Stuff To Blow Your MindFrom the Vault: The Matter of Everything, with Suzie Sheehy
In this classic episode of Stuff to Blow Your Mind, Joe chats with physicist Suzie Sheehy, author of "The Matter of Everything: How Curiosity, Physics, and Improbable Experiments Changed the World." (originally published 08/08/2023)
Hey, welcome to Stuff to Blow Your Mind. Yesterday was a holiday, so we didn't have time to put together a brand new episode for today, so we're going into the vault. This is going to be The Matter of Everything with Susie she This is an interview that Joe conducted with the author of the Matter of Everything, How Curiosity, Physics and Improbable Experiments Changed the World. This was originally published eight eight, twenty twenty three. Let's dive right in.
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Hello, and welcome to the Stuff to Blow Your Mind podcast. My name is Joe McCormick. My regular co host Robert Lamb is not with me today, but he'll be joining me again the next time. Today's episode is going to be an interview. This is a conversation I had with the accelerator physicist and author Suzie Sheehy about her recent book The Matter of Everything, How Curiosity, Physics and Improbable Experiments Changed the World. Susie's publisher sent us a copy of this book for review, and I really loved it. So it's a history of modern physics experiments from Runken's cathode ray tube and the discovery of X rays all the way up to the Large Hadron Collider and beyond. And what makes this book really special in my opinion, is that it focuses not just on theoretical advancements, but on the labor of designing and building experiments to test those new ideas. And because it illuminates so much about the experimental apparatus behind the progress of science, I think this book has a lot of interesting things to say, not just about the history of our quest to understand matter and energy, but about epistemology and critical thinking and work to read from her author bio. Susie Shehe is a physicist, science communicator and academic who divides her time between her research groups at the University of Oxford and the University of Melbourne. Her research addresses both curiosity driven and applied areas, and is currently focused on developing new particle accelerators for applications in medicine. Again, the book is called The Matter of Everything, and I guess that does it for the introduction. Here is my interview with Susie Shehe. Susie Shehey, welcome to the podcast.
Thanks Joan, nice to be here.
So I wanted to start off talking about how I think a lot of the histories of physics that I've read focused more on the theoretical side, like what led to the insights theoretical physicists had, how they dreamed up their models, and things like that. I really loved that this book was intensely focused on the experimental component of physics, and there was a lot of focus on the details of the experiments, how they did it, and understanding experiments as human projects operating under constraints. What kind of insights do you think are revealed by looking at the history of particle physics through the experimental lens, in particular, especially things that you might miss if you only talk about physics as a sort of history of ideas.
Yeah, you phrased that so beautifully in there by the way, the importance of experiments. So I'm an experimental physicist, right. So one of the things that I observed when I sort of started on the journey of writing this book was that almost every other comparable book was written by theoretical physicist, and so you'd get these stories where you get this wonderful insight of say Einstein or one of the key theoretical physicists of the age, and it was like it was almost like they came to these insights purely from their own personal genius, right, And this was the story of physics that I was taught pretty much when I did at university as well, but it was also the story that comes across in these books. And I don't know whether this is just like an egotistical aggrandizing thing that people do. Certainly these people are very very smart, right, but they're not islands. And I think that's one of the key insights that you get from taking a different approach to looking at the history and looking more at the experiments and more at the wider view of how physics progresses. And I think any theoretical physicist today would all and hopefully also though is historically would admit that, you know, their work is nothing without the work of the experimentalists, because at the end of the day, physics is a subject which is trying to describe the universe, our actual universe, not just some theoretical, mathematical universe that doesn't really exist. And so the only way to meet those two things in the middle is through experiment. You have to actually get out there and and test nature. But that's where a lot of people, I think, naively think that we just we know what we're doing with that that we just we can go out there and build an experiment and test or find this thing, and that once the theorist predicts it, that it's a straightforward journey. So that's I think the next sort of key insight there is that it is not a straightforward journey to discover and uncover the nature of our universe, especially on these tiny scales that we're looking at that are so much smaller than what we can see with our own eyes. And so when you delve into that, then as you say, there's this detailed development of how experiments actually work, whether that's electronically, whether that's because they require two thousand people with different expertise to actually put them together, and also just that co development of technology and instrumentation along with the development of ideas and insights about the universe, and it really is sort of a logistic development. So there's I think a few things there about throwing out the long genius stereotype, managing to recognize how important it is that we actually interact in the real world and do experiments, and then just the unpredictable nature of doing those experiments at all.
You mentioned in the book that some people think that Derac's equation is the most beautiful equation in all of physics. I'm sure that people who have a lot of math and physics knowledge would consider that subjective. But it made me curious about the different ways that instruments within science can be perceived not only as useful or accurate, but sometimes esthetically beautiful. So I was wondering about the other side of that. As an experimentalist, Do you have an opinion on what is the most beautiful experiment in all of physics? Or do you have at least a few candidates?
Oh that's nice. Yeah, I think I definitely appreciate the beauty of a well designed experiment that can sort of cut through all the background noise and find the thing that they're looking for. But I'd say I appreciate the beauty of an experiment in multiple dimensions though, right, so you can. I can appreciate the beauty of an experiment which serendipitously found something that it didn't expect, as well as appreciating, you know, the sort of really well designed, very specific experiment. But now you're putting me on the spot if you asked me what my favorite experiment was, I mean, in the book, I really focus on twelve key experiments that I chose from what could have been thousands honestly, and focused on how those had contributed to our knowledge of particle physics over about the last one hundred and twenty years. And I think it's easier probably for me to choose a favorite from the earlier ones of those because they're smaller, it's easier to understand all the different parts of the experiment. And so in that sense, in a beauty and esthetic appreciation sense, I think I'm going to say the cloud chamber. And this was developed in the early nineteen hundreds by a physicist named CITR. Wilson Charles Wilson, whose first love was actually meteorology, but he was working in the Cavendis Lab in Cambridge in the UK, alongside all the people doing all the early work in radioactivity, so he was very well versed in radioactivity and those ideas. But he invented this chamber originally to try and study clouds and the interaction of light and electricity in the atmosphere, and then he later realized when someone held an X ray tube, or he and a colleague held next ray tube to the side of it that he could see the passage of radiation through this chamber, which had a sort of in his case water vapor and nowadays we use alcohol vapors, and these little trails would form, like little tracks of cloud as the radiation went through and left a little bit of energy inside the chamber. And I find this beautiful because it's really the first time as a species that we get to visualize radiation. We get to visualize this thing which is otherwise extremely uh you know, abstract and difficult to understand, and now we're seeing its effects almost in real time, so you can photograph as particles pass through, and then we get and I think the beauty comes in because it's this lovely interaction between our own capacities as humans and the development of a new instrumentation. Because then you can take you can leave these chambers up on mountains, you can take photographs of the interactions there, and from that we discover lots of new things, including we discover antimatter for the first time. So the positron is the opposite version of the electron, and when they come together, they annihilate, but they can also be produced in pairs electron positron pairs, And there were positrons detected by a guy called Karl Anderson in the US, and he discovered them in his experiments before he'd read about Direct's beautiful equation. I'm coming back to the equation again now. He actually wasn't aware of Dirac's work, which was published in nineteen twenty nine, but in nineteen thirty two he'd built this enormous chamber with this huge magnet around it and legged it up a mountain and discovered this type of anti matter. And I find that really beautiful because then he's literally able to use our internal sort of track recognition, you know, our patent finding system, our brain to look at the photographs and actually see that there's something new there. And there were other particles discovered later as well, the new one being a key one, which is a heavy version of an electron, and it was really the instrument of choice for many many years in the field, and it came from a meteorologist. So I don't know, there's something in that story for me which is just beautiful about how we can use our creativity sort of reuse of ideas in adjacent fields to really make amazing discoveries.
