Transcription
Welcome to the eponymous novel podcast. The main topic that we started out on was timeless principles of wealth creation, and then we've been touching a little bit on internal happiness and peace and well-being. But I am, first and foremost, a student of science, and failed physicist, if you will. I loved physics. I wanted to pursue it, but I never felt I was going to be great at it, and I was pulled into more technology, which is applied science. Nevertheless, I've remained a student of science. I remain fascinated by it, and all of my real heroes are scientists because I believe that science is the engine that pulls humanity forward.
I've been lucky to live in an age where scientific progress and technological progress seem not likely, but inevitable. So we've gotten used to this idea that life always gets better. Despite all the complaining that goes on about how productivity growth is stagnant, the reality is, anyone who owns a smartphone or drives a car, or even lives in a house, has seen technology improve their quality of life over and over again. We take this progress for granted, and it's thanks to science. So I continue to be fascinated by science. And to me, science is also the study of truth. What do we know to be true? How do we know something to be true? And as I get older, I find myself incapable of having attention span for anything which is not steeped in truth.
So the background on this particular podcast series is, I thought I knew a lot about science, and there was a lot about science that I took for granted, such as what scientific theory is and how scientific theories are formed. Most of us have a vague idea of it, and it can range from some people think science is what scientists do, which has a definitional problem as in, what is a scientist? And other people think, well, science is making falsifiable or testable predictions, and maybe that's closer to it. And then sometimes people say, what's the scientific method? And what is the scientific method? And then they start describing their junior high school chemistry experiment and lose the trail after that. Especially in these days where we're told to quote unquote believe in science, which is an oxymoron. People respect science, but they don't understand what science is. The idea of what science is is getting hijacked sometimes by well-meaning people who want to convince you of the science, and sometimes by not so well-meaning people who just want to influence the way that you think and feel and act.
I was very pleasantly surprised a couple of years back that I reopened an old book, which I had read, or I thought I'd read, about a decade ago, called "The Beginning of Infinity" by David Deutsch. Sometimes you read a book and it makes a difference right away. Sometimes you read a book and you don't understand it, then you read it later at the right time, and it makes a difference. This time, when I reopened this book and I went through it much more carefully than I had in the past, meticulously rather than reading it to read it and to say I was done reading it, I read it to understand the concepts and the topics, and stopped at every point where something was new. It completely started reforming my worldview. It changed the way that I think. And I would credit this book as being probably the only book in the last decade, except maybe a few of Nassim Taleb's works and maybe one or two other scatter books, that I feel made me smarter. They literally expanded the way that I think. They expanded not just the repertoire of my knowledge, but the repertoire of my reasoning. People throw around words like mental models a lot, and I find most mental models not worth reading or thinking about or listening to because I find them trivial. However, the mental models that came out of "The Beginning of Infinity" are transformational because they very convincingly, completely change the way that you look at what is true and what is not. Karl Popper laid out the theory of what is scientific and what is not, what is a good explanation, what is not. And what Deutsch does is he expands on that dramatically in "The Beginning of Infinity." But even that is to do it a disservice. The wide-ranging nature of what he covers in "The Beginning of Infinity" is incredible. He goes from the theory of knowledge, which goes by the fancy word epistemology, all the way to quantum mechanics and physics and multiverse theory, to infinity and mathematics, to the reach of what is noble and what is not noble, universal explanations, the theory of computation, what is beauty, what systems of politics work better, how to raise your children. These are all-encompassing, long-range philosophical ideas.
"The Beginning of Infinity" is not an easy book to read. To some level, Deutsch could not but write for other physicists. He has a certain peer group that he respects and who respect him, and he has to meet them at their level. So he has to write for other physicists and philosophers. Part of what I wanted to do was I wanted to understand these principles in the book, verify, confirm them for myself, or not. I love the old motto from the Royal Society, which says "Nullius in verba," which says, "Take no one's word for it." In other words, figure it out yourself. That's the only way you know anything. So I wanted to confirm the principles in "The Beginning of Infinity" or to refute them for myself. So to do that, I was reading and rereading the book. I started reading some blog posts on it, and then eventually I found a guy online named Brett Hall, and I started listening to his podcast, which was called "Talkcast," but "Tok Cast" for the theory of knowledge cast. And Brett, I'm going to let you introduce yourself, but I would say that listening to your podcast has helped me clarify a lot of these principles, and I would love to have you talk with me so that we can both understand the depth, the clarity, the reach, the importance of these ideas, and then hopefully someone else out there can become smarter by it.
Hello, Naval. And it's great to be here. You've raised so many interesting aspects of "The Beginning of Infinity," which has become a real passion of mine. Like many people who enter into science, when I was at school, I thought, well, I want to be an astronomer. When I enter university, I want to go and do a physics degree, do an astronomy degree, and then become a professional astronomer. It wasn't until one day I was in a bookstore and I found this book called "The Fabric of Reality" by David Deutsch, and I started reading it. And the first chapter described what I was trying to achieve in my life. It was putting into words what I felt my university studies, what my general outlook on life was about. Because David Deutsch says there, the ancient philosophers thought that they could get an understanding of the entire world. And then later on, as time passed, modern science made it seem as though this was an impossible project. There's no way you could understand everything about reality. There's too much to know. How could you possibly know everything? David Deutsch presents at the beginning of "The Fabric of Reality" this idea that you don't need to know absolutely every single fact that needs to be known in order to understand fundamentally everything that can be understood. He was presenting this vision. There are certain fundamental theories in science and outside of science. And his four theories that he had were quantum theory, the theory of computation, the theory of epistemology, and evolution by natural selection. That these together formed a worldview, a lens through which you could understand anything that could be understood.
I saw a beautiful video with him on YouTube where he was making the same points, where he was saying, you don't have to memorize and know every fact. You don't have to know where every particle moved. But if you understand the deep underlying theories behind everything, then you know at a high level how everything works. And this can all be understood by a single person, a single brain, a single human being. It's accessible to anybody. And that is a jaw-droppingly powerful idea. We can have explanations that can reach the entire universe. And it's worth going through the four that you'd mentioned. Quantum theory is one of them. Theory of computation is another one of them. The theory of evolution is another one of them. And then the theory of knowledge, or epistemology, is the fourth. That's the way he presented it in "The Fabric of Reality." Is it interesting that relativity is not in there? He regards quantum theory as being deeper than the theory of relativity. At some point, most physicists expect that we're going to have a unification of quantum theory and relativity. It's not to say that in that worldview, that we're dismissing relativity, but his guess is that quantum theory will be more foundational than what the theory of relativity is. There'll be a space-time of the multiverse. That's why relativity doesn't appear amongst them.
