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Intro. [Recording date: February 7, 2020.]
Russ Roberts: Today is February 7th, 2020 and my guest is physicist and writer Alan Lightman. He is the rare person who gracefully straddles science and the humanities, having written numerous journal articles and books in physics, seven novels, a poetry collection, many other books. This is his second appearance on EconTalk. He was here in November of 2018 talking about his book, Searching for Stars on an Island in Maine. Alan, welcome back to EconTalk.
Alan Lightman: Nice to be with you, Russ.
Russ Roberts: Today we're going to extend our conversation from that previous episode where we talked about awe. We're going to talk today, I hope, about science, religion, related topics. While it's unstructured, I do hope to head in the direction of meaning--a small, minor question, the meaning of life. Other things. We'll probably get into what we know and what we can't know. So, bear with us. I think the journey will be of interest even if we don't quite reach any particular destination.
Alan, let's start with the material nature of the human body and the idea that we are literally stardust. What does science tell us about this, and how do we know what we know or at least what we think we know?
Alan Lightman: Well, biologists believe that we are nothing but atoms and molecules. And, of course, in earlier centuries, many people believed that there was some special essence in living things that was not subject to the laws of physics and chemistry, that was different from ordinary matter that made a thing breathe with life. And, some people called that the soul.
But, there is pretty much consensus now among scientists that that supernatural essence does not exist--that we are simply a collection of atoms and molecules. Certainly, a special collection, because the arrangement of atoms and molecules in living things is different from that in rocks and other inanimate matter. So, we're made out of atoms and molecules.
So, the second part of the story is: Where did those atoms and molecules come from? It's an interesting story. We think that all of the atoms and molecules in the universe, except for hydrogen and helium--the two smallest atoms--were made in the nuclear reactions in stars. What happens is that in the nuclear reactions at the centers of stars, which is what powers stars, what gives them their heat and light, light elements--hydrogen and helium--are fused together to make heavier elements like carbon, oxygen, iron, silicon. And, that's the origin of the heavy elements.
And, some stars that are very massive explode; and their material is spewed out into space. And then eventually that material, as it's floating through space, it coalesces and forms planets and solar systems.
And, so all of the material of our body, except for the hydrogen and helium, was literally made in the nuclear reactions inside stars. And, if you could tag each one of the atoms in your body and follow it backwards in time as it went through the various materials that you've eaten during your lifetime and then to the air, soil, water, back billions of years ago to the time that the earth was formed, and even before that when material that formed the earth was in a gas cloud circling around, eventually each one of those atoms, each particular atom that you had tagged, maybe tagged it with your social security number, would eventually end up at the center of a star.
Russ Roberts: And--pardon my naivete--there's a lot to say about that, obviously. Of course, my first thought for a non-scientific person is, 'Aw, come on, you're kidding.' But, there is a great deal of evidence for this; and it is so extraordinary. One is tempted to say miraculous. That would not, I guess, be the appropriate word in the context of the conversation so far.
But, explain to me just how--let's take a simpler example. Let's take a seed. So, if I have an apple and I have a seed of the apple and I plant that seed and it turns into an apple tree--and of course that might require--in many plants, that requires all kinds of complicated things to happen along the way. Sometimes a wasp, a particular species of wasp has to be involved, or fire has to be involved. But, once that tree germinates and grows, it becomes this leafy, physical thing we call a tree made of wood, leaves, branches, twigs. Maybe other things, pine cones. Inside the seed itself were all of the atoms that ultimately became that tree?--
Alan Lightman: No.
Russ Roberts: or was it the process of sun and rain?
Right, so explain that. And, in humans--
Alan Lightman: Well, of course a full tree weighs much more than this, a seed of a tree. So, all of the atoms could not possibly have been inside of the seed. So, those atoms that began forming the trunk and the limbs and the leaves of the tree, those atoms come from the air and the soil.
Russ Roberts: And the water processes, that--
Alan Lightman: And, water--
Russ Roberts: Sunlight--
Alan Lightman: The energy to catalyze all of that comes from the sun. But the atoms themselves come from the soil and the air. That's where the atoms themselves come from. The process of the metabolism of the tree, the use of sunlight to power the different chemical reactions needed for the tree to live, that does not require the creation of atoms. It does not involve the creation of atoms.
Atoms, except for a very, very small number of atoms that change by radioactivity, atoms are not created or destroyed. The atoms in the biosphere of earth, which includes the oceans, the air, and the soil, those are pretty much remain constant in number.
And, as I said before, all those atoms eventually originated inside particular stars. So, I hope that that--it is an amazing story. But there's a great deal of scientific evidence to support that story. But, let me pose another story to you that might seem equally miraculous.
Your mother had a mother, and that mother had a mother, and that mother had a mother. And, if you keep tracking all of those mothers backwards in time, eventually you come to a woman in a cave, maybe in France 100,000 years ago sitting by a fire. And, that person was your progenitor. And, if that person is--this may be several thousand generations ago--if that person put their fingerprint on, say, a piece of parchment, and her daughter put her fingerprint on a piece of parchment, and her daughter put her fingerprint on a piece of parchment, today, you could have that piece of parchment with several thousand fingerprints on it. And those were all your progenitors.
So, that ancient woman, 100,000 years ago, sitting by the fire, she didn't know anything about you. She didn't know anything about the modern world, about cities, about automobiles. And, yet she was the beginning of that lineage that came to you. And there's--even though even that story also sounds miraculous; but there's no doubt that that is true.
Russ Roberts: And, people like to point out that Genghis Khan had a lot of offspring, and a surprising number of people might have some of his DNA [deoxyribonucleic acid] around today. That primal woman you are talking about--we'll get at some point, I think, into some religious issues. A lot of people, I think, look at the Book of Genesis and find it ludicrous to think that woman's name was, say, Eve, hypothetically. I don't think that's the point of the Book of Genesis, is to help us understand the name of the first woman or the first man. And, maybe we'll talk about that.
Russ Roberts: But I want to step back, even a couple steps back, and make sure I understand you about the stars. So, you said the heavy elements were created in the stars, in the nuclear process. But, hydrogen and helium, the lighter elements, were present in the beginning. Is that correct?
Alan Lightman: Yes, that's correct. They were present very shortly after The Big Bang. Not right at The Big Bang, but [crosstalk 00:11:40].