Yeah. I love that example too, And there's a kind of beauty and a kind of lightness and elegance to it that in a way seems contrasted by other experiments you described that are also incredibly important and wonderful stories to understand, Like one that stands sort of opposite it in my mind is the story of Ernest Lawrence's team and their cyclotron. And this chapter struck me as interesting in part because I think this is the one where you illuminate a history of what struck me as interesting mistakes like you mentioned a faulty reading from an accelerator experiment due to I think it was like deuteron coding on target elements. Please correct me if I'm getting this wrong. And also an incident where they accidentally made the whole lab radioactive without realizing it, which interfered with their measurements on a Geiger counter like device. So what is the role of error and making a mess in scientific experiments?
Do you know? I've been thinking about this more since writing the book, and I think we don't. I think we don't acknowledge the role of error and failure enough in science, in fact, we try and cover it up. It's a huge there's a huge issue in fact with failed experiments not being published, and in some fields like medicine, that's that's a huge issue. Actually in physics it's less of an issue, but it still happens. But Ernest Lawrence's example of the cycloton is a fantastic example where by sort of realizing their mistakes and their errors, they really made progress in their understanding. So, as you say, they developed this particle accelerator of this circular machine, and then over time they realize that they're not seeing the results that they think they should be seeing because, for example, in one in one situation, basically everything could become radioactive, and so all of their measurement devices were just picking up the background radiation and not the radiation they were trying to look for. But that helped them understand what was happening in the machine as it was accelerating, and they missed a number of key discoveries that were made by other research groups around the world, but they didn't mind too much. And Lawrence sort of had this mindset which is relevant to the question of errors and failures, which is. You know, he sort of would like to say there's research enough for everyone, or there's discovery enough for everyone, and so he was this big believer that he was quite quite a futurist, I guess because at the start of his career he was I think late twenties early thirties when he first invented the cyclotron, and he invented it because he couldn't see a path of the existing technology to the end of his career even you know, he was sort of looking thirty years in the future, going, well, these technologies are just they're going to be outdated by the time I get to that point, So I'm going to have to invent something new to give myself, you know, a path of growth through my career. And boy did he get it, you know, he really The cycloton was an incredible invention and they're still built today in hospitals to generate radioisotopes for medical procedures, which is very, very useful. But obviously along the way he could be perceived at having failed to make key discoveries in physics. So I think induced radioactivity was one of the ones that he missed actually, and was found by Julio and Curri in France. That's Marie Carey's daughter, Irene Kiri. So I've been thinking about this since writing the book, and I think I'd like to make the analogy with in the arts. Right, So if you if you have a creative practice in the arts, failure is an error. It's just an inherent part of it. And it's also very much acknowledged that by failing or making an error, you may just stumble upon something new, a new way of doing something, a new invention. I'm even thinking in the culinary world, you know. I know of a chef who who now runs a three Michelin starred restaurant in the UK, and one day he accidentally dropped hot coal into a vat of cooking oil and so they later, you know, decided to taste it and see how it tasted, and it tasted amazing, and he uses it in his signature dishes in a three Michelin starred restaurant now. And I love those stories of where errors lead you to new things and new ideas. And I do think in science we shy away a little bit from that, or we like to sort of cover it up and then we publish a paper that says, the story was a very linear one, and you know, we made all these discoveries, and in digging into the history of these experiments, which were so critical in understanding particle physics, I did discover that there was probably more failure than even I expected. And as an experimentalist myself, I've just come to accept that I often don't fully know what I'm doing because no one has ever tried to do it before. And sometimes I'm going to try things and they're going to fail. And there's a constant process in my lab with my students and staff of sort of openly talking about this right in it, you know, being candid about it and sort of being like that's all right, you know, like it's okay that it failed. You didn't know what you were doing because nobody knew what they were doing. But for example, you know, you might consider an earlier experiment in the book by William Rodkin, who discovered X rays, and he discovered them because a sort of painted fluorescent screen across his lab was glowing when he had a tube, a cathoedray tube on in his lab, and he noticed the glow and he decided to investigate it. Now we often refer to that as serendipitous, but depending on your perspective, you might consider it to be an error. You know, you probably shouldn't have had the wrong detector, you know, sort of out in the lab at the time. The other person that comes to mind is Robert Milliken, who did twelve years worth of experiments trying to measure what's called the photoelectric effect, which is the electrical current that flows when you shine light on particular metals. And this is an interesting one where along the way, the early phases of quantum mechanics had come around, and Einstein in particular had come out with this equation which predicted what should happen when you shine this light onto different metals. And the upshot of Einstein's theory was really abhorrent to the experimentalist. To Robert Milliken, he called it the reckless hypothesis, and that's because this hypothesis implied that light would be acting more like a particle than like a wave in this experiment. And so he set out to prove Einstein wrong, spent twelve years in the lab trying to do it, and all he did was pre Einstein right to a better precision than anyone had before. So again you might think, and he even thought that he was failing, right, He thought he was failing as an experimentalist. He was really struggling whether he had to build all his own equipment from scratch. And then at the end of twelve years he sort of comes out with this result, which I think even when he published it he still didn't fully believe, but he was able to sort of say, well, it is consistent with Einstein's prediction. And then later on about another ten years later, he was awarded the Nobel Prize for that and another famous experiment that he did about the charge on the electron, and he changes his tune. And I found this fascinating that, you know, this very fallible nature of the experimentalist, of sort of thinking one thing is going to happen and holding this bias that you know, no, nature can't possibly work that way. It's ridiculous. It's preposterous that a particle could be a wave. You know, sorry, a light could be a wave and a particle. And then he gets through his Nobel Prize speech or lecture and then he's saying, you know, however, many years ago, when I set out to demonstrate Einstein's photoelectric theory. So's he's making out like him meant to do it all along, and I was I was shocked. I was like, did someone transcribe that incorrectly? I don't think so. And so so it turns out that, you know, I think his bias against it was what it gave him this force, this will power to persist at his experiment for twelve years because he was just like, emotionally, he was just like, this cannot be right, this cannot be right. And you know, you would you would say that he failed in that enterprise because he was wrong, and I Stein was right. But this is I think this is how science progresses, and it's an important part of how science progresses is that, yes, we're all human, we're all you know, we're coming with our biases, we're very fallible. But isn't it amazing that we can then, you know, use the scientific process and apply you know, a sort of apply things to that that process to try and UnBias ourselves from the results and come out with the knowledge that is, you know, sort of accurate, regardless of the fact that you didn't believe it going into doing the experiment. I think that's actually a pretty amazing thing that we can do.
