Physics Is Far Stranger Than You Think - Jim Al-Khalili

1. 0:00 – 2:27

   Intro

   1. JAJim Al-Khalili0:00

      ... 99.99% of the volume of the atom is just empty space. So, when I slam my hand down on my desk, the reason it comes to a stop is not because solid matter has hit solid matter. It's because the electrons in the atoms on the surface of my hand are feeling the electric repulsion, negative charge, of the electrons in the atoms in the surface of the desk. And it's electromagnetic repulsion that is giving matter this sense of solidity. That's why you can't walk through brick walls. (wind blows)

   2. CWChris Williamson0:33

      What was Keats's problem with Newton?

   3. JAJim Al-Khalili0:37

      Uh, he didn't ... I mean, I guess he didn't like science. He didn't like that Newton had destroyed the beauty of the rainbow. He said, "You've reduced it to its prismatic colors." You know, when Newton's work on, you know, the prism and, and all the different colors of the rainbow. So, as far as Keats was concerned, the rainbow was beautiful in and of itself, uh, but if you try and explain it scientifically, somehow that makes it cold and, and rational or hard and no longer beautiful. And of course, Keats was wrong.

   4. CWChris Williamson1:09

      Is there not an element of that, that mystery and suspense and a lack of uh, understanding about something that sort of adds a bit of magic? Or do you think that understanding it en- en- enhances it even more?

   5. JAJim Al-Khalili1:22

      Well, n- no, no, I agree. I mean, absolutely, it's, it's, you know, the anticipating what you've got for Christmas as a kid, you know, and the presents have yet to be unwrapped. Once you've unwrapped them, yeah, you know, you're happy you've got what you wanted, but it's sort of ... from then on, it's sort of downhill, right? So, so yeah, the mystery, the anticipation is, you know, p- part of the, the pleasures of, of, of life. But you get that in science as well. The h- you know, even in science, the, the, the excitement, the, the, uh, the pleasure that we derive from doing scientific research is the journey. It's the, it's the trying to solve the mystery. Once we've solved the mystery, once we've discovered, you know, the Higgs boson or gravitational waves, it's yeah, okay, tick that box, move on to something else. So, I think it, it applies in science as well as not in science. Science isn't about reducing everything to cold hard facts and then, you know, that's it. The hard rationalism is no longer ... No, I mean, science can be spiritual. Science can be uplifting and, and wondrous as well.

   6. CWChris Williamson2:26

      I noticed

2. 2:27 – 9:18

   Understanding Dark Matter

   1. CWChris Williamson2:27

      that you've sort of hinted there at a scientific version of hedonic adaptation, where you are chasing after the Higgs boson and you're chasing after it and chasing after it and you build this big thing and it's underneath Switzerland and somewhere else, and then you find it and then you go, "Right, okay, we've done that. Now what, what are we gonna discover next?" So, it's scientific adaptation.

   2. JAJim Al-Khalili2:47

      It, it is a bit like that. I mean, I should say, of course, those scientists and engineers who built the Large Hadron Collider and, and, and spent decades, you know, designing and preparing for this experiment and finally, you know, getting the data, of course they wanted to find the Higgs boson. Otherwise, you know, they're (laughs) ... what? You've spent how many billions of dollars building this thing and ... So, they want ... But for the rest of us, it would have been more exciting had they not discovered it, 'cause that would have meant there's new stuff to discover. It means our current theory is, is, is, uh, missing something. Back to the drawing boards, potential Nobel Prizes. We don't want ... We try to find the answers, we try to seek the truth, but we sort of don't want it to come to an end.

   3. CWChris Williamson3:31

      Is dark matter and dark energy, at the moment, a, a big, um, element of that? That we have this stuff that kind of theoretically needs to be there and yet no one can find any evidence for it?

   4. JAJim Al-Khalili3:44

      Yeah. Well, I mean, it's probably not fair to say we don't have evidence for it. We have evidence so we know it's there, we just don't understand its origin, what it's made of and so on. Uh, um, there's, there was a, um, an article written by Stephen Hawking about 40 years ago where he said, you know, "Is the end in sight for theoretical physics?" So, he was suggesting that you just need to dot some Is, cross some Ts, and we'll have a theory of everything explaining all physical phenomena in the universe. At the time, they were just starting to think about superstring theory, this new mathematically powerful theory that describes all the, the forces of nature. And they thought they were nearly there. And of course, it turns out, well, not that string theory is wrong, but there's, there's plenty more we have yet to understand. We are further away from a theory of everything than we thought. Dark matter we know is there. We, we can see its gravitational pull. It's inv- ... I mean, a better name for the, for it would have been invisible matter or transparent matter. We know it's there because it has a gravitational pull, like all types of matter. It, it can attract things towards it, it holds galaxies together and so on. We just don't know what it's made of, and that's frustrating. It's a fun kind of frustration, but it's a frustration nevertheless. Dark energy is similarly, it's something that's making the universe, making space expand ever more quickly. So, we know that's happening 'cause you can see distant galaxies moving away faster and faster and faster, but we don't know what it is that's causing that anti-gravity push of everything away from, from everything else. So, we're a long way from having all the answers, and that's good. That keeps us in work.

   5. CWChris Williamson5:23

      Am I right in saying that the ratio of dark matter to physical matter is actually in the ... it's swayed toward dark matter as well?

   6. JAJim Al-Khalili5:32

      Yeah, I think it's something like five to one or something like that, I think. Yeah, there's, there's much more dark matter than visible, so... (laughs)

   7. CWChris Williamson5:39

      That we can't interact with. It's so wild.

   8. JAJim Al-Khalili5:41

      Yeah.

   9. CWChris Williamson5:42

      I read, um, The Five Stages of The Universe, which is a really, really interesting book, and they said that, um, during the Big Bang, there were almost exactly equal parts of matter and antimatter.

   10. JAJim Al-Khalili5:58

       Mm-hmm.

   11. CWChris Williamson5:58

       I think it was, um, one million to one million and one.... in the particles, but the one was matter rather than antimatter. And that one out of every one million versus 1,000,001 ratio-

   12. JAJim Al-Khalili6:13

       Yeah.

   13. CWChris Williamson6:13

       ... is, that's all the matter that's left-

   14. JAJim Al-Khalili6:16

       Yeah.

   15. CWChris Williamson6:16

       ... in the universe. Dude, that blew my mind.

   16. JAJim Al-Khalili6:18

       'Cause everything else cancels out. (laughs)

   17. CWChris Williamson6:19

       Exactly. But you think, okay, so how much more matter could there have been?

   18. JAJim Al-Khalili6:23

       Yeah. Yeah.

   19. CWChris Williamson6:24

       Well, a million times more.

   20. JAJim Al-Khalili6:26

       Yeah. Well, you can sort, you can probably work out how much more matters 'cause that matter and antimatter annihilated to form energy. Uh, and, and so we can measure the, the, how much energy there is in, in the, in the universe as well. But the, the real puzzle is why was it 1,000,001 versus a million? Why weren't they exactly balanced, equal and opposite? That asymmetry b- the imbalance between them, that's another big outstanding puzzle in physics.