Russ Roberts: Well, that was my question. So, if we go back before the stars were formed, when we believe as best as we understand it, that the universe was a singularity, meaning a point--of, I don't know how to describe it. You'll help me, but let me try to say it. Then you'll correct it. The universe was a point of infinitely small space and everything in that--what I'm trying to understand is, what was in that? Was that you say it wasn't the hydrogen and helium?
Alan Lightman: Yes, energy.
Russ Roberts: Energy?
Alan Lightman: Energy.
Russ Roberts: So, try to tell me, explain to me. I'm tracking back. I go back into--I'm made of oxygen and nitrogen and hydrogen and carbon. And, so I go back to the furnace of a star.
Alan Lightman: Maybe you go back before that.
Russ Roberts: I go back to the woman in the cave. I go back to the woman in the cave. Then I go back to the star. But, the star, you are saying--much of me was created within the star. But that star, that process, that nuclear furnace was generated by the thing we call The Big Bang--which doesn't help me so much. But, flesh that out, Alan.
Alan Lightman: Well, the Big Bang came along before the first star.
Russ Roberts: Correct, I get that.
Alan Lightman: The first star was--yup.
Russ Roberts: What's in the singularity? What's inside that point, that--the original point?
Alan Lightman: Well, we go back beyond the creation of stars, and we go back earlier and earlier in time until we come to a moment in the past, about 14 billion years ago, when all of the observable universe was in a region smaller than an atom. And, what was in that region was pure energy. And, as the universe expanded away from that singular point, some of that energy was converted into matter. And, we know that energy can make matter. Einstein showed us that in 1905, and it's embodied in his equation E=mc2 [Energy equals mass, times the speed of light squared] which shows the equivalence of energy and matter.
We have confirmed that you can create matter out of energy in our giant particle accelerators, like the one at Fermilab in Chicago and CERN [Conseil Européen pour la Recherche Nucléaire] in Switzerland. We've been confirming that since the 1940s.
So, inside that primeval nugget, that primeval seed, was pure energy. And as the universe expanded, some of that energy became hydrogen and helium. Well, first it became quarks, which are particles much smaller than atoms. And those quarks coalesced to make protons and neutrons and electrons--well, not electrons: electrons were already there. Protons and neutrons, which became the nuclei of atoms. And hydrogen and helium, the first lightest elements were formed at that time.
It was millions of years later that the first stars formed. So, for the first, say, 100 million years, all we had was hydrogen and helium. After around 100 million years or so, some of the hydrogen and helium gas began pulling itself together via gravity and as it pulled itself together, the middle, the interior began heating up due to the compression, and eventually, stars were formed. And, in those stars, the heavier elements that you mentioned--carbon and nitrogen and oxygen--were formed.
Eventually, those stars blew up. Some of those stars blew up. Out of the debris, solar systems were formed. And, eventually one-celled organisms, then bacteria, and then eventually other kinds of very small creatures, and eventually human beings.
Russ Roberts: But, do we understand--you told a story about, and of course this is all storytelling. I don't mean to suggest this is fiction by calling it storytelling, but this is the best we understand it with what we understand about the laws of the universe. You said that the first 100 million years there was just some atoms floating around. A quiet time for the universe. Those first 100 million years must have [crosstalk 00:16:38].
Alan Lightman: Well, it was pretty hot--
Russ Roberts: very slowly.
Alan Lightman: It was quiet in terms of life and stars. There was no life at that time, but it was hot.
Russ Roberts: And, so when those atoms coalesced to form stars, it's tempting to think of a star as just a bright point of light. It's not. It's a complex furnace producing heat.
Alan Lightman: Yeah. It's like our sun. Our sun is a star.
Russ Roberts: Yeah, producing heat and light. How did the process--do we understand anything about how the furnace--I'm going to keep calling it a furnace for lack of a better metaphor--
Alan Lightman: No, that's good.
Russ Roberts: this furnace that's going to create these heavier elements--where did the building blocks of that furnace come from? How did they coalesce to form that--not just a thing, but a thing that makes things?
Alan Lightman: Right. Well, the furnace has hydrogen and a little bit of helium inside it, and it's very dense with a very high density, much higher than the density of ordinary matter, and also very hot. It's hot because gravity has compressed this material the same way a tire heats up when you compress it. It heats up. And, so this proto-furnace, pre-furnace, gets hotter and hotter, and so the hydrogen atoms are whizzing around in this high heat.
As they whiz around, they collide with each other. And, if they collide with each other with enough force, they stick together. It has to be allowed a force because there's an electrical repulsion between the hydrogen atoms that keeps them from getting too close together. But, if they're whizzing around fast enough and they slam against each other hard enough, they can overcome that electrical repulsion. And then a nuclear attraction, a nuclear force, which is an attractive force, pulls those protons together; and they join together to make the nucleus of a helium atom. And, then eventually a carbon atom, and then eventually a nitrogen atom.
This fusion process that occurs inside the so-called furnace is one in which atoms come close enough together for the attractive nuclear force to bind them together. The nuclear force is like a glue. And, if the atoms get close enough, that glue latches onto them via the nuclear force, and binds them together into heavier elements. So, you might start with two protons, which are two hydrogen nuclei. They join together to make a helium nucleus, and then several of those helium nuclei join together to make a carbon nucleus.
Russ Roberts: I got it. So, the furnace itself, it's not like a 3D [three dimensional] printer. It's more like--it's the natural consequence of the underlying forces of the universe that we have a pretty good understanding of--the nuclear force, gravity, electricity, and the [?repelling?] [crosstalk 00:20:22].
Alan Lightman: Right, electrical force, nuclear force. We understand them pretty well.
Russ Roberts: So, one more clarifying question, and for listeners who are wondering where this is going, trust me. I don't know if any of you have left, but this is not normal EconTalk talk, but I hope it's okay. It will get a little more down to earth--literally.
When you said it starts off as pure energy, that moment where we go from pure energy to matter, is a really short moment, correct?
Alan Lightman: Yes.
Russ Roberts: Very short.
Alan Lightman: Yes.
Russ Roberts: How short? I think you said a trillionth of a trillionth of a trillionth of a second in an essay, once. Something like that.
Alan Lightman: Yeah, something like that. Something like a trillionth of a trillionth of a trillionth of a second, that's when you start converting some of the energy into matter.
Russ Roberts: So, is that the Planck epoch?
Alan Lightman: The Planck epoch is earlier than that. The Planck epoch is 10 to the minus 43 seconds. That's one divided by one with 43 zeros after it.
