt them we also need stars to form probably second generation stars because one star makes heavy elements but then it's got to May second-generation stars in order to have planets and also the expansion rate must be tuned because if the universe be expanding too slowly it collapsed too soon if it expanded too fast then gravity wouldn't be able to combat the kinetic energy and galaxies wouldn't fall so all those things are required and there must be some fluctuations in the early universe in order for the in order for there to be some thing to feed on the density contrasts the Kapiti smooth universe would stay smooth forever now what Kosmos are trying to do is to understand and quantify these things and understand how they came about these numbers which all are basic numbers of physics our strength of the forces etc they must have been imprinted at some very early stage in the universe we don't know quite how early but I think very early indeed in most people's pictures I like to show this picture this shows the very early universe and this is actual size this is the size of the universe when it's a trillionth of a trillionth of a second old and this is a time when it's thought that many of these key features were imprinted in it and the physics at that early stage is very uncertain we can extrapolate back quite a long way but when we get back to that tiny tiny fraction of a second where all these important numbers were imprinted we still don't have any firm foothold because the physics is far beyond anything we can directly simulate in the lab or in the accelerator at this point I'd like to insert a health warning a hazard which I want to briefly mention some speculative issues first how big is our universe well we can see this huge range of galaxies out to a distance of 10 or 12 billion light years they're sort of horizon around us but there's no reason to think that's all there is just like if in the middle of an ocean you can the mast of your ship and you see a horizon around you but you don't message think the ocean finishes just just beyond your horizon and the same is probably true in the universe in the universe we can't be sure of what happens beyond the horizon but the expectation is that there is far far more to our universe it goes on far further than we can actually see one reason for that is if we look as far as we can in that direction and in that direction then conditions look the same to a precision of one thousand a hundred thousand so if this part of some finite structure then that structure must be much bigger than the scale we can actually see but some theories suggest that it goes on even further than that maybe even so far that all combinatorial options are played out so there would be somewhere else another lecturer with similar people in listening to a lecture but the distance you have to go to find that replica is hugely greater it's 10 to the power of 10 to the 200 a huge number so there's no possibility of seeing that replica because it'd be far far beyond the horizon and moreover even this isn't all because what I'm talking about now is the aftermath of our Big Bang but some theories suspect that there could be other quite separate regions of space-time one idea is what's called brain Worlds the idea that there could be separate three-dimensional cosmos is embedded in some common four-dimensional substratum to give an illustration supposing that you have a lot of ants on a sheet of paper that's their two-dimensional universe they might be unaware of another population of ants on a parallel sheet of paper so likewise there could be another universe just that far away from ours but if that distance is measured in a fourth spatial dimension and we imprisoned in our three we wouldn't know about it that's one possibility which some people talk about with a straight face and this is a this is a cartoon of an idea which is taken much more surgical eternal inflation we are in some region showing bottom rights but that is just one bubble as it were in some infinite hierarchy so these ideas are taken quite seriously and if there are many big bangs this raises another important question which is are the laws of physics the same in all of them they may be but it could be that some of the laws of physics depend on how the Big Bang cooled down it's different at different ones and that's very important for the apparent fine-tuning which seems to have been required in order for our universe to exist and this is a sort of decision tree that we hope eventually to be able to settle how many big bangs are there one or many if there are many are they all the same in the physical laws govern them or some of them difference and if we have the the right hand thing then we can say that our universe is governed by what we think of universal laws but they're really as it were by laws in our cosmic patch and could be different elsewhere and we are in a universe by laws that allow complexity where there could be sterile or stillborn universes which are disconnected from ours so remember the hazard warning sign is still on this is still very speculative if I needed a logo for my research group I'd choose this and Ora Boris the image depicts the interconnectedness of the micro world on the left and the cosmos on the right the inner space of atoms and the outer space of the universe the links between small and large left and right and our everyday world of life and mountains is in the middle it's determined by atoms and chemistry and there are other links between left and right on this diagram we are determined by aftman chemistry but there's a link halfway up because stars are fueled by the nuclei within those atoms and also though I've