And like the culture of experiment is the constraint on that. Yes, yeah, well, regarding ideas that are wrong but persistent. One of my favorite characters in the book is Ernest Rutherford, and there's a part where you quote Ernest Rutherford saying that he was originally brought up to think of the adam as. I think the quote is a nice hard fellow red or gray in color, according to your taste, and that struck me as very funny. But then you also mentioned in a footnote that even many physicists still, despite knowing better, thing of sub atomic particles and atoms as little balls. How do you visualize sub atomic particles or do you at all? And is there a better way we should try to picture this scale of matter in the mind's eye or is it pointless to even try?
So I'm going to sheepishly admit that like all the other physicists I've asked, we don't want to admit it. But because the first time we were ever introduced to the concept of atoms and particles, they were little hard spheres. When you say protons and neutrons and electrons and the atom, I have. I have a terrible picture in my head that's I know is completely wrong, and yet it persists. You know, I have this this, Yeah, I have little hard spheres in my mind, just like Rutherford did. And I mean this is a This is a huge disservice that we do ourselves, I think, by persisting to describe in this way. But here's here's I think a key point about the models that we have in our heads, and I will answer the question about how better to visualize it in a moment. Physics and all the natural sciences really are sciences of different scales, and all the models that we have and all the theories that we have apply on different scales. So if you're a chemist or a biologist, it's well, other than some realms of chemistry, it's probably okay for you to visualize atoms and particles as little heart spheres. Because the models that predict the behavior which you're interested in on the scale that you're interested in, which is now much more macroscopic than microscopic. You know, it works perfectly fine, it can sort of approximate it. And quantum mechanics, though, is obviously the science when we get down to that very very small level, and we've realized that it no longer works in the same analogous way to say, billiard balls on a billiard table, and it works in a very different way. Everything is much more probabilistic. Nothing is as certain. We can't know things like the position and the momentum at the same time precisely, so everything becomes a little fuzzier. If I were to try and encourage you to properly visualize an atom, first of all, you know, the central nucleus of an atom is extremely dense and extremely small compared to the outer side of the atom. And Rutherford had another beautiful analogy for this, which is that if the electrons, which now you're considering in your head, the electrons to be kind of a wave or a sphere or a sort of much more, you know, much less like a little hard dot and much more like a probability cloud, that cloud would be at the walls of a cathedral. And if that was the size of a cathedral, then the nucleus in the center would be the size of a fly or a pee in the middle of the cathedral. So, first of all, the scales inside the atom are very different to the pictures that we look at when we're taught this kind of science, because you just can't fit those scales on a page and have them be sensible, right, so we condense everything down. So first of all, for most of us, the scales of what things look like inside the atom are kind of wrong. And this was also something that really blew the minds of even people like artists like Vasily Kandinski was really affected by this idea that the atom is mostly empty space. It really shifted his perception on what nature was made of, because suddenly everything around us that seemed solid is made of almost nothing, and it's purely the forces between these sort of ephemeral objects which are creating our experience of everything around us. Which back in twenty eighteen, I give a Tetec city talk and people have reflected back to me that the moment when they got shivers was when I said that you're not even touching the chair beneath you, you ever so slightly above it, And it's just the forces between the electrons in the chair and the electrons in your body opposing each other that makes you feel like you're in contact with the chair, but you're never The particles are never actually physically in contact with each other. It's just the electromagnetic force and gravity. First of all, that is a different way to view it. The scale is a different way to view it. And then not just the not just the electrons a wave like, but also those fundamental particles at the center, the protons and neutrons have constituent quarks. And even then, you know, we say that there's two types of quarks up and down quarks inside the protons and neutrons, but there's really a whole lot more so. It's kind of like that Nora's box. It's like if you go down further, you open it up and you're like, oh, there's all this other mess in there as well. And it depends how had I look at, what energy scale I look at, And it's just you know, so I like to imagine the nucleus as sort of as a you know, a group of protons and neutrons. But then if I try and visualize opening up those protons and neutrons, that's where even my brain goes, Nope, nope, I cannot do that. That's too comfixt.
So you give a bunch of examples in the Book of Discoveries in the history of particle physics that were thought by some to be pure intellectual curiosities with no practical use, only to later become very important in broader civilization. Maybe they become the backbone of whole new genres of technology, or unlock new discoveries, sort of unlock new wings in the mansion of physics. Do you want to tell the story of one or two examples like this?
