Sir Martin Rees Public Lecture: Surviving the Century

[Music] thank you [Applause] welcome welcome to Perimeter Institute here in Waterloo Ontario Canada and my name is Greg dick I'm the director of educational outreach and it is a pleasure to welcome everyone here both those of you here in the Mike Lazaridis Theatre of ideas and those of you watching online Perimeter Institute would like to acknowledge that we are located on the traditional territory of the ad wand'rin the action are big and the Haudenosaunee people's premier Institute is situated on the Halderman tract land promised to the sickness Six Nations which includes six miles on either side of the Grand River now before we get to the lecture I'd like to tell you about secrets of the universe it's an IMAX 3d documentary made in association with perimeter Institute it premiered in the Smithsonian Institute in Washington DC over the summer and will be showing on giant screens across Canada and the globe over the next year and I would like to say first that this project like all of our educational outreach is is made possible through the generous the generous public support from our governments of Ontario and of Canada and our private support from donors like you now to celebrate the launch of secrets of the universe we are sending a lucky winner and a guest to Geneva Switzerland to go to CERN and go underground to see the Large Hadron Collider I've been there and it's awesome so if you want to enter these sweepstakes do so by November 17th 2019 go to inside the perimeter see a slash contest to enter so that's inside the perimeter see a slash contest and for those of you watching online you can join the conversation on social media our handle is at perimeter and use hashtag P I live you can chat with perimeter scientists throughout the talk and I will also take questions the online questions for the Q&A at the end and now it is my pleasure to introduce tonight's very special guest speaker serve Martin Rees Sir Martin Rees is the astronomer royal of the United Kingdom and one of the world's leading minds in cosmology astrophysics and the existential crises that face us here on earth he is a former Prez the Royal Society and master of Trinity College Cambridge he is the author of numerous books including his latest book on on the future prospects for humanity he'll be signing copies of his book after the talk in the atrium and tonight he will share perspectives on the global challenges we all face environmental societal and technological and explain how science can help us overcome them ladies and gentlemen please welcome Sir Martin Reese good evening ladies and gentlemen it's a great pleasure and privilege to be here we've mentioned I have the title astronomer royal and once I was asked does this mean you do the Queen's horoscopes and I said solemnly if she wanted one I'm the man she'd ask and then this chap who is an Indian tycoon said what's your predictions and I said stock marks will fluctuate trouble in the Middle East and other surprising things like that he took me seriously they then came clean and said I'm only a astronomer and he then lost all interests in my predictions and rightly so because scientists are rotten forecasters although not quite as bad as economists but despite all this I have written a book with a rather pretentious title on the future but my forecast tonight will be rather tentative especially in front of an audience where there are people are far more expertise than me the theme of my book is really this the earth has existed for 45 million centuries but this century special it was first when one species ours has the planets future in his hands we're deep in the Anthropocene we could irreversibly degrade the biosphere or we could trigger the transition from biological to electronic intelligences or misdirected technology could cause a catastrophic setback to civilizations but even with a cloudy crystal ball there are some things which we can predict a few decades ahead for instance by mid-century the world will be more crowded 50 years ago world population was about three and a half billion it's now about seven point seven billion it goes be mainly in Asia and Africa as shown in this map where reading the scale in proportion to the amount of growth in the last 25 years but the number of births worldwide peaked a few years ago and it's actually now going down nonetheless world population is forecast to rise to about 9 billion by mid-century and this is partly because most people in the developing world are young owing to recent growth and they will have longer lifespans than their predecessors so the histogram on the left with lots and lots of young people will become rather more like that on the right which shows Western Europe and the main growth is in East Asia and it's there that the world's human and financial resources will become concentrated and I think we can look forward to the end of four centuries of North Atlantic hegemony and as more urbanization to prevent mega cities becoming turbulent dystopias will surely be a major challenge to governance to feed 9 billion people by mid-century we require further improved agriculture low till water conserving and GM crops and maybe some dietary innovations converting insects highly nutritious and rich in protein into palatable food and making artificial meat to quote Gandhi there'll be enough for everyone's need but not for everyone's greed population trends after 2050 are harder to predict enhanced education and empowerment of women surely a benign protein itself could reduce fertility rates in the places where they're now highest in India and in particular in sub-saharan Africa but if families in Africa for instance remain large then according to the UN that continents population could double again between 2050 and 2100 Nigeria would then alone have a population of 900 million equal to the population at that time of both Europe and North America added together and Africa's population would get up to 10 times Western Europe's but optimists say that each extra mouth brings two hands and a brain but its geopolitical stresses of that scenario which are rather worrying because sub-saharan Africa can't escape poverty in the way that these sort of Asian Tigers Taiwan and Vietnam did by undercutting Western manufacturing costs which robots can do that now and everyone in Africa they may not have good sanitation but they do have mobile phones and they know the injustice of their fate and migration is easy this is the recipe for instability multiple mega versions of the tragic boat people crossing the Mediterranean today so when important message I think is wealthy nations especially in Europe should urgently promote growing prosperity in Africa and not just for altruistic reasons but so much for population now another thing if you manage is collective impact on land use and climate pushes too hard the resultant ecological shock could irreversibly impoverish our biosphere extinction rates are rising we are destroying the book of life before we've read it already there's more biomass in chickens and turkeys than in all the world's wild birds the biomass in humans cows and domestic animals is 20 times that in