had no time to describe it galaxies are held together by dark matter which has believed to be some particles even smaller than atomic nuclei so the links between left and right the left is the domain of the quantum and on the right hand side Einstein's theory of gravity holds sway general tivity and quantum theory are the two great pillars of 20th century physics but they haven't yet been meshed together in a single unified theory in most contexts this doesn't really impede scientific progress that's because the domains of relevance of those two theories don't overlap a chemist doesn't need to worry about the gravitational pull between the different atoms in a molecule conversely an astronomer doesn't need to worry about the quantum fuzziness in the orbit of a planet whistle tanta so so big but if we think of the very beginning of the universe everything was squeezed so dense that we have to worry about both these theories quantum fluctuations could had shake the entire universe when it is compressed and so to understand the very beginning to understand what banged and why it bangs were the many big bangs or we will have to understand the synthesis symbolized as were gastronomically at the top here between the very small and the very large but before leaving this picture there's a third frontier at the bottle neither the very large norther very small but the very complex and the most complicated things are we ourselves we're actually midway on a log scale between atoms and stars they're big compared to atoms quickly got layer upon layer of structure but we're small compared to stars we're not so big and we get crossed by gravity and incidentally we are fairly accurate in the middle the geometric mean of the mass of a proton and the mass of the Sun is 50 kilograms with a factor of 2 of the mass of most people here and we are midway between atom and stars and to understand ourselves we have to understand the atoms were made of but we also have to understand the stars that made those atoms and the problem of this third frontier is complexity even an insect with this layer upon layer of complexity is harder to understand and a star where intense heat and compression by gravity preclude complex chemistry this picture incidentally is the famous drawing of a flea by Robert Hooke who was one of the first people to use a microscope and he published a book and he was actually a great enemy of Newton Newton's least favorite Pharaoh the Royal Society but he was not only great scientist but a great draftsman and he produced this wonderful book and you can imagine the fascination when the public saw these pictures for the very first time but even a flea is much more complicated than the star finally I want to draw back from the cosmos from what even may be a vast array of cosmoses and zoom back closer to here and now to our planet orbiting a typical star in our galaxy I want to emphasize first that even if there isn't any life out there it doesn't mean that life is forever a trivial afterthought in the cosmos that's because of the vast time that lies ahead where life can spread from the earth far away the stupendous time spans have evolutionary past are now part of common culture maybe not in Kansas and a few places like that but in most places this is a common culture that we have emerged over about 4 billion years from simple beginnings but even people who are familiar with this tend all too often to somehow think that we are the culmination of the process and no astronomer could honestly believe that the reason for that is that the time lying ahead is even longer this is a time-lapse picture showing the sun's origin from an in stellar cloud its evolution and eventually it'll become a red giant it's less than halfway through its life and it's got 6 billion years before the fuel runs out and then flares up engulfing the inner planets so the future of our Sun is longer than its past and the expanding universe will continue far longer perhaps forever to quote Woody Allen eternity is very long especially towards the end so any creatures who witness the sun's demise six billion years from now they won't be humans Davy is different from us as we are from a buck this been as much time for evolution between now and then as there has been over the past history of the earth and moreover as I said earlier evolution in future is going to be far faster than Darwinian selection so post human evolution here on earth and beyond could be as prolonged is that a winning evolution just led to us and even more wonderful and Darwin himself recognizes this he realized that not one living species would exist forever and there would be new species in future so we're maybe barely at the halfway stage of evolutionary development finally we're all familiar with these iconic pictures of our planet from space Earth's delicate bars their contrasting with the sterile moonscape where the astronauts left their footprints and we've had these images of course for 40 years an environmental icon now suppose that some aliens have been watching our planet viewing it like that not just for 40 years but for its entire four and a half billion year history what would they have seen well over nearly all that immense time Earth's appearance would have changed very gradually continents drifted the ice cover waxed and waned successive species emerged evolved and became extinct but in just a tiny sliver of the earth history the last one millionth part just a few thousand years the aliens would have seen the patterns of vegetation altering much faster than before this signal to start with agriculture and the pace of change accelerated as human populations rose and then there are other changes even