"The Beginning of Infinity" reminds me the most of "Gödel, Escher, Bach" as a book, in that it's very wide-ranging. It stitches together ideas from many different disciplines. It's very difficult to understand and follow completely. Everyone claims to have read it, but as far as I can tell, very few people understand it. I had this experience in college where I first found "Gödel, Escher, Bach," and I remember that I put it on my bookshelf and I started reading it, and started reading it, and started reading it. About a year later, I was probably about halfway through it, and then I just ran out of time and other things going on. And I remember that I would approach my other friends in college and I would say, either this is a great book, you should read it, or I would say, have you read it? And they'd all say, yeah, yeah, that's great. And a week later, they'd roll back and say, yeah, read "Gödel, Escher, Bach." It was great. And I felt like the stupidest person in college. And it was only years later that I realized nobody has read it. As you get older, you get more confident in those confessionals where you either say, either I didn't read it, or I read it at a constant pace, and when I encountered something I didn't understand, I kept going. I went back much later, and I still confess to this day, I have not read all of "Gödel, Escher, Bach." But at least at this point, I went through and I found the parts that were most interesting to me, which were the Gödel parts, and skipped the ones that were not as interesting to me, which were the Bach parts, and I did read those and I did try and understand them.
"The Beginning of Infinity" is similar. Everybody has it on their bookshelf in my social circle. Many claim to have read it, but very few have gotten it. I do go back to this point that was first eloquently stated on Twitter by a character named Illa Certain, where he said, "I don't want to read all the books. I just want to read the best 100 over and over again." And I would say that I'm currently stuck in a loop where, at least in science, I am only going to read "The Beginning of Infinity" and "The Fabric of Reality" over and over again until I understand them fully. If I had read them 20 years ago, I would know a lot more because then I would have chosen the right books and the right authors to read subsequently. It's going to be a hard book to follow. You should buy a hardcover and electronics so you have both, and the audio, get in every way possible. If you can get through it on the first sitting and understand all the points at a deep level, then congratulations. But we're hoping to break it down for you. The difference with "The Beginning of Infinity," you're getting a worldview. You're not being given the standard take from physicists about how to understand quantum theory. You're not being given the standard take of how to understand knowledge from philosophers, and you're certainly not being given the standard take of how to understand mathematics for mathematicians. Deutsch is qualified in all these areas. He's an expert in all these areas. So the worldview itself, what's at the core of it? Deutsch's worldview is that reality is comprehensible. Problems are soluble. It's a deeply rationally optimistic worldview. It believes in good explanations, good scientific explanations, and progress. Progress is inevitable as long as we have these good explanations. Good explanations have tremendous reach. They are acts of creativity. Humans are problem solvers and can solve all problems. All sins and evil are due to a lack of knowledge. One can be optimistic about constant progress. That's what the title "The Beginning of Infinity" refers to, that we're the beginning of an infinite series of progress. It's a very optimistic take. It believes that we are at home in the universe. The universe is ours as a resource to learn about and exploit. That material wealth is a set of physical transformations that we can affect. That everything that is not forbidden by the laws of physics is eventually possible through knowledge and knowledge creation. He also talks about how humans are universal explainers. That anything that can be known and understood can be known and understood by human beings in the computation power of a human system. It's all noble. It's all noble by humans. We're the beginning of an infinity of knowledge. And as we understand things using good explanations, and we create new theories that are constantly being destroyed and replaced by better ones, there's no endpoint in sight. There's no perfection. Every theory can be falsified and improved. That we are on our way to being able to do everything that is not forbidden by the laws of physics. What does the transforming is knowledge. We can take some raw material that had no particular use, and within that raw material, we might find uranium nuclei, which then can be used in a nuclear reactor to create energy or bombs. We can find within something that for almost the entire geological existence of the earth sat there inert and would have done nothing absent people. People are the entities within the universe that create explanations. They're able to explain what raw materials might be transformed into. Now, what are they transforming these raw materials into? Civilization. People creating knowledge end up becoming literally a force of nature. If we seek to explain something like the shape of a galaxy or the shape of a star, any astrophysicist will give you a story based upon the known laws of physics about how gravity will pull things into spheres, how the laws of thermodynamics will cause certain kinds of gas to heat up and expand. All of the known laws of physics are sufficient to explain what we see out there in the cosmos. But the laws of physics alone will not be able to explain the appearance of Manhattan. You have to invoke things other than merely the fundamental laws of physics. You need to invoke the existence of people and their capacity to explain the world scientifically, philosophically, politically, because it's all of those things that will come together to explain why we have certain structures like skyscrapers in Manhattan. This is a profound idea. It's an idea that seems to have been overlooked by scientists, many of whom have a reductionist idea about how to explain what we see in our environment. They will seek to explain only the natural phenomena that are in our environment. Of course, everyone wants to know how the laws of nature work. But if we want to understand how the universe from this point onwards, whether it's locally on our own planet, eventually the solar system, eventually the galaxy, is going to evolve over time, we're going to have to talk about the knowledge that people create and the choices that they're going to make into the future. This is a different vision of the place of people in the universe. Stephen Hawking famously said, "People are nothing special. People in chemical scum on a very typical planet orbiting an average star in the outer suburbs of a very typical galaxy, which is one among hundreds of billions of galaxies in the universe." This vision of what people are and of what the planet Earth is, it's true in a trivial sense, but it misses the point that in people are a hub of a kind. We are, so far as we know, the sole place in the universe which is creating knowledge, an open-ended stream of knowledge that could transform the rest of reality in the same way that gravity is able to pull that galaxy into a particular shape. Knowledge in the future will be able to shape the course of the planet, the solar system, eventually the galaxy. We will have this profound impact upon everything that we can see around us. And there's nothing that the laws of physics, the laws of chemistry, or even the laws of biology can predict what is going to happen in the future. The attempt to predict the future growth of knowledge is impossible. That's the nature of knowledge because knowledge creation is genuinely an act of creation. It is bringing something into existence that wasn't there prior. If you could predict it, you would have invented it already. A lot of our deeply pessimistic worldviews come from a straight-line linear extrapolation of negative trends while ignoring positive trends. And positive trends mostly come through creativity and knowledge creation, and it's inherently unpredictable. So every generation has these doomsayers and Cassandras, the modern Malthusians, who say, "On this trajectory, we're all going to die." They're very popular for the same reason that zombie movies and vampire movies are popular. But the reality is that they cannot predict what we're going to do in the future that is going to improve our quality of life and save us from inevitable ruin.
