Category Archives: LHC Exhibition

Collider in the Palace of Westminster

Sian Worsfold describes an extraordinary encounter between the worlds of politics and science.

The nation’s newly-minted Nobel prize winner, Professor Peter Higgs, was guest of honour at a special event arranged for Lords and MPs to celebrate the Science Museum’s groundbreaking exhibition, Collider.

On Monday night in the Palace of Westminster, a series of special events began to celebrate the launch of an exhibition that allows visitors to step inside the epic Large Hadron Collider at the European Organization for Nuclear Research in Geneva, better known as CERN.

The opening events were kicked off by an exclusive reception in Portcullis House hosted by the Parliamentary Office of Science and Technology (POST), in collaboration with the Science Museum. MPs, Lords and other distinguished guests had the opportunity to meet leading figures from the field of particle physics, including Professor Peter Higgs, Dr Stephen Myers, CERN’s Director of Accelerators and Technology, and Andrew Taylor, Executive Director of STFC National Laboratories.  

Ian Blatchford, Director and Chief Executive of the Science Museum Group, talks about the importance of the new Collider exhibition for the Museum. Credit: Smith and Scholey

Ian Blatchford, Director of the Science Museum discussing the Collider exhibition. Credit: Smith and Scholey

Guests included Andrew Miller MP, Chair of the Science and Technology Select Committee; Liam Byrne, MP, Shadow science spokesman; Gerry Sutcliffe MP; Julian Huppert MP; Lord Jordan; Dr Lutz-Peter Berg, Science and Technology Attache for the Swiss Embassy; Dr Stephen Benn, Director of Parliamentary Affairs, Institute of Biology; and particle physicist Jon Butterworth.

They were invited to explore and interact with exhibits provided by some of the UK’s leading particle physics groups, including UCL, Imperial College, University of Cambridge and Science and Technology Facilities Council (STFC), and talk to researchers about their latest work.

Dr Chris Tyler, Director of POST, compered the event with the opening speech delivered by Adam Afriyie MP, Chairman of POST and former Conservative science spokesman. Ian Blatchford, Director and Chief Executive of the Science Museum Group, thanked supporters of the exhibition, which brings the epic collaborative endeavour at CERN to life with objects, cutting edge theatre and digital techniques. Curator Ali Boyle, Deputy Keeper of Science and Medicine at the museum, and Dr Harry Cliff, particle physicist at University of Cambridge and the museum’s Fellow of Modern Science, also gave an overview of the challenges of recreating the world’s greatest experiment for visitors, and treated guests to a sneak preview of the exhibition trailer.

Dr Stephen Myers, CERN’s Director of Accelerators and Technology, gave an overview of more than 40 years experience of creating collisions at CERN, while Andrew Taylor conveyed his excitement at the STFC and Science Museum working together on the exhibition.

Popular exhibits included a ping-pong accelerator provided by Professor Jordan Nash from Imperial College and a display entitled ‘What is the LHC?’ from Mark Wells at STFC. This featured a scale model of a section of the LHC, highlighting how this international endeavour has advanced a range of scientific fields, from physics and engineering to computational science. Steve Wotton from the Cavendish Laboratory at the University of Cambridge entranced parliamentarians with a cloud chamber and a spark chamber, to demonstrate that high energy particles are all around us.

Adam Afriyie, Chairman of POST, congratulates Professor Peter Higgs on his recent Nobel Prize for physics. Credit: Smith and Scholey.

Adam Afriyie congratulates Peter Higgs. Credit: Smith and Scholey.

Guest of honour, recent Nobel Prizewinner Professor Peter Higgs, received many congratulations throughout the evening for his landmark contribution to the field of particle physics. He was in high demand with everyone, from recent science graduates and Fellows to star struck MPs. At his side was his University of Edinburgh colleague, Alan Walker.

As it began to rain outside, Professor Higgs was given a special umbrella, decorated with an image of one of the great ‘eyes’ of the vast LHC, the CMS detector.

Collider runs at the Science Museum from 13 November 2013-6 May 2014. To find out more visit sciencemuseum.org.uk/collider.

LHC: Lip Hair Champions

Content Developer Rupert Cole explores some famous moustaches in particle physics ahead of the opening of our new Collider exhibition on 13th November. 