   21. CWChris Williamson6:51

       What's your thoughts about the fine-tuned universe? You've mentioned there about dark energy, and I think-

   22. JAJim Al-Khalili6:58

       Mm-hmm.

   23. CWChris Williamson6:58

       I- i- is that the cosmological constant? Is that what dark energy causes?

   24. JAJim Al-Khalili7:01

       Yes, that's, that's... The, the consensus is growing that that's what dark energy is.

   25. CWChris Williamson7:07

       Okay. And that is so fine, the, the, the amount of push that that causes for galaxies to move apart ever so slightly. And I think the fine-tune universe theory is that you have all of these different constants and the strong and weak forces, and any one of them, a knife edge either way, would completely ruin the rest of them-

   26. JAJim Al-Khalili7:30

       Yeah.

   27. CWChris Williamson7:30

       ... and wouldn't permit matter to exist the way it does. What's your, what's your thoughts about the fine-tuned universe?

   28. JAJim Al-Khalili7:35

       Well, I, I, I mean, obviously, we... There could be an underlying reason why these physical quantities have the values that they do. I mean, it's... Thank goodness they do or we wouldn't be here talking about it. Um, the, the lazy explanation, but is still sort of appealing for most people, is that our universe isn't unique, that, um, our universe is just a bubble within a higher dimensional multiverse in which every possible universe exists. And so, there'll be lots of other universes in which the constants of physics have different values, and those universes w- won't have evolved to, to develop galaxies and stars and planets and, and, and life in, in at least one place. Um, and so we are the lottery ticket winners. You know, it's not fine-tuned, just that one universe had to have the right combination of constants to give rise to the structure that we see. So, it's not surprising, you know, it's like a lottery ticket. How? It's so unlikely, you know, that I've won the, the ticket. Well, somebody had to win it, and it's you, you know, it's us possibly. (laughs)

   29. CWChris Williamson8:40

       Is that, is that the... Is that called the observation selection effect? I think that's the reason-

   30. JAJim Al-Khalili8:46

       I think, I think, yes, I think it's, it's, it's... People talk about it as being the anthropic principle, but yes, the observation selection effect. I think I've, I've vaguely heard of that term.
3. 9:18 – 21:27

   Distrust for Scientists

   1. CWChris Williamson9:18

      So it seems to me that science has gotten a bit of a bad rap over the last few years. There's pretty much no subject area where scientists and researchers aren't treated with, um, aggressive skepticism, if not outright contempt, uh, at least by some areas of the general public. Have you noticed this trend recently as well?

   2. JAJim Al-Khalili9:37

      I think there's always been anti-science sentiments from people either who are suspicious of it for whatever ideological reason, you know, or cultural reason or religious reason. Um, and then there's, you know, people who, you know, you, you have your own biases and your own worldview, and you don't like anything that goes against that. And of course, this, this... We, as humans, we've always had this problem, this issue, but of course it's been amplified by the internet and social media. And so, that, that's democratized the voices of everyone on the planet, and therefore, you know, we are hearing every possible argument for or against. I don't know whether there are more people who are anti-science now, I just think they tend to shout more loudly, uh, and, and they do have a voice now, whereas in the past maybe they didn't. So, we tend to think things are worse than they probably are.

   3. CWChris Williamson10:31

      Yeah. Isn't that interesting that, um, no one would, no one would criticize the fact that everyone's, uh, egalitarian ability to talk online, to communicate their ideas, you know, universal good. Pretty much everybody would, would probably say that. But the problem is, um, in the past, the only people that were able to get a platform to be able to reach a million people instantly were those that had very slowly over time proven their worth of being somebody-

   4. JAJim Al-Khalili10:59

      Yeah.

   5. CWChris Williamson10:59

      ... that could reach a million people. Whereas now-

   6. JAJim Al-Khalili11:01

      Yeah.

   7. CWChris Williamson11:01

      ... you know, you take the right video of your cat and-

   8. JAJim Al-Khalili11:03

      Yeah.

   9. CWChris Williamson11:04

      ... there you go. There's a, there's a million views.

   10. JAJim Al-Khalili11:07

       (laughs) . Yeah, I mean, there's good and bad about social media and, and, and YouTube and so on. You know, as I say, it's democratized our voices, so it's, so we're not just fed the information from the, the, the powerful or those with vested interests. Um, also, I mean, I, I love Twitter, you know, because I follow the right organizations and people that are giving, going to give me the news that, uh, that I, I'm going to find interesting. But yeah, it has meant that everyone has a say. Now, the, the, the difficulty that many people have is how do you discriminate from those who've earned their stripes, who know what they're talking about, who have the expertise because they spent years studying, thinking, reflecting on, uh, what they, what they're telling you, and those who, who, it's just mere opinion and sort of ideal- ideology? Um, it's difficult for the average person to have to dig in and investigate, well, where is this information coming from? Is this from a trustworthy source? What... Is this, is this evidence valid? Uh, um, and, and so, uh...... it's still something we're struggling with as a society, how, how to cope with so much information coming at us all the time.

   11. CWChris Williamson12:19

       Yeah. Well, increasingly, the value or the, the, the smartest people are the ones that are the most discriminating now, you know?

   12. JAJim Al-Khalili12:27

       Yeah.

   13. CWChris Williamson12:27

       You have to be, uh, because there is way more noise than signal on the internet-

   14. JAJim Al-Khalili12:34

       Yeah.

   15. CWChris Williamson12:34

       Um, and, and again this is (laughs) I'm not advocating for, uh, removing everyone's Twitter accounts, but it's definitely easier if the only people that have voices are people that have earned to have voices. Then it means that you don't need to be as discriminating with what you read-

   16. JAJim Al-Khalili12:49

       No.

   17. CWChris Williamson12:49

       ... because you've, the, the gatekeeping has already been done-

   18. JAJim Al-Khalili12:52

       Indeed, yeah. Absolutely.

   19. CWChris Williamson12:52

       ... on the front end rather than the back end.

   20. JAJim Al-Khalili12:54

       Yeah. And, and no, you're right. It is, and, and this, this is what's leading to the sort of the polarization of so many views and opinions on, on online. Those people who know enough about a particular issue also probably know where the weaknesses are in their arguments, also know what they don't know, and also they're probably less prepared to get into a shouting point-scoring match. And so they tend to retreat, and they just leave that forum for the two extremes that are just lobbing missiles at each other. Um, I mean, one of them may be more right than the other, one of them may... (laughs) But, but, uh, it's, it's led to this, you know, black and white, no room for nuance, no room for someone to say, "Well, you know, you've got a point, but you've also got a point." Uh, you can't say that. Look, if you're not 100% with me, you're against me. And, and the people who know about the subject know that it's, it's more complicated than that, and so because they're not prepared to say, "I am 100% on one side or the other," they retreat. And of course, that's, that's the danger, then you've, you've left it just to the extremes.