The value is in the knowledge, and the knowledge is inside the observer and the creator. In other words, the human. It's not inside the thing itself. For example, oil is useless unless you know how to refine it, burn it, and use it for combustion. Information is useless unless there's a brain there to receive it. There could be a signal broadcasting English into outer space, but if there isn't a creature capable of understanding what that language is, how it works, and who's conveying it, then it's just modulated electromagnetic frequencies that don't mean anything. So a lot of the information and a lot of the value is within a particular knowledge-bearing entity. As science grows its reach, we've gotten to a very reductive science where we break things down to smaller and smaller pieces, and then we try and explain things on the basis of that. And there is a counter-trend in science, which is complexity theory, where we talk about emergent properties and higher-level systems, where we're starting to now look at systems as they operate chaotically and unpredictably at a micro-level, but at a macro-level, we can make certain statements about them that do have explanatory power. So humans are unique in our capability to understand things.
There's a phrase that you're going to hear both Brett and I use over and over again, and that phrase has "good explanations." Good explanations is Deutsch's improvement upon the scientific method. At the same time, it's beyond science. It's not just true in science, but in all of life. We navigate our way through life, and we do it successfully by creating good explanations. If you take away nothing else, try and understand what a good explanation is. A good explanation, first and foremost, is testable, falsifiable. You can run some experiment in the real world to see if it's true or not. Stepping back from that, it's a creative explanation. It looks at something that's going on in the real world and says, "This is why it's happening." It is a creative leap that says, "This is the underlying explanation for how the thing works." For example, when I talk to my young kids, and we're out watching the sunset, I keep telling them, "Is the sun setting? Is the sun going somewhere? Is the sun moving? Or is it maybe we're moving? And we're moving in such a way that it looks like the sun is setting?" Which is the proper explanation? Because looking at it naively, you would think the sun is hurtling across the sky, and there goes the sun again, going around the Earth. But that may not be the only explanation. There is a completely creative explanation that seems to fly in the face of the obvious observation of the sun's movement, but could also fit the facts. But it requires some creativity. And that creative explanation is that the Earth is rotating. Good explanations don't have to be obvious. They're not derived from just looking at what happened in the past, but they are testable. There are experiments we can run to figure out, is it the sun that is going around the Earth, or is it the Earth turning?
Brett, would you say that a scientific theory is a subset of a good explanation?
Yes, they're the testable kinds of good explanations. Falsifiable theories are actually a dime a dozen. This doesn't tell you anything about the quality of the explanation you're being given. The example that's used in "The Fabric of Reality" is the grass cure for the common cold. If someone comes along to you and says, "If you eat 1.0 kilograms of grass, it will cure your common cold," they have a testable theory. The problem is that no one should test it. Why? Because they haven't given you an explanation as to what the mechanism is that would enable grass to cure the common cold. And if you do eat the 1.0 kilograms of grass and it doesn't cure your cold, they can turn around and say, "1.1 kilograms might do it, right? Or you need a different kind of grass, or you need to always do it on a different day." It's always testable, but you're not getting anywhere. You're not making any progress. So I think the second piece of good explanation is hard to vary. It has to be very precise, and there's a good reason for the precision. The famous example he used in "The Beginning of Infinity" is, why do we have seasons on the Earth? And there was the old Greek explanation, well, it's driven by Persephone, the goddess of spring, that's when she can leave Hades, and there's this whole theory involving gods and goddesses. Not only was that not easily testable, it was very easy to vary. Persephone could have been Nike, and Hades could have been Jupiter or Zeus. It's very easy to vary that explanation without the predictions changing. Whereas if you look at the axis tilt theory of saying the Earth is angled at 23 degrees relative to the sun, and therefore would expect the sun to rise here in the winter and over there in the summer, the facts on that are very hard to vary. It makes risky and narrow predictions. They can predict the exact length of summer and winter at different latitudes, and you can test that very precisely. So beyond it being a creative theory that is testable and falsifiable, it should be hard to vary. The pieces of that theory without essentially destroying that theory. And you certainly don't want to vary it after the fact, like your grass example. Oh, it was one kilogram, now it's 1.1, now it's 1.2. Finally, the predictions that it makes should be very narrow and precise, and they should be risky. For example, I believe in relativity. Was it Eddington who did the experiment and showed that starlight gets bent around an eclipse? And that was a prediction that Einstein had made in relativity, which turned out to be true. That was a risky prediction that took a long time to confirm.
That's an excellent example of what's called a crucial test, which is sort of the pinnacle of what science is all about. If we do a test and it doesn't agree with a particular theory that we have, that's problematic. But that doesn't mean that it refutes the theory, because if you were to refute the only theory that you have, where do you jump to? You don't have any alternative. If we were to do a scientific test tomorrow and it was inconsistent with the theory of general relativity, then what? There is no alternative to general relativity. In fact, when there have been experiments over the years that seem to have been inconsistent with general relativity, guess what? They've all turned out to be faulty. If you had to choose between whether or not general relativity has been refuted by your test, or your test is flawed, go with the fact that your test is being flawed. In the case of Eddington's experiment, we had two viable theories for what gravity was. We had Newton's theory of universal gravitation on the one hand, and we had Einstein's general theory of relativity on the other. This experiment that you described of how much the light was bent during a solar eclipse, the correct way of describing what happened is not that we showed that general relativity was correct in some final sense, but rather we refuted Newton's theory of gravitation. Newton's theory was ruled out because it was inconsistent with the test, while general relativity was consistent with the test. This doesn't mean that general relativity is the final word in science. It means it is the best theory we have for now. And there's a whole bunch of reasons that we might think general relativity ultimately has to turn out false. We never have the final word. And that's a good thing. That's a really positive, optimistic thing, because it means we can keep on improving. We can keep on making progress, and we keep on discovering new things. There is no end of science. The long-thought-about idea that so many have feared, that one day progress will come to a halt, that science will end. In fact, we are at the beginning of infinity, and we will always be at the beginning of infinity, precisely because we can improve our ideas, because we're fallible human beings. So none of our theories are perfect, because we aren't, and our process by which we create knowledge isn't perfect either. It's error-prone.