It’s that time again: Movember – the eminently charitable moustache-growing month raising awareness for men’s health. But what, you might reasonably wonder, has facial hair got to do with particle physics? Well, I have a theory; one backed by hard pictorial and anecdotal evidence…

The Cavendish lab’s moustachioed students, 1897. Credit: Cavendish Laboratory

The Cavendish lab’s moustachioed students, 1897. Credit: Cavendish Laboratory

Consider the glory days of Cambridge’s Cavendish Laboratory, during which the first subatomic particle was identified, a revolutionary particle detector invented, and the atomic nucleus split by one of the first particle accelerators. Significantly, the great Cavendish leaders and pioneers of this period cannot be accurately described as clean shaven.

Joseph John Thomson

JJ Thomson has a “rather straggling moustache,” wrote a talented student called Ernest Rutherford in 1896, “but a very clever-looking face and a fine forehead”. In another letter to his fiancé, Rutherford made the additional comment that Thomson “shaves very badly”.

We may detect a hint of jealousy in Rutherford’s description of Professor “JJ”. As, according to one chronicler of the lab’s history, the young student Rutherford possessed only “a thinly sprouting moustache”.

JJ Thomson. Credit: Cavendish Laboratory

JJ Thomson. Credit: Cavendish Laboratory

Nevertheless, concealed in Thomson’s supposedly wayward bristles was a creative and audacious genius. At the time, the Cavendish’s director had been performing his groundbreaking experiments on cathode rays. The next year he shocked the scientific world when he announced the existence of a particle smaller than the smallest atom – later dubbed the “electron”.

Ernest Rutherford

Once the rambunctious New Zealander’s lip-hair had acquired its full bushy substance, he was well on the way to scientific stardom.

His first momentous contribution to physics came in 1902 at McGill University, Canada. Rutherford and his colleague Frederick Soddy explained what radioactivity actually is – the process of atomic decay.

Soddy described his co-discoverer simply as an “exuberant natural, young man with a moustache”. Biographers would later characterise Rutherford’s ever-growing asset as reminiscent of a “walrus”.

By the time he succeeded his old moustachioed mentor, JJ Thomson, as Professor of the Cavendish, Rutherford had already discovered the atomic nucleus (1911) and managed to split nitrogen atoms in half, causing them to transmute into two oxygen atoms (1917-19).

But it was at the Cavendish that he ushered in the era of accelerator physics. Contemporaries recall a particular accessory: a pipe, containing the world’s driest and instantly-flammable tobacco.

Ernest “The Walrus” Rutherford. Credit: Science Museum / SSPL

Ernest “The Walrus” Rutherford. Credit: Science Museum / SSPL

On one Spring day in 1932, Rutherford entered the lab in a famously foul mood. His pipe “went off like a volcano” – having pre-dried his tobacco on a radiator. Impatient at the progress his young researchers John Cockcroft and Ernest Walton had made with their 800,000-volt proton accelerator, he instructed them to “stop messing about… and arrange that these protons were put to good use”.

At Rutherford’s suggestion, they immediately installed a zinc-sulphide scintillation screen – a device which causes charged particles to sparkle when they hit – into their wooden observation hut. A few days later, Walton saw on this screen evidence that their machine was splitting the nucleus of lithium atoms!

Had the authority of the tache and pipe not intervened, the Cavendish men may have been pipped to the discovery by the clean-shaven American teams, who boasted the biggest and best of accelerators.

Charles Thomson Rees Wilson

CTR Wilson, one of Rutherford’s fellow students at the Cavendish, was a
“modest” personality with a similarly unassuming moustache. He spent 16 years assembling cloud chambers – a device he initially invented to study meteorological phenomena.

A keen mountaineer – an activity that always complements well-trimmed bristles – Wilson derived inspiration to build cloud chambers when he was atop Ben Nevis, observing beautiful optical effects.

His third and final chamber, completed in 1911, was later described by Rutherford as “the most original and wonderful instrument in scientific history”. Incredibly, it could capture with photographs the tracks of particles. Wilson had invented the first detector that could visualise and record the subatomic world.