Sure? I think let's start right at the start the discovery of the first subatomic particle of the electron, and this was done using the same experimental equipment basically as the X ray discovery. So A Catherine Retube and JJ Thompson in England in eighteen ninety seven sort of picked up where others had left off and realized that he could do a series of experiments bending around the beam of so called cathode rays. So that's a glowing, glowing green ray down the center of this tube that they didn't and they didn't know how it worked at that time or what it was made of. So he set out to investigate the nature of these cathode rays by deflecting them with electric fields and magnetic fields and catching the charge and seeing how it moved around, and as a result of all of those experiments, which I should say he definitely needed help with, even though I say it was him, he had to have his expert glass blower, Ebenezer Everett create all the experimental apparatus for him, because JJ Thompson, despite being like the leading physicist in England at the time, was I think I can't remember the exact phrase, but it was like exceptionally helpless with his hands is the phrase that comes to mind. So that's a quote of someone describing his experimental skills. So somebody else had to create all of his paradus. But anyway, he was able to use Ebenezer's apparatus to bend the electrons, to bend the beam around, and from that he managed to establish that not only is the beam made of particles, but that those particles were lighter than any atom that had ever been observed before, and so he was able to establish that this must be some kind of new fundamental particle which we now call the electron, which is about two thousand times lighter than the heaviest atom that had been seen before, and he was able to tell that that was really a fundamental component of matter. Because it didn't matter which cathoide he used. So the cathode is the part that the rays jump out of, and if it was just an atom, then you would expect if you change the cathoid or have you changed the gas inside the tube, that the results would vary, and they didn't. So that told him that this electron was somehow inside every single type of atom that he was working, so that that was an amazing discovery. And they used to be a toast in the Cavendish Lab in Cambridge where he made this discovery, and they have this annual party where you know, they sort of I don't know sings, they make up songs and they make up poems and they have a fancy dinner and you know, having spent over a decade myself in the UK at Oxford, I'm kind of imagining this in a wood paneled room, you know, with candlesticks and fancy, fancy food and everyone's wearing black tie. And there used to be a toast at this annual event where they would toast to the electron and they would say, to the electron, may it never be of use to anyone, because when he discovered it, it really was just him trying to figure out the fundamental nature of how these rays happened in this in this tube that numerous scientists had in their labs around the world. And in the few years after he discovered the electron, he also discovered the process called thermionic emission, which is the process by which the electron actually jump out of materials when you heat them up. And this then became an incredibly important piece of knowledge, which he obviously published and wrote all many things about, because a few years a few years later, an electrical engineer would sort of pick up this information and a previous discovery that had been made by Thomas Edison when he was trying to manufacture reliable light bulbs, and they'd put those two ideas together and come up with the first electric valve. So that is a device which can control the flow of electricity. You apply a small voltage and it either lets the current pass or it stops the current. And then more and more electronic devices then were invented after this, and in order to make those devices, they were one hundred percent reliant on JJ. Thompson's materials, on his theories, and on the things that he had developed as a result of his experiment, and those early tubes were very similar in their makeup to the tubes that Thompson was working with. Anyway, it's all very similar technology. But one thing I find quite interesting is that Thomas Edison just you know, he sort of made this discovery which was called the Edison effect, which was kind of about the flow of electricity, but he hadn't fully understood it. He just if he put an extra electrode inside a light bulb, he noticed that it affected the flow of electricity, and he patented it, but he couldn't think of any good ideas for it, so he just set it aside and ignored it. And if that had been the history, then nothing, you know, nothing would have been done about it at all. And I'm always amazed that people sort of look at Edison and his trial and error approach and they hold it up as this example of amazing innovation, and I'm like, well, okay, but he ignored possibly the most important thing he ever discovered. And it was only because other people picked up the ideas and understood it through JJ Thompson's investigations and his theories that then it led to the first electronic devices, the first and our ability through vacuum tubes to create things like the telecommunications industry to you know, and long distance communications. The first computers, all of the early electronics were based on these vacuum tubes, and of course that's changed a bit now everything's based in silicon and in the future, who knows what it will be based on. But if that fundamental investigation hadn't happened at the right time, and that knowledge wasn't there for the electrical engineers to build off, I sort of questioned, perhaps we'd have got there eventually with the electronics industry, but the story would have looked very, very different. So that's I find that an interesting example of the ways in which this sort of curiosity driven research, you know, trying to uncover the nature of the universe, and our innovation stories and our entrepreneurial stories kind of merge all into one and you start to see it not as one is superior to the other, but that they are essential to each other, and that we need both approaches and we can't just always sort of seed fund some entrepreneurial project or support some you know, innovator who's full of energy. You actually do need the people in the background doing that curiosity driven research in order to have new knowledge for those people to build on.
Well, speaking of the people in the background, another interesting thing to me about a lot of the stories you tell are that some physics experiments that are very important in history are surprisingly laborious. Like I think of the example of particle counting, these experiments that involve just staring at a screen for hours and counting flashes of light by hand. Yeah, what are some of the ways that crucial physics discoveries depended on types of work that people might not think of when they try to imagine what scientists are doing.