There are two other scientific thinkers that I like who are unrelated to David Deutsch, but come to very similar conclusions. One is Nassim Taleb, who's popularized the idea of the Black Swan, which is that no number of white swans disproves the existence of a black swan. You can never conclusively say all swans are white. You can never establish final truth. All you can do is work with the best explanation you have today, which is still better than ignorance, far better. But at any time, a black swan can show up and disprove your theory, and then you have to go find a better one. The other fellow who I find fascinating is Gregory Chaitin. He is a mathematician who is very much in the Kurt Gödel vein, where he tries to explore the limits and boundaries of what is possible in mathematics. One of the points that he makes is that Gödel's incompleteness theorem doesn't say that mathematics is junk. It's not a cause for despair. Gödel's incompleteness theorem says that no formal system, including mathematics, can be both complete and correct. Either there are statements that are true that cannot be proven true in the system, or there will be a contradiction somewhere inside the system. So this could be a cause of despair for mathematicians who view mathematics as this abstract, perfect, fully self-contained thing. But Chaitin makes the argument that actually, it opens up for creativity in mathematics. It means that even in mathematics, you are always one step away from falsifying something and then finding a better explanation for it. It puts humans and their creativity and their ability to find good explanations back at the core of it. At some deep level, mathematics is still an art. There are very useful things that come out of mathematics, and you're still building an edifice of knowledge. But there is no such thing as conclusive, settled truth. There is no settled science. There is no settled mathematics. There are good explanations that will be replaced over time with more good explanations that explain more of the world.
This is something that we inherit from our schooling more than anything else. It's part of our academic culture and breeds into the wider culture as well. People have this idea that mathematics is this pristine area of knowledge where what has proved to be true is certainly true. Then you have science, which doesn't give you certain truth, but you can be highly confident in what you discover. You can use experiments to confirm that what you're saying appears to be correct, but you might be wrong. And then, of course, there's philosophy, which is a mere matter of opinion. This is the hierarchy that some people inherit from school: mathematics are certain, science is almost certain, and the rest of it is more or less a matter of opinion. This is what Deutsch calls the mathematician's misconception, is that mathematicians have this intuitive way of realizing that their proof, their theorem that they've reached by this method of proof, is absolutely certainly true. In fact, it's a confusion between the subject matter and our knowledge of the subject matter. If I quickly compare it to physics, we have this domain called particle physics, and the deepest theory we have in particle physics is called the Standard Model, which describes all of the different fundamental particles that there are, and the interactions between these fundamental particles, the forces that exist between them, and the gauge bosons which mediate the force between particles like electrons, protons, and neutrons. Now, what is matter made of? We would say matter is made of these particles, the particles described by the Standard Model of physics. But does that rule out the fact that these fundamental particles might themselves consist of even smaller particles? We have this idea of string theory. So our knowledge of what the most fundamental particles are, and what in reality the most fundamental particles are, is different. So too in mathematics. Deutsch explains that mathematics is a field where what we're trying to uncover is necessary truth. The subject matter of mathematics is necessary truth, in the same way that the subject matter of particle physics are the fundamental particles. But because the subject matter of fundamental particle physics are the fundamental particles, that doesn't mean you actually find the fundamental particles. All it means is that you have found the smallest particles that your biggest particle accelerators are able to resolve. But if you had an even bigger particle accelerator, you might find particles within those particles. This has been the history of particle physics, by the way. We used to think that atoms were fundamental. Then, of course, we found that they contain nuclei and electrons. In the nuclei, we found out there were protons and neutrons. Inside the protons and neutrons, we found out they were made up of quarks. And that's where we're at right now. We're at the point where we say that the quarks are fundamental and the electrons are fundamental. But that doesn't mean that we're going to end particle physics right now. What we need are further theories about what might be inside of those really small particles. Comparing that to mathematics, if necessary truth is the subject matter of mathematics, our knowledge of that necessary truth is what mathematicians are engaged in. They're engaged in creating knowledge about necessary truth. And because a mathematician has a brain, which is a physical object, and all physical objects are subject to making errors of degradation via the second law of thermodynamics, or simply just the usual mental mistakes and errors that any human being makes, a mathematician is just as fallible as anyone else. Then what they end up proving could be an error.
So if I understand this point, even mathematics is capable of error because mathematics is a creative act. We're never quite done. There could have been a mistake in your axiom somewhere. Ultimately, even mathematics is a creative act and can have error within it. All knowledge is conjectural. It's always being guessed. It's our best understanding at any given time. You're right to say that the axioms might be incorrect. How do we know that an axiom is incorrect? Traditionally, the answer has been because it's clearly and obviously the case. How can you prove that x plus 0 must equal x? Well, you just have to accept that it's true. But if we consider something like Euclid's Elements, for example, "Draw two points on a piece of paper. Now, through those two points, a unique straight line can be drawn." This was accepted as true for centuries. When anyone listening might want to try the experiment for themselves, take a piece of paper, take a pen, draw two dots on the piece of paper. Now, how many unique straight lines can you draw through those two dots? It should be fairly obvious to you that only one such line can be drawn. However, we now know that's false. I just want you to reflect as you're staring at the piece of paper through which only one straight line is being drawn. You have the feeling of certainty. You are absolutely sure that you're not wrong. This feeling is something we should always be skeptical of, because when people have been absolutely certain, even in a domain as apparently full of certainty as mathematics, they've been shown to be wrong. So how can we show it wrong? Here's what you do, and you might think that I'm cheating, but then again, you have to reflect on, did you understand what I was saying when I first told you to draw a unique straight line through these two points? Here's what I want you to do: bend the piece of paper. Think in three dimensions. Wrap the piece of paper around a basketball, if you have one. Now consider the ways in which you could draw a straight line through those two points. You could punch a hole through one of those dots with your pen and push it out through the other side, through the other hole, and now you have a different straight line. You have the straight line that is drawn with your pen, and you have a straight line that is literally your pen that has been pushed through these two dots. So your initial feeling of absolute certainty that only a unique line could be drawn through these two dots is false. And you might be thinking, "That's unfair. That's cheating. You were thinking in two dimensions." No, you were thinking in two dimensions. I wasn't. I was thinking of more dimensions than that. Karl Popper has this wonderful saying: "It is impossible to speak in such a way that you cannot be misunderstood." This is always the case. So even in mathematics, where we try and be as precise as possible, it's possible for people to make errors, to think false premises about what the argument is that they're trying to make. And by the way, this particular example of Euclidean geometry, because geometry was traditionally always done in two dimensions on a piece of paper, was resolved by various people and led to geometry in curved space, which led to Einstein coming up with the general theory of relativity. So it is questioning these deepest assumptions that we have, where we think there's no possible way we could be mistaken, that leads to true progress, to genuine fundamental change in the sciences and everywhere else.
