Science Authors

"Later sections... describe the gargantuan instruments that enabled scientists to detect... elusive particles at the heart of the standard model... as the and... Higgs boson. Through each tale, The Matter of Everything explores how the pursuit of basic science has led to unexpected discoveries... These findings now underpin cancer treatments, personal electronics, and... how scientists investigate the way lava flows deep below Earth’s surface. Sheehy carefully considers each of these breakthroughs through the lens of the people who defied the odds to uncover the mysteries of our universe."

"In this book, I will take you through twelve key experiments that marked... a discovery... we now see as essential to our understanding of the world... [T]hese experiments embody the spirit of enquiry that stems from human curiosity. ...[T]hey have changed our lives in almost every aspect, from computing to medicine, from energy to communications and from art to archaeology."

"Physics will always be, at its core, about understanding our place in the Universe..."

"Beginning with the discovery of s, Sheehy... continues... through a series of experiments that led to the discoveries of the electron (1897), atomic nucleus (1911), and measurement of the (1923). By the end of the first third of the book the theory that the atom is the smallest piece of matter is in tatters and the remaining chapters of the book describe the fascinating experiments physicists designed to better understand the particles that make up an atom."

"Accelerator physicists constantly discover new ways of creating beams to help learn... about particle physics. ...[T]he nearest hospital almost certainly houses a particle accelerator. ...We build particle accelerators to study viruses, chocolate and ancient scrolls."

"[E]xperiments take us to that frightening frontier of vulnerability: the real world."

"While a theoretical physicist's ideas must take into account the results of experiments, an experimental physicist has a more nuanced job. She is not simply testing out the ideas of theoretical physicists; she is asking her own questions and designing and physically building equipment she can use to test those ideas. ...[H]er practical knowledge ranges from to chemistry, from to ."

"The reason we can say today that we know all this stuff, that we think our theoretical models represent reality, is not because we have pretty mathematics but because we have done experiments."

"I suppose I was trying to figure out the meaning of my own existence. ...I went about it in a more indirect way: I set about trying to understand the entire Universe."

"Our view of the smallest constituents in nature has changed rapidly in the last 120 years... Some way into the twentieth century this work became known as "high-energy physics,"... Today the study of all the many particles and how they formed, behave and transform is simply called particle physics."

"[A]s I studied more physics the question... at the core... was: "What is matter, and how does it interact to create everything around us—including ourselves?""

"I'd just been asked by four particle physics professors... my PhD interview was conducted over an unstable internet connection... "what do you find fascinating about particle physics?" ...I told them of my wonder at the way physics seemed to be able to describe everything: from the smallest s to the atoms that make up our bodies, up to the largest scales of the Universe, and how all of this was connected. Particle physics, I said, was the foundation of it all."

"Five years earlier... [a]s my eyes adjusted to the darkness, the true wonder of this designated "dark sky site" revealed itself. ...The stars and planets weren't up there and I wasn't down here: it was all part of one enormous physical system called the Universe. I was a part of it too. ...I'd never really felt my place in it until that moment."

"The Standard Model of particle physics classifies all known particles in nature and the forces through which they interact. ...[O]ur current version came about in the 1970s. This theory is an absolute triumph: it is mathematically elegant and unbelievably precise, yet it fits on the side of a mug."

"Suddenly, nothing else mattered. I wanted to know... about gravity and particles and and relativity. About stars and atoms and light and energy. Above all, I wanted to know how it was all connected and how I was connected to it. ...[I]t mattered to me as a human ...if I managed it even a little bit, I'd not have wasted this little blip of time as a conscious being. I decided to become a physicist."

"So that's one example of how a wave can be used to accelerate particles, but... I brought along some scale model protons [large beach balls] and I thought what I'd get you to do is for you guys to be the wave and the scale model protons are going to accelerate across the wave [beach balls moved by audience hand wave]... Eleven-year-olds do this really well, I'm warning you. You've got competition."

"Try something for me. ...Hold [the tube] halfway down. [Half of the lamp goes out] ...You're grounding any of the electrons which are... moving inside there..."

"I mean you guys are a rubbish accelerator, but we do that very very precisely. ...So what happens in a synchrotron... is that you have to time that wave very very precisely with the increase in the magnetic field in order to get the particles all synchronized, and that's why we call it a synchrotron."

"[A]... Large Hadron Collider radiofrequency cavity... is one of the devices, and... operates at... superconducting temperature at 400 MHz... [T]his is one of the devices into which we pump a large amount of RF energy, send the particles through and as they go through, as you demonstrated very nicely, they gain a little bit of energy..."

"In the days of Cockroft and Walton, when they were first developing particle accelerators they didn't know about the dangers of radiation, and so one of the ways that they counted the events... what was happening in their experiments, was... to sit... under the beam. The beam would come down, some nuclear reaction would happen, and... his fluorescent screen... would light up every time what they were looking for happened... [T]hey would sit there and count each time it lit up, sitting underneath the beam, being irradiated. ...[T]hese people lived relatively healthy lives, and Cockroft and Walton got a for work, which doesn't justify it, but there have been people who have stuck their heads in particle accelerators."