Yeah, I think there's a We love them, we love the moment of discovery, right, but we're often unwilling to figure out exactly what went into that discovery. And I have to say it's often it often comes as a surprise to people as you say how laborious it was. So that example you're talking about is in those early days of nuclear physics, where the only detectors we had were these fluorescent screens that lit up when high energy particles hit them. And so in Cambridge in the UK especially, they trained all their students and all their staff of how to sit in a dark room and look through a microscope at these plates when they were radioactive sources present and count each flash of light. But of course every human eye and brain is different, and so everyone was everyone was trained up and kind of measured to see how good they were at this particle counting. Right, So there's all these I mean. To get reliable scientific results, you need things like calibration. You know, these boring things, you know, the things that are not sexy or exciting about science. Good calibration. You need to know your instruments very, very very well. And I think any physicist today would tell you that until you know your experiment inside out, you will not get reliable results from it. And it's something that frustrates the heck out of undergraduate students in the lab when they're learning physics and they're trying to recreate experiments that were done in the past, and even though they've got apparatus that someone has prepared for them that should be working, they're still driven mad by the intricacies of it. And this is the reality. I mean, unfortunately, but you know, it's the reality of experimental life, which is that this stuff is not easy. And if it was easy, we would have done it hundreds of years ago, right, But it's difficult, it's often laborious, and often what we're trying to do in inventing new technologies and pushing at the cutting edge of technologies in experimental science is sometimes to get around the laboriousness, or even just to create a method to collect enough data that we can actually that we can actually use. So obviously, nowadays we don't use people sitting in a room particle counting. But there was a whole phase of experimental physics where after the technologies were invented that allowed you to photograph the tracks of particles. Well, then who processes the photographic data? Right? Who maps out those tracks and who turns all of that into tables that can be analyzed and searched for new physics. And the answer that most people probably don't realize is women did it. And in the early days these women were called there was the computers, So the women who did calculations by hand before the computer meant something very different to us. And in particle physics even into the forties, fifties, and sixties, you had the so called scanning girls and women who almost all women. There were some men who did it should I should say, who would sit at these enormous light tables with the with the copies of the photographic images, and they would follow a very precise sort of protocol in mapping out where the interesting things were in those photographs. And there were many, many discoveries made this way, something I do find interesting in the history. And I'm sure we'll get to the discussion of women in physics in a moment. But while some of these women were so called scanning girls, it was also considered to be a task that all the physicists should also know how to do. And this continues to this day. Even when you get these big collaborations like the large hadron collider, there's a sort of commitment to the experiment that you do some of this grunt work, you do some of this laborious work, and today that means sitting in a control room and overseeing the running of enormous colliders and detectors. But back then it would mean that you would do your share of analyzing these images. So this in a way is inseparable work. It specialized work, but it's work where the physicists did as well, and there were female physicists at that time who were also doing these kinds of analyses. And I almost wonder in this time, and this is just a it's just an idea that has come to me a number of times, I almost wonder if the women who were working as physicists in those laboratories were somewhat overlooked because the women's work at the time was as the scanning girls mostly, you know, and so there was this gender divide in roles. And even though the women were contributing, and some of them were physicists not you know, they weren't just hired as scanning girls, and yet their contributions were overlooked far more often than the contributions of their male colleagues. And I do wonder how this gender divide in the roles of this grunt work actually played into that overlooking at the time. But that's just one It's just one aspect of the sort of gendered nature of physics as we as we now know it, I think. But yeah, the I think a lot of people would be really surprised by how laborius a lot of the work is. And of course that's where automation nowadays and even AI tools are just changing the game. So dramatically because now that you can automate all of these processes and all of our detectors are you know, full of electronics instead of photographs. You know, the process of actually gathering the data is now much much easier, and so people and people can access the data around the world, including via the World Wide Web, which was invented at SNE just for that purpose. And so now we can focus on the analysis and we can focus on the physics, and the contributions to the hardware software become the grunt work and that part of the project as the experimentalist. So yeah, it's an interesting shift through time.
Coming back to the issue of women in the history of physics, you mentioned in the book this idea of the Matilda effect in physics, and it strikes me that there are at least two different ways that the historical discrimination against women in physics manifests. There's one where there's just direct limitations on their participation, like some researchers having projects they considered not suitable for women to work on, or the marriage bar where women who had previously been involved in research were disallowed from doing so after marriage. But there are also cases where women researchers made significant contributions to physics discoveries, and their role in this work was sometimes deliberately censored from public records and recognition. Could you talk about a couple of these examples.
Yeah, sure, I think that's really insightful that there are these different ways in which women's involvement in physics was a stopped, as you say, you know, sort of prevented, but then also that their contributions were diminished. And that second one is really where the Matilda effect comes in. So one person I'm thinking of here, her name is Marietta Blau, and she was a researcher in Austria, and she invented a new type of particle detector. So I talked before about how beautiful I thought the cloud chamber was. That's a very active detector. Things have to happen in real time. You have to photograph things in real time. It's very laborious to look after. And what she invented in staid, because she had a background both in physics and photography, was a photographic plate method of detecting particles. So she had this very thick so called emulsions, and they would create stacks of these emulsions for high energy charge particles to go through. And this now, instead of being looked after and photographed it every minute, could just be left at the top of a mountain for a month, two months, and it would just collect data over time and then it would be pulled apart and analyzed. And blouse invention led to a whole load of discoveries, and she herself was actually nominated for the Nobel Prize but never won it, and her invention led to I think at least I can think of at least two other Nobel Prizes that relied on her invention of this photographic emulsion method. But she also actually made amazing discoveries with it herself, one of which she called a star of disintegration, which was when a high energy cosmic ray coming from space came in and was sort of a direct hit on a heavy nucleus and then that nucleus itself sort of loaded and it left this amazing shower like a super and nova on the on the photographic emulsions. And this was a you know, she published, I'm pretty sure that one was published in Nature and her her sort of contemporary or not long after she was working there was an Indian physicist named Bieber Chowdery working in India, and she was one who was told that her professor didn't have any suitable projects for her as a woman, but she persisted anyway, and eventually sort of I guess, won him over because she ended up working with him. And she used similar photographic plates, but not of such great quality because she didn't have them available to her. It was during World War two and she was in India, so the supply chain wasn't great. But she actually uses photographic plates up mountains in India. And then she managed to discover the two different types of particles, which we would now call the muon and the pion, and those were those were some of the first observations of those particles, and as far as I can tell, it was the first time when it had been really recognized that there were two different particles. But I think she couldn't quite because of the quality of her equipment. She couldn't quite sort of say what was what or you know, the difference in masses between the two or something like that was missing. But this is the first authored paper in nature, and this time I know it was definitely in nature. You know, the top top journal in the world, and then in the nineteen fifties, so not long after Cecil Powell working in England. Sorry, his Nobel Prize was nineteen fifty. I think his work would have been late forties. He used exactly the same technique with superior