   21. CWChris Williamson13:56

       Yes. Yeah. The, there's a few, so many interesting things here, one of them being that, um, especially in the internet, any acceptance of either a lack of understanding or a lack of knowledge on your part, which would be, uh, I guess like intellectual humility, um, or a concession around somebody else's point, even if it's not all of it but a little bit of it-

   22. JAJim Al-Khalili14:17

       Mm-hmm.

   23. CWChris Williamson14:17

       ... that's seen as a, uh, weakness from the opposing side and a lack of commitment from the most extreme-

   24. JAJim Al-Khalili14:25

       Yeah. Yeah.

   25. CWChris Williamson14:25

       ... people on your own side.

   26. JAJim Al-Khalili14:27

       Yeah. I mean, it's something we've seen all along in, in politics, for example. You know, a politician will not admit a, a mistake or not, uh, or they won't admit that they were wrong about something, uh, or very rarely anyway. Um, and it, and it's also so, so far removed from the way we do science, you know? In science, admitting your mistakes is a strength. It's, it shows that you are doing good science, that you're prepared to say, "Well, I thought that, now I think this." But you're right, you know, in, in, in, in so many parts of wider society, that is seen as a weakness, you know? When scientists have said at the early days of the pandemic, uh, "In order to protect yourself from the virus, you just have to wash your hands." You know, and, uh, I guess you, you might know, Chris, that in the UK, we, the, the mantra was, "Wash your hands while singing happy birthday twice over." And you kind of-

   27. CWChris Williamson15:20

       Oh, I didn't hear that. No, thankfully-

   28. JAJim Al-Khalili15:21

       All right. Yeah, that was-

   29. CWChris Williamson15:21

       Thankfully, I was saved from that atrocious suggestion.

   30. JAJim Al-Khalili15:25

       That was the thing. Ap- apparently, that was the way to tell the, you know, the, the, the stupid public that you need to spend a good few seconds washing your hands thoroughly. Sing happy birthday through twice, and that's enough. Ridiculous notion. But anyway, a few months later, of course, we discover that the virus is mostly transmitted through aerosols through the air, uh, and then th- what you, you best do is make sure you're in ventilated rooms, open windows, social distancing, masks, and so on. And a lot of people said, "Oh, hang on a minute, you told us we just had to wash our hands and we'd be protected. Now you're telling us this. You know nothing. I don't believe anything therefore you say." The problem is not understanding how science works, that science could, you know, you can only base your ideas and your views and your hypotheses and theories on the evidence and observations that you have available at that time. With more data coming in, you learn more, and that may mean you have to change your mind. It may mean you're, you are more confident on, uh, about your hypothesis, but it also may mean that you were wrong. Um, getting that message across and, and maybe exporting it to wider discourse in society I think would be, uh, absolutely beneficial for, for it to be... So if you, if you're in a, you're arguing with someone and say, "Actually, no, I think you've got a good point there. Uh, I think I was wrong about that. I, I now understand where you're coming from." For that not to be seen as a concession, as a weakness would be wonderful. But, I mean, that may require changing human nature which is-
4. 21:27 – 29:14

   Faster-than-light Neutrinos

   1. JAJim Al-Khalili21:27

      the early days.

   2. CWChris Williamson21:28

      What's the story about faster than light neutrinos?

   3. JAJim Al-Khalili21:32

      Right. So, in, in my book, in The Joy of Science, I talk about the... how science can... We... As scientists, we can never be certain that something is right. We always have to say there's a possibility that the sun won't rise tomorrow, or, you know, that there w- our, uh, particular understanding about something i- isn't right, we've missed something. But with... there are levels of confident, confidence. There are degrees of, of, uh, of confidence that our ideas and notions are right, and you get to the point where you say there's certain things that are, you know, we're, we're very, very sure about, n- near 100% certain but never quite. Uh, and one of those, I use this example from physics that Einstein tells us in his special theory of relativity that, um, the speed of light is the fastest possible speed in our universe, that it's basically woven into the fabric of space and time. It's not just a number that Einstein plucked out of the air and why not something a little bit faster. That is... That's the maximum speed possible in our universe, and light happens to be able to travel at that maximum speed. Well, we're all confident about this. Um, a decade or so ago, there was an experiment where particles called neutrinos were produced at CERN in Geneva, and these particles are very light, they are very weakly interacting with the rest of matter. That means that they can travel through matter, through the earth itself as though the earth isn't there because they're not bumping into anything. They don't do much bumping. And so, the, the beam of these neutrinos was fired in a straight line from Geneva to this mountain in Italy, uh, um, where there's a, a laboratory, the Gran Sasso laboratory, uh, under a mountain in Italy. So, because of the curvature of the earth, they were actually traveling slightly un- uh, underground to, to, to follow a directly a straight line. The experimentalists who captured, they managed to capture a few of these particles at the other end, and they measured because they knew the distance precisely, they knew the timing, the start and finish. They calculated they had got there by traveling slightly faster than the speed of light. And, uh, you know, there, it's a press release and, and, uh, you know, the, the world media was excited. They, to their credit, the scientists said, (laughs) "Tell us where we've gone wrong 'cause this is crazy." You know? But most physicists, including myself, didn't believe it. We said, "No, we are so confident..." You know, we're not certain. Einstein could be wrong. But we're so confident that the speed of light cannot be exceeded, there must be something wrong with these results. And, and you know what... And, you know, some people said, "Oh, see? This is, you know, you arrogant scientists. You, you, you think you know it all." And we say, "Well, look, no, no. In fact, it would be great, in fact, if we can f- if these neutrinos traveled faster than light, that means our, our understanding of physics would be wrong, we have to rewrite the, the laws of physics."... chances are we would, we, it's, it's wrong because so many other experiments that confirmed the speed of light being the maximum, they'd have had to have been explained away somehow. I, on Twitter, I said, "If I, if the speed of light really is exceeded by these neutrinos, then I will eat my boxer shorts live on TV." And forgetting that there are journalists who follow me on Twitter, and so before I knew it, I found myself on, on BBC News one evening where they interviewed me about, about this. And I, I had to repeat this thing about boxer... So I had to go through this really embarrassing, you know, pretending (laughs) . I, I, I knew it a day in advance, so I, so I, I had a, a spare pair of shorts with me, so I had this... Made, made this sort of act of, you know, sort of... R- and then pulling out my boxer, and I would ............................ They said that would make great telly, so I believed them. Um, and I was getting, you know, uh, r- recipes, people saying how to cook your... You know, what dressing to put, you know, if you cook your boxer shorts. Anyway, it turned out that, I can't remember how much later, but the experimentalists in Italy realized they, there was a loose connection behind one of the timing devices in, in their instrumentation, and if that was clicked into place properly, suddenly the timing between start and finish was different, and in fact these particles traveled slower than the speed of light. So Einstein lives to fight another day. So I just use this as an example that, you know, extraordinary claims need extraordinary evidence. You can't dismiss something like Einstein's theory of relativity just because, you know, you've got an idea or because you've carried out one test. Y- y- there's a, there's a... A lot has gone in to try and knock Einstein's theory of relativity off its pedestal, and we want to. We want to knock it down, because that means there's more th- for us to discover, and yet it has survived, and so gradually because we've tried to disprove it and we haven't been able to, we gain more and more trust in it. And that's when we talk about we have a theory in science that we all trust. It could be Einstein's theory, it could be Darwinian evolution, it could be plate tectonics, it could be the germ theory of disease. We are so confident that they're right they might as well be facts. That doesn't mean we are certain. It's just highly unlikely that we're wrong.