Russ Roberts: It's less than a trillionth of a trillionth of a trillionth.
Alan Lightman: Yes. That's much less. A trillionth of a trillionth of a trillionth of a second is 10 million times longer than that. The Planck epoch is where quantum physics and gravitational physics all come together.
And, we believe that our universe was actually created during the Planck epoch. We can't really talk about time and space earlier than the Planck epoch because at that time, at the Planck epoch, when the universe was 10 to the minus 43 seconds old, space and time did not behave as they do now.
Russ Roberts: Too dense. Too dense.
Alan Lightman: Yeah. Positions in space were constantly changing. Space itself was being warped. Time was not flowing in a linear manner as we experience it today. We can't even talk about time and space earlier than the Planck era. We have no language to describe it.
Russ Roberts: Okay. So, here's the tough theology question. I'll try to--I don't know if I can say this coherently. I didn't write it out, but I think I know based--I think I could ask this question based on what I've read you say elsewhere, which is the following.
So, in some sense we--you used the word, we 'believe.' That's an--English language word. It's a casual-conversation word--
Alan Lightman: Not scientific.
Russ Roberts: Right. It's not a scientific word. So, as a religious person, in some sense--and I'll try to flesh that out, what I mean by that at some point maybe in this conversation, because faith is a tricky thing to describe. It's inherently--there's ambiguity about it. I think it's challenging. But the--I'm going to give, maybe not a fair overview of this, but I'll do my best and then you can react to it.
So, we understand all of the--we can go back in time. We can play the film backward in our imagination, back the hundred thousand years to the woman in the cave in France. Then I'm going to go back 14 billion years minus a trillionth of a trillionth of a second, or the Planck epoch. Take your choice. I'm going to go back a long way.
Which reminds me of the joke of the guy in the natural history museum who said, 'That dinosaur is one million and 12 years old.' And, they say--the people on the tour say, 'Well, how come so precise?' He said, 'Well, when I got here 12 years ago, they said it was a million years old.' I've got to throw that in.
But, anyway, so we go back to almost 14 billion years, not quite because we're going to leave out the first nano-, nano-, nano-, nanosecond. And, we know in theory--sort of, kind of--everything, all these processes, we play the tape backwards, we get there.
But, the very first fraction of a second is veiled from us. We think we understand something about it. We call it 'pure energy.' We understand that--that's not a made up phrase like 'Odin, the Norse God.' It has some intellectual content, 'pure energy.' And, yet, to some degree it is a conceptual hand-waving because we don't understand--we believe it's not possible to understand--the processes that were at work in that first nano-, nano-, nanosecond.
So, in some sense we've got almost all of it. We understand all 99.9999999. And, so then the question is: That remaining fraction of a second, is that just like a footnote, or is that like the whole thing?
And, I'm going to make a parallel analogy, which I've heard from Nagel or Chalmers, I think--one of them, I can't remember which one. You know: 'We understand almost everything about the physical world except consciousness, so we've pretty much mastered it.' And, their reaction is kind of, at least I think Nagel's is, 'Well, if you can't understand the one thing that allows us to understand everything else, you really haven't explained much of anything.'
So, in some sense--I'm going to ask you two impossible questions. The first question is: How would you describe the magnitude of our ignorance about that first nano-, nano-, nanosecond? And, the second is--and I think I've read you say that, read you right; I think you've written it or spoken--that: There is room for God in that first nano- nanosecond as long as God then plays by the rules, lets the universe spin forward in it's immutable laws that we have fathomed.
So, my question, then, is: If that is true, do you believe that the unfolding of the universe to this moment right now, the one that we're having this conversation in, is it in any sense deterministic?
Because, fundamentally, by rolling back the tape--we could roll it forward, too, and we imagine that's what science has tried to do. We've tried to say, 'If I were standing,'--whatever that means,--'after the Planck epoch, after the first nanosecond, everything after that is going to be predetermined. The stars are going to form. Once I know the rules. The stars form, the bacteria of--the earth forms. Matter forms. Bacteria come along, small animals, big animals, people, consciousness. The conversation between Russell Roberts and Alan Lightman on February 7th, 2020.' Is there any room for a force in the universe--we'll call it God--that does something other than that first nanosecond? And, then sits on the sidelines and watches.
Alan Lightman: Well, are you asking--
Russ Roberts: So, there's two questions--
Alan Lightman: whether God is there--
Russ Roberts: Yeah: What's the significance of the fact that we don't understand the first nanosecond? And does that, if that's somewhat significant, what role does that leave for the things we don't understand?
Alan Lightman: Right. Yeah. Well, most physicists believe that, eventually, that we will understand the first fraction of a second, the Planck time, when we have a theory called quantum gravity. And, quantum gravity is a theory that we don't yet have, but we believe that we will have at some point. When I say a theory, I mean a set of equations that explains nature. This would be a set of equations that successfully merges quantum physics, which was developed in the 1920s, with relativity theory, which was developed a little bit earlier than that by Einstein. And, we believe that when we have a set of equations that we call quantum gravity, that we will understand what happened at the Planck time, and we will understand how our universe came into being out of a so-called quantum fluctuation.
We know that particles can materialize out of energy. We've demonstrated that in the laboratory and in our particle accelerators. And so, it is believed, that is all of our theories and everything we know about physics today, tells us that our entire universe came out of a fluctuation; and the quantum--we call it quantum foam--that existed before T=0 [Time equals zero]. That's what all of our physics points to. We don't know the details yet earlier than the Planck time because we do not yet have this theory of quantum gravity. But, a lot of very smart physicists are working on it.
So, the question of whether, uh, God could intervene after the Planck time: First of all, the question of God itself, I probably said this on your earlier program, but science cannot prove or disprove the existence of God. It has to be taken as a matter of faith, the existence of God. Um--all of the evidence that we have from all the experiments that we've done, all the theories that we've created, all the predictions of those theories, and then the tests of those theories against the experiment, tells us or suggests to us, that the universe is a lawful place. That is, that there are certain laws of nature, like Newton's formula for gravity, that hold throughout the universe. And, we haven't seen any phenomena that violate the laws of nature.
Now, we haven't discovered all of the laws of nature. In particular, we have not yet discovered the law of quantum gravity.