"Over the last century the experiments... have gone from single-room setups led by one person to the largest machines on Earth. The era of "Big Science," which began in the 1950s... now... involve collaborations of over a hundred countries and tens of thousands of scientists. ...[N]o individual country can achieve these feats alone."

"The Standard Model tells us that all the matter that makes up our everyday existence is composed of just three particles. ...[T]wo types of s called "up" and "down" which forms our s and s. These... with the electrons make up atoms, held together by forces: electromagnetism and the strong and weak nuclear forces."

"This is actually a real one. ...This is ...the smallest radiofrequency accelerating cavity in the world... This one is from a project called the which is one idea of the next generation of colliders to reach even more precise measurements in particle physics, and the inside of this thing is machined to a sub-micron precision... [T]here's a hole at the end. ...This one's for electrons, which are a very small beam, so it can be very small hole, and they travel through there. ...These are the RF ports. These are the vacuum ports. ...[T]his thing would give an electron an energy gain of ...probably 10 million electron volts. This is also a very very high gradient cavity so it gives a lot of energy in a very small space. ...The higher the frequency the smaller they get. ...That one operates at 30 GHz. It was actually so small and the machining tolerances were so tight that they've actually decided to go for 12 GHz instead... because it makes the engineering slightly easier."

"So my name's Suzie. I'm a physicist... an accelerator physicist, and I work at the University of Oxford. I run a research group there in... high intensity s... I... spend half my time at Harwell campus... I'm also a member of the , not the other ISIS, just to be clear."

"What I'm going to talk about today is the fascinating world, and I really think it's wonderful, of particle accelerators."

"So that's 5 things you should never do with a particle accelerator. Thank you."

"[T]his is called the Standard Model Lagrangian, that curly \mathcal{L} at the start is for Lagrangian... and there's lots of different components of that. Now if I write it out in full, I get what is the most egotistical physics teacher in the entire world. So if I wrote it out in full... really you don't need to read it, I promise, all of the different terms in that equation describe an interaction between different types of particles and force carriers..."

"[D]on't be afraid to challenge yourself. Don't shy off doing something just because you think that it's hard. It's when we're doing something hard that we really make a difference. So dig deep and don't be afraid to dream."

"I'd just like to leave you with my advice in choosing your career... [F]ind something that makes you sit up and think, "This is really important" or "This is fascinating" or "This is what I'm passionate about" and it can be in any area... Something like space might get you, of climate change... you might really like astronomy, or you might be more passionate about world hunger, injustices in the world, the availability of water, energy, health, aging, anything like that. Think about it, and do something about it. That's all, really, you need to do, and make a career out of doing something about it. Because if you do something that you're passionate about, and you love... You're not even going to feel like you're going to work each day. ...You're just going to feel like you're getting up and you're doing what it is that you're passionate about..."

"Has anyone heard of a particle accelerator other than the Large Hadron Collider? ...We actually have two at Harwell... If you were pushed, could you give a back of the envelope explanation of how a particle accelerator works?"

"So what about the heat from the beam? Well this is a challenge... [I]t's actually incredibly difficult to stop the beam, and if you put your head in front of the beam... it would actually go straight through and out the other side. In fact it has enough energy to go through your head and out the other side about 100,000 times before it loses all it's energy... [T]hat's actually one of the issues they had to deal with when designing the machine, is how do you stop the beam... [W]e want to stop it occasionally, intentionally..."

"So when we're thinking about radiation and radioactivity, it is worth keeping in mind that just the fact that something is radioactive does not means it's harmful..."

"It depends on which accelerator we're talking about, but let's consider the . ...It's minus 271 degrees. ...This is a picture of one of the 15m long s, one of the [beam] bending magnets in the machine... but it's extremely difficult to get your head in there. So... you wouldn't stick your head in the dipole. You'd stick it in somewhere easier... that wasn't cooled down to minus 271."

"The amazing thing about this collection of particles, which admittedly looks arbitrary until you learn it in more detail, is that you can take the entire description of every known particle and interaction, other than gravity, in the universe, and write it down on a mug."

"I will leave you with some photographs of some of the places that my career in physics has taken me so far, and I hope to add many more to this list in the future."

"[Y]ou may have seen... when the LHC was in the news, diagrams that look a little bit like this. These are called s after the famous physicist, Richard Feynman... [W]hat... most of my colleagues in particle physics do, is they take this [full Standard Model] equation, they figure out which particle's interacting and how: what's coming in, what coming out. They do twenty-one pages of calculations, and they come out with a number that is the probability of that interaction happening... [D]epending on which particles go in, you choose a different term that corresponds to those, and which particle comes out, you choose a different term that corresponds to those. Turn the handle and you get your result out the other end. I just taught you quantum field theory in about 2 seconds."