   4. CWChris Williamson27:00

      Explain to me how something can pass through the Earth, like a neutrino. How, what, what, what's happening there?

   5. JAJim Al-Khalili27:06

      Well, matter is ultimately mostly empty space. So, you know, the Earth is m- is, is m- made of minerals and, you know, um, various compounds, involving, you know, silicon and, and, uh, oxygen and so on. Ultimately, down at the atomic scale these are individual atoms, and individual atoms are a tiny nucleus with electrons buzzing around the outside. But most, 99.99%, of the volume of the atom is just empty space. So when I slam my hand down on my desk, which you can't see, it's just out of shot, but I'm sure you can imagine, the reason it comes to a stop is not because solid matter has hit solid matter. It's because the electrons in the atoms on the surface of my hand are feeling the electric repulsion, negative charge, of the electrons in the su- in the atoms in the surface of the desk. And it's electromagnetic repulsion that is giving matter this sense of solidity. That's why you can't walk through brick walls. But if you turned off electromagnetism, then there's nothing to stop those electrons from passing through, and that's what neutrinos are doing. They have no electric charge. They are electrically neutral, and so they don't feel the electromagnetic force. They feel what's called the, the weak nuclear force. There are two forces that operate inside atomic nuclei, and that's the only way neutrinos can interact with matter. Of course there's also the force of gravity, but the neutrino is as near as damned massless. It doesn't have any mass at all, so forget gravity pulling it one way or the other. So it travels through the Earth zipping through the empty space, through all the atoms, and only if it were to interact directly with, say, an electron or within the, the atomic nucleus will it be stopped in its tracks, which is highly unlikely.

   6. CWChris Williamson29:10

      That is wild. (laughs) That's so wild.

   7. JAJim Al-Khalili29:13

      (laughs)

   8. CWChris Williamson29:13

      Talk

5. 29:14 – 38:40

   Constructing the Theory of Everything

   1. CWChris Williamson29:14

      to me... We've mentioned about, uh, about string theory, uh, uh, and general relativity at the moment. Can you explain what the challenge is of coming up with a, a grand unified theory at the moment? Why, why, why can't we get things to fit together?

   2. JAJim Al-Khalili29:31

      Yeah. I mean, uh, usually in physics when we talk about a grand unified theory, we tend to mean a theory that still excludes gravity. So it's a theory that encompasses the other three forces that we do have theories for, uh, the electromagnetic force and the two nuclear forces, um, what w-

   3. CWChris Williamson29:50

      You don't have one for gravity at the moment?

   4. JAJim Al-Khalili29:52

      We have a theory for gravity which is Einstein's general theory of relativity, but it's a very different kind of construct. It's a theory about the curvature of spacetime. It's not a theory of, of subatomic particles bumping into each other or a, a theory of the quantum world. And so when we talk about grand unified theory, what we mean is one theory that covers all the building blocks of matter down at the, the subatomic scale, but without the force of gravity. When we bring gravity in, we start talking about a theory of everything.

   5. CWChris Williamson30:26

      Okay, that's what I meant.

   6. JAJim Al-Khalili30:27

      Or, yeah, yeah, exactly.

   7. CWChris Williamson30:27

      What's the problem with doing that?

   8. JAJim Al-Khalili30:29

      So, um-... quantum mechanics has been tremendously successful in explaining the, the microscopic world. Uh, uh, you know, we have now w- uh, quantum mechanics developed in the 1920s then evolved into what we call quantum field theory. Quantum field theory explains all the interactions of matter and light and, and, you know, the, the, the, the building blocks of, of atoms beautifully. But gravity is the odd one out and, you know, gravity on the cosmic scale, gravity is th-, is, is the daddy, you know, it's, it's the most important, um, phenomenon, um, it shapes the structure of the entire universe. But you bring it down to the level of atoms and gravity is much, much weaker. You know, two electrons will repel each other because of their negative charge but they have masses, so you might think, "Well, don't two masses, uh, pull together?" Uh, well, they do but it's so tiny, it's so weak, it's negligible. So we have Einstein's general Theory of Relativity which gives us the structure of, of the cosmos. It tells us about the Big Bang, about how the universe is expanding, uh, the structure of galaxies and so on. Uh, it's the, it's our best theory of gravity, it's our best theory of the nature of space and time. But it's very different from the quantum world and the theories describing the quantum world. So we need to unify... We want to unify the theory of the small, quantum mechanics, and the theory of the large, general relativity. But because they're very different structures, we don't know how to mesh them together. And most physicists working in this area say, "Well, there must be a way of doing it." You know, there, there's, uh, we can think of examples in the physical universe where both theories will apply. For example, inside a black hole, um, or just after the Big Bang, um, but we don't know how to bring them together. So that's sort of the holy grail of physics to find a theory of quantum gravity. String theory is one of the candidates for such a theory but we don't know for sure if it's right. Now, this, the physicists working in string theory will say, "Yeah, yeah, yeah. It's pretty mu-... We're pretty sure it's right. We're just, you know, working through the maths." There are physicists who are working in other, on other potential candidate theories who say, "No, string theory is a load of rubbish." Then there are other physicists who, who would argue that too many bright people have devoted their lives to string theory and all it is, is neat maths. Uh, it's, it's, uh, it's very powerful maths but it's not telling us something about the real world that we live in, and so stop wasting your time guys and fund my research because I wanna do something that's, you know, that's not string theory. So it's just a bit of a, you know, what camp you're in, this, uh, it's almost like, you know, ideological views as to, you know, are you for or against string theory?

   9. CWChris Williamson33:31

      Yeah. I had s-

   10. JAJim Al-Khalili33:32

       But, you know, it's, it's interesting.

   11. CWChris Williamson33:33

       I had, uh, Michio Kaku on the show last year and-

   12. JAJim Al-Khalili33:36

       Mm-hmm.

   13. CWChris Williamson33:36

       ... you know, it, it, it's interesting hearing somebody that's dedicated so much time to one particular type of theory, uh, because, uh, for all that scientists try and update their priors and, you know, their Bayesian agents and all this stuff-

   14. JAJim Al-Khalili33:50

       (clears throat)

   15. CWChris Williamson33:50

       ... you do think, look man, if you've dedicated a 50-year career to one particular type of theory, your ability to say, "Do you know what it is? This, this isn't working, guys. We're up to 11 dimensions."