more abrupt within 50 years little more than one hundredth of a millionth of the Earth's age the carbon dioxide in the atmosphere began to rise an ominously fast the planet became an intense emitter of radio waves the total output from TV cellphones and radar transmissions and something else on presidented happened small projectiles launched from the planet's surface escaped the bass fear completely some were propelled into orbit some went to the moon some beyond to the planets well if they understood astrophysics the aliens could confidently predict that the biosphere would face doom in a few billion years when a Sun flares up and dies but could I have predicted this unprecedented runaway fever less than halfway through the Earth's life even in this concertina timeline extending millions of years into the future as well as the past this century therefore may be a defining moment it's the first in our planets history where one species ours has Earth's future in his hands and it'll be us who determined what happened in the future will life eventually stabilize will it be some spasm and disaster will some of the planets so some of the projectiles launched from the earth spawn new oases of life elsewhere so those decisions depend on us this century and so we're the stewards of this planet at especially crucial era and I think that's a message for all of us whether we are astronomers or not thank you very much [Applause] and I like the way you put long now into such a miniscule short now I got an amplifier on and yeah could we see the I want to take you're still here yes Martin Martin has been speaking into brightness and that needs to yeah look people this is what discovering life in the universe is going to be like it's been darkened in the end it turns out there's people out there laughing all this time you end on a note of we're stewards of the planet and you also had a kind of a down view on well at least the option that said he won't find anything either because it's not detectable or because it's not this yes yes and if it's not there and we're the only life and we're also the stewards of it now how cosmic is that responsibility well I think it is a cosmic responsibility because if life or intelligent life is rare and there are arguments it may well be then it couldn't be unique to the earth within the galaxy and therefore the earth though tiny is especially precious place but moreover as I briefly mentioned if that's the case it doesn't mean that life is forever a trivial afterthought in the cosmos that's because it would be possible in the time lying ahead for post human life either organic or silicon-based to spread right through the galaxy there's plenty of time for that to happen that could happen in far less than a billion years and so the life even if now limited to the earth could be an important feature of the galaxy in the far future so the stakes are in a sense very high in that if we were to snuff out life now I think he's very unlikely then we destroy not just ourselves but that great potentiality and so to give us IT service analyses supposing that you clobbered the first fish that crawled onto dry land it might have been unprepossessing looking creature but you would have destroyed the potentiality of land-based life similarly whatever we think of ourselves however mr. topic we are then we should realize that perhaps we are not the combination wellyou've you wrote a book in the most recent book I think is called our final hour and it's a kind of a will we get out of the century alive and you seem to feel the question is quite open I can't tell if you're a pessimist or a person he was trying to warn people to be careful yes well the book which I wrote I entitled it our final sensory question mark my English publishers left out the question mark and then the American publishers Oh God retitled it up final our sorry which I thought was well silly title but I guess it's Americans like instant gratification and and the reverse but the theme of the book was indeed that this century is indeed especially crucial one because it is the first when one species ours does have the future patent in its hands and I had two themes really one is the familiar one that we are collectively putting more pressure on resources in environment because there more of us will be 9 billion by mid-century and raised more demanding of managing resources so that's says we need to contend with and climate change etc but also we are individually more empowered by technology and is also a greater threat from small individuals who want to be disruptive because they will have more power in the future than now but for both those reasons I did think that there was a 50% chance of something as bad as a nuclear war by the end of a century I don't think we wipe ourselves out but there could be a severe setback due to a misuse of Natural Resources or misuse of of technology so that was really my concern but if you asked am i optimist I think I'm a technological optimist but a political pessimist in that I think it's clear that we will have indeed we now do have available the knowledge to make a world with far less poverty and sharing the benefits of globalization but we're not doing that and as we develop our new technology then clearly the potentiality is a grater for loss of the risks of greater and that is my concern there's well a long answer I'm sorry about that question from Peter Schwartz it's a long time long term fate of humankind depended upon whether we can exceed the speed of light and escape our solar system or are we stuck with nine useless planets yes well I think it's true that if you look at the other planets I mean there's a there's none that