emulsions to discover the pion. And in his earlier writing, in his It's definitely at least one textbook that he writes about, he acknowledges biber Chowdery's earlier work and references her Nature paper. And then when he wins the Well Prize in nineteen fifty, every reference of his that referenced her work and not used in the citation for the Nobel Prize. So all the papers that are cited of his for the Nobel Prize were the ones that didn't recognize the earlier work of this woman working in India. And I had never heard of her before I wrote this book. I'd never come across her story. But I thought that was phenomenal because Powell himself was not you know, he wasn't a rephensible human. He was a very left leaning liberal person. He had an unusually high number of female physicists in his lab in Bristol in the UK, and I think he himself was I haven't looked into his sort of journals and things, whether they exist. I would love to know how he felt about the fact that he had recognized the precedent and the Nobel Prize committee had not. And so Biber Chowdery is someone that even my particle physics colleagues have never heard of, even though she made this amazing discovery. And so these kinds of behaviors of sort of the ignoring of the women's contribution, like people will use their contributions but won't acknowledge them properly. And so we get this historical track record of you know, the Nobel Prize winners who are almost always men other than Marie Currey because she was so damn good no one could deny it. And you get these contributions of these women sort of falling by the wayside. And it's called the Matilda effect after Matilda Gage, who was a suffragist who first recognized that the contributions of women, and back then she was talking about the contributions to technology, but she first recognized that these contributions were being overlooked or attributed to their male counterparts or peers or even their husbands, and not properly attributed to the women who made them because of the biases that existed in our society. And a historian named Margaret Rossiter sort of coined this term the Matilda effect, named after michielda Gauge, and really encouraged all of us to look for those stories when we're looking at the history of especially technological fields and highly technical fields like physics, where there is a lack of women today. First of all, because and even I wasn't aware of this, that you know, you will probably find women that you weren't aware of, and this was absolutely my experience in writing this story. But secondly, she then encouraged us to write their stories back in because you know, there's sort of no other way to correct the record, and they have simply been overlooked. And so I mean, what could I do other than you know, it was sort of a call to arms as far as I was concerned, because here was I, you know, a female physicist today, having never heard of these women who made these amazing discoveries. And I thought, well, if I've never heard of them, and I'm writing a book about the history of these experiments then probably no one else has ever heard of, and that turned out to be true, and so it was just such a wonderful privilege actually to take up Margaret Rossiter's you know, sort of call to arms and write their stories back into the main stories of the history of these experiments, because they're so so important and to me as a female physicist working today, it made me realize, you know, all of the people who laid the foundations of my field, whom I sort of grew up in the field thinking that they were pretty much all men other than Marie Curriy, that that was false, and it created for me this sense of sort of belonging that I didn't expect to get. Out of the process of writing this book, I sort of thought, Wow, women like me have always been that, Women who've been curious about the universe, women who've wanted to be in the lab and using their technical skills and making these contributions to society and to our knowledge, have always been there. This isn't a weird thing that I'm doing. I'm not unusual to want to do this. And yeah, I've since had that sentiment reflected back by women young and old. Actually, you know, sort of young women starting out thinking of whether physics is for them. I've had some lovely feedback that they, you know, sort of read the book. They read about these women who fought, you know, I mean it was so hard to achieve them as well, because often these women were denied formal education in physics and weren't even allowed in the lecture theaters. So to realize that they were there and the things that they achieved, just you know, it was a very very encouraging and positive thing for me, even though in their own lives it was obviously a very negative experience sometimes. But to me today these stories, writing them back in brings I think, a new perspective on who gets to do physics.
It's definitely a powerful thing learning these stories. So I want to come to the part of the book where you talk about particle accelerators. Clearly you have a love for accelerators. That's your field. Imagine somebody who is generally positive about science, but views particle accelerators, especially the big projects, the big colliders, as maybe too big and complicated to be charismatic, as like objects of the imagination, and maybe views their findings as too abstract to digest. What would you tell this person to give them particle accelerator fever, like, how would you make them fall in love?
Oh? That's really that's really interesting. So I think we live in an interesting time in terms of particle accelerators because you know, obviously they're very well developed now, and we have these enormous machines. So the Larde hydron collider in Switzerland is twenty seven kilometers in circumference one hundred meters underground. Right, it's fricking enormous and it's very difficult to wrap your head around. First of all, I would say to anybody who doesn't find that kind of experiment charismatic on paper, I implore you to go and visit. It will blow your mind. Honestly. It is just such an enormous feet of human ingenuity. And today, in order to achieve these enormous experiments, we all have to work together and collaborate, and CERN is an amazing example of that, and the big national labs in the US have also been great examples of that, where you're bringing together experts from so many different areas because these projects are things that we cannot achieve alone. Now, CERN is a wonderful example, because it was created post World War two somewhat as a peace building project. So in its remit or in its constitution is science for peace. So they are not allowed to work on any defense related projects, are not allowed to work on anything with weapon ability. It's probably the word that I should use. They're not even allowed to turn a profit, not even in the gift shop, which took some people by surprise. And I've had a few people comment on that, but I noted that in the book. But to me it was obvious because it's CERN, and they exist, you know, to seek new knowledge in physics, and they exist sort of for the best of humanity in a sort of grand sense. And so after nineteen fifty six, you've got people working at cerne across borders from countries who were at war just a few years earlier. And this continues today. You know, there are both Russian and Ukrainian scientists working at CERN alongside each other. And so CERN really is this amazing human project where we've learned to collaborate with thousands of people to achieve things that certainly one lab can't do alone, one nation can't do alone. These are truly global projects. So much so that sort of successful collaboration that even the UN has come to people at CERN, have come to people at CERN and tried to work together on Okay, how come STERN is so successful in its collaboration right? What can the rest of us learn from the way that CERN collaborates that could benefit the rest of the world, Even if the technology doesn't float your boat. I think the human collaboration aspect of it is something which most people find quite inspiring. The other side of that is actually around the technology itself. And as you say, I'm a total nerd for particle accelerators. It is my professional day job. I designed particle accelerators. I love it. They're great machines. And one of the reasons I love it, and the reason I chose it back when I chose my PhD topic, was because someone who turned out to be my PhD supervisor he called me and he was like, so, this isn't what you applied for, because originally I applied to do particle physics with Higgs Boson type stuff. And he said, okay, hear me out. Hear me out. I want to design a new type of particle accelerator to treat cancer. And I was just like, what, what do you mean why you find things people? And it turned out I was just I just was a bit naive. I didn't realize that you could use these technologies at smaller scales for all sorts of societal applications. So about half of all cancer treatments are actually done using small particle accelerators. For what's called radiotherapy, which is one of the most successful forms of cancer treatment that we've ever had, and it's a small electron accelerator. It generates X rays and then you shape those to the tumor inside the body, and the whole accelerator actually rotates around the patient to be able to deliver beams from different angles. And nowadays we have more advanced forms of cancer treatment using heavier particles like protons and carbon ions that are more precise in the way that they deposit the dose. And that was the area that I did my PhD on, and even today I run a research group about accelerators for medical applications. And so when you look at it, there's about fifty thousand particle accelerators in the world, and only a fraction of a percent are actually used for particle physics. And so what has happened since we first invented accelerators in the nineteen twenties