00:00:19.000 So what can we know about what this conference is calling a day in the deep future?
00:00:29.000 I guess we're all curious about what life will be like by then, what new opportunities will have opened up for people and what problems they'll be thinking about, including maybe about their own future.
00:00:49.000 Also, what we may be able to do today to improve the chances of the fake outcomes and try to prevent the less favorable ones.
00:01:06.000 But before we can even think relevantly about any of that, there's a more fundamental issue that we need to address first, namely what kinds of things are knowable in advance and what is not.
00:01:25.000 I want to tell you about a fundamental limit on the power of science and technology and reason to predict the future.
00:01:43.000 And also about what we're going to have to do about that.
00:01:49.000 So, prophecy, fortune telling has always been popular to date.
00:01:58.000 People want to know whether their plans are going to succeed or fail.
00:02:03.000 And there's always been profits claiming to be able to find out.
00:02:12.000 What they really do is just either tell people, tell the punters what they wanted to hear and take their money, or they threaten them with doom unless they behave righteously, in some sense.
00:02:29.000 And either way, they're just making stuff up. They have never had genuine knowledge of the phenomena that they purport to predict.
00:02:42.000 And for most of history, nor did anyone else. People just used a wishful thinking or superstition or at best, they used traditions and rules of thumb that had worked in the past.
00:03:05.000 Or were thought to have worked, often they hadn't, often structures collapsed, crops failed, ships sank, people died of treatments that were supposed to be cures.
00:03:23.000 Nowadays, such tragedies are much rarer because we have scientific knowledge, which is predictive. That's the defining characteristic of science.
00:03:36.000 And that allows mistaken scientific theories to be corrected when they make false predictions, which allows for cumulative improvement in our ability to predict.
00:03:51.000 And it's not just cumulative. Progress is exponential.
00:03:57.000 And that's basically because scientific knowledge is not just testable, it's explanatory, it derives its predictions from the understanding of how things actually work.
00:04:12.000 So, we don't predict the maximum safe load of a bridge from past experience anymore. We predict it by understanding what makes structures in general stand up.
00:04:27.000 And that allows for new designs of bridge that are not covered by any existing rules of thumb. And it also allows bridges to new ways of creating knowledge, like new scientific instruments and computers and communication and sheer wealth.
00:04:51.000 So, the, the, the, one of the things that explanatory knowledge provides is, is wealth, which allows for the creation of new knowledge in the sense of increasing the repertoire of physical transformations that human beings are capable of causing or preventing also.
00:05:13.000 And as this repertoire expands, and we increasingly cause the outcomes that we prefer, our ability to predict those outcomes, those same outcomes correspondingly increases.
00:05:30.000 Some things remain technically unpredictable because they're random or because they're so complicated that they can't be distinguished from random. But that's no impediment to predictability in the practical sense, because if science predicts that something is random, we can play the odds.
00:05:49.000 And again, technology allows us to change the odds in our favor. So, I can, if there's a random process such as weather, then I can use an umbrella, not only to change the probability that I will get wet, but also to increase my probability of predicting whether I will get wet.
00:06:15.000 And so, the faster we gain new understanding and new technology, the faster our predictions also improve. And so, you might expect that our ability to predict the future would be greater now than ever before in history.
00:06:34.000 And that isn't so, because there's one thing in our future that nothing whatever is capable of predicting, and that is the future course of knowledge itself.
00:06:49.000 And a simple example, if there were a method of predicting today, some scientific truth that is only going to be discovered next year, then by using that method, we would have predicted that we would have gained that knowledge today, and that's a contradiction.
00:07:08.000 The future is not random. The more we know, the more we are able to correct errors, and so the less random the future becomes. What we are going to discover is determined by what we shall want, and by what the laws of physics, the laws of nature allow, and, and by what ideas are true.
00:07:36.000 And none of that is random, but none of that is noble in advance either.
00:07:43.000 We can't even predict for very long what future discoveries are even going to be about.
00:07:53.000 The possibilities that are opened up by a new discovery are very often new discoveries in their own right. For instance, on this day, 50 years in the past, nobody had ever connected together two computers in different buildings.
00:08:11.000 Nobody had a computer in their home. Nobody could operate a computer except a handful of specialists, and no one predicted the consequences of computer networking, the internet.
00:08:25.000 And today, home computers would be a global network, which is a major channel of trade and communication and entertainment and education, and, nor did they know when they connected those first networking cables together, that they were igniting a process which by today would be instrumental in the overthrow of dictators.
00:08:54.000 To what people will want, 50, 50 years ago, some far-sighted people realised that the new technology of jet airliners was soon going to make it normal for ordinary people to travel abroad for jobs and education and holidays, and they were right.