wild mammals biodiversity is crucial for human well-being but for many environmentalists preserving the richness of our biosphere has value in its own right over and above what it means to us humans and to quote the great Harvard ecologist here Wilson mass extinction is the sin that future generations would least forgive us for so the world's getting more crowded and there's a second firm prediction it regretted to get warmer the famous Keeling curve here which has measured the concentration of carbon dioxide in the atmosphere over the last 50 or so years shows this rising trend the oscillations incidentally are because there are more trees in the northern hemisphere than the south so in the autumn when the leaves fall off the trees the co2 goes up and that's taken up again in the spring but the main point is that superimposed on those lessons there is this rising trend which is what of course is worrying because carbon dioxide is a greenhouse gas and the fifth IPCC report presented a spread of predictions four different assumptions about future rates of fossil fuel use and associated rises in the co2 concentration these are fairly familiar graphs it's important to mention that there are some scientific uncertainties in the feedback effects we know what the co2 itself does but we don't know how the rise in co2 affects the change in water vapor cloud cover and things like that so the bars on the right hand side indicate the range of uncertainty for each of the four different scenarios for future fossil fuel-burning how about covering some details of those but this just shows the range but despite the uncertainty the most important message is that under businesses user scenarios may be gone burning fossil fuels we can't rule out later this century really catastrophic and irreversible warming and tipping points triggering long-term trends like the melting of Greenland ice cap this is what we urgently need to prevent but because the trouble is that politicians mode gain much resonance by advocating and welcome lifestyle changes or high carbon tax when the benefits accrue mainly to distant parts of the world and a decade in the future they will only act if they think voters are behind them and that's why what matters is what in their inboxes what's in the press and also demonstrations so we should welcome the recent demonstrations especially those involving young people because the young people are those who will still be alive at the end of a century they are not going to agree with economists who discount the future so much that what happened after 2050 carries no weight so we should welcome these demonstrations and hope that policies will realize that the voters are behind them in dealing with climate ace as also they should be in other things like cleaning up the plastic in the earth in the in the oceans but it's a political challenge and I think this one win/win roadmap to a low-carbon future which I'd like to mention and this is that nation should accelerate their research and development into all forms of low-carbon energy generation and into other technologies where parallel progress is crucial energy storage batteries compressed air pump storage flywheels hydrogen etc and smart grids because the faster these clean technologies advance the sooner will their prices fall so they come affordable too for instance India we're more generated capacity will be needed and where the health of the poor is now jeopardized by smoky stoves burning wood or done but where if renewable energy is too expensive there'd be pressure to build coal-fired power stations so we need a real crash program to develop cheap clean energy for the world Sun and wind are of course the frontrunners but other methods have geographical niches tidal and geothermal for instance and also because of local intermittency of wind and Sun we need continental scale DC grids we need to carry cell the energy from the sunny south to the Klaudia and less sunny north and we need to have grids to carry energy east-west to smooth a low peak demand in different time zones all across North America and I would hope perhaps all the way from Europe to China as part of the Chinese belt and road development that's what we need and I mentioned Sun and wind but despite wide ambivalence about nuclear energy I think it's worthwhile to boost R&D into a variety of fourth-generation concepts which could prove to be more flexible in size and safer than the 1960s vintage designs now been used small modular reactors for instance and a potential payoff for fusion is so great that is surely worth continuing experiments and prototypes of that indeed if we had to think of a more inspiring challenge for young engineers than devising clean and economical energy systems for the world and incidence reminds me that this is a scientific institution and its engineers who are going to do this and inform engineers and I'd like to put in a bit of pre-emptive modesty speaking as a scientist because engineers rather like a cartoon in The New Yorker many years ago and the cartoon showed two beavers looking up at a big hydroelectric dam when beaver said to the other I didn't actually build it but it's based on my idea and that fairly truly reflects the balance of effort between armchair theory and what's actually practical and feasible and actually works which is what engineers do and we need the engineering but it's mostly based on science and since we're in one of the international temples of extreme theoretical science I'd like to say often tell my colleagues that the Swedish engineer who invented the zip fastener made the greater intellectual leap than most of them will do in their lifetime so that's a bit of modesty but it really is the case that most of the brain power is needed in the technology and the Applied Science and we should be evangelists for new technology not Luddites without it the world can't provide food and sustainable energy for the expanding and border mounting population reaper dates but we need wisely directive technology clean energy is one well it isn't incidentally which I should have mentioned is a plan B if we don't control co2 emissions geoengineering where we put some sort of dust in the upper atmosphere to cool down the planet that's something which would cause all kinds of international problems because different countries will want to adjust the thermostat differently the only beneficiary with the lawyers because if nations could litigate over bad weather that's a bonanza for them but geoengineering said we want to avoid at least the top kind of geoengineering there the second kind where you simply extract the co2 from the air fear on doing the Geoengineer we done unwittingly by burning fossil fuels that is benign but that is very expensive of energy and isn't feasible at the moment so that's the technology that we don't want to develop at the moment but we do need wisely directed technologies and many are anxious though that some technologies are developing so fast if we may not properly cope with them and we might have a bumpy ride through the century that's another theme of my book in fact where ever more dependent on elaborate networks of all kinds electric power grids air traffic