But for all of the laws that we know about and all of the phenomena that we have observed, there is quite a lot of evidence that we live in a lawful universe. And, 'lawful' would include the idea of a deterministic universe.
Quantum mechanics tells us that there's a slight bit of indeterminism--that we can predict averages, but not, for example, the time that an individual atom will emit light. But, aside from that detail, which is not quite the same as that we don't understand consciousness, we believe that the universe is deterministic and lawful place.
Whether or not God started off the universe and then sat on the sidelines, that is something that science really cannot know. Although, we do believe that at some future date that we will have a theory of quantum gravity, which explains how the universe could have emerged from a quantum fluctuation.
Now the question of what produced the quantum fluctuation, what produced the laws of nature--that is something that we really can't know even in principle. And, if you are a believer, you can say that that was the role of God, to create the laws of nature.
Russ Roberts: It's turtles all the way down, just to make a--
Alan Lightman: Yes.
Russ Roberts: a Bertrand Russell reference.
And, of course if we get to that quantum, the theory of quantum gravity, we won't, like you say, we won't know why it works that way. We don't understand why the universe is a lawful place.
We can presume that its lawfulness allows us to observe that lawfulness, which is somewhat interesting. It's not definitive. It's, I think for a believer, a religious believer, it is comforting that the universe is a lawful place to be explored by the consciousness of human beings, and understood in increasing amounts.
But, there is a fundamental level of unknowability at some point. Whether it's the reasons behind it, the causal--of course, I should say, it's not clear that causation has any--we're human beings. We want to have a causal story. We want to know. And, it's like if you believe in God, human beings ask, 'Well, what came before God?' We want to know who made God. We want to know--we demand a Before. And, it's a human failing, I think, of consciousness that, for both believers and scientists, right? We want to know what made--
Alan Lightman: I remember what Saint Augustine said when he was asked, 'What came before God?' And, Augustine answered that nothing came before God because God created time and space. And, so even the word before had no significance.
Russ Roberts: The human concept to help us order things, we don't--it doesn't--
Alan Lightman: Yep. It's a human question.
Russ Roberts: By definition almost, God would be beyond before . And similarly, I guess, as a scientist who doesn't believe in God, one who doesn't, can argue that what caused the cosmic--excuse me--the quantum fluctuation, is irrelevant. It doesn't--it's nothing.
Alan Lightman: You can also say it's a philosophical question. That it lies outside the realm of science.
Russ Roberts: Correct.
Russ Roberts: Sometimes, when I talk about the fact that I live a religious life and I believe in God, that people respond that--I've mentioned this before that--'I thought,' they still say, 'I thought you were smart.' And, sometimes I respond, snarkily, saying, 'Well, either you don't understand religion,' or, 'I'm not as smart as you think I am.' But I often, sometimes I respond, 'Well, Isaac Newton was pretty smart. He believed in a creator.' And, they say things like, 'Well, he wouldn't now.'
Alan Lightman: Well, so did Isaac Newton. I mean, I think that there are many, many smart people who believe in God . And this is one of the objections that I have to people like Richard Dawkins, a very famous biologist. He wrote a book called The God Delusion. And, I think that he has a very condescending attitude towards believers. He said exactly what you just said, that you can't be smart and also believe in God.
Russ Roberts: But, I think you can.
Alan Lightman: I do, too.
Russ Roberts: Yeah. So, but then the question is, I mean, I'm not going to bare my soul totally here on the air, but I mean, I think that is a challenge to faith and belief that God cares about us, the belief. There's different conceptions of God. You can have a God who--the time a watch-maker kind of God who winds the watch and lets it unfold the way I suggested a little bit ago. I don't think--I'll come back to that in a sec, but I want to make sure I let you finish your answer. Is the universe determinate? You said there's--I mean, once that thing started, does it lead to Alan and and me talking?
Alan Lightman: Well, we know that quantum physics plays a role in the universe. And we--quantum physics is a theory that was developed in the 1920s, and its effects are largest at very, very small scales, the sizes of atoms and so on. And, if you were able to look at nature at a very, very small scale--you had a super-strong microscope and you were able to look at individual atoms--you would find that subatomic particles behave as if they existed in several places at once, at the subatomic scale. And, so the particles at a subatomic scale act partly like waves and partly like particles. There's a--reality takes on a hazy character at the subatomic size.
And, the laws of causality, of strict cause--every effect has a cause--they don't apply precisely at the subatomic scale. They apply at a macroscopic scale, say, the size of a pumpkin seed. But, when you go to very, very small scales, strict causality does not apply.
So, the idea of determinism, the idea of cause and effect, is something that we have developed for the macroscopic universe. The scale of the universe is much larger than individual atoms. And at that scale, strict determinism seems to apply. But, if you look at the very, very small scale, it doesn't.
It's sort of like looking at a beach from a thousand feet up. If you look at the beach very, very closely, you see individual grains of sand. That's sort of the lumpiness of nature when causality doesn't strictly apply. But, if you look at a beach from a thousand feet up, you don't see the individual grains of sand. It looks smooth. And, so our ideas of determinism and cause and effect relationships seem to be created by averaging over lots of little grains of sand.
Russ Roberts: But, that doesn't answer the question of whether--I mean, I don't understand the answer as to whether that leaves no room for free will--
Alan Lightman: That--yes.
Russ Roberts: in your view.
Alan Lightman: Yes. Well, the--if we talk about--well, if you talk about God, which we don't understand, of course, you could hold the belief that God acts at the quantum level, and can violate strict causality whenever he, she, or it wants to. But, in terms of free will, my view on that is, free will--which is decision-making--that happens in the brain and the--
Russ Roberts: Kind of.
Alan Lightman: Well, we think it does. Okay. I'm speaking now as a scientist.
Russ Roberts: Yeah. No. But, even--it's tricky. Sorry. I misspoke[?]--what I meant by that snarky comment was we think we're in control sometimes of what we decide and because it's in the brain. And, of course, sometimes the brain decides later what the reason was. And, that's all I meant by that. Go ahead. Carry on.
Alan Lightman: Well, the unit of action in the brain is the neuron, we believe, and the connections between neurons. Wherever decisions are made in the brain it has--or not made--it has something to do with neurons and the communication between neurons.
And, neurons, and even the tiny filaments that connect one neuron to another, contain many, many millions of molecules. And, when you're looking at--and not individual atoms and molecules--and therefore quantum effects probably do not play a role in the actions of neurons, just because you've averaged over all of those grains of sand by the time you get to something as big as a neuron.