00:09:16.000 That revolution happened, but they also thought that by today, all that jet travel would be supersonic, and that has not happened.
00:09:28.000 People at some point decided that supersonic travel is morally unacceptable, and also the moon colony, the Mars expedition, and nuclear power. By even the late 1970s, people no longer wanted what people had wanted at the early 60s.
00:09:52.000 Because of that unpredictable change, their prediction of what our lives are going to be like was false.
00:10:04.000 That's part of a wider impediment to prediction, namely unforeseen problems.
00:10:12.000 Fads and fallacies and blunders that are going to seem like a good idea at any time in the next 50 years by definition, we can't foretell now.
00:10:23.000 So predicting our future is nothing like predicting the strength of a bridge.
00:10:29.000 Every significant innovation has unpredictable effects, and they have not gone effects, and after a few steps of that, the consequences and their consequences come to be the major component of what is happening.
00:10:47.000 And as knowledge grows faster, the time for that to happen becomes shorter and shorter.
00:10:55.000 The growth of knowledge is the only impediment to our ability to predict the future, but in this respect it's decisive, it will impose an ever closer planning horizon beyond which we are blind to the most important determinants of what is going to happen.
00:11:14.000 So we face a paradox. The more we create knowledge, the less we know about our future. And yet, as ideas are transforming our lives ever faster, it becomes ever more necessary to plan and prepare for that effect.
00:11:33.000 This is a new predicament for our species. Historically, knowledge was very sparse, it changed very rarely, and the little that people thought they knew was also mostly wrong, and so prediction of the type that I've been discussing was correspondingly easy.
00:11:55.000 One could predict what life was going to be like in 50 years' time, because it was going to be much like one's own life. Something like a plague might strike unpredictably, but the means of coping with plagues would be unchanged.
00:12:11.000 There'd be a different king, but the role of a king would be unchanged. The rules of the land, the people's means of making a living and the patterns of their personal lives, their values, their common sense, none of that would have changed.
00:12:33.000 Our situation is profoundly different. All those things are already changing on a time scale much faster than a human lifetime.
00:12:45.000 Now, mistakes are inevitable, and the exponential growth of knowledge causes an exponentially increasing rate of mistakes, unforeseen mistakes. And so, and we need to prepare for contingencies that we don't know about today because they're going to be dominated by knowledge that we do not yet have, or by ignorance that we do not yet know is relevant.
00:13:12.000 Now, do we do that? Well, fortunately, the answer to that is knowable. The only thing that can solve this problem is the same thing that caused it in the first place, the power of explanatory knowledge, because some explanations do reach beyond the planning horizon.
00:13:35.000 The one example is the argument that I've just been giving that the planning horizon has got to come ever closer. And another is that although the content of our explanations will be changing, the nature of explanation itself will not.
00:13:52.000 Even beyond the planning horizon, problems will be soluble by, by conjecture and criticism, creative thought, error correction, and that will itself give right a new problems and so on.
00:14:05.000 So therefore, consider what kind of knowledge is needed to cope with unforeseen dangers and disasters, both unintended and also the malevolent use of technology by criminals or enemies of civilization.
00:14:21.000 The only possible defense against that against the unforeseen is a general purpose knowledge.
00:14:29.000 It's like to prepare for an epidemic of a known disease, you can stockpile known cures and known preventive means, but to cope with unknown diseases, one needs general explanations of how diseases and healthy processes work.
00:14:46.000 The same holds for all unknown dangers and unknown opportunities. We can only prepare for them with explanatory knowledge that was not created for the specific purpose that it will eventually be used for, but for its own sake.
00:15:04.000 We also need the means of implementing unforeseen solutions that's technological knowledge and again as powerful and general as possible and wealth, the ability to cause transformations as large as possible.
00:15:22.000 The knowledge notoriously can be used for good or evil, but the growth of knowledge is good if it ever slows down where already in danger, among other things that the world's bad guys need only get ahead in one unpredictable way and they'll threaten unlimited harm.
00:15:42.000 Because they try to improve their values and objectives to and also their means of making decisions, have what it takes to stay ahead and discover and implement defenses in time, if they choose to make fast enough progress.
00:16:02.000 Martin Rees has a metaphor for the unknowable future that we are playing Russian-led with science as the gun and technology as the bullets, but that would be random.
00:16:18.000 What we're actually facing is almost the opposite, basically just the structure of the physical world and its immutable laws, but we are running into a world of unknown dangers and opportunities and our only defense against that is the universality of explanatory knowledge and the desire to create it and to apply it.