   16. JAJim Al-Khalili34:03

       Yeah.

   17. CWChris Williamson34:03

       "We're kind of wrapping the theory around itself in order to be able to make it fit, something to do with the, w- what we're seeing in the real u-" Is it possible that the theory of the big and the theory of the small simply don't m- blend together or would that w-, would that be impossible? Do they have to be able to mix?

   18. JAJim Al-Khalili34:24

       I used to think th- that, that was a possibility and maybe we just have to live with, you know, the, th- the, the, the, w- you know, one will-

   19. CWChris Williamson34:32

       Mutual incompatibility, yeah.

   20. JAJim Al-Khalili34:33

       Mutual incompati... Because they, because they apply at different scales entirely and therefore the, n- never the two shall meet and we don't, we never have a scenario where we worry. But you can imagine a situation where you have two electrons, you know, that, that we can describe the, uh, interaction between them using quantum mechanics, quantum field theory. But electrons have mass and mass, Einstein's Theory of Relativity tells us mass and energy shape spacetime. So spacetime will also be affected where those two electrons are sitting. So, n- what happens not only has to be described by, ultimately, by, uh, um, quantum mechanics but we also need to des- use general relativity to describe the very tiny curvature of spacetime around those two electrons. Um, it, it's a tiny, tiny effect that's negligible but then, but that's a limit, so you know that-

   21. CWChris Williamson35:33

       It's happening. It's actually there.

   22. JAJim Al-Khalili35:34

       ... it's ha- it's, it's happening. There must be a theory that, that incorporates both as an umbrella, both general relativity and quantum mechanics.

   23. CWChris Williamson35:43

       How wild is it that there's something that so many people, so many smart people have dedicated so much time and, and, and resources to-

   24. JAJim Al-Khalili35:49

       Yeah.

   25. CWChris Williamson35:51

       ... and yet you've kind of not really got anything that's that compelling? You've got, uh-

   26. JAJim Al-Khalili35:58

       Mm-hmm.

   27. CWChris Williamson35:58

       ... plausible potentials, um, and, and n- not anything that people are up in arms as, "Yep. (snaps fingers) There we go. Signed, sealed, delivered."

   28. JAJim Al-Khalili36:06

       Yeah. I know, and a lot of physicists, you know, until about 10, 20 years ago, a lot of physicists were very, um, confident that we, that we were nearly there, you know, whether they're working super string theory, M-theory, loop quantum gravity, you know, they were quite bullish about the fact that, "Yeah, you know, this is definitely the right way, it's very powerful. We'll, we'll get there." But it has stagnated over the last decade or so.... uh, and, and we haven't made the big advances. You know, the, the, the last really truly surprising advance in physics was back in 1998 when we discovered dark energy. You know, the, the stuff that we've done in the 21st century, confirming the Higgs boson, uh, d- discovering gravitational waves, well, they were both expected. Right? Th- they, they were both ticking a box confirming what we suspected anyway, so they weren't big surprises. So, we are right in a situation now where the frustration is growing. At the Large Hadron Collider, they've not discovered any more particles after the Higgs boson. They were hoping to discover a whole host, a family of particles called super symmetric particles.

   29. CWChris Williamson37:11

       What, what are they?

   30. JAJim Al-Khalili37:11

       Nothing. Well, they would be particles that would help, um, explain what I was talking about earlier, about a grand unified theory that unifies the electromagnetic force, the weak nuclear force, and the strong force in- into one all-encompassing theory. If you wa- want such a grand unified theory, even before gravity, then you s- one candidate is, is that that theory has to have this mathematical property called super symmetry. And if super symmetry is a, a property of, of our universe, then that means there are super symmetric particles that, uh, that aren't, they, they don't hang around for very long. They're, they're very unstable. But given enough energy in a lo- in a particle accelerator, you can create them for, you know, fleetingly. And we've, we've thought we've had the conditions to create them, and, and we've not seen anything. So, that's a frustration. Dark matter, we don't know what it's made of yet. We'd have thought we'd have figured that out by now, but experiment after experiment has found no evi- not no evidence, 'cause we know it's there, but no evidence of what dark matter consists of. There would have been a nice explanation, which is that dark matter is made of a type of super symmetric particle, (laughs) which would have been sort of ticked both boxes.
6. 38:40 – 46:50

   Theorists vs Experimentalists

   1. JAJim Al-Khalili38:40

   2. CWChris Williamson38:40

      Who has got the most pressure on them at the moment? Is it the theorists or the experimentalists? Who needs to up their game?

   3. JAJim Al-Khalili38:47

      Theorists never have pressure. Theorists just, you know, we'll, we'll come up with ideas. When I say "we," only 'cause I'm a theorist, but I don't work on those sort of foundational questions. And, you know, if, uh, if there's a suggestion that it's wrong, that there's some- something missing in the maths or that an experiment is frivolous, fine. We move on. Ah, that was yesterday's the- There, there are physicists working at the foundations, the very borderline of what we know, who, who very often don't even bother publishing their papers in peer-reviewed journals. They'll write them as preprints, so they stick them up online just as a temporary measure for others in the field to read them, because they know in six months from now, they'll have moved on to some other idea. So unfortunately, it is the experimentalists who are dealing with the real world, not with just, you know, pretty maths, who sadly have to up their game, because after all, physics ultimately is an empirical science and it relies on observations and evidence and data. So, we've got- they've just- we've just got to be cleverer as experimentalists to design the experiment that points us in the right direction.

   4. CWChris Williamson39:50

      What's the next big experiment that's coming? Is there a super Large Hadron Collider? Is that happening?

   5. JAJim Al-Khalili39:56

      There's still talk. There, there, there, that's still something that's in the planning stages, but, you know, which countries would be involved, what it would actually look like, where it would be built is still something that, uh, that is being discussed. After the Had- Large Hadron Collider took a couple of decades to be built, and it hasn't, you know, we haven't reached the end of what it can, may be able to deliver, you know. Maybe upgrading the Large Hadron Collider will be regarded as a much cheaper way. And, and there'll be reluctance from governments to, to fund something that's gonna run into the many tens of billions of dollars if, you know, they look at the Large Hadron Collider and say, "Well, it delivered the Higgs boson, which we sort of knew was gonna be there anyway. Um, how can you, you know, promise us lots of new physics with something much bigger?" Um, and thing is-

   6. CWChris Williamson40:48

      Mm. So, what is there? Is there, is there anything coming up experimentally that's interesting? Any new, I don't know, telescopes or detectors?