So, I think that the brain is a deterministic system, but the question of whether we are aware of making a decision, and whether we are conscious of making decisions, that's a completely different question. Because, it's very possible that the neurons in the brain can cause actions. Say, a few neurons can say, 'I'm going to raise my arm at this moment.' That may happen at an unconscious level, and we are not conscious of those neurons having synchronized in such a way to make that decision. And, in fact, some experiments have been done to show that we actually make decisions sometimes before we are consciously aware of having made those decisions.
So, the brain is a very complicated thing, which we don't completely understand. And, as you said earlier, we don't understand consciousness. And it's very possible that the brain is a completely deterministic system, but the level of the brain for which we associate consciousness is not aware of every decision made or when it's made.
Russ Roberts: I think most of us know this from casual experience. While you were talking--no, I'm serious. While you're were talking--why are you laughing?
Alan Lightman: Well, I'm laughing that I think we do a lot of things that we're unhappy about later on. And, maybe we weren't consciously making that decision, but that's a good excuse for many misdeeds.
Russ Roberts: Yeah. But, it just seems--while you were talking, I paused mentally and noticed I was moving my thumb and forefinger together. And, I didn't plan on that. And, it was going before I noticed it.
Alan Lightman: Right.
Russ Roberts: Daydreaming--
Alan Lightman: Yeah--
Russ Roberts: I realize, 'Oh, I missed my turn.' We know that wasn't because I thought, 'I think I'll daydream for a while and when I'm done I'll make the turn off the freeway.'
Russ Roberts: Anyway, so I'm going to come back to this--by the way, we're now about 40 minutes into this conversation; we haven't gotten close to what I wanted to talk about yet, but--it's all[?] prelude. But, the best part is uet to come for the 8% of the listeners who are still hanging in there. And, if you are, let me know. Let me know if you think of this. But--
Alan Lightman: Well, they might be listening unconsciously.
Russ Roberts: They are. They're commuting many of them. We know that from survey data that I've collected, and they are probably thinking about the next turn and have lost the thread here.
But, you started off saying that in previous centuries, ancient times, human beings thought maybe there was a soul. Now we believe, scientists believe, there's no soul. There's only chemicals and matter.
And, the part of this I find strange about that is this idea of emergence, and I was recently talking to Azra Raza about cancer on the program, and I quoted something she mentions in her book, The First Cell, which I found helpful: it's a wonderful metaphor. She is quoting a neurosurgeon, Ayub Ommaya, and they were talking about consciousness and the reductionism that's often invoked--that consciousness can be reduced to just some physical processes we haven't fully understood. Electricity, neurons firing, chemistry, etc. And, he said the following. He said,
Azra, taking apart the Taj Mahal brick by brick to discover the source of its beauty will yield only rubble. It is the same with the brain. The emergent complexity from simple individual parts accounts for its essential mystery.
So, while there may not be a physical thing that we're going to be able to scan and see called a soul, or consciousness, it's pretty clear to me that the component parts that are the physical things make up something together that we don't understand. Maybe we will some day, but we don't understand today. That is emergent, that is complex, that is greater than the sum of the whole. If you want to call it a soul, obviously that has divine aspects to it that you don't want, one doesn't have to accept.
But, I think the more interesting point, at least for science, is that it's really complicated and that studying it at the finer and finer levels of detail, eventually it's going to only yield rubble. We're not going to master it. And, I think some philosophers have come to that conclusion in a less poetic way.
Alan Lightman: Well, I agree totally with that viewpoint: that for very complicated systems that consist of many parts that we can understand--and this is all material now, material parts--that we can understand the behavior of individual neurons, the way that they send electrical currents through themselves and chemical signals to other neurons. But when you put a hundred billion of them together, or maybe in just 1 billion together, that we don't understand even qualitatively what you get out of that, the emergent phenomena of consciousness. So, I think that that's a very reasonable point of view.
Russ Roberts: So, let's turn to the human side now. Let's move away from some of the physics, although we're going to have to invoke it and use it. You suggest in a conversation with Rebecca Goldstein that things that don't last can't have meaning. And, you talk about the example of the ant colony. You call it the--
Alan Lightman: The Smart Ant Condundrum.
Russ Roberts: The Smart Ant Conundrum, yeah. Explain the Smart Ant Conundrum.
Alan Lightman: Well, first of all, let me say that I don't know whether in order to have meaning, something has to last a long time. That's the view that I had for many years, but I now am uncertain of that view.
But, the Smart Ant Conundrum is this: Suppose that you have a colony of very smart ants, super-intelligent ants, and these ants are able to develop a host civilization with music and painting. And, they are able to build ant buildings; and they're able to have intimate relationships with each other; and they're able to write books; and so on. And, then one day--
Russ Roberts: And it lasts--most ant colonies don't last that long.
Alan Lightman: Lasts a hundred years. Yeah. Let's say this colony lasts for a hundred years.
Russ Roberts: Which is unusual, right? They usually don't last--
Alan Lightman: Which I unusual for ants. But, let's just say that it does last for a hundred years, and the descendant ants inherit all of the paintings and literature of their forebears.
But, after a hundred years, there's this heavy rain and a flood and it totally washes away the ant colony so that there's no traces left. There are no ant books left, no ant paintings left. There's no ant buildings left. There's absolutely nothing left of this ant colony. It's gone from the face of the earth.
Russ Roberts: Except for its atoms, which would now been redistributed elsewhere and gone back into the soil.
Alan Lightman: Yes--
Russ Roberts: That's just my cheap shot at you, Alan. Go ahead.
Alan Lightman: That's good. You're conscious and listening.
So, the question is: Did that ant colony have any meaning? And, does it have any meaning today in the cosmos where there's no trace of that ant colony? So, that's my question, and course is, it raises the question, does something have to have permanence in order to have meaning?
Russ Roberts: And, a related question, which it's not exactly the same--it's interesting how hard is to talk about these things--did that colony matter? You could ask the question of whether, is there any meaning to it for eternity, for posterity, for other creatures coming after it. But, you could also ask, 'While it was here did it, did it matter at all? Did it have any significance?' You could argue, maybe some--if human beings observed the colony and told their children about them, does that somehow change the seeming meaninglessness for the ants themselves?
But, the reason I like the analogy, the metaphor, the story--even though I'm going to push back against it--the reason I like it is that it is somewhat descriptive, perhaps, of the human condition.