control International Finance just-in-time delivery and so forth and unless these globalized networks are highly resilient their manifest benefits could be outweighed by catastrophic breakdowns real-world analogs of what happened to the financial system in 2008 and these could cascade globally our cities will be paralyzed without electricity supermarket shelves empty within days if supply chains were disrupted air travel can spread a pandemic worldwide within days now and social media can spread panic and rumor and psychically economic contagion literally the speed of light but what about these new technologies advances in biotech Diagnostics vaccines and antibiotics offer huge prospects for improving health and of containing pandemics for instance but the same research innovations have controversial aspects give an example in 2012 researchers in Wisconsin and also in Holland showed it was surprisingly easy to modify the flu virus to make it both more virulent and more transmissible some this was a scary portent of things to come and they need the US federal government stopped funding these so-called gain-of-function experiments and also the new CRISPR cast nine techniques for gene editing are hugely promising but their ethical concerns about for instance the recent Chinese experiments on human embryos for instance and also worries about possible runaway consequences of so-called gene Drive when you can drive a particular species to extinction that may be fine if it used to wipe out the mosquito that carries a Zika virus for instance that's been tried but some nasty people have wanted to wipe out the grey squirrel in England because it can't compete very well with the brown squirrel but of course if you modify the balance of species you may have run away unintended consequences this is where we have to be very cautious about what we do but in applying these powerful techniques of gene editing gain-of-function etc clearly we need regulation but I worry that whatever regulations are imposed on grounds of prudence or ethics can't be enforced worldwide any more on the drug laws kin or the tax laws I worried that whatever can be done will be done by someone somewhere and that's a nightmare whereas an atomic bomb can't be built without large-scale special-purpose services which can be monitored by inspectors biohacking involves small-scale you loose widely available equipment indeed biohacking is burgeoning even as a hobby and competitive game and we know all too well that technical expertise doesn't guarantee balance rationality the global village would have its village idiots and they'll have global range the rising empowerment of tech sir groups or even individuals and powered by bio as well as cyber technology will pose an intractable challenge to government's and aggravate the tension between three things we want freedom privacy and security and all these concerns I think a fairly near term within the next 10 or 15 years but what about 2050 and Beyond on the bio front we may then expect two things first a better understanding of the combination of genes that determine key human characteristics looks intelligence etc these we found by using AI to analyze huge numbers of human genomes but then having done that you may have the ability to synthesize genomes that match these features designer humans and indeed the great physicist Freeman Dyson conjectures a time when children will be able to design and create new organisms just as routinely as his generation played with chemistry sets but if it really becomes possible to as it were play God on a kitchen table ecology leave now species may not survive unscathed and what about another transformative technology robotics and artificial intelligence AI as I'm sure everyone knows has been exciting advances in generalized machine learning deep mind a London company now bought by Google achieves a remarkable feat its computer beat the world champion in the game of Go and then in the game of chess and now beat human experts in optimizing proton folding and the computer to play go and chess was not like the computer that beat Kasparov 20 years ago which was by expert players if we're just given the rules and gained expertise by playing hundreds of thousands of games against itself in a single day the programmers don't themselves know how the machines made seemingly insightful decisions it is of course here's the human go player who looked a bit surprised to be defeated but it is of course the speed of computers which allows them to succeed by brute force methods in these games and computer can learn to identify dogs cats and human faces by crunching through millions of images not the way babies learn and they learn to translate by reading millions of pages of multilingual text in Europe they're given the European Union documents their boredom thresholds infinite the social implications though of these machine learning achievements are already ambivalent if we are sentenced to a term in prison recommended for surgery or even given a poor credit rating we would expect the reasons to be accessible to us and contestable bias if such decisions were entirely delegated to an algorithm I think we'd be entitled to feel uneasy even if presented with compelling evidence that our average the machines made better decisions than the humans they use herbed a our systems will become more intrusive and more pervasive records of all our movements our health and our financial transactions will be in the cloud managed by a multinational quasi monopoly and to be other privacy concerns are you happy if a random stranger sitting near you in a restaurant or on the train can bar facial recognition identify you and invade your privacy or if fake videos of you become so convincing that visual evidence can no longer be trusted and the arms race between cyber criminals and those times to defend against them will become still more expensive and vexatious these are all near-term concerns computers succeed by reinforced learning on these big training sets but it's not so easy to get them to learn common sense and to learn about human behavior which that involves observing real people in real homes or workplaces and the machine would feel centrally deprived by the slowness of real life and we will be bewildered it's like us watching trees grow they think so much faster than that and to quote Stuart Russell who's a leading expert on AI at Berkeley I quote he said the machine could try all kinds of things scrambling eggs stacking wooden blocks chewing bars poking its finger into electric outlets but nothing will produce a strong enough feedback loop to convince the computer was on the right track and lead to the next necessary action so robots can't really learn by watching human beings the common sense and etiquette which are important to all of us and of course though they have the advantage of speed robots are still clumsier than a child in moving pieces on a real chess board they can't jump from tree to tree like a squirrel though a Boston Dynamics robot there is can apparently do somersaults but in a rather clumsy way and of course another context where humans have the edges of the go plane computer used hundreds of kilowatts of