You said that we went from atoms in the time of Democritus down to nuclei, and from there to protons and neutrons, and then to quarks. It's particles all the way down, to paraphrase Feynman. We can keep going forever, but it's not quite forever, right? At some point, you run into the Planck length. There's the Planck time, there's the Planck length, there's even the Planck mass, which is actually quite a large mass. These things don't have any physical significance. It's not like the Planck time is the shortest possible time, and it's not like the Planck length is the shortest possible length. The reason for that is because these Planck things are part of quantum theory, but length is not described by quantum theory. It's described by the general theory of relativity. And in that theory, space is infinitely divisible. There is no smallest possible length or time. This illuminates an ancient tension between the discrete and the continuous. Because quantum theory seems to suggest that things are discrete. For example, there's a smallest possible particle of gold, the gold atom. There's a smallest possible particle of electricity, the electron. There's a smallest possible particle of light, the photon. In quantum theory, we have this idea of discreteness, that there is a smallest possible thing from which everything else is built. But in general relativity, the idea is the opposite. It says things can continuously vary. And if the mathematics requires that things be continuously variable, so they can be differentiated and so on, the idea there is that you can keep on dividing up space, and you can keep on dividing up time. So physicists understand that there is this contradiction at the deepest level of our most foundational explanations in physics. And it's one of the reasons why there are these attempts to try and unify quantum theory and general relativity. Because what is the fundamental nature of reality? Is it that things can be infinitely divisible, or is it that we must stop somewhere or other? Because if it's infinitely divisible, then quantum theory might have to be subservient to general relativity. But we just don't know.
There goes my solution for Zeno's paradox, which is before you can get all the way somewhere, you have to get halfway there, and before you can get halfway there, you have to get a quarter of the way there, and therefore you'll never get there. One way to get past that is say, even a series of infinite things can have a finite sum. Just run the infinite series and sum it, and we learned pretty early on that it converges. But another thought I had was that you have to cover a minimum distance, a Planck length, and therefore you will get there. It's a finite series of steps. But you're saying we just don't know.
Yes. So if the laws of physics say that we can cover one meter in a certain time period, then that's exactly what we'll do. And our current understanding of the laws of physics say precisely that. So Zeno's paradox is resolved simply by saying that we can cover this space in this amount of time. It's silent on whether or not space is infinitely divisible. When someone asks you, "Is space infinitely divisible?" Then I would say, "Yes, it is." And they might turn around and say, "How do you know?" And I would say, "General relativity." "How do I know that's true?" Well, I don't know that it's true. However, it is the best explanation that we presently have of spacetime. And then they might get into a discussion about, "Well, if it's infinitely divisible, then you're presented with Zeno's paradox all over again." And I would say, "No, you refute that by a simple experiment." So we don't know how it is that we can travel through all of these infinite points if, in fact, there are infinite points. Zeno's paradox is about the domain of pure mathematics. But we don't live in a world of pure mathematics. We live in a world of physics. And if the physics says that we can traverse an infinite number of points in a finite amount of time, then that's what we'll do, regardless of what the mathematics is. Every mathematical theory is held inside a physical substrate of a brain or a computer. You're always bound by the laws of physics. And these pure abstract domains may have no mapping to reality. The overwhelming majority of theorems in mathematics are theorems that we cannot possibly prove. This is Gödel's theorem, and it also comes out of Turing's proof of what is and is not computable. These things that are not computable vastly outnumber the things that are computable. And what is computable depends entirely upon what computers we can make in this physical universe. The computers that we can make must obey our laws of physics. If the laws of physics were different, then we'd be able to prove different sorts of mathematics. And this is another part of the mathematician's misconception. They think they can get outside of the laws of physics. However, their brain is just a physical computer. Their brain must obey the laws of physics. If they existed in a universe with different laws of physics, then they could prove different theorems. But we exist in the universe that we're in, and so we're bound by a whole bunch of things, not least of which is the finite speed of light. So there could be certain things out there in abstract space which we would be able to come to a more full understanding of if we could get outside of the restrictions of the laws of physics here. Happily, none of those theorems that we cannot prove at the moment are inherently interesting. Some things can be inherently boring, namely all of these theorems which we cannot possibly prove as true or false. Those theorems can't have any bearing in our physical universe. They have nothing to do with our physical universe. And this is why we say they're inherently uninteresting. And there's a lot of inherently uninteresting things.
Does probability actually exist in the physical universe, or is it a function of our ignorance? If I'm rolling a dice, I don't know which way it's going to land, so therefore I put in a probability. But does that mean that there's an actual probabilistic, unknowable thing in the universe? Is the universe flipping a coin somewhere, or is it always deterministic? All probability is actually subjective uncertainty. Randomness is subjective. If you don't know what the outcome's going to be, so you roll a dice, that's because you individually do not know. It's not because there is uncertainty there deeply in the universe. What we know about quantum theory is that all physically possible things occur. This leads to the concept of the multiverse. And rather than refute all of the failed ways of trying to understand quantum theory, we're just going to take seriously what the equations of quantum theory say. What we are compelled to think about quantum theory, given the experiments, is that every single possible thing that can happen, does happen. This means that there is no inherent uncertainty in the universe, because everything that can happen actually will happen. It's not like some things will happen and won't happen. Everything happens. Now, you occupy a single universe, and in that universe, when you roll the dice, it comes up a two. But we know somewhere else in physical reality, it comes up a one, somewhere else a three, a four, a five, and a six. If I'm rolling two dice, then the universe in which they sum up to two is less than the number of universes in which we roll a seven, because that can be three or four or five and a two, and so on. So the number of universes still does correspond to what we calculate as the probability. Yes. This leads to what Deutsch calls the decision-theoretic way of understanding probability within quantum theory. Decision-theoretic means you assume this proportionality between the universe is this way of splitting things up. So if you're rolling two different dice, then the universes proportion themselves into measures. And what a measure is, is it's a way of talking about infinities.
There is a video on YouTube which has Deutsch explaining the famous quantum double-slit experiment, which is about particle-wave duality. Is light a particle or a wave? You pass it through a slit, depending on whether there's an observer and interference or not, it ends up in a wave pattern, ends up as individual photons. And this is the famous experiment which has baffled people for a long time and caused them to revise their worldview. The one that led Einstein to say, "God does not play dice with the universe."
Correct. Einstein was a realist at the time when the founders of quantum theory were trying to develop a good explanation of what precisely was going on with these experiments in quantum theory. Einstein rejected all of them on the basis that they weren't realistic, and he was right to do so because none of them made any sense. And to this day, none of the other alternatives make any sense. Now, Einstein didn't know about the multiverse. We had to wait until Hugh Everett in the 1950s was able to devise a simple, realistic way of understanding quantum theory. But if I go back to this idea of the double-state experiment, it is often claimed that particles have a duality to them. Sometimes they're particles, and sometimes they're waves. The electron, for example, given certain experiments, will behave like a particle, and in other experiments, it behaves like a wave. People who hear this think, "Well, okay, that kind of explains what's going on." For example, in the photoelectric effect, you shine a light at electrons, which literally means you're firing a photon, a particle of light, at an electron, and you can knock the electron out of the atom. This is supposed to be proof positive that light in the form of photons and electricity in the form of electrons are both particles, because they're bouncing off one another, and this is what particles do. Waves don't do that. You watch water waves at the beach, you'll see they pass through each other. They don't bounce off one another. Waves will bounce off particles, but they won't bounce off each other. Prior to Young's double-slit experiment, we actually relied upon Newton's ideas of light, and Newton's idea was that light was corpuscular, as he said, which means made of particles. And then Young came along, and he shone a light through two slits cut into a piece of paper, and what you find when you project that light onto another sheet of paper is not just two beams of light. You find what's called an interference pattern, where the light has interfered with itself, in the same way that when waves pass.