   7. JAJim Al-Khalili40:54

      (sighs) Well, I mean, the, the big, the big excitement at the moment... Uh, there, there are certainly new, new, um, terrestrial telescopes that are being built. But the big excitement at the moment is the James Webb Space Telescope. So, this is the, the, uh, successor to the Hubble Space Telescope. So, the James Webb Telescope has, has been launched. It's, it's, it's, you know, going to be providing us with information about the universe in far greater detail than we've ever had before. Um, it, it might tell us something about the s- the structure of matter, about dark energy. It might tell us, w- give us some hints as to whether there's a signature of, of life on, on exoplanets. Um, so a lot of- certainly in, in the world of astronomy, a lot of careers, uh, are being built on what's going to come from the James Webb Telescope. In, in, in particle physics, the other big science in physics, things aren't quite as rosy because, you know, the Large Hadron Collider hasn't l- I guess lived up to its promise, and I'm sur- there'll be particle physicists who will hate me for saying that. But viewed from the outside, you know, where the headlines are, that we haven't seen the new breakthroughs and the discovery of new particles that might've led to breakthroughs.

   8. CWChris Williamson42:12

      What area of research do you wish more funding was put into? What do you think would be an interesting, uh, area to have more funding given to?

   9. JAJim Al-Khalili42:22

      Well, I mean, the area that's, uh, exciting and fast-moving at the moment, I guess there is funding going into it, is, is in, in quantum, uh, uh, quantum technologies. D- developing quantum, uh, uh, uh...... devices that rely on the weirder aspects of quantum mechanics. Now, if ... And I say weirder, quantum mechanics in the sense, it's, it's ... By, by weird I mean counterintuitive and more profound because, of course, you know, the fact that we are talking, r- recording this, this podcast over Skype is thanks to quantum mechanics because without quantum mechanics, we wouldn't have had any of modern electronics. We wouldn't have understood how to, uh, uh, the properties of superconductors and chips and, and, and so on. So, the 20th century technologies, everything from lasers to, to, to, you know, start of smartphones is all thanks to quantum mechanics. Now in the 21st century, we're developing a new generation of, of technologies like quantum computers, like quantum cryptography and quantum teleportation. There are ... They're very sort of, they're very clever quantum sensors that rely on these strange ideas in quantum mechanics of two particles being separated and yet entangled with each other so that one, the fate of one dis- um, affects the other and so on. Uh, and so I think this is an area that is rapidly developing. More funding should go into it, but I guess, uh, you know, it'll be driven by once a science has a, an application in the marketplace, then, you know-

   10. CWChris Williamson43:58

       Capitalism comes in and takes-

   11. JAJim Al-Khalili43:59

       ... capitalism kick- kicks in.

   12. CWChris Williamson43:59

       ... takes over. Yeah, exactly.

   13. JAJim Al-Khalili44:01

       Ex- ex- exactly.

   14. CWChris Williamson44:02

       Did I see that, um, quantum computers had managed to do two plus two equals four?

   15. JAJim Al-Khalili44:07

       Yes. Amazing, isn't it? So they've confirmed that. (laughs)

   16. CWChris Williamson44:10

       (laughs)

   17. JAJim Al-Khalili44:11

       I mean, IBM and Google, uh, and, and the big, the, the big guys are making impressive progress in, in, in quantum comp- ... We're, we are still a way yet from having a, a desktop quantum computer, but, you know, um, they are starting to get, you know, incrementally more and more good at what quantum computers do. And what compu- quantum computers, they're not going to replace our everyday computers or supercomputers. There'll be, there'll be certain tasks that they can do much, much more quickly than the most powerful computers we have today.

   18. CWChris Williamson44:48

       Have you, have you got any idea of what they would be useful for?

   19. JAJim Al-Khalili44:51

       Well, um, things like, um, sifting through lists, simp- sifting through data, um, uh, solving prob- certain problems in, in, in mathematics. I mean, but people would argue that, uh, a quantum computer will be able to decipher encrypted codes, you know, out what the public key access ... The reason why it's safe to put your credit card details online, um, essentially relies on the fact that multiplying two large numbers together is much easier than breaking up their answer into the two numbers that you had to mul- so the prime factors of, of large numbers. Quantum computers will be able to crack that much more quickly than, uh, a classical computer.

   20. CWChris Williamson45:40

       Oh, fantastic. So quantum computers can brute force their way into my email account? (laughs)

   21. JAJim Al-Khalili45:44

       Yeah. But, but luckily, in line with that, we will also be developing new techniques of encryption using quantum mechanics as well.

   22. CWChris Williamson45:52

       It's an arms race.

   23. JAJim Al-Khalili45:53

       So, so it's an arms race between quantum encryption and quantum, you know, um, uh, um, key, key cracking, code cracking. Um, but, uh, yeah, I think there are lots of ... In, in science the- there- there's the hope that quantum computers can help us understand certain structures in physics and chemistry, for example. You know, down at the quantum atomic scale, the world, it behaves quantum mechanically and we want to understand it, we try to... We create simulations, uh, models on our computers. Well, it's far better to create a quantum simulation of a quantum process using a quantum computer than not a- not really a quantum simulation using a non-quantum computer. So, you know, lots of chemists and nuclear physicists and condensed matter physicists would be very keen to use quantum computers to study matter down at the quantum scale.

   24. CWChris Williamson46:49

       Do you think that

7. 46:50 – 54:59

   Are Mars Missions a Waste of Time?

   1. CWChris Williamson46:50

      the mission to Mars, to try and live and set up a base on Mars is a good use of time and resources?

   2. JAJim Al-Khalili46:57

      Uh, that's a difficult one. I think, um, I think there's still a lot more mileage in sending non-human missions to, to Mars and the other planets. You know, our, uh, development of robotics and AI, which is another fantastically ex- exciting area of science and technology, is developing so quickly that I don't think ... I mean, very soon, it's gonna be very hard to justify sending humans to Mars. Uh, s- the added expen- ... If, if I worked in that area, I'd be arguing passionately that you need humans on the ground to be digging, um, but dispassionately standing away from it, I could imagine many m- you know, we could fund many more projects to Mars and the moons of Saturn and Jupiter, uh, th- without human intervention than far fewer projects where we're sending people to those planets. So it'll come. I mean, no, it's not ... You know, we're not gonna be stuck on Earth forever, provided we don't wipe ourselves out and we solve climate change and we don't start a nuclear war with Russia and, and all that business. There will come a day when, of course, we're going to be, you know, populating the solar system and beyond. But at the moment, I think there's more mileage in terms of the limited scientific, uh, research funding that we have to send unmanned spacecrafts to the, out to the sol- solar system.

   3. CWChris Williamson48:21

      That's an interesting way to look at it, uh, if we dance through the minefield that is existential risk appropriately, and we miss artificial- misaligned artificial general intelligence and we evade engineered pandemics and so on and so forth. Um, one of the problems is that you kind of have a- another arms race going on, uh, a literal race between the amount of x-risk that you are prepared to deal with, uh, at home on Earth and the number of other options that we have outside of that, right? And slowing down the speed of technology production, the, um-... earn of potential black balls that Nick Bostrom talks about. Each time that you create a technology, it could be white, good, could be gray, kind of good, kind of bad, or it could be black, which is totally terrifying a- and, and can kill us all. Um, that means that there is a degree of urgency, um, because f- ... we can't take a God's eye perspective and just slow down, which would be my ... I- if w- we had the option-

   4. JAJim Al-Khalili49:19

      Mm-hmm.