and thirties is as we invent these new technologies and the knowledge of how to accelerate beams of fundamental particles and control them, more and more applications have emerged, So not just in cancer treatment, but also in industries. So you can use particle accelerators to change the color of a gemstone by bombarding diamonds, you know, diamond companies, to can change the color of a gemstone often from clear to pink. Now that's you know, that's quite capitalistic, isn't it. You're just trying to gain a bit more money. That's not really a very very very useful thing. But actually all the devices that we use today rely on electronic chips, and today those are so small that you have to implant ions one by one. You can't do that using chemistry. You have to do it using effectively a small particle accelerator. And so almost everywhere you look, in every aspect of society, you will find somewhere in there a story about how we use this really advanced technologies to create sort of the modern world around us. And yet we almost always don't know don't know that it's there. And some of the most I think inspiring work that happens there is when we're looking at things like you know, in the environment or in cultural heritage. So we're able to do really advanced dating techniques putting together you know, the deep prehistorical story of our Earth and our species and other species across large tracts of time because we have these techniques that come from fundamental physics. And so this is where I get really excited, is because I'm like, Okay, so I can sit in the lab every day, I can design these machines, I can test them, and they can be used for everything from you know, looking at an artwork to discover for whether it's real or fake, to shrinking the shrink wrap that goes around a Christmas turkey. That's a real application. Polemer cross thinking is the technical term, but you know, you know, to uncovering the Higgs boson in the secrets of the universe. And to me, the fact that it's the same physics and the same area of research that I can do that that contributes to all of these different areas of our society. That gets me really excited because I'm never bored. I can always choose a new application, I can always choose a new type of machine to work on. And we're always trying to make improvements in the energy efficiency, you know, trying to make things smaller and better and cheaper, and just trying to push forward the frontiers of these technologies using our knowledge of fundamental physics, in order to do some good in the world, you know, to actually make a difference to people's lives. And that's why I show up in the laborary day and I've had a lot of people say, wow, I had no idea that you could do that with physics. That's amazing. And so I've been told on a number of occasions that my job today is kind of the current equivalent of being a rocket scientist, you know, I'm sort of working on this cutting edge of technology which is taking us to new frontiers of knowledge and exploration. And while it's not quite as dramatic as a rocket, when you start up one of these machines, it is to me incredibly inspiring. And every approach that we take, whether it's collaborating, you know, in a multidisciplinary sense, I collaborate very strongly with cancer researchers nowadays, or collaborating across different nations and different technical skills. I think really this type of research is sort of unique in a way, but it's also representative of the approach that I think has led us to so many successes, both you know, both in science but also in terms of improving our lives as people.
I have a question about how you approach experiments in physics. When you're doing an experiment and you're getting results that are not at all what you expect to see, how do you prioritize exploring the options that what you expect to see is wrong versus there is something wrong with your method.
I always err on the side of assuming I'm an idiot, so maybe just imposters in drome, But no, okay, this is kind of what I mean about ensuring you one hundred percent understand your apparatus. So typically when you start out an experiment, and I'm thinking here of just a small experiment that I built in the UK, and when we first started using it, we'd get all these like electrical signals that we just didn't understand, and so my assumption there was not that the fundamental thing that I was trying to study was wrong. My assumption almost always is to assume that I don't understand my experiment well enough, and to devise little tests and little questions and little experiments to test my understanding of the equipment and to test you know, I'll always pull it back to a test case where I'm like, Okay, I should one hundred percent know the outcome of doing this test, so then I run that test, and if that one is still failing, then I'm like, Okay, there's something wrong with the equipment. And maybe there's something wrong, or maybe I've dialed it in wrong, or I've got the wrong impedance matching, or I've got, you know, like something, something that I've failed to recognize is important in the experiment doing what I wanted to do. And I think that would be a familiar experience to almost every experiment, which is to go in with this overabundance of optimism that everything's going to work first time, and then slowly work your way through the many, many, many ways in which you were wrong until you really fully understand everything that's happening. And then if you're testing your theory or maybe there isn't a theory. Maybe you're just testing something that doesn't have a theory yet, and if then it's coming back and giving you a result that you don't expect, then you start to get those little you know, I'm getting shivers just saying it's ridiculous, isn't it. But like those little shivers which say, oh, this is something new, this is a knowledge gap, this is a potential to discover something that no one's ever seen before. And it's in that mode where you're both confident in your experiment that you can really ask the questions about the nature of reality. And in that moment, I think more often than not, you want to be wrong right. You want nature to be throwing a curveball at you. You want it to be something surprising, and those are I think those are the moments in which would be the closest that I think you would get to having sort of a Eureka moment or that moment I've seen something new for the very first time. And it's only by working your way through those smaller steps that you can get to that level of confidence. And I think a lot of people don't realize that that is very much the day to day role of an experimental scientist is working your way through these annoying things, and you have to learn to love that process, right, You have to learn to love the small bits of understanding and the small discoveries that come along the way. You know, maybe you've discovered a new way of arranging your apparatus that happens to give you, you know, ten times more signal than you had before, and that's really satisfying. And so I think experimental science for that reason, it sort of appeals to people who like to tinker. It appeals to the detail orientated mind. At the same time, it has to appeal to people who have that bigger vision, you know, who have that longer term time frame, Because if you expect to go into the lab every day and make one discovery every day, you're going to be solely disappointed. But if you can keep in mind the big picture and work toward that over and often it is years, you know, and keep that enthusiasm and keep that wonder that happens in the lab every day, I think that's the sort of personality type that fits experimental science very very well.
There's a point about your book that I really love you in talking about how big projects like the large Hadron collidor you've talked about this today as well, are illustrative of deeper points about human collaboration. And I wonder if, in a way you even alluded to this earlier when you were talking about what types of experiments are easier to talk about in the setting like you know, our conversation today. I wonder if these big collaborative stories like the large Hadron collider are more difficult to fit in the shape of a compelling and memorable narrative than stories with a single protagonist. Obviously, a lot of the most inspiring and amazing stories in your book are about these huge megaprojects with these unthinkable amounts of coordination and collaboration. Are there tricks to telling those stories in a way that makes them work as stories? But it's still true to the reality.
It was very difficult, Yes, So I will definitely acknowledge it is so much harder to write about enormous collaborations than it is to write about a few individuals. And I think in terms of the story, you know, the story arc or the narrative creation process. I had to find my own route through that, and so I was looking for things like, okay, well, you know, if I'm if I'm creating a sort of story arc, so you know, what would my crisis moment be, What would you know, what would a sort of pinnacle moment be. What is my like sort of inciting idea that sort of sets sets that story off on a journey. And you can find those things within the stories of the big experiments. It does make it harder to focus on individual, but I actually, in the end, especially for the large Hadron collider, I use myself as an example of a tiny, tiny individual within this enormous collaboration, and that worked for me partly because I actually didn't go on to continue in that collaboration. I worked in it as a student. I did this very very small project which people love to to recite the name of the project that I did, which was it was the design of a no hang on, I'm going to get it, I'm going to get it wrong. But it was the design of a monitoring system for the heating, sorry for the heaters of the cooling system of the inner detector of the Atlas experiment.