power but the brain of mr. Lok we the human challenger uses about 30 watts just like a lightbulb and he could do many other things as well as just playing go but machines are clearly catching up where will lay has the biggest impact they take over some manual work but they will just take over manual work indeed plumbing and gardening will be among the hardest jobs to automate but they will supplement humans in professional areas routine legal work coding medical diagnostics and even surgery and the big social and economic question is then will this new machine age be like earlier disruptive technologies the car for instance and create as many jobs as it destroys or is it really different this time the money earned by robots will clearly generate huge wealth for an elite of individuals and companies but I suggest in my book that to preserve a healthy society will require massive redistribution of that income to ensure that everyone has at least a living wage but this shouldn't be a handout it should be achieved by creating huge numbers of upgraded public service jobs where the human element is crucial and which are now undervalued and where the amount is huge among these of course I'd especially emphasize carers for young and old but also custodians guards in public parks and so on if enough such jobs can be created and published supported to re-employ those now doing mind-numbing jobs in call centers and Amazon warehouses that's surely a win-win situation to be welcomed I could see this massive redistribution happening in China in Scandinavia maybe in Canada though I think it's less likely in countries that fetish low tax rates like my country and the United States but let's now look still further ahead how human or human-like will future robots be hey I can cope with things where it doesn't have to look human-like at all and cope with complex fast changing networks traffic flows or electric grids for instance and the Chinese could have an efficient planned economy of a kind that math could only dream of and AI can help science to perhaps you can find the recipe for a high-temperature superconductor or find the best chemical composition for drugs or settle where the string theory really describes our universe it can help with all those things but what of a machine to veldt a mind of its own would it stay docile or go rogue popular cultures of course portray a dark side when AI gets out of its box infiltrates the internet of things and pursues goals misaligned with human interests we even treat humans as an encumbrance well this is fascinating science fiction but some AI pundits of course take it seriously and think that the field already needs guidelines just as biotech dolls but others like for instance Rodney Brooks the inventor of the Baxter robots and the Roomba vacuum cleaner regardless concerned as premature he thinks it'd be a long time before artificial intelligence will worry us more than real stupidity but be that as it may it's likely that society would be transformed by autonomous robots even though the jury's out of whether they'll be idiots avoir or displays superhuman capabilities this is the futurologist Ray Kurzweil now working at Google he argues that once humans have been surpassed by machines the machines will themselves take over and design and assemble even more powerful machines to be an intelligence explosion he wrote a book called the age of spiritual machines where he predicted that humans would transcend biology by merging with computers in old-style spiritualist parlance they would go over to the other side we then confront the classic philosophical problem of personal identity could your brain be downloaded into a machine if so in what sense would it still be you should you be relaxed about your original body then being destroyed what would happen if several clothes were made of you these are ancient conundrums for philosophers the practical ethicists may need to address them later in this century because while is worried that his nirvana may not happen in his lifetime so he wants in the meantime for his body to be frozen in liquid nitrogen and the company in Arizona that will freeze and store your body so that when immortals an offer you could be resurrected or your brain downloaded others have gone in for this too and I was surprised to find in fact that three academics in England who I know have gone here for this cryonics to paid the full whack the third took the cut price option of just watching his head frozen I was glad all three of him Oxford not from our University and I told them I'd rather in my days in an English church yard than an American refrigerator but of course research on Aging is being prioritized seriously we don't know if the benefit will be incremental or whether aging is a disease that can be cured dramatic life extension would plainly be a real wild card in population projections with huge social ramifications but it may happen along with human enhancement in other forms and it's just least surely on the cards that human beings their mentality and their physique may become malleable through the deployment of genetic modification and cyber technology moreover this future evolution a kind of secular intelligent design would take only centuries in contrast to the thousands of centuries needed for Darwinian evolution and this is a game-changer when we admire the literature and artifacts that have survived from antiquity we feel an affinity across a time gulf of thousands of years with those ancient artists and their civilizations but we can have zero confidence that the dominant intelligence is a few centuries from now we'll have any emotional resonance with us even though they may have some algorithmic understanding how we behaved and now I want to turn to another technology space my special interest because it's beyond our earth in environments hostile to humans that cyborg and AI technologies have the most spectacular scope and where these changes will happen fastest and will worry us less during this century the whole solar system will be explored by swarms of militarized probes far more advanced than the wonderful Cassini instruments designed in 1990s we spent 13 years exploring Saturn's moons and the european probe rosetta which landed a robot on a comet or the NASA probe New Horizons which sent back these pictures of Pluto 20,000 times further away than the moon think back to the computers and phones of the 1990s when the probe that took these pictures was designed and realized how much better we can do today the next step also in space will be the deployment in space of robotic fabricators which can build large structures for instance Jon telescopes with huge gossamer thin mirrors assembled under zero gravity and solar energy collectors but what about manned spaceflight with all these advances in robotics the practical case for sending people into space gets weaker so will man space forever be resurgent it's 50 years since Niels Armstrong's first small step on the moon and I cherished this picture signed for me a few years ago by seven of the Apollo astronauts in the 1960s there was of course a space race between America and Russia NASA then got about four percent of the federal