Alan Lightman: Of course.
Russ Roberts: So, because we believe that we will be washed away. So, we may as well finish our narrative. We've got the pure energy that starts, the stars that form, the furnaces that create, the heavier material, the earth that comes about, eventually a woman in a cave, you and me. But, we don't, going forward, we have an idea of how that's going to end too. So, carry that out.
Alan Lightman: Well, we don't know for sure how it's going to end for us. We do know that in several billion years our sun is going to expand and incinerate the earth.
Russ Roberts: Do you say million or billion?
Alan Lightman: Billion.
Russ Roberts: Oh, a few. Phew.
Alan Lightman: Billion. Billion.
Russ Roberts: That's an old joke. Sorry about that.
Alan Lightman: You've got time to go to the grocery store.
Russ Roberts: I've always loved that one. It's another tour guide joke in a museum. Sorry. Right. So, in a few billion years, go ahead.
Alan Lightman: In a few billion years, the sun is going to expand and it's going to incinerate the earth.
Russ Roberts: It's going to expand past our orbit even, right?
Alan Lightman: Yeah, it will.
Russ Roberts: Physically. It's not just going to get really hot. It's going to--
Alan Lightman: No, its outer layers are going to expand. It's going to expand into another kind of star called a red giant. And, so unless we have managed to build rocket ships and get out of the solar system, which I think that we probably will in a few billion years, but unless we've managed to do that, there will be no trace left of planet earth and the civilization that we have created. So, that's like the anthill getting flooded.
Russ Roberts: But, even if we get out of the solar system, every star is going to go cold eventually. Right?
Alan Lightman: Every star will go cold, so we will have to find some energy source. But, I think that because we have recently discovered that the universe is accelerating--that was discovered in 1998--and around a hundred billion years or so, there probably will not be any life at all in the universe. It will be just cold and lifeless and there will be no consciousness in the universe. So, then, you can ask the question, did it matter that there was life in the universe?
Russ Roberts: I'm hearing a--I'm not going to be able to quote it from memory exactly. But, I'm hearing that poignant line from Camelot, that 'in one spot there was this'--just, does it matter that during 'this brief moment,' 'before it was riven and torn apart' by the jealousy and love triangle of Lancelot and Guinevere and Arthur, 'there was this enchanting spot.' So, just, it just going to be gone and we're gone. We're done. And people should--
Alan Lightman: Yeah. Does it matter that there's life in the universe for--I mean, if you imagine that our universe will keep expanding forever, and that's all the evidence that is, is it will keep going on for billions and billions and billions and billions of years, infinitely, the period of time in which there was life in the universe. And, I don't just mean life on our planet, but I mean life--
Russ Roberts: Any kind--
Alan Lightman: Any [?] the universe, that is a relatively short period of time in the total history of our universe. So, did it matter?
Russ Roberts: And, of course--I think that I'm going to go back to your ant analogy. T reason it's such a good analogy--a good metaphor, excuse me--is, you can imagine that in the extraordinary size of the universe today, the earth is a very small part. We are the equivalent of ants. We are in some physical sense insignificant.
And, the problem I think with the metaphor is that it presumes that there is something large that's watching us. Just like we look at the ants: we look at the ants and go, 'Huh.' Forget a hundred years. Let's just say we see an ant carrying a very large piece of debris, which I've seen, you've seen, it's a beautiful sight, this ant struggling with something sometimes maybe as big or bigger than itself. And, then suddenly something comes along and steps on it. Or you might, as a child you might have crushed an ant, and it's gone. It doesn't matter. It's not conscious really. It's got a brain the size of a pinhead. And, you and I, we have these big brains with all the neurons firing. But, in the grand scheme of 10-to-the-23rd stars spread out across the sky, it's trivial. Trivial, beyond. It's no more significant than the arm of an ant even. Forget it, it's nothing.
But, of course, that presumes that there's something out there. In a way it presumes a God that looks down to consciousness as some kind of--we're human. We have this need to think this way. Your story implicitly assumes there's something to mock the insignificance of the ant colony. And once you have that idea, then suddenly you could imagine it's not so insignificant. If there is beyond our--
Alan Lightman: If there is some eternal observer, like God--in fact, God is the only thing that we know that could be eternal: it's part of the definition of God. But, if there is some eternal observer, then I think that that alone gives significance to all of this.
But, if there is no eternal observer, and if there is no consciousness in the universe--because consciousness requires life. Suppose that there is no more life after a hundred billion years. And, if there's no God, then there is no observer.
Russ Roberts: Yeah, I liked the metaphor that God is the playwright and we have our roles to play, and we have some freedom with the script, perhaps, to craft our lines and our actions to some extent. We can't fly to Mars, but maybe we will someday; but we can't do it right now. I can't do it by myself.
So, I'm stuck on this earth. I make this decision to start a podcast. I'm foolishly trying to educate and entertain people across the world, to no purpose, obviously. But, here I am. I don't know why I'm compelled to do it, but I'm doing it.
And, you listening out there, after you heard that thing about the earth going cold, I know you threw off your headphones and said, 'Oh, I thought something mattered and now it's time to--I was wrong.' We don't feel that way. Right? It's an amazing thing that we don't feel that way. We feel like we matter--
Alan Lightman: We do.
Russ Roberts: And, if there were that consciousness that watched it and that--it would be no less meaningful and no more meaningful than the extraordinary performance I saw this past few days of Next to Normal, that moved me incredibly deeply, that made me cry. And, it had me thinking about it for days afterward. But, of course, I'm going to die. And, my love for that performance is ephemeral.
And yet, you could argue that that divine consciousness is watching and experiencing the drama of EconTalk and every blade of grass and so on. And, that's what it's all about. And, I don't really believe that, even as a religious person--that we're here to be God's entertainment and that the universe is God's backdrop for our little planet's behavior. Though, I wonder about it sometimes. But, that consciousness would redeem something. I'm not sure it would make life meaningful. I mean in a way you could argue it's worse. We're just serfs in this grand, divine show. I don't know. It's hard to know whether that makes it better or worse.
Alan Lightman: Well, yes, and the scenario that you described is comforting. But, let me pose the question from a different direction. Suppose that meaning exists only in the moment. So, it doesn't make sense to ask whether there's meaning after the anthill has been flooded or after all of the stars have burned out and the universe is cold. That: there was meaning when it lasted, and that's the only time there is a meaning.