would be habitable in any comfort and terraforming of Mars and long-term is a possibility so I don't think that space living within our solar system is going to be attractive to more than a few intrepid pioneers if we look very far ahead then of course the first pioneers could use all the techniques of genetic modification to adapt to their alien environment and that will be the start of the posthuman era but also miniaturized robots could of course spread far more rapidly than anything organic and even to other stars would take a long time but of course if the human life is irrelevant then then that could happen and of course the other idea again from science fiction is to descend information at the speed of light but of course we do have to go more than the speed of light if we want to go to other parts of the galaxy in contradiction to human life time do you see any hope for faster than light I don't I mean there is there are hypothetical time machines but the only one that's been worked out involves creating a black hole weighing as much as 10,000 Suns and that seems a pretty tall technological order and also if we could make a time machine it would allow us to go away fast into the future and in effect to see the speed of light but his boat allows to go back into the past we can't go back to the past we don't expect therefore to have tourists in the future invading us question from Jim Kurtz could you comment on whether the Milky Way our galaxy has been in a collision well it's it's not been in a major collision because if if it had collided with a big galaxy after its disk formed then the disk would not survived the disc would be disturbed and it would end up as a sort of amorphous elliptical galaxy so there's been no big collision in the last six or seven billion years but our galaxy did grow by the agglomeration of smaller members and there are small galaxies in orbit around it falling into it in fact as the imaginary cloud through the two small galaxies which are orbiting at the distance of about 150,000 light-years and they will eventually merge with our galaxy so our galaxy's accreting smaller neighbors but we can say it hasn't had a big crash like the one in that movie not in the last seven billion years certainly not in the last time of the song we stuff would not allow there to be a disc I presume there is no other large galaxy on the collision course that we know well there is actually as Andromeda and Andromeda is coming towards us and it is quite likely that Andromeda will crash into our galaxy in about four or five billion years and we can't be quite sure which we know the Sun will still be around for that if life is still around it will be in the thick of that it will but it won't affect things very much because the the gas in the two galaxies will shock and will merge will heat up but the stars are so widely spread at the chance of two stars colliding is very small so what happens is the sort of phases of the orbits and the stars will mix up but there won't be stellar collisions so the Sun and the planets would be unaffected by such goodness anything happen quickly in the course of something like that I mean they know they don't hit it it sounds like it's sort of a slow-motion ballet it is it's happening on timescale of 100 million years or so the only rapid things that happen in astronomy are when stars are evolved and exploding and then of course we get explosions we get two phenomena down to a fraction of a second I mean neutron stars spinning around at 700 revs per second sending out flashes every revolution and so small things like that can who couldn't change very fast but some of you as big as the galaxy can't change in a human lifetime another astronomical question from one of the remote listeners who's listening in on their computer Paul backways what is the theoretical limit of resolving power for telescopes assuming no limit to the cost or size if you could have the biggest of all possible scopes when I think in invisible lights if you do it in space then there's no limit you certainly get down to much better than microsecond of course it's the Earth's atmosphere that stops that so in in the optical and the x-rays then you could get a micro arcsecond even nano arcsecond in the radio there is a limit because interstellar gas produces a kind of twinkling at radio frequencies rather like the twinkling which the atmosphere produces in visible light so the radio telescopes there is an image although it's still and then I was less than a millisecond but in the optical there's no limit anywhere near being achieved in a foreseeable future and so the problem of detecting planets around other stars is that you do need a big telescope to get the resolution and also need sensitivity because you have to detect a very faint objects can it's very close in the sky to very bright object to start another astronomical question from another remote listener Elliot Hoffmann what cosmic surprises would you hope and expect to encounter in the next 25 years or so that would immediately change human consciousness about ourselves in natural world the cosmos I suppose you can run that question backwards what kind of surprises have we had like that in the past yes because by definition I can't tell you what surprises would be 35 years will give us a history the ones that blew our minds before yes well I mean I think the detection of neutron star this 40 years ago the fact you know if you tell people that there would be stars so small that they weigh more than the Sun and can spin it nearly a thousand Reds per second that's pretty mind-blowing and black holes were theoretical construct but we now are certain that they exist in the