budget had that pace continued there would have been footprints on Mars long before today but of course once the race to the moon was won by the Americans there was no motive for continuing this requisite expenditure and NASA now gets about 1.5 percent of the federal budget but of course hundreds more have ventured into space subsequently but anti-climatic lee they've gone into low-earth orbit no further and done no more than circle the earth most of them in the international space station show and this really only makes news when something goes wrong when the Lu fails for instance or when the Canadian astronauts perform stunts like this Hatfield playing his guitar these make great public interest but will it be any inspirational Apollo style project there's no denying that nasa's curiosity probe trundling across a giant martian crater and leaving the tracks which you can just see the course of the way up that picture that may miss some exciting things that a real human geologist would detect but machine learning is advancing fast as his sensor technology in contrast the cost gap between manned and unmanned missions remains huge NASA's man program ever since Apollo has been impeded by public and political pressure into being exceedingly risk-averse Space Shuttle failed twice and a hundred thirty-five launches test pilots was willing except this 2% level of risk but the shuttle had unwisely be promoted as safe for civilians and each failure was a national trauma so because of the safety culture NASA will confront political obstacles in achieving any grand goal within a feasible budget China has the resources to D reduce government and maybe the willingness to undertake an Apollo star program but leaving aside the Chinese I think the future of manned space flights lies with privately funded venturers prepared to participate in a cut-price program far riskier than Western nations could impose on publicly supported civilians along mask SpaceX and jet palaces Blue Origin will soon offer orbital flights to paying customers what an American I would only support NASA's unmanned program I'd argue that private enterprise like those should front all man's missions as cut-price high-risk ventures but still be many volunteers some perhaps even accepting one-way tickets driven by the same motives as early explorers Mountaineers and alike by 2100 courageous thrill-seekers may have established bases independent from the earth on Mars or maybe on asteroids musk himself aged 48 I think says he wants to die on Mars but not on impact and you might but don't ever expect mass emigration from Earth no way in our solar system offers an environment even as Clement as the top of Everest or the South Pole and here I disagree with musk and with my late colleague Stephen Hawking I think it's a dangerous delusion to think that space offers an escape from Earth's problems dealing with climate change on earth is hard but it's a doddle compared to terraforming Mars there's no planet B for oddly risk-averse people nonetheless we should cheer on these brave space adventurers because they'll have a pivotal role in spearheading the posthuman future and determining what happens in the 22nd century and far beyond this is why they'll be ill adapted to their new habitats so they'll have a more compelling incentive those of us on earth to redesign themselves they'll harness the super-powerful genetic and cyber technologies that have been developed in coming decades these techniques will one hopes be restrained here on earth but settlers on Mars will be beyond the clutches of the regulator's and we should surely wish them good luck in modifying their progeny to adapt to alien environments so it's the spacefaring adventurers not those of us country adapted to life on Earth who will spearhead a posthuman era and this raises the question astronomers are most often asked is there life out in space already or is the galaxy waiting for our progeny in the far future to spread through it and of course electronic intelligences are near immortal a million your voice is no deterrent to them well we all agree that we don't know it's as life out there well not quite all because I get letters from people you say they've met the aliens they've been abducted by them and I tell these people do they really think that if the aliens had made a huge effort to traverse interstellar space they just meet once who well known cranks make a call circle and go away again seems unlikely to me and I tell these people to write to each other and not write to me well more seriously we noticed there's no way in our solar system where there's any advanced life it could be some freeze-dried bacteria on the Red Planet it could be something under the ice of Enceladus this is a moon of Saturn but if we widen our horizon beyond our solar system to remember the stars then prospects are very different indeed and very exciting we've learnt in the last 10 or 20 years that most stars in the sky are orbited by retinues of planets just as the Sun is orbited by the earth and the other familiar planets but the evidence is mainly indirect we don't observe the planet but detected influence on the motion or brightest of the stars orbiting simplest technique is this that if a planet moves or transits across the face of a star then the star dimmed slightly and if you watch observe the star and these regular dim beings you can infer there's a planet orbiting it and this NASA spacecraft called Kepler stared for three or four as an area of sky containing 150,000 stars and mana stirred them every hour with a very high precision to find just these effects and it found literally thousands of stars in its sample which had planets and this rather silly cartoon illustrates the summer system they'd found where the this shows to scale the orbital periods and the masses and sizes of the planets and what we've learned is that almost every star has a planet around it and one in every six stars has a planet rather like the earth about the mass of the earth and about the distance from its parent star such that water could exist neither boiling away nor staying frozen and are some very strange systems this is a system where there are seven planets orbiting around a very faint star called an M dwarf it's a miniature solar system the stars one percent is priced as Sun and these seven planets have years which are from one on 1/2 Earth days to about 20 Earth days and these planets was there closing they be tightly locked presenting their same face to the Sun or others moon presenta same face to us so half of the planet if who lives on ever be in brightness all the time one in perpetual darkness so I guess had been a kind of apartheid everyone would live in the bright half except the astronomers would be on the other side in the dark bit we don't know what these plans would look like this is just an artist impression but the trouble is we now only infer these planets indirectly from their effect on the star they're orbiting we die to actually see them and that's a big challenge to imagine the challenge let's suppose that the were some aliens with a big telescope say 30 light years away from the earth they would see our Sun as an ordinary star and a