CTR Wilson, 1927. Credit: AB Lagrelius and Westphal

CTR Wilson, 1927. Credit: AB Lagrelius and Westphal

It seems remarkable that the humble moustache may have had such a crucial role in the foundation particle physics. Never again would the Cavendish be led by lip-hair champions; and considering the lab’s unprecedented success in this golden period, we can reliably infer the cost of this absence.

I leave you with the words of Arthur Eddington: “An atom which has lost an electron is like a friend who has shaved-off his moustache.”

Next week you can see Thomson’s cathode-ray tube, Rutherford’s atomic models, the Cockcroft-Walton accelerator, CTR Wilson’s cloud chamber, and much more at the Science Museum’s new Collider exhibition. 

For more famous physics moustaches click here.

LHC: Lifting Heavy Contraptions

Curator Ali Boyle on how the Collider team are installing some of the larger objects in our new exhibition. 

It’s just three weeks to go until Collider opens with a flurry of exciting events. Which means that we’re getting to the best part of exhibition work – after all the planning, the objects are finally starting to make their way onto gallery.

That’s sometimes easier said than done when your objects come from CERN. A few are so large that we’ve had to install them on gallery early and build the rest of the exhibition around them. First up was the object we call The Beast, a 2-tonne section of one of the giant dipole magnets that keep the LHC’s particle beams on course.

Thankfully it was only a section – a whole LHC magnet weighs in at 35 tonnes and is 15 metres long. And our basement gallery is a lot easier to get to than a tunnel 175 metres below ground, the challenge faced by CERN as they upgrade the LHC’s magnet system.

dipole_lifting

Conservator Richard (in white) supervises The Beast being lowered onto its trolley. (Credit: Alison Boyle)

Another 2-tonne behemoth, delivered from CERN that morning, followed – an accelerating cavity from LEP, the Large Electron Positron collider, which previously occupied the tunnel that now houses the LHC. The copper cavity, used in the first phase of LEP operations, looks like something Jules Verne might have imagined.

The LEP cavity's storage sphere is carefully lowered into place. (Credit: Alison Boyle)

The LEP cavity’s storage sphere is carefully lowered into place. (Credit: Alison Boyle)

Of course, being the Science Museum, we’re used to big bits of kit. The LHC objects, although hefty, were a piece of cake compared with getting the planes in. Or handling the 4-tonne Rosse Mirror, which we moved into its current position in Cosmos & Culture in 2009.

Made of speculum, a mixture of copper and tin, the Rosse Mirror is six feet in diameter. It is one of the few surviving original pieces of the largest scientific instrument of its day, the enormous telescope built by the Earl of Rosse at Birr Castle in the Irish midlands and known as the  ‘Leviathan of Parsonstown’. The mirror was donated to us in 1914 – here it is being delivered.

Easy does it … moving the Rosse Mirror into the Western Galleries, 1914. (Credit: Science Museum)

There’s a clear distinction between ‘doers’ and ‘watchers’ in this photograph. On Collider this week I was definitely the latter. As those keen observers of the museum world, the Ministry of Curiosity, point out, curators rarely do the actual muscle work.

So, rather than take my word for it, why not ask someone who really knows about moving big bits of particle accelerator around? Lyn Evans (or ‘Evans the Atom’ as he’s dubbed in the press) was Project Leader for the LHC build. Next Wednesday 30 October, thanks to our friends at the London Science Festival, you can hear him talk about the LHC’s engineering challenges at Science Museum Lates. He’ll be joined by Collider‘s very own Harry Cliff, who’ll give a sneak preview of how we’re bringing CERN to South Kensington. Not all of it obviously, as that would be a bit too heavy…

Discover more about the Higgs boson and the world’s largest science experiment in our new exhibition, Collider, opening on 13th November 2013.

The last particle?

Could the Higgs be the end of particle physics? We’re still a long way from answering one of the biggest questions of all, says Dr Harry Cliff, Head of Content on our Collider exhibition.

The 2013 Nobel Prize in Physics has been awarded to François Englert and Peter Higgs for their work that explains why subatomic particles have mass. They predicted the existence of the Higgs boson, a fundamental particle, which was confirmed last year by experiments conducted at CERN’s Large Hadron Collider.

But today’s celebrations mask a growing anxiety among physicists. The discovery of the Higgs boson is an undoubted triumph, but many note that it hasn’t brought us any closer to answering some of the most troubling problems in fundamental science.