"[S]ometimes some of our craziest ideas, and I've been through some pretty crazy ideas of things that you could do with a particle accelerator here... [S]ometimes they turn out to be surprisingly good ones if you do them in the right way, and these machines are not just useful for particle physics. They're useful for all sorts of other things like cancer treatment, like killing bacteria in food, and other things I haven't discussed like carbon dating, and imaging down to the atomic scale, and all sorts of other things..."

"Most people now, when I say particle accelerator, think of... the bohemoth. This is the . It is almost 27 km in circumference, which is why the tunnel looks almost straight. It's about 100 meters underground, over the border between France and Switzerland. ...Inside these magnets here, these big blue long ones it's one of the coldest places in the universe at 1.9°K above . ...[I]t accelerates two beams of s, from inside the atom, in opposite directions at 99.99999% (that's the exact number) of the speed of light and smashes them into each other... [I]t is what I like to call an impressive shiny huge piece of kit that's bigger than everyone else's!"

"I have a demonstration... which is the simplest particle accelerator I could make.... in a giant salad bowl. ...[W]hen it goes over the charged strip it picks up the same charge and it gets repelled ...then it hits the grounded strip and it dumps all of that charge, but it keeps its momentum, it keeps rolling around ...So every time it goes over one of those four [repelling] strips ....it gets a kick, or gets accelerated and it gains energy again and again. ...In this demonstration, the ball has to change charge, and fundamental particles don't change charge, so in this case my voltage in constant and the ...[ball] changes charge, in a real accelerator we have a constant charged particle, and that means we have to change the voltage."

"Why couldn't you put your pet in a particle accelerator? ...It doesn't have an electric charge. ...He's slightly too big, and the other thing... he's going to be affected by the vacuum in the pipe of the machine..."

"Building up charge, actually building up , is the key to giving particles energy in a particle accelerator. ...Now some of the first particle accelerators were actually genuinely using this mechanism of having a belt and some rollers, and building up lots of voltage. They were called Van de Graaff accelerators. They still exist. I've worked on one... If they're the same charge, which get repelled, and there's force there, they're pushed away and they gain some energy... [I]n the case of an accelerator we'll get our particles... going faster and faster and faster toward the speed of light."

"Now there's another one... that might not have an electric charge... The gold atom, yes. Can anyone suggest a way to get that gold atom into a particle accelerator? ...You can ionize it. Thank you. So to ionize a gold atom you can rip the electrons off or add more electrons on... Give it an electric charge, and then we can put it into a particle accelerator. So that's the kind of particles we need."

"The next thing we want to do with those particles is to give them some energy. That's the basics of how an accelerator works. I've got a machine here called a which does that..."

"Four different types of particles: electrons, s, s and gold atoms. ...Can anyone suggest which one you can't put in a particle accelerator? ...A . Yep! Do you know why? Because it isn't charged. Thank you very much. ...[I]t doesn't have an ."

"What I'm going to do is suck out all of the air out of this container and see what happens to marshmallow man, or indeed, what might happen to our pet bunny rabbit in a particle accelerator. ...Oh my gosh it's huge! That's amazing! Sorry, we haven't tested this. I didn't realize it was going to be this good. ...That's probably what would happen to your little bunny rabbit, but in a slightly more horrific fashion."

"What is a particle accelerator? ...This is the ...the world's biggest particle accelerator. It's 27 kilometers in circumference ...buried about 100 meters underground between the borders of France and Switzerland, near Geneva."

"It's really hard to convey in a few minutes, how amazing it is that we know this about the universe, and the predictive power that it has... [T]hat is the reason why we really built the Large Hadron Collider."

"That's only one particle accelerator. There are actually over 26,000 of them in the world."

"I want to go back to about the late 1920s and 1930s when a new type of was invented, called the . These are still in operation today, but the original ones... This is a patent from... and this is 2 Ds as we call them... electrical cavities which would sit inside a whopping great ... [W]e start in the center with some particles, and they always have to be charged particles. So either electrons, s... s, charged atoms. Things like that, and we give them a bit of a kick, because there is a voltage between these two [Ds] halves, and each time the particle moves between those two halves they get a little bit of a kick, a little bit of energy. Now because they're sitting in a whopping great magnetic field, the effect... that has on a charged particle is to actually bend it around a corner. So it bends around a corner and it comes back again crossing this gap, gaining a little bit more energy and... as it continues to gain energy it spirals out... So the limit in the energy in this machine is mostly how big you can build your magnet, and how much iron you're willing to afford. Now this really was the original type of... high energy particle accelerator, and this is a photograph of Ernest Lawrence and his student Milton Stanley Livingston, who I should say, actually built the thing... [T]his machine got up to about 1 million s."

"So my number two thing you probably shouldn't do with a particle accelerator. You probably shouldn't put your head in the beam... On this one I want to have... a vote... What might kill you first? ...Would your head freeze because of the ? It's at minus 271 degrees Celsius] in some accelerators... take the Large Hadron Collider for example. There the magnets are pretty cold, or would the heat from the beam make your head explode, or would your head explode from the , or would you die from the dose? ...I want a show of hands for which one you think would get you first."