sense of most galaxies and smaller ones were widespread so those are two big surprises we have learnt to considerable surprise that our universe is speeding up in this expansion not slowing down which means that as well as the gravity which is causing the expansion to slow down because everything exerts two gravity's pulling everything else there's some other way we can diffuse force which is pushing everything away from everything else and we don't know what this force is it implies that even empty space somehow exerts a force which opposes gravity and that's a really big surprise which has come about in the last ten years and I think it's very important that's the reason astronomy is advanced so fast is that technology has advanced technology sensitive detectors on the ground and in space and of course computer power to handle the data and do simulations and of course the field of planet and stars I mean first a planet around a normal star was found by Maya in Geneva only 15 years ago and now this is a major field of astronomy a really fascinating one and so that's an example of how an entire new field can develop it in a decade so it sounds like you're saying if the technology is continuing to get better as a steady pace or an accelerating pace then it will turn up surprises of this well I think it will and and of course the timescale for constructing big telescopes is a decade or so I mean longer if funding is slow and we can predict that within 20 years there will be no they certainly could be a finding we're available these instruments that could detect earth-like planets I mean not indirectly by their shadows but actually pin pinpoint them and study the light problem so that's an example where we can predict with some confidence what we will be able to do 20 years from now and we can't do but of course when we do have those instruments then as well as doing what we can predict them to they will perhaps disclose some completely unsuspected features that's been the history of most instruments in the past they've in most cases done what they were supposed to do but they have also made entirely unexpected discoveries and I think that's the wonderful thing about science especially astronomy as the front is advanced the periphery gets longer as it were and more new problems can be attacked and if I think of cosmology when I was a student there was big debate about was there a big bang how old was the universe etc and all those debates have been settled and the questions were now debating about the first tiny fraction of a second of a universe and what the dark matter is made of et cetera couldn't have been posed back then and that and that's the signature of a really vibrant and rapidly advancing science there's a question along now a question from Felicity hammer the Royal Society would you just recently celebrated is 350 yes anniversary and and the question is would you speak to the issue of the characteristics and attributes of a long-term institution what does it take long that foundation well well start early okay yes well I mean it is to the Thule Society who started in 1660 when a group of the amateur gentlemen scientists gathered to hear a lecture by Christopher Wren famous now as an architect but he was then professor of astronomy at Oxford and he gave a lecture on astronomy and they decided form a society and that society got a Royal Charter and in 1916 60s they met regularly to have experiments done for them they were they were a variety they dissected weird animals they started explosions and they heard travelers tales and they did some rather gruesome experiments they did blood transfusions between dogs and even from a dog to a man and the man survived and and so of course health and safety doesn't allow us to do these experiments today the Society's meetings have changed their character but I think yeah but one thing that happened very early in the war society was the founding of the first scientific journal because scientists of course throughout Europe they correspond with each other but then the first journal was set up and people like Huygens in Holland published their papers in this one journal and that was the way information was disseminated and that's of course being the model for the way science is done I think many of us feel that perhaps the scientific journal is getting a bit obsolete in the in the age of the web but it's been the dominant means of disseminating science and you know peer reviewing it to accredit what is to be taken seriously so that's been something which the society has done but what society now like the National Academy of Sciences in this country is involved very much in all the issues of policy that have a scientific I mention I mean things like environment energy climate bioethics etc all areas where science a big impact on policy and where frankly there are too few politicians with adequate knowledge or understanding these are all areas where academies have an important role and often they work together because lots of these global problems are really global and they need to be tackled by scientists warned over the world and that's why we in the world you do have a lot of contact particularly with the American National Academy of Sciences but with others simply to try and raise on the agenda these important issues in particular those of coping with the crises of the next half century but its century because science moves very quickly the political the government's that you're being helpful to move pretty quickly and yet here and there's laboratories like the Cavendish they've been around for quite a while doing very fast moving science how does this mix of fast-moving content and durability