Through small apertures, natural geological gaps, they will interfere with one another. They produce crests in some places and troughs in others. They can cancel each other out. This was supposed to be proof to some of the early physicists that light, in fact, was a wave.
And now we get to quantum theory, and we find that things we thought were certainly particles, like electrons, when we do the same experiment with them, they interfere with one another. So it appears as though we've got particles acting like waves and waves acting like particles. The resolution to this is not to admit nonsense.
So this is what often is explained in quantum theory lectures at an undergraduate level: that you have to accept that something like a photon is born as a particle, it lives as a wave, and then it dies again as a particle. Which is nonsense. And the reason it's nonsense is because the photon doesn't know that it's alive and it's dead. It doesn't know what experiment it's participating in. So we have to come to a deeper understanding of how to explain what is going on in this double-slit experiment.
Because if we fire either a photon or an electron at that double-slit apparatus, and we put a detector at either of those slits, then we will detect a particle. So we can detect that we fired a particle, we can detect that a particle is going through those slits, and we can detect a particle at the projection screen as well. When you do this experiment in the laboratory using electrons, you can see the dots where the electrons strike, hitting the screen. But you don't get a simple pattern that you would expect if you're firing cannonballs at a wall where there are two holes in the wall through which the cannonballs can go. You would expect that all the cannonballs are going to go through those two holes and land in one of two positions behind the wall. But with particles at the quantum level, that's not what happens. Something is going on.
And the only explanation is that when we fire a photon, there's the photon that we can see in our universe, but there's also photons in other universes passing through the apparatus that we cannot see. And these photons are able to interact with the photon that we are able to detect. This is where the concept of interference comes in. Interference is an old concept in physics. It goes back to waves. Waves certainly interfere. But we need to understand the way in which particles can interfere one with another: particles that we can observe, and particles that we can only assume to observe, given these experiments. And this is why we are forced into acknowledging the existence of these other particles, and not only these other particles, but other universes in which these particles exist.
Now, people might object at this point and go, "How dare you invoke in science things that cannot be seen, things that cannot be observed? This is completely antagonistic towards the scientific method, surely." And I'll say to anyone who's thinking that right now, almost everything of interest that you know about science is about the unobserved.
Let's consider dinosaurs. Dinosaurs are unobserved. You say, "Oh, hold on, I've been to the museum, I've seen a dinosaur." Now, you have seen a fossil. And a fossil isn't even a bone; it's an ossified bone. It has been metamorphosed into rock. So no one has ever seen a dinosaur. We have seen things that look like dinosaurs and interpreted them to be huge reptilian, bird-like creatures that, when we assemble their skeletons, we make up a story about what this thing was that walked the earth tens or hundreds of millions of years ago.
In the same way, no one has ever seen the core of the sun, and no one will ever observe the core of the sun. But we know about stellar fusion. We know that hydrogen nuclei are being crushed together there to form helium, in the process producing heat. We don't see the Big Bang. We don't see the movement of continents. Almost everything of interest in science, we do not observe. Even many of the things that we say we have seen, we've actually just seen instruments detect those things. So we're watching the effects through instruments and then theorizing that there are other universes out there where the photons are interacting with the photons that we can see.
There are many scientists, philosophers have talked about this concept of a multiverse. But this is a very strict, very sober understanding of what a multiverse is. All of these universes in this multiverse obey the same laws of physics. We're not talking about universes where there are other laws of physics. This should be no more surprising than historically, when it used to be thought to be the universe consisted of our planet, and around our planet orbited everything else: other planets, stars, the sun, the moon orbited around us, existed on this tiny planet. Then our vision of reality got expanded a little bit. We realized, in fact, we were not at the center of the universe. The sun was at the center, and these other planets were, in fact, bigger in some cases, in the case of Jupiter and Saturn and the gas giants, bigger than what our planet of Earth is. The sun was a lot bigger than what we are. So our universe became larger. Then we realized that we were just one star system among many in a huge galaxy of hundreds of billions of stars. Then later, we realized that this galaxy is one of hundreds of billions of galaxies. So the history of ideas and the history of science is a history of us broadening our vision of exactly how large physical reality is. And this is another step in that general trend. And we should expect it to continue. It shouldn't be that hard for people to accept that this is the way to understand things.
Do we know everything about quantum theory and how this multiverse works? No. We haven't united this multiverse with general relativity. We need a space-time or a geometry of the multiverse, which we don't have yet.
So, getting back to good explanations, where do these explanations come from? There's currently an obsession with induction. Induction being the idea that you can predict the future from the past. You can say, "I saw one, then two, then three, then four, then five, so therefore next must be six, seven, eight, nine." There's a belief that this is how new knowledge is created, this is how scientific theories are formed, and this is how we can make good explanations about the universe.
What's wrong with induction and where does new knowledge come from? You did mention the black swan earlier, and I'd like to go back to that. The black swan is an example that various people have used over the years in order to illustrate this idea that repeatedly observing the same phenomena over and again should not make you confident that it will continue in the future. In Europe, we have white swans. So any biologist who's interested in birds will be observing white swan after white swan and apparently concluding on that basis that therefore all swans are white. Then someone travels to Western Australia, and there you notice that there are swans that otherwise look identical to the ones in Europe, but they're black.
Let's consider another example of induction. Ever since the beginning of your life, you have observed that the sun has risen. Does this mean that scientifically you should conclude the sun will rise tomorrow and rise every day after that? This is not what science is about. Science is not about cataloging a history of events that have occurred in the past and presuming they're going to occur again in the future. Science is an explanatory framework. It's an error-correcting mechanism. It's not ever of the form: "The sun always rose in the past, therefore it will rise in the future." There's all sorts of ways in which we can imagine the sun won't rise tomorrow. All you need to do is to take a trip to Antarctica, and there, for some months of the year, the sun doesn't rise at all. If you go to the International Space Station, you won't see the sun rise once per day and set once per day. It will rise and set repeatedly over the course of your very fast journey around the Earth.