to the earth as in Carl Sagan sighs phrase a pale blue dot very close in the sky to its star son but billions of times fainter but if their telescope was powerful enough to actually observe the pale blue dot you could learn quite a bit about it because the shade of blue will be slightly different depending on whether the Pacific Ocean or the landmass of Asia was facing them so they can infer that there were continents and oceans lengths of the day and by analyzing the light carefully they could refer to oxygen in the atmosphere and maybe lots of green stuff on the lab we can't do that yet but within 10 or 20 years we be able to draw inferences just like that about earth-like planets around other stars this be done partly by the Space Telescope James Webb telescope but rather better by this telescope we will play European astronomers and Europeans are not very imaginative in their nomenclature it's called the extremely large telescope and it's being built now on a mountaintop in Chile and it's got a mirror which is 39 metres across and that's bigger than the length of this lecture on I'd guess it's a mosaic of 800 pieces of glass and this will have the combination of resolution and sensitivity to actually analyze the light from planets like the earth around nearby stars and that will indeed be very exciting but of course habitable doesn't mean inhabited but for that the most of us that's the number one question although we know there are lots of habitable planets we don't know the likelihood that they will have life on them that's because we know not much about how life got stars on earth we understand the winning evolution but we don't know what triggered the transition from complex chemistry to the first metabolizing reproducing system will call alive we don't know if it's a rare fluke or whether it would have happened in any environment like the young earth of course we know even less about the likelihood of intelligent life even if we had simple life being widespread in terms like words to be rare but it's such a fascinating question that I think these SETI searches are well worthwhile even if the chance of success is small and I'm actually a chair of an advisory group for your ramona's breakthrough listen project which is trying to do this but as a topic for another lecture or maybe with a question period I want now to indulge briefly in some speculations on the really far future bearing in mind that I'm speaking an institution that thinks about the more speculative kinds of cosmology first let's think about timescales this is a familiar time chart showing the history of life on Earth taken about 4 billion years for us to evolve many people who are familiar with this somehow think that we humans are the culmination of it all but no historico believe that because our Sun is lessened halfway through its life it's not 6 billion years more before it dies any creatures witnessing the demise of the Sun when it will look something like this will be as different from us as we are from slime mold and of course even when the Sun dies the universe will go on expanding maybe forever to quote Woody Allen eternity is very long especially towards the end so because of these vast expanses of time in the future even if life had originated only on the earth it need not remain a trivial feature of the cosmos humans could jumpstart a diaspora whereby ever more complex intelligence spreads through the whole galaxy var self-reproducing machines transmitting DNA it's trust for 3d printers or such like interstellar voyages would hold no terrors for near immortals and this has implications for SETI searches because if the emergence of intelligence on another world had follow the similar evolutionary path to us happened here then were we to detect et we most unlikely to catch it in the brief sliver of time when we're still inorganic for which our earth between four and a half billion years before technology emerged it's been around for a few millennia maybe in one more millennium it'll be superseded by electronic intelligence which will then go on for billions of years so that means that it's far more likely if we detected something artificial it would be not an organic civilization but something which was created by a long-dead organic civilization that therefore means its identity if we discovered something artificial is most unlikely that it would be a signal that we could decode it would be so alien from human beings maybe a by-product or even a malfunction of some super complex interstellar technology that could trace his lineage back to alien organic beings but they might long ago have died out well let's now widen our horizons even more to the entire cosmos which could eventually be within the range of post-humans the death of stars would be no impediment to them nor the merger of our galaxy with Andromeda in four billion years or perhaps we'll be like this train crash here two galaxies merging together the simulation shows what happens and that drama doored hit us about four billion users and if you look further away we see that there are many many billions of galaxies as we can see and these galaxies and emerge remnant of us and the Andromeda galaxy will persist for hundreds of billions of years time enough perhaps to approach the peak intelligence limit where all the atoms that were once in stars could be transformed into some vast structure as intricate as a living organism or silicon chip but even so even with all this some parts of space-time would still be unreachable we can see billions of galaxies here each harboring billions of planets but it's still only a finite number observations are constrained within a horizon the shell around us which delineates the limit of the distance light can have traveled since the Big Bang but that shell has no more physical significance than the circle that delineates your horizon if you remember the ocean you don't think the ocean necessary stops just beyond your horizon so the observable universe is only a fraction of the aftermath of our Big Bang we'd expect far more galaxies located and observed we beyond our horizon most astronomers would guess that as extend that he's 100 times further because just a minimum you could extend so far that all combinatorial possibilities will be repeated far beyond the horizon because all have avatars making the right decision when we make the wrong one which may be some minor comfort to you but that's not all our Big Bang may not be the only one as is illustrated in this cartoon it could be just one island in a vast cosmic archipelago this is Andrei Linde the Russian cosmologists idea of eternal inflation and our many other ideas the multiverse ideas are still spectra to physics that's because we don't have a battle-tested theory which describes the very beginning of our Big Bang and indeed a challenge for 21st century physics and for the this institution is to see which part of this decision tree is correct and to address two fundamental questions first are there many big bangs or just one second if there are many are they all governed by the same physics because other big bangs have cooled down differently ending up with different geometry different particles forces of