   5. CWChris Williamson49:20

      ... I would say, "Look, let's just slow technology down by 100 times, and let's go super incremental with everything that we do." Because if you take a s- ... a, a very, very, very long civilizational, uh, timeframe with this, you think, "Well, what's the rush?"

   6. JAJim Al-Khalili49:36

      Mm-hmm.

   7. CWChris Williamson49:36

      The only rush for us to get somewhere else is to counter the risk that we're creating because we can't have, um, a global coordination around the development of technology. It's like, look, I want, I want every single c- line of computer code to be tested for whether or not it's malicious-

   8. JAJim Al-Khalili49:53

      (laughs)

   9. CWChris Williamson49:53

      ... step by step by step.

   10. JAJim Al-Khalili49:54

       Yeah. Yeah. I- i- in an ideal world, of course. I mean, I th- it's ... That sort of happened in things like ... in, in areas like genetics, you know, where scientists s- ... in most countries, not everywhere, have, you know, taken a s- ... a moratorium on, on, on gene editing, germline editing, and so on, you know, the ... Uh, where in, in ... and ideally, it could be a, a wonderfully powerful tool, where you could go in and, and snip away mutations and, and, and, uh, you know, combat, um, genetic diseases. Um, but of course, in the wrong hands, it can lead to all sorts of horrific scenarios. Um, so yeah, I think ... So, a lot of scientists are saying, "Hang on a minute. Step back. Let's think about this. Let's examine the ethical and moral implications of what we're doing." But it's not ... It won't happen everywhere, and, and it's not happening in other areas. You know, the, uh ... Artificial intelligence is, is another example. We're not slowing down the, the, the pace of development in robotics and automation and machine learning and so on. It's happening and coming at us very quickly. We're not ... You know, it's not like Terminator, Terminator and Skynet are just around the corner, but we don't seem to be able, or the powers that be have no appetite for slowing down that technology. So, the best we can do is get talking about it, get that conversation going, and, and try and keep the ethical and moral debates about what we should and shouldn't do in, in the same race-

   11. CWChris Williamson51:33

       At the forefront, yeah, precisely.

   12. JAJim Al-Khalili51:33

       ... at the f- ... Uh, i- with, with the technology. If we can't slow the technology down, we better speed up our conversations.

   13. CWChris Williamson51:38

       Yeah, I like that. The, uh ... I, I wonder whether or not the intention is going to be to air-gap Mars from Earth. But, uh, uh, that seems like a complete waste as well. You go, look, like, what are we, what are we going to Mars for? Are we going to Mars because we want to have a, uh, second cradle of humanity in which we are protected from any of the potential concerns? And ... But then if one of those and w- ... one of the big forerunners, you know, it's whatever, one in six chance over the next 100 years that AI is going to destroy civilization based on Nick, uh, l- ... uh, Toby Ord's book. If that's the case, if that's one of the real, real reasons that we're going, then you, you need to be air-gapped from the Earth. You need to be able to have nothing be sent-

   14. JAJim Al-Khalili52:24

       Mm-hmm.

   15. CWChris Williamson52:25

       ... to Mars. No signals, no communication, no nothing. And you go, "Well, okay, well, we're also there to do research, to be able to improve our quality of life here on Earth." So, you, you can't have both. So, what we may need to do ... it, it ... There's gonna have to be a trade-off made here. Look, what do you want?

   16. JAJim Al-Khalili52:39

       Mm-hmm.

   17. CWChris Williamson52:39

       Do you want to be able to go to another planet and use it for research and for sending back information and for scientific testing and stuff like that? Or do you want it as the w- ... uh, e- ejector seat emergency-

   18. JAJim Al-Khalili52:52

       Mm-hmm.

   19. CWChris Williamson52:52

       ... backup system for civilization? 'Cause I, I, I don't think-

   20. JAJim Al-Khalili52:56

       Yeah.

   21. CWChris Williamson52:57

       ... that you can do both.

   22. JAJim Al-Khalili52:58

       We're, we're, we are not looking that far ahead to see Mars as that ejector seat, the, the escape route if things go to pot here on Earth. We are sort of making s- ... the, uh, taking the calculated risk that we will resolve and solve the problems here on Earth, and that we are not going to design, uh, a virus that's gonna kill everyone. We're not going to, uh, uh, you know, mutually n- nuclear destroy the world. Um, we're not gonna be hit by, um, a, a meteorite. Um, and I think it's, it's ... You know, climate ... People say, "Well, we've got to go to Mars because, you know, we're destroying th- the, the Earth's climate." Well, however bad climate change affects our planet, it's still many orders of magnitude more preferable than the environment on Mars. You know, we're n- ... We're, we're in ... We're not talking about terraforming Mars at the moment. We're not talking about seeding it, giving it its atmosphere back again and so on. So, you know, it's still a long way from being a place where any more than just, you know, a handful of researchers who are well-trained go over there to do research. It's not somewhere where we can go and, and live. It's so far in the future that, you know, b- ... we're not prepared to put in that sort of ... And we, we didn't even put money into sort of pandemic preparedness, e- ... despite so many people saying, "Pandem- ... A pandemic could come at any moment, guys." And, "Yeah, yeah, yeah." You know, and sure enough, it did. Uh-

   23. CWChris Williamson54:35

       And no one's got any PPE or, or hand sanitizer-

   24. JAJim Al-Khalili54:38

       Exactly. Exactly.

   25. CWChris Williamson54:38

       ... or toilet roll a couple-

   26. JAJim Al-Khalili54:40

       Yeah.

   27. CWChris Williamson54:40

       ... of weeks in.

   28. JAJim Al-Khalili54:40

       Yeah.

   29. CWChris Williamson54:40

       And that, and that was a real, you know ... a, a, a real possibility, so, so when we think with, with Mars and, and using that escape, it's so far in the future that people just aren't ... It's not on the horizon at the moment. Yeah. You're right. I would way sooner take a hot Earth over a, um, cold Mars.... you know.

   30. JAJim Al-Khalili54:58

       Indeed. Yeah.

8. 54:59 – 1:01:57

   Sense-making in a World of Opinion

   1. JAJim Al-Khalili54:59

      (laughs)

   2. CWChris Williamson54:59

      Uh, so you, one of, one of the best quotes that you've got in your new book is that you won't reach a clearer understanding of what's going on by valuing opinion over evidence. One of the problems that we have is when there's so many conflicting claims about what the evidence is and what it says, that's very difficult to work out. And I also think (clears throat) another element of this is, which is being facilitated by the cult of personality/social media is, increasingly we, we, we follow people, not ideas now.

   3. JAJim Al-Khalili55:29

      Mm-hmm.

   4. CWChris Williamson55:29

      So, um, Elon Musk, 80 million Twitter followers, like, uh, the, Space X, four million Twitter followers. Cristiano Ronaldo, 40 million Instagram followers. Real Madrid, eight million. Right? We, we follow people-

   5. JAJim Al-Khalili55:43

      Mm-hmm.