There's another example from science like this: on a heat source, put a beaker of water. Then put a thermometer into that water and turn on your heat source. Then record, as the time passes, what the temperature of the water is. You will notice that the temperature of the water will increase. You can do this with a saucepan at home. So long as the heat source is relatively constant, the temperature rise will be relatively constant as well. So after one minute, the temperature might go from 20 degrees Celsius to 30 degrees Celsius. Imagine every minute it climbs by another 10 degrees Celsius. But at some point, it's going to stall when it hits the boiling point, precisely.
Now, if you're a thoroughgoing inductivist or even a Bayesian reasoner, and you don't know anything about the boiling temperature and what phenomena happens at that temperature, you can join all of those lovely lines into a perfectly diagonal straight line and extrapolate off into infinity. After two hours, according to your Bayesian reasoning, according to your induction, we should assume that the temperature of that water will be a thousand degrees Celsius. But of course, this is completely false. What actually happens is once it starts boiling, it stays at its boiling temperature. We get a plateau, and this plateau of temperature, about 100 degrees Celsius, remains there until all the water boils away.
Now, there's no possible way of knowing this without first doing the experiment or having already guessed, via some explanatory means, what was going to happen. No method of recording all of these data points and extrapolating off into the future could ever have given you the correct answer. The correct answer can only come from creativity. And notice that science is not about predicting where the trend starts and where the trend goes. In fact, if we want to explain what's going on with the water, we refer to the particles and how, as the temperature increases, the kinetic energy of the particles starts to increase, which means the velocity of the particle starts to increase. Eventually, those particles in the liquid state achieve escape velocity from the rest of the liquid. At this point, we have boiling. But that escape velocity, the technical term is latent heat, requires energy. And for this reason, we can have heating of something like water without any temperature increase. That's what science is. That whole complicated story about how the particles are moving faster, this invocation of the term latent heat. It's not about trends and predictions. It's about explanation. Only once we have the explanation can we, in fact, make the prediction.
Going even further, it's not just science. When we look at innovation and technology and building, for example, everything that Thomas Edison did and Nikola Tesla did, these were from trial and error, which is creative guesses and trying things out. If you look at how evolution works, through variation and then natural selection, where it tries a lot of random mutations and it filters out the ones that didn't work. So this seems to be a general model through which all complex systems improve themselves over time. They make bold guesses, and then they weed out the things that didn't work. Things like a beautiful symmetry to it across all knowledge creation. It's ultimately an act of creativity. We don't know where it comes from, and it's not just a mechanical extrapolation of observations.
The most famous example on this, we mentioned black swans, we talked about boiling water, but the fun and easy one is the turkey. You could have a turkey that's being fed very well every single day and fattened up, and it thinks that it belongs and lives in a benevolent household where the farmer comes and feeds it every day until Thanksgiving arrives, and then it's in for a very rude awakening, or I should say, an ending that shows you the limits of induction. Precisely. The theories have to be guessed. And all of our great scientists have always made noises similar to this. It's only the philosophers or certain mathematicians who think that this is the way that science happens, that it's this inductive trend-seeking way of extrapolating from past observations into the future. Einstein said that he wasn't necessarily brighter than most other people. It's that he was passionately interested in particular problems and he had a curiosity and an imagination. Imagination was key for him. He needed to imagine what could possibly explain these things. He wasn't looking at past phenomena in order to come up with general relativity. He was seeking to explain certain problems that existed in physics. Induction wasn't a part of it.
Good explanations rely on creativity. These good explanations are testable and falsifiable, of course, but they are hard to vary and they make risky and narrow predictions. That's a good guiding point for anybody who is listening to this podcast and trying to figure out how they can incorporate this in their everyday life. Your best theories are going to be creative guesses, not simple extrapolations.
I had a bunch of asides that I wanted to dive into, like finding path integrals, because it seems to me that there's some kind of a deep symmetry between multiverse theory and finding path integrals. You're absolutely right. He believed in multiple histories, but to the extent that he thought that these were actually physically real things or merely mathematical objects is open to question. He was relatively silent on the matter. He was certainly a realist. But he made one of the worst quips. An absolute genius, probably next to Einstein, second greatest physicist of the 20th century, but he said, "If you think you understand quantum theory, you don't understand quantum theory." Which is nonsense. Whoever understood quantum theory? David Deutsch understands quantum theory. So that was one of the few occasions where Feynman fell into irrationality and pessimism.
I think it was Planck who said, "Science advances one funeral at a time." Yeah, unfortunately, even the best get stuck behind. I see this in my own field, where you have some of the greatest investors of our time, like Warren Buffett and Charlie Munger, who are just absolute geniuses, but they cannot wrap their minds around cryptocurrencies. The idea that there's going to be an extra-sovereign money that is native to the internet, is programmable, is as foreign to them because, to them, money is always something that has been provided by the government and controlled by the government. And they just cannot imagine it any other way. So it's just the nature of people.
There's also the theory of Solomon of induction. I'm going to mangle the description, but it says if you want to find a theory that explains why something is happening, and now a theory here is something that's encoded as a binary string, then the correct theory is actually going to be a probability-weighted theory that takes into account all the possible theories, but weighs them based on their complexity. So the simpler ones are more likely to be true, and the more complex ones are less likely to be true. And you sum them all together, and that's how you figure out the correct probability distribution function for your explanation.
That's similar to Bayesianism, isn't it? In both cases, they're assuming that you can enumerate all the possible theories, but you can't, because that's the creativity coming in. It's very rare in science to have more than one viable theory. In physics, we mentioned Newtonian theory of gravity, and there was general relativity. That's one of the rare occasions where you actually have these two competing theories. It's almost unknown to have three competing theories. What confuses people is that induction and Bayesianism work really well for finite, constrained spaces that are already known. They're not good for new explanations.
Bayesianism is: "I got new information. I used to weight the previous probability predictions that I had. Now I've changed my probability based on the new data. So I believe that something different is going to happen." For example, I don't know if you remember the Monty Hall show. Monty Hall calls you up, and there's three doors, and there's treasure behind one of them, and then two of them don't have anything. And you pick which door it's going to be, door number one, two, or three. Then he opens one of the other two doors and shows you there's nothing behind it. Now, do you want to change your vote? The understanding of naive probability says, "No, I wouldn't change my vote. Why should it matter that one of the ones he showed me doesn't have something? The probability should not have changed." But Bayesianism says, "You've got new information. You should revise your guess, and you should switch the other door." And the easier way to say that is imagine there were 100 doors, and then you picked one at random. Then he opens 98 of the remaining 99, shows you there's nothing. Now, do you switch? And of course, you'd want to switch, because what are the odds that you picked one of the 100 in the first place? Now your odds are 99 out of 100. And people discover this and say, "Of course, now I'm a smart Bayesian. I can update my priors based on new information. That's what smart people do." And therefore, I'm a Bayesian. But it in no way helps you discover new knowledge or new explanations.
