University Of Oxford Alumni

"A lot of s' food is irradiated before they send it up so that they... aren't going to get sick from it."

"So they had to put a lot of effort into designing... the , which is a massive long block of very dense , which absorbs the energy. But even then there's so much energy that they can't just dump it directly on it, or the would make the thing explode. So they actually have to paint the beam in... a swirly pattern... to spread out the load of the heat from the beam on this huge graphite block."

"So we can't use it as a weapon of mass destruction. This is another one... that someone told me that you shouldn't do with a particle accelerator... [Y]ou shouldn't eat it, which is true."

"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..."

"So what is ? It's energy in the form of moving particles or waves, emitted by an atom or another body as it changes from one energy state to another. That's the official definition."

"So it sounded like a crazy question, but if you had a brain tumor you might very well want to stick your head in the beam of a particle accelerator."

"[O]ne of the reasons we want to do this is because we want to drive... an . This is where you take a , a fission reactor. In the core, instead of having , it has an element called , which is... much more abundant, and you don't have to refine it. You can use all of it. Hook up to the reactor a particle accelerator, a very high power proton accelerator. So the protons come in and they smash into a heavy metal target and create s... [T]hose neutrons... drive the reaction in the reactor, so without the accelerator there, the reactor is subcritical. It doesn't produce energy. It doesn't sustain a , but once you add in the accelerator you can continue to drive the reaction and generate energy... [I]n fact you could transmute existing nuclear waste into something much shorter lived and much safer."

"So there's some really interesting applications of accelerators, way outside of the realm of particle physics, that we're starting to get a handle on."

"The only problem is [that] the accelerator for this is about 10 times more powerful... than we can currently make. So there's lots of challenges for people like me who design accelerators, to try and come up with ways of making them more and more powerful, for very good reason."

"[Y]ou can have two... main types of radiation, which are ionizing, or non-ionizing."

"There are foods which are naturally radioactive, but most of us would like to think we've never eaten food that actually been in a particle accelerator. ...That sounds a bit crazy. ...In the UK we don't eat many things that have in a particle accelerator but things like herbs and spices, and some other things occasionally go through a process called cold pasteurization, electronic pasteurization, which uses electrons from a to treat the food. ...It is legal in the UK and in the EU, and it's fully authorized... [T]here's a number of foods... which have been irradiated, or could have been irradiated, and that goes... from bananas, sometimes... to slow down the ripening process... so they have a longer shelf life... [A]s you increase the amount of radiation that these things are treated with... from some grains, seafood to kill bacteria, herbs and spices are a more common one, and then even sometimes higher doses on things like poultry, to kill ."

"In answer to some of the questions that we had a few years ago when the Large Hadron Collider started up... "Could it destroy the world?" ...The most convincing answer to me as to why it couldn't, is because we have particles in outer space from cosmic rays and things like that, at much much higher energies than we could ever dream of creating in the lab. And so far they haven't done anything catastrophic to us and we're perfectly fine. So in terms of just reaching a higher and higher energy... it doesn't really matter what we do in the lab. We should be safe on earth from these high energy particles."

"So you can actually put your head in the beam of an accelerator and survive it. And he's not the only one to have done it."

"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 yes, you probably have eaten something that's been through a ..."

"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."

"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."

"What about the ? ...People have done studies in outer space of astronauts and how long they could survive in the vacuum... That information say that you can survive in outer space with your spacesuit open for about ten seconds before you're ripped apart by the vacuum. So I don't think that's going to get you first."

"But they did, in fact. One of the interesting things I discovered, they did put a particle accelerator in space, which I think is fantastic."

"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."

"What has stayed constant is a certain chippiness. Canadians feel both superior to and dependent on America, thus resenting it; they often get mistaken for Americans, and are afraid of being culturally subsumed. They feel the rest of the world ignores them, which is a pretty accurate perception. And they're always trying to define who they are (not American, not British, not boring) and not quite succeeding, being presented with the daunting challenge of a country that covers five-and-a-half time zones, speaks two languages and contains a province that periodically wishes to secede (and if it did so would set the four Atlantic provinces adrift)."

"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."

"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."

"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."

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

"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..."

"Number three. Don't use a particle accelerator as a death ray. When I was putting together this lecture I asked... my very esteemed colleagues, "Has anyone ever tried to develop an accelerator as a weapon?" And they said, "Oh mumble, mumble cold war, space, Star Wars something or other... No" That was their conclusion... They were wrong."

"They developed this machine which was only about this big [~1 meter] and they used ultra-lightweight materials, and it only weighed about 50 kg. So compare that with a 27 kilometer long ring. ...It was only low energy but they... sent it up in a rocket and they actually tested it in space and brought it back down... and they tested it again on earth, and it still worked, which I think is an incredible feat of engineering... [P]eople really haven't heard of this experiment... It's called the BEAR (Beam Experiments Aboard a Rocket) project in 1989, and I have a contact who worked on it..."

"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 ."

"In the churchyard she was set down while her male relations dug into the ground. A smell rose, of loam and of rain. Yetemegnu was brought to the front. Now she could see the priest who clambered into the shallow grave; see his censer swinging, one corner, another, another, overlaying earth with pious perfume. Hear the final prayers. Watch the bending backs lower their freight into the ground, head to the east, feet to the west, feel, like a blow to her own body, the first handful of soil land upon her mother."

"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."

"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."

"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."

"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."

"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."

"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."

"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."

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

"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."

"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."

"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."

"[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'll tell you very briefly how they work. ...The first thing we need is some ...s, or even atoms themselves perhaps."

"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 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..."

"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."

"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."

"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."

"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."