Or an even more profound question: Maybe we are just deluding ourselves to talk about meaning. Maybe meaning is a totally human construction, is a desire that we have that is a byproduct of a very advanced brain. There are other animals that get along perfectly fine without beating their chest and wondering whether there's meaning in the world or not. And, maybe meaning is just a human construction.
Russ Roberts: It seems to be. I raised this question when we talked before: why we care. I think it's a deep question. I know it doesn't bother most people, but I find it fascinating that we want meaning. We want purpose. We like to think our life matters. I don't know if I've used this image before, but the prisoner who is a forced while in prison to turn this crank that's in his cell. And when he's finally released after 20 years, he's excited because, besides freedom, he wants to see what the crank has been--what he's been generating, what he's been turning.
And, when he gets outside the other wall[?], there's nothing there. It's just a crank. It was just an empty punishment.
That's unbearable. We like to believe that our work matters, that our investment and our time. I think one of the reasons it's hard to accept Bryan Caplan's thesis on this program, which he's put forward--that parenting is pretty much irrelevant. That your kids grew up the way they're going to grow up regardless. It's hard to accept. It might be true, but it's very hard to accept given the amount of time and effort and love we put into it. We want to believe deeply--it's not enough for it to be true--but we do want to believe that it matters.
And I do think, I find it: It's extraordinary that our consciousness has evolved to, although we have a deep urge for physical satisfaction, obviously, sex, fame, money, gluttony, and so on--often those do not lead to happiness. Yhey don't lead to satisfaction. And, that's puzzling given that if we are, quote, "just animals" that will live and die and have no significance. We don't like that. We certainly don't like it; it's puzzling why it troubles us.
Alan Lightman: It is puzzling. And, I don't think we will ever know the answer to that. But, it could be that the desire for meaning, the desire for significance, the desire for mattering is a byproduct of a very advanced brain. And, it's probably true that those desires do not have any survival benefit--that they were not selected by the Darwinian process to help us survive, but they are just byproducts of a smart brain--which does have survival benefit.
I think I mentioned before that there are plenty of times where you invent a tool for one purpose, but then you find that it does something else. Like a hammer that was designed to hammer nails, but that also you discover later that it also works very nicely as a paperweight. I know that sounds like it's a real slander of this exquisite desire for meaning and mattering, but it could be that it's simply an unintended byproduct of an advanced brain.
Russ Roberts: Yeah, it could be. It also could be that it was put in there by, again, a very far-seeing force that set things in motion.
Alan Lightman: Yes, it could be that too.
Russ Roberts: Because there's more than one of those. In this recent essay I wrote, which I shared with you, called "Transients and Transcendence"--
Alan Lightman: Yeah, great essay--
Russ Roberts: Thank you--it's not just that we care about meaning, we also have this love of beauty. I mean, why am I crying while watching this bunch of actors on a stage? I want to salute Rachel Bay Jones, phenomenal.
One answer is, well, I've got this empathy built into my system that evolved through altruistic family relations over small clans. I understand that argument; it's possible.
But, why does it sweep me away? Why does standing in Yosemite and looking down the valley take my breath away? Why can that give me goosebumps? And, yeah, it could just be the result of this other stuff. But, there is this nontrivial--to say 'nontrivial' doesn't begin to cover it--this enormous part of our qualia--our consciousness experience--is, that is so disconnected from everything physical about us. I guess that's part of the consciousness conundrum. I guess we're not going to do a great job on that, I don't think, but maybe.
Alan Lightman: Well, I agree. It's awe-inspiring. And there's the scientific explanation for it. I mean, Darwin talked about why it is that we respond to beauty as something that promotes reproduction. And then there's the other explanation, which is more spiritual: which is that some spiritual being put that into our bodies, into our minds, into our selves. I think it's impossible to ever show that one explanation is right and the other is wrong.
Russ Roberts: So, I want to now shift gears a little bit, and before I do, I want to get the quote about Camelot correctly, which is a beautiful lyric by Loewe, I think, Lerner and Loewe, who wrote Camelot, "Don't let it be forgot, that once there was a spot, for one brief shining moment, that was known as Camelot." So, that's nice poetry.
Russ Roberts: But, I want to shift gears to the scope of science. I recently was talking to Peter Singer on the program about happiness, and I hope I'm going to be fair to him. This episode hasn't aired yet, but will have aired by the time our conversation airs, Alan. Where he was talking about how the science of happiness, that we have made some progress in understanding what makes people happy, and it's only a matter of time before we get better at that.
I talked about Richard Layard's work. And I suggested, to his shock and horror, which is I think us[?] both, that I didn't think we'd ever understand that. I don't think it's scientific. I don't think we have a science of happiness. I don't think it's fruitful to try to measure happiness with a number and to then find what correlates with it and try to change policy to raise that number. And he was so taken aback, he basically said, 'Well, I don't have anything to say because,' you know, 'you're an economist.' He couldn't understand how I could feel that way. Of course, in some sense, I'm a lapsed economist.
But, I'm curious whether you think there are corners of the human experience, they may be quite large--they may be auditoriums and football stadiums--of places where the analytical methods of science don't apply.
Alan Lightman: Well, I definitely do, and I think happiness is one of them. I think the feeling that you had watching that play, the feeling that I have when I lie on my back on a clear night and look up at the sky and am drawn into the stars, I think that those experiences are fundamentally not analyzable by the methods of science.
When I say that, I don't believe that they are supernatural experiences, but I just think that they are experiences that happened at such a complicated level in the human brain that are related to the emergent phenomena that we're talking about--that science is really not going to get anywhere by trying to reduce them to a series of electrical impulses between neurons.
Russ Roberts: And, yet you believe that we will have a theory of quantum gravity, although, you didn't say that explicitly. You said, 'most scientists believe,' or you had a phrase for it.
Alan Lightman: I think that we will.
Russ Roberts: But, you do think there are parts of the human experience, at least--and of course, I'm tempted to say, 'Well, yes, the physical world we will understand, but not the human.' But, of course, we are physical, that's part of what you're suggesting, what you do believe. But, you are suggesting there are aspects of it that are not amenable to--for example, you don't think that we'll get better at the science of marriage, of putting people together based on skin temperature and heart rates and other chemical measures that my Apple Watch will tell me. When my great grandchildren are on a blind date, they won't be able to look at their Apple Watch and see that there's a match and just say to the other person, 'Well, yeah, let's go get married.' You don't think that's going to happen? You're laughing. Shame on you, you're a scientist.