of institution how does that point well it's interesting I think any durable institution has to change I think although I mean I'm in University which is a celebrate hundredth anniversary but it was not it was not the same eight hundred years ago as it is now is it's a work in progress even today and that's true of any vibrant institution but I think there is a certain attraction and extra responsibility if you are part of the institution that has history which you can on the whole admire it does make you feel that you do have a special responsibility although the missions of any society is just like a university have to change over the decades Robyn Sloan has a question are there big questions of large-scale scientific projects that we amateurs non-specialists can contribute to meaningfully what skills should we learn what gear should we buy or invent there's large scale science even talking about it yes any of the Royal Society perspectives on things or large scale science what role amateurs have well I think of course traditionally amateurs have had a role in subjects like geology and Natural History but I think the the advent of the web has had a tremendous effect in that it allows people to participate in science to take an example when a comet crashed into Jupiter about ten years ago lots of people watch that in real time on the on the Internet and of course SETI at home is an example where they've been this year millions of people's involved and based in the UK deserve protocol Galaxy Zoo which is asking people to try and classify the morphology of galaxies and to to help in the way that in the old days people have would have studied rare species so lots of cases where the public can participate and the internet makes it much much easier for them to participate and also of course the Internet is really level the playing field between major institutions in countries like this and people working in small institutions in say India Africa because in the old days if you were in India or Africa then you've got scientific journals either not at all or months late whereas now you get these journals whether you get the information on the web instantly I'll give you an example of the list let me give two cases in involving India a hundred years ago there was an Indian Clark called ram anujan who sent letters to came with Professor gh Hardy and these were all kinds of mathematical formulae and gh Hardy fortunately didn't dismiss this as some greening scribbler but realized that the writer of this material had really preternatural insight into mathematics and he invited ram anujan to come and work in cambridge is a very famous romantic story but the contrast I wanted to allude to is that in night in 2002 a professor went to students at Campo in India made a discovery in mathematics it was a new way of factorizing prime numbers which is important for code theory and they put that on the internet and within one day 20,000 people have downloaded it and they've been seminars convened in institutions in many countries to discuss these results so instant recognition for Indian students now by the internet as contrasted with the good luck which prevented ram anujan living in obscurity so that's an example of how the participation in science has been hugely widened by well thanks to the internet we had GenBank that came along and the peculiarity that people were putting up new genomic data in half-baked mode immediately as you suggest and then it got sort of baked in public by various people confirming or denying what they were discovering and so on and suddenly science flipped from where one became a specialist and sort of sequestered ones data and ones theories and who drew into himself into a science of sharing and it used to be that the more control you head over your material the more you got promoted in science and now it's flipped to the more you Sharia material as long as it's good the more you get promoted in science so that's a flip then you're describing the rest of this engagement that more and more people can have it sounds like we're moving into an era of a golden age of amateur science it's like the 19th century only instead of the gentleman is whatever well it's it's a amateurs and professionals and bloggers etc and of course datasets are much much larger now not just in astronomy but in genomics and climate science and all these things are huge datasets and more and more people now have the chance to access and download and analyze I mean you need to have some sophistication to analyze a large data set but I think it's very important that in subjects where data is gathered there should be some protocol about whether the discover has proprietorial rights whether they should be made publicly available I mean in the case of the Hubble Space Telescope for instance the custom has been that the observer has a data for a year and then it's in the public archive and that archive is maintained in the way anyone can use it to be in debates about climate records etc which haven't always been kept in a form that can be made available readily and understandable by people but that's terribly important it's important that the archive should be accessible and maintained in a standard format because more and more people are going to want to check and it's important that they should now as the Royal Society you've had to watch over not just your your previous domains of science but bloody well everything for five years and you and I were just did a gathering of 330 scientists at this Sipho camp for a couple days hit at Google as you scan across the sciences what do you see where do you see the action what's going on well if take it personally