See cooling system.
Now the monitoring system, Yes, the monitoring system for the heaters of the cooling system. Okay, if you have a cooling system and you don't want it to all like clog up with condensation, right, so sometimes you need heaters on there to bring the temperature back up and stabilize it, like you need to be able to move the temperature in two directions. Anyway, So that was my crazy, you know, tidy little project that I did for three months when I was a summer student as an undergraduate working at CERNE. And it was illustrative though, of this idea that you know, I was this sort of tiny cog in this enormous machine. And I think the way I used that story was also to sort of saying I doubted that this machine could ever work, because if I was making this contribution and deep within my code was the ability to switch the whole machine off, then surely, you know, statistically this thing was never going to work. And so I was as surprise as everybody else. Well, I don't think the actual rest of the collaboration would have been surprised when it worked, but I was surprised from my experience when it worked as well as it did when they started the machine up. Of course, people who remember back in two thousand and eight. Will remember that it worked for about seven days before it blew itself up, and then they spent a year fixing it before it came back online. And I was at an event the other day where someone referred to the startup of the large hydron collider, in which they said about two thousand and eight, with a shake of the hand. You know, this is sort of you know this Italian style like wobble of the hand that means roughly they did that. They said it suddenly in about two thousand and eight, and it was all about that hand wobble of like, oh, that means the machine blew itself up and it had to be fixed for a year. But anyway, so I'm getting off the track onto the large hundred collider. But I think, I think, yes, it is much more difficult to write narratives about enormous collaborations. But I think that speaks to something a little deeper, is something which has come out of conversations with people now that we're studying even larger colliders. So the next one, potential next iteration is one hundred kilometers in circumference and will take about forty years to build, to design and build that's getting to the same lengths as or longer than a lot of careers in the field, and so I think we are running into and it's something that I've been talking to people about, a sort of two big, too long, too complex problem with these collaborations. And even though they I find them more inspiring in what they have been able to achieve. If I was given the choice again, now you know, I'm a student, I'm raring to go in this field, I'm really interested, what would I choose to work on, for saying, my PhD now at the age of early twenties, embarking on a PhD, which can be anywhere between about three and however many years, you know, seven eight years. For some people, it's a huge commitment and a huge chunk of your life at that age. And totally I hear stories of professors who are struggling to recruit students to projects for the sort of next mega colliders because they're like, well, there's not going to be any data to work with for forty years, Like how am I going to have a career in this Why would I commit three to seven years to something that might not even be built? And so I don't want to make out like there's a cris there's or a lack of people who are interested and very committed to this field. But I just hear inklings of dissatisfaction or sort of little little inklings of trouble, and I'm I'm curious about that, and I'm curious about how we're going to resolve that. And I guess there's two parts. Either we find a way to resolve that through the career structure and through having shorter projects alongside these big, long ones that you keep people motivated and keep everyone working, or we really have to think about are these projects too big? Should we really be focusing all our energy on technologies which can shrink down the size of future collided projects, which is very very difficult although they are in progress. And also just refocus back down on the sort of structure in which these collaborations work, because realistic, you've got groups of about ten to twenty people in a research group in a university. Those work on specific sub areas of the experiment, and then they all join together and eventually you get, you know, two thousand people. And so it's not that two thousand people are sort of a negalitarian, you know, flat structure who all somehow know each other and communicate. That would be absolutely wild. There is a substructure, and so I'm interested in how we can use that substructure that works very well in small, close knit groups who then go out and work with other groups around the world. Perhaps there's a way we can do that in the time domain as well. Right, So, perhaps there's a way of having more contained sections of projects, perhaps with applications, you know, that sort of keep people interested on that sort of you know, few year timescale that can drive things along. So maybe instead of in the future, instead of contributing to hardware or sitting in a control room, maybe you can cotributing to the societal applications of the spin offs of the work that you're doing, alongside developing the longer term curiosity driven part. That's just my idea. It's very much an unsolved thing. But I think if I was given the chance again, I would struggle to commit to a project that wasn't going to have data for forty years. So I do want to acknowledge that it's a very interesting time for young people to be entering the field. In that sense.
Right at the end of the book, you offer a couple of big lessons that you think we need to embrace for the future of physics and collaborative research projects. Do you want to mention those before we sign off?
Yes.
So, I think some of the things that I've learned through writing the book around collaboration and this curiosity driven research is that it is so important that we value it, that we value its impact in society, and that we create space for people to do this kind of research, not just space, but also it requires funding. And I know it sounds a little daddy to mix curiosity driven research and money, but in our society those two things are going to have to go hand in hand. So, you know, even the future, we want to be able to create collaborations so we can really get the best out of specialized skills that people have to the betterment of society. We need to really think about how we value things that don't set out with a goal in mind, and I think we need to center those and we need to really value the fact that somebody would commit their life and their career to something where they don't even know what the outcome is going to look like. We need to protect that with everything that we have because that is such a generative force in our society for good.
Susie Shehei, thank you so much for talking today. It has been a privilege and a.
Pleasure lovely to be here. Thanks Joy.
All Right, well that's it for today. Thanks again to Susie Shehi for being so generous with their time. If you want to pick up a copy of the book, it is called The Matter of Everything, The Matter of Everything, and it's out in hardback, in ebook form and as an audiobook narrated by Susie herself. Stuff to Blow Your Mind is primarily a show about science and culture, with core episodes on Tuesdays and Thursdays of each week, but we also put out a number of other offerings. On Mondays, we do a listener mail episode where we feature messages that listeners like you send into our email address, which is contact at stuff to Blow your Mind dot com. On Wednesdays we run a short form episode called The Artifact or the Monster Fact, and on Friday we do a special format show called Weird House Cinema, which is devoted purely to the study and appreciation of strange movies, good or bad, well known or obscure, as long as they're Weird, and then on Saturdays we feature an older episode of the show from the vault Huge thanks to jj Posway, our excellent audio producer. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hello again, that email addresses contact at stuff to Blow your Mind dot com.
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