Alan Lightman: Right. I think that what you just said is going to crash the stock of all of these online dating services.
Russ Roberts: But, I'm serious in that I do think--I interviewed Robert Burton, the neuroscientist, and he has a wonderful book which we talked about called On Being Certain. And I've come to believe that human beings really like certainty. It's very convenient. It frees up your mind to do other things.
And so, one of the things we struggle with is numbers. We find them very seductive, and as a result, we're prone to believe things that are uncertain when, in fact--as certain when in fact they are uncertain--because they have numbers attached to them and they look like science. I consider them faux science, scientism, these kinds of things about, say, the science of happiness or dating or other fundamental human experiences. When I suggest that you should read novels and watch musicals and talk to your friends about to get a better understanding of them, some people laugh at me and say, 'Are you kidding? That's, first of all, that's not science. You can't learn anything from that. Secondly, we're making progress. We'll eventually figure it all out just a matter of time.'
Alan Lightman: Well, I think that I share your point of view on this even though I'm a scientist, and of course, you're an economist and--
Russ Roberts: Social scientist--
Alan Lightman: Yes: the 'dismal science.' But, what I'm reminded of is something that a novelist once said about the novel, and that is: Once you fully understand a character in a novel, that character is dead for you.
Russ Roberts: Oh, that's fantastic.
Alan Lightman: And, I think that we human beings, and despite all of the progress we've made in science, we are very, very complex entities, objects. There are just layers and layers of complexity and contradictions and paradoxes. That, what makes good art and makes a good character in a novel is embracing that ambiguity in human beings.
And I think it's related to everything we've been saying of why you feel transported and brought to tears when you watch the play. And, why I feel like I'm falling into infinity when I lie on my back and look at the stars: That there's an unquantifiable, un-rational aspect of being human. And even the novelist--the writer of the novel--should not fully understand the characters in the novel. There should be layers of uncertainty and ambiguity and the unknown.
And finally, this reminds me of one of my famous quotations from Einstein, who said that the most beautiful experience we can have is the mysterious: 'The mysterious lies at the cradle of true art and true science.' And I just love that quote.
Russ Roberts: It's so beautiful. Yeah, I had a different thought. It seems to be a stretch of EconTalk where I'm doing a lot of singing. I'm not going to sing this though, but I am going to quote a song. This happens to be my brother' and his wife's song, "It Had to Be You." I've always loved this song. He says, the lyricist--I'm just blanking on who wrote it but--I'm going to hold off, we'll look it up. But, anyway, he says, 'Some others I've seen might never be mean, might never be cross or try to be boss, but they wouldn't do. For nobody else gave me a thrill with all your faults, I love you still.' It's that thrill, the unpredictable, the fact that you don't do what I want, that you're not my pawn, my robot, my puppet--that I can't fully understand you--is what makes love magical. But, there's a part of this of course that wants someone that loves us unconditionally and is--
Alan Lightman: And predictably.
Russ Roberts: And predictably; but the Einstein in us--
Alan Lightman: Part of us doesn't want that.
Russ Roberts: The Einstein in us--it reminds me also of, you know, Faulkner liked to play with interviewers, and I think he sometimes said things just to entertain himself. But, he said once, and I just love this, he said--and he was a novelist, a great novelist as well. It's the most, for me, the most glorious part of writing a novel, which is: he said, 'Oh, all I do,' as if it's simple, 'All I do is I just follow my characters around and write down what they say.' Of course, that's the ultimate hand-waving, right?
Alan Lightman: Right.
Russ Roberts: It's like, it's an inside joke in a way because it masks the extraordinary complexity and creativity of his characters.
But, when you're writing a novel, it's one of the most exhilarating things when you realize, 'I'm going to go figure out what's going to happen next,' and you don't know. And you might script it and you realize, 'Nah, that's not plausible. I can't--he wouldn't have done that.
Alan Lightman: Right, you need to be--a good writer of novels is surprised by his or her characters. And, you need that element of surprise to bring the characters to life; and bringing them to life means that they resonate with the reader, that they seem, 'Yes, this is a real flesh and blood character full of all of the ambiguities and contradictions of real people.'
Russ Roberts: So, you wrote a book called Einstein's Dreams, such a wonderful book, and if people out there haven't read it, I strongly recommend it. It's a glorious book. Wonderful imagination. And I just want to think about the following thought experiment. Maybe we'll end on this. As far as we know, there was a man named Albert Einstein who was born in the 19th century and died in the middle of the 20th and transformed the world. There's a huge amount of romance about him, right? He was an extraordinary mind, obviously; but we also romanticize the extraordinariness in all kinds of ways. And right now, by mentioning that name, Einstein--I don't know how many listeners are left at this point, but there's more than me and you, I'm pretty sure: there's at least a lot of you out there.
And, when I say Einstein, this thing pops up in your brain--the things you've read about him: maybe you see a mustache and some hair and maybe you might, as in your case, a quotation comes to mind. So, there's that Einstein that's currently alive, even though his ant colony has been swept away. He's currently alive in so many ways. Obviously, his ideas are alive. But, the awareness of Einstein is alive, right, in my brain, your brain and so on.
Then there's this other Einstein, this Einstein that Alan Lightman created when he wrote a book called Einstein's Dreams, where he imagined Einstein as a dreamer, conceiving time in all the different ways he could have thought about it.
Then there's this other even stranger creature called Snopes or Raskolnikov or Natasha--a totally fictional character of Tolstoy or Dostoyevsky or Faulkner--who is in our brains all around the world, long after their authors have died.
And, we aren't going to find that neuron. It's not going to show up on a scan. Where's the Einstein character of Einstein's Dreams in Alan Lightman's brain? Certainly where that character was before the book was written is even more mysterious, but the fact that it's still out there for thousands and thousands of people who've read your book; and it's just this, I don't know how to pronounce it, chimera, this phantasm that is purely imaginary, but in a way, just as real as the actual man. This is an extraordinary, beautiful thing.
Alan Lightman: Yeah, it is amazing.
Russ Roberts: Fills me with awe.
Alan Lightman: Yeah.
Russ Roberts: My guest today has been Alan Lightman. Alan, thanks for being part of EconTalk.
Alan Lightman: Thanks for the interesting conversation.