what kind of excite to you that you see going on outside your own tree is well I mean I think the biggest trend is advanced in in computer simulations because I I should i showed a simple computer simulation in my subjects and the main change in my subject has been that we can do realistic simulations of stellar evolution galaxy evolution etc and computer simulations are now invading more and more Sciences in fact in chemistry there are some things which were done experimentally with now can be done have better by computer simulations and so I think that's a big trend because of the hugely rapid advance in computer power to do simulations and process large amounts of data and that cuts across all things I would say but also I think the much greater openness of science to to people in all countries we had a question from david claussen basically raising the question which is often raised about computer modeling of reality is you know the sort of the climate models said they well the ice is going to melt in 40 years and then it didn't annulled it much sooner than that and people say well why should we believe anything else about these models what is wrong about that important matter are I guess the question I have is is say what we are what is really good about models and you started on that and then also what things to be worried about about models and what is the trend or models likely to get significantly better for a long time as there are Moore's law of modeling well I think in a way there is because of the growth in the speed of power of computers but nonetheless there are some problems which is so complicated that no foreseeable models will be a very adequate representation of reality I mean if you think of climate then the present climate models of course have two deficiencies one is that they don't deal with the water vapor and cloud cover very well and also they don't have spatial resolution and what we want to know is what the climate impacts will be on particular regions and the models don't have that resolution and they pay a long time before they before they do and I think a similar story could be told in in other fields that many phenomena are very very complicated and even with Moore's law a long time before the computer but there certainly an aid to aid to intuition if nothing else you know when the map is the territory and it gets very interesting indeed not a question in a sense that your first wonderful participation with law now is to do one of the early predictions for long bets it's number nine in the list anything is featured for that reason and your prediction in 2002 was that by 2020 there will be an event of bioterror or bio error that causes a million deaths and we're now about half way along in that the voting on it there's four hundred and four hundred people that think that you're right and four hundred fifty people who think that won't happen [Music] halfway long what do you think yes well obviously I desperately hope that I'm wrong in this case but but my concern really was that biotechnology is developing very fast and there are greater risks of error or terror and also because populations are crowded in mega cities in the developing world that is the place where any epidemic natural one could become catastrophic I mean you think Natalie epidemics like SARS it was jolly lucky that didn't get to a developing world city which couldn't cope with so well if it did but I think the risk is that there may be some some error or indeed some some genuine terror which if it happened in area where it couldn't be cope with adequately could really be catastrophic in 2020 when we have a in conversation again you've either won or lost that prediction suppose the event has not happened would you then do a next 20 years or would the prediction of well done the next one here is it'll happen or is your expectation that what we're doing is getting a sort of a non existence proof here well I mean I think this goes back to the theme of my book I think there is a genuine worry that a few individuals who want to cause widespread devastation will be able to do it more easily with new technology and they could in a past and so there is there is this risk and I think the genuine tension between security and privacy in that if you want to be sure that people aren't surreptitiously misusing these dual use technologies then we do need to be fairly intrusive but I think the good news is that only the older generation seems to care about privacy well if you look what younger people surely on Facebook itself like then it looks as though everyone is watching each other to the extent that we can be assured that it would be conspicuous if someone were being too secretive but I do worry about a few extremists like echo freaks who think the world would be better off without human beings and we know there are some such people some people are that empowered by technology could do huge damage and people with the mindset of those who now design computer viruses may start doing the same with real viruses so I think these are genuine concerns and that's why I I do feel that it's going to be very hard to maintain freedom and privacy in a world where a few people can do far more damage than they ever could in the past I detect it very guarded up in this that you can see a lot of things that can go wrong yes but great hope it's they don't yes you and [Music] you [Music]

Channel: Long Now Foundation

Views: 5,845

Rating: 4.8461537 out of 5

Keywords: Space, Technology, Royal Society, cosmos, astronomer, civilization, SETI, METI, dark energy, Kepler telescope, solar system

Id: xA_eeE3VWF8

Length: 99min 47sec (5987 seconds)

Published: Thu Jun 25 2020