different strengths and so forth in the latter case many universes could be stillborn or sterile because the laws prevailing in them might not allow any kind of complexity we therefore wouldn't expect to find ourselves in a typical universe but a typical member the subset which allows complexity to evolve this is what's called anthropic selection and in this case what we call the universal laws may in the grand perspective of the multiverse be just parochial bylaws in one cosmic patch as it were so just as Earth may be a very special planet among zillions of others so on this far grander scale our Big Bang may have been a special one some physicists foam at the mouth of this idea but our preferences are relevant to the way physical reality actually is we don't know which branch of this decision tree is correct and should surely be over minded space and time on the grandest scale could have a structure as intricate as a rich ecosystem current concept of physical reality could be as constricted as the perspective of the earth available to a plantain whose universe is a spoonful of water about ten years ago I was on a panel at Stanford University where we're asked by the chairman Bob Kirchner how much we bet on the multiverse concept he asked how much will you bet on a scale would you bet your goldfish your dog or your life I said I was almost at the dog level and Andrei Linde who had spent 25 years promoting eternal inflation he said he'd almost bet his life on it and later on being told about this the great theorist Steven Weinberg said he'd happily bet Martin Reese's dog and Andrei Linda's life well Andrei Linde a my dog and I we'll all be dead long before this is settled but it's not metaphysics it's highly speculative but is exciting science and it may well be true well forces have not got more time to get more deep into speculations so let me end by zooming back in from the universe even from an ensemble of universes to the realities here and now even in the context of a concertina time line stretching billions of years into the future as well as into the past then as I said at the beginning this century is special it's the first when our species had vanished future in its hands and we could inaugurate this transition into post human evolution even more marvelous and what's led to us on the other hand if we screw up humans could trigger bio cyber environmental catastrophes that foreclose all sort of potentialities so technology as I've emphasized in my book and all through needs to be wisely directed and directed by a set of values which science itself can't provide so I found conclusion is that our earth this pale blue dot in the cosmos is a special place it may be a unique place where it's stewards at especially crucial era and that's an important message for us all whether or not we're astronomers thank you for listening [Applause] very good thank you so much we're gonna open the floor to questions so for those in the theater the microphone is right there and online I have a whole list of questions so we'll start here Martin here's the question that it's easy to get pessimistic given all the challenges you've described how do you remain optimistic for Humanity yes well cheerfulness does keep breaking in of course as dr. Johnson said when he was asked why he wasn't a philosopher um but I think we must realize that probably for most people this is the best time to be alive some people of course were fine in the past but far more people are leading reasonably happy comfortable lives now than any previous generation so we shouldn't be pessimistic about that but what does make me a bit pessimistic is that although clearly the lives of people today are much better than the lives of the average person in medieval times the gap between the way things could be and the way they are is much wider in medieval times it wasn't very much they could do to improve things whereas now there is a huge amount we could do to make a better life and to take one example of the wealth of the 2,000 richest people in the world would be sufficient to double the income of the bottom billion in the world and the fact that that's not happening is one of many ethical indictments of our current civilization so I think we can be happy that there is an improvement but I think we must be pessimistic about the gap between the way things are on the way they could be thank you let's go in the theater here hi there I just want to preface this by saying I'm not an expert on any of this and definitely not one of the smartest people in the room you touch briefly on designer babies and I think a lot of us would agree that having a designer baby to prevent a heritable disease would probably be okay and maybe even someone who just was a little on the slow side or maybe you know was order just like could use a little tuning up I'm sure some of us would be ok with that but I think a lot of people get really uncomfortable when you start getting people above average like the people you know that can eat anything they want and still stay skinny the people who will learn something overnight and be smarter than you when we're able to do that that would cost a lot of money so the rich are no longer getting richer the also getting smarter and what do you think that would be ethical or where would you stop that no if I had more time I'd have said exactly what you've just said I think it's certainly acceptable to Jean edit if it's something like Huntington's disease we're changing one gene can save people from fatal disease but of course the Chinese case when they reduce propensity to HIV and possibly led to other is that was thought not to have the same balance of benefits over over risks and of course when it could when we come to the stage be able to design humans and that'll be quite a long time in the future which we need to understand the genome and attributes of depends on many many genes then of course there is going through the issue of is it ethical and if it's allowed will it lead to a more fundamental kind of inequality than we have now so indeed that is a very deep ethical question I think and and that's why I rather hope that that will be effectively regulated and left to the crazy guys on Mars let them do it the next question Roger you mentioned how the poorest billion can and should be lifted out of poverty by redistribution of wealth from the wealthiest mm of course the wealthiest mm we'll never agree to such an arrangement voluntarily so are you in fact Cohen for expropriations do in a way with capitalism and switch into socialist economy and I hope that you do I didn't quite catch the last bit do you in fact call for expropriation of wealth and doing away with capitalism and switch into a socialist economy of some sort I think the answer is yes I think the any calls are gross and should be reduced and I think they could be reduced tremendously without eroding incentives etc so I certainly think that the growth in financial inequality is damaging to the health of society and it could be reduced and should be reduced yes thank you thank you all right here's an online question I just lost it but it's coming back there seems to be a rise in anti-scientific sentiment lately