That's the uncontroversial use of Bayesianism, which is a very powerful tool. It's used in medicine, of trying to figure out which of these medicines might be more effective than others. So there are whole areas of mathematics like Bayesianism which can be applied in science without controversy at all. It's where we say that Bayesianism is the way in which we can generate new explanations, or the way in which we can judge one explanation against another. In fact, the way in which we generate new explanations is creativity, and the way in which we judge one explanation against another is either experimental refutation or straightforward criticism of realizing that one of those explanations is just a bad explanation.
Induction also says that prediction is the main reason for the existence of science. But it's not. It's explanation. You want an explanation of what's going on, even if you can't necessarily predict with any certainty what's going to happen next. In fact, knowing what's going to happen next with some degree of certainty can be deflating. And the unknown can be far more fun than having absolute certitude about what tomorrow will bring.
This brings us to the related point: science has never settled. We should always be free to have new creativity, a new conjecture. You never know where the best ideas are going to come from. And you have to take everything that's made in good faith seriously. And so this idea that the science is settled or the science is closed is nonsense. And it implies that we can all agree upon the process with which we come up with new theories, rather through creativity and conjecture. And the door is always open for new people with new ideas to come in and do that. As Popper said, "We're all equal in our infinite ignorance." So even if someone claims expertise, they might even be valid in their claim to expertise. There's an infinite number of things they do not know. And those infinite number of things they do not know could affect the things they do know. So the child who is coming through school, who is not expert in anything, can still come up with an idea that can challenge the foundations of the greatest expert, because the expert, like the child, is ignorant about a whole bunch of things. They could have error that does not preclude someone else who lacks that fine-tuned knowledge from being able to point out there's an error, and here's a better idea.
A lot of the theories as to why we're imminently going to create an AGI are based on a naive extrapolation of computational power. It's almost we'll do the induction of more and more computational power, and AI has already gotten good at vision and beating us at chess and at video games, so therefore it's going to start thinking soon.
Another offshoot that I want to discuss is this idea that humans are this resource consumers on the Earth, and we're eating up all the Earth's resources. So having more humans on the Earth is a bad idea. Whereas if you believe that knowledge comes from creativity, then any child born tomorrow could be the next Einstein or the next Feynman and discover something that will change the world forever with creativity that has non-linear outputs and effects. But at the moment, we're very concerned about the pollution or the loss of certain species. And these are legitimate concerns for some people. But it should never be at the expense of the long-term vision that perhaps we can solve all of those problems and far more, if only we could have progress at a faster rate by using the resources that we have available to us.
There's a question why the world always seems to be full of more pessimists than optimists, especially when we still live with mostly enlightenment values and such tremendous innovation. There are probably multiple reasons for that. But it's just easier to be a pessimist than an optimist. It's harder to guess how life is going to improve. It's easier to linearly extrapolate how it's going to get worse. You could also argue that the risk of ruin is so large that you can't come back from it. That maybe we're hardwired to be pessimists, because if you're correct when you're optimistic, then you have a small gain. But if you're wrong when you're optimistic and you get eaten by a tiger, it goes to zero. So maybe we're hardwired to be pessimistic in that sense.
If you're an academic of some kind, then being able to explain all of the problems that are out there and how dangerous these problems are and why you need funding in order to look at these problems in more depth, that appears to be the intellectually serious position. Someone who claims that we can solve this, it sounds a little bit kumbaya, even though it's quite right that in fact collaboration, cooperation, and resource exploitation will actually be the thing that's going to drive this knowledge economy forward, so that we can solve with these problems. It always seems more intellectually serious if you can stand up there with a frown on your face in front of a TED Talk audience and say, "These are all the ways in which we're going to fail and which we're going to come to ruin." I'm guilty of having recorded one of these doomsayer podcasts about enders blowing up the Earth. That was the one podcast that I regretted the most. We had a great conversation, but I don't fundamentally agree with any of the conclusions that might come out of that, which say the world is going to end. So we should slow down. The only way out is through progress. And subsequently, I haven't promoted as much as I promoted my other podcasts. And upon reading Deutsch, I realized why. It's because it's easy to be a pessimist. It's an easy trap to fall into. But it implies that humans are not creative. It doesn't acknowledge all the ways that we have innovated our way out of previous traps.
And fundamentally, entrepreneurs are inherently optimistic because they get rewarded for being optimistic. As you're saying, intellectuals get rewarded for being pessimistic. So there is always a lot of incentive bias here. As an academic, you may be incented to be pessimistic. As an entrepreneur, you may be incented to be optimistic. If you're a pessimist, you get your feedback from other people. It's a social act. You're convincing other people of your pessimism. And so far, most of their pessimistic predictions have turned out to be false. If you look at any timelines on which the world was supposed to end or environmental catastrophes were supposed to happen, they've been quite wrong.
But if you look at the optimistic entrepreneurs, they are rated by feedback from nature and free markets, which I believe are much more realistic feedback mechanisms. In general, professions in which you get your feedback from other members of that profession tend to get corrupted. When you see a journalist writing articles to impress other journalists, or a restaurateur running a restaurant that's designed to impress other foodies and other restaurateurs, those end up not being practical and high quality. They may receive accolades and prizes within certain elite circles, but they're not reflecting reality. Where someone who is getting feedback from either mother nature, like a scientist or an experimentalist, or from free markets, where other people are voting with their money and their time, those are going to be much better predictors. The people who are operating in the real world and are getting paid for it tend to be optimists. The people who are operating in ivory towers are incented to be pessimists.
To be an entrepreneur, you need to be optimistic about the fact that you're creating something that other people are going to find value in. And people who have a pessimistic philosophy tend to have a pessimistic psychology as well. If you're constantly thinking about all the ways in which the world is going to rack and ruin, then this has a day-to-day impact upon your outlook on the rest of society, and on your family, on your friends, on everything, because you think that this world is condemned. So you're going to feel that weight upon your shoulders, and it's going to come through in the way in which you present yourself to the rest of the world. We see a lot of this on social media right now. Entrepreneurs are typically too busy to spend a whole lot of time on social media, but you do get scientists, academic journalists who are depressed with life because they have a pessimistic view of reality. And that's got to have an impact upon their subjective experience of the world, unlike people who are creating, trying to bring something new into existence.
Unfortunately, the pessimism is self-fulfilling. All evils are due to lack of knowledge. Rational optimism is the way out. The data supports it, history supports it, and we can always come up with good explanations through creativity to improve our lives and everybody else's lives. So stay optimistic.