   6. CWChris Williamson55:43

      ... we don't follow things. Right? Or ideas.

   7. JAJim Al-Khalili55:46

      Yeah.

   8. CWChris Williamson55:46

      Um, and when you're n- not going to value opinion over evidence, and there's way too much conflict around what that evidence is or what their opinions are, and then because we have this sort of natural seduction for people, all of that mixed together, I think it just creates a very difficult landscape for people to do sense-making in.

   9. JAJim Al-Khalili56:04

      Yeah. Again, I mean, this is, uh, i- in a sense, I mean, apart from, uh, the size of the problem, it's not a new one. You know, we've always had prophets and, and, and, uh-

   10. CWChris Williamson56:16

       Cassandras.

   11. JAJim Al-Khalili56:17

       ... Cassandras, yes. We've had, you know, the, the, the, those who will lead, those who will be listened to, those who have the, the, the, the, you know, the, the, the, the s- strength of personality that is going to attract followers. Um, it's just that the internet and social media has allowed anyone to, to, to try their luck at this. And, and of course there's gonna be those who, for whatever reason re- m- you know, whether because they're multi-billionaires or because they're, um, they're great at sport, or simply because they got lucky and, and for s- whatever reason, you know, you look at some of the, the influencers on, on Instagram, you think, "What is it? What, w- where's your talent? Where's, you know, w- how come people are listening to you?" And there is, doesn't seem to, it just ha- it has happened. Um, I don't think we've yet come to terms with how to deal with how social media in particular has amplified what are problems that have always existed in humanity. The same with things like conspiracy theories, and the same with, um, things like ideological... You know, you, in the past, you know, generation or two ago, you got your views from a newspaper that you read, uh, a- and that, and, and because it aligned with your political opinions, for example. And, and that was fine. And w- and we all had, we all lived in our confirmation bias echo chambers. Uh, it was fine. The internet and s- social media haven't created a new problem, they've just amplified a problem that is part of human nature, and we haven't yet figured out. You know, it may be that we, we restrict the voices to those that we as a society decide know what they're talking about, um, but we haven't figured out the right way of doing that that, that people can agree on that seems to be fair.

   12. CWChris Williamson58:02

       Yeah. Well, I was thinking, as you were talking earlier, about a new type of verification system. You know, you've got your blue ticks.

   13. JAJim Al-Khalili58:09

       Mm-hmm.

   14. CWChris Williamson58:10

       But maybe, maybe a, a gray tick or a, a yellow tick means that this person has reached a particular level of, uh, a number of citations on their work-

   15. JAJim Al-Khalili58:21

       Yeah. Yeah.

   16. CWChris Williamson58:21

       ... within their specific field or whatever. Because i- it is becoming increasingly effortful, and there's, there is no solution to this, to just cut through the noise and find a little bit of signal. Uh, and what you get after a while, and I see this in myself, I, I just kind of check out of discussions. Uh, a-

   17. JAJim Al-Khalili58:38

       Yeah.

   18. CWChris Williamson58:39

       ... the sort of apathy sets in. It's like, well, uh, I don't know. If I can't work out what's right, uh, or what's wrong, and if any time that I try to find it out I'm told that I'm a, a, a conservative or a shill or a gr- you know, a gr-

   19. JAJim Al-Khalili58:54

       Mm-hmm.

   20. CWChris Williamson58:55

       ... wha- uh, whatever word you want, sheeple, grifter-

   21. JAJim Al-Khalili58:57

       Mm-hmm.

   22. CWChris Williamson58:57

       ... you go, "I, whatever."

   23. JAJim Al-Khalili58:59

       Yeah.

   24. CWChris Williamson58:59

       Like, in that case I'm not gonna engage.

   25. JAJim Al-Khalili59:01

       Yeah.

   26. CWChris Williamson59:01

       And, and that's even worse. You know, people simply not engaging because it's either too effortful or daunting for them to go ahead and do it.

   27. JAJim Al-Khalili59:10

       Yeah. I'm, but, but if you know it's not going to lead to anything, if you know neither, there's not gonna be any compromise, and at least when you're, you know, in, in a bar with friends or whatever, you, you know, you're, when you're face to face and you, you probably, you know you, you're, you're not going, you're gonna see them again, you know, your paths are gonna cross in the f- in the future, you tend to reach some sort of a compromise very often. You know, it might, things might get into a chat too much. But on social media, because everyth- everyone is invisible f- from everyone else and, and it's so instantaneous and you don't have to think about what... Uh, and, and, you know, you can put a really good argument against something, but what comes back is, you know, they've ignored that and, and they've, they've taken a different direction, but just as strident. Uh, so it is soul-destroying.

   28. CWChris Williamson59:53

       (laughs)

   29. JAJim Al-Khalili59:54

       And, and, uh, uh, uh, uh, uh, but I, I tend not to. There are, there are certain debates that I won't get into at all. I mean, you know, the, the transgender debate. Absolut- absolutely polarizing society, m- mainly a generational issue. But, but no one's allowed to say, "Trans rights are important, but I can understand why some women feel uncomfortable." To, to say that, the, the, the, uh, you know, one side will say you're transphobic, the other side will say, you know, "You're, you're, you're anti-feminist, a mis- misogynist." And so there's no nuance in, in many debates on social media. And so you're right, you know, it's not just if you are arguing from one side and not realizing, not getting anywhere with the opposing view, it's also if you, if you realize that actually this issue is more complicated than either side will admit because they've narrowed it down to memes and tweets, uh, and no one wants to listen to nuance, then you also pull yourself away and say, "Well, okay, there's, there's no point. I, if, if I'm in the middle, both sides are gonna attack me, so I might as well say nothing."

   30. CWChris Williamson1:01:01

       Yeah. Being out on the extremes, uh, guarantees you agreement from at least one.
9. 1:01:57 – 1:02:45

   Where to Find Jim

   1. CWChris Williamson1:01:57

      Al-Khalili, ladies and gentlemen. If people want to check out your stuff online, where should they go?

   2. JAJim Al-Khalili1:02:02

      I have a website, jimalkhalili.com without the hyphen. Um, oh, actually no, it does have a hyphen. (laughs)

   3. CWChris Williamson1:02:07

      (laughs)

   4. JAJim Al-Khalili1:02:07

      I tell people the wrong address. Um, uh, where, uh, you know, you can find out about my books, my... I'm, I'm still an active researcher working at University of Surrey in England and, uh, you know, teaching students. But I also do a lot of science communication, so some of the stuff you can find on my website.

   5. CWChris Williamson1:02:24

      Jim, I appreciate you. Thanks for the day.

   6. JAJim Al-Khalili1:02:25

      My pleasure, Chris. Thank you.

   7. CWChris Williamson1:02:27

      (upbeat music) What's happening, people? Thank you very much for tuning in. If you enjoyed that episode, then press here for a selection of the best clips from the podcast over the last few weeks. And don't forget to subscribe. Peace.

Episode duration: 1:02:46