how do we compact this trend in favor of science well this is a difficult question I think again let me be optimistic I am gratified by the amount of interest in science even the silent which is far from everyday concerns I mean for young kids dinosaurs on space are the most popular topics and that illustrates how people are fascinated by the wonder of these things and that should be encouraged I think one of the troubles is that in the era of social media extreme and ill-informed opinions get more traction more easily this I think is the origin of populism that in the past the public media like the newspapers they were filtered by reasonably competent people and so the extremes were damped out whereas now as the reverse is the case and I think that's also true of the extremes of anti science that they along with all other kinds of extremes flourish on the internet but I think since you mentioned science I think it is very important that everyone should have a feel for science because as I think I indicated most of the decisions that have to be made by politicians if they involves a health the environment energy they all environment they all involve some science they involve economics and ethics as well but they involve science and so to be an informed citizen people need to have some feel for these subjects as also they need to have some feel for numbers so they can't be bamboozled by bad statistics so everyone needs to have some scientific background but I'd also like to say that apart from it being important for citizen it's part of our culture I think it's a shame if people don't understand about Darwin and about the cosmos etc and science is part of our culture and it's the only universal culture it's travels all boundaries of faith and nationality and that therefore means it's selves we all have in common and that's a further reason for trying to hope that most people have some feeling for it and appreciation of it thank you and question here given your extensive experience both in research and in politics and more particularly your adviser role I'm curious to know if you have any strong recommendations for how we can coordinate multinational efforts with respect to innovation in this space and the motivation comes from a place of the fact that a lot of as you said social media is pervasive and the fact is a lot of Millennials as well as Generation Z those under 18 are very interested in sort of this vision for a transhumanist future and we live currently in a society where the structures are either difficult to navigate or seem at odds with each other so to rephrase the question for simplicity what is your recommendation for multinational collaboration yes yes well I won't talk about the more futuristic transhuman part of your question but I think it is clear that we need to have more organizations rather like the instant atomic energy age see and the World Health Organization to cope with the environment and energy and probably with AI because the multinationals straddle national boundaries and if it wants to regulate them it's got to be some international body which does that so I think we do need to have these multinational bodies and also because many of the problems its confront us on government climate etc can't be tackled on the national basis they've got to be tackled multinationals so say we do have to give up some of our sovereignty one exception I say one reason why I plugged the idea of R&D into clean energy being exceeded up is that that's one example where you don't need cooperation it's in everyone's interest to be first in developing some exciting new kind of clean energy because they get the world market and I may I preach this in when I'm in Britain because so Britain has been ahead of most other countries in having legislation to move towards zero carbon by 2050 and but of course even if we do that then we are only 1% of the problem but I think our country has perhaps produced more than 1% of the world's clever ideas over the last 200 years and if we really focused on the energy then perhaps we could as indeed could Canada do more to reduce co2 emissions by helping India and China to cut theirs rather than cutting our own thank you all right one last question and I say it with a bit of a wink and an apology but it's got three stars so I have to have to read it do you think we will ever discover or even encounter intelligent life elsewhere in the universe and if so what would that mean for Humanity yes okay well I did sort of loot that but let me just say a bit more I think again we just don't know it could be that technology is so rare does it only really happened from the flesh-and-blood creatures which were evolved on this planet but many people think that Sun lately and therefore it's worth having a look for any kind of artificial seeming artifacts and artificial seeming emissions from objects so this is a SETI program but I think the one take I would put on this is that if we do detect something then the scenario I gave for the evolution of on this planet which is a full billion years emerging technology of a few thousand years and then the machines take over that suggests that if we detect something which is manifestly artificial it's not going to be a flesh-and-blood civilization it's going to be some electronic artifact may be left behind or evolved from that civilization and that this means that it's most unlikely that it will be some sort of decodable message it's very unlikely and I'm incidentally and people probably know what - so-called family paradox which has you know if the loss of aliens why aren't they here already why haven't they come and come and eat enough so cetera this is worried and some people say we shouldn't send out any signal because they would say well they're but they would know they know we're here already if they exist but I think the point I would make is that if the future intelligences are sort of intelligently designed automata probably electronic then they'll be different from us because our emergence has required a combination of intelligence and aggression but the evolution of these posthuman electronic intelligences may lead to developing intelligence but it's no reason why it should lead to aggression and so one answer to the Fermi paradox is that there are lots of these entities out there they're all living controvert of lives and they're not aggressive and they're out there and they're so difficult most we have noticed ladies and gentlemen sir Martin Rees [Applause] [Music]

Channel: Perimeter Institute for Theoretical Physics

Views: 26,677

Rating: 4.7818184 out of 5

Keywords: physics, theoretical, perimeter, institute, canada, ontario, science, stem, Martin Rees, Astronomer Royal, astronomy, ethics, public lecture, education, environment, cosmology

Id: Hm-xn-L0z4Y

Length: 76min 46sec (4606 seconds)

Published: Thu Oct 03 2019

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[u/ragica]

"In his public lecture at Perimeter on October 2, 2019, Sir Martin Rees (UK Astronomer Royal) explored how advances in biotech, cyber-technology, robotics, and space exploration could allow for a bright future for humanity, as well as the very real risks we face as a society."