A senior physicist went so far as to tell me that he was “totally unexcited by the discovery of the Higgs boson”. Though not the typical reaction, this discovery threatens to close a chapter of 20th century physics without a hint of how to start writing the next page.

Until July last year, when physicists at the Large Hadron Collider (LHC) announced its discovery, the Higgs boson remained the last missing piece of the Standard Model of particle physics, a theory that describes all the particles that make up the world we live in with stunning accuracy. The Standard Model has passed every experimental test thrown at it with flying colours, and yet has some rather embarrassing holes.

According to astronomical measurements, the matter described by the Standard Model that makes up the stars, planets and ultimately us, only accounts for a tiny fraction of the universe. We appear to be a thin layer of froth, floating on top of an invisible ocean of dark matter and dark energy, about which we know almost nothing.

Worse still, according to the Standard Model, we shouldn’t exist at all. The theory predicts that, after the Big Bang, equal quantities of matter and antimatter should have obliterated each other, leaving an empty universe.

Both of these are good scientific reasons to doubt that the Standard Model is the end of the story when it comes to the laws of physics. But there is another, aesthetic principle that has led many physicists to doubt its completeness – the principle of “naturalness”.

The Standard Model is regarded as a highly “unnatural” theory. Aside from having a large number of different particles and forces, many of which seem surplus to requirement, it is also very precariously balanced. If you change any of the 20+ numbers that have to be put into the theory even a little, you rapidly find yourself living in a universe without atoms. This spooky fine-tuning worries many physicists, leaving the universe looking as though it has been set up in just the right way for life to exist.

The Higgs’s boson provides us with one of the worst cases of unnatural fine-tuning. A surprising discovery of the 20th century was the realisation that empty space is far from empty. The vacuum is, in fact, a broiling soup of invisible “virtual” particles, constantly popping in and out of existence.

The conventional wisdom states that as the Higgs boson passes through the vacuum it interacts with this soup of virtual particles and this interaction drives its mass to an absolutely enormous value – potentially up to a hundred million billion times larger than the one measured at the LHC.

Theorists have attempted to tame the unruly Higgs mass by proposing extensions of the Standard Model. The most popular of which is “supersymmetry”, which introduces a heavier super-particle or “sparticle” for every particle in the Standard Model. These sparticles cancel out the effect of the virtual particles in the vacuum, reducing the Higgs mass to a reasonable value and eliminating the need for any unpleasant fine-tuning.

Supersymmetry has other features that have made it popular with physicists. Perhaps its best selling point is that one of these sparticles provides a neat explanation for the mysterious dark matter that makes up about a quarter of the universe.

Although discovering the Higgs boson may have been put forward as the main reason for building the 27km Large Hadron Collider (LHC), what most physicists have really been waiting for is a sign of something new. As Higgs himself said shortly after the discovery last year, “[The Higgs boson] is not the most interesting thing that the LHC is looking for”.

So far however, the LHC has turned up nothing.

If supersymmetry is really responsible for keeping the Higgs boson’s mass low, then sparticles should show up at energies not much higher than where the LHC found the Higgs. The fact that nothing has been found has already ruled out many popular forms of supersymmetry.

This has led some theorists to abandon naturalness altogether. One relatively new idea known as “split-supersymmetry” accepts fine-tuning in the Higgs mass, but keeps the other nice features of supersymmetry, like a dark matter particle.

This may sound like a technical difference, but the implications for the nature of our universe are profound. The argument is that we live in a fine-tuned universe because it happens to be one among an effectively infinite number of different universes, each with different laws of physics. The constants of nature are what they are because if they were different atoms could not form, and hence we wouldn’t be around to wonder about them.

This anthropic argument is in part motivated by developments in string theory, a potential “theory of everything”, for which there are a vast number (roughly 10500) different possible universes with different laws of physics. (This huge number of universes is often used as a criticism of string theory, sometimes derided as a “theory of everything else” as no one has so far found a solution that corresponds to the universe we live in.) However, if split-supersymmetry is right, the lack of new physics at the LHC could be indirect evidence for the existence of the very multiverse anticipated by string theory.

All of this could be rather bad news for the LHC. If the battle for naturalness is lost, then there is no reason why new particles must appear in the next few years. Some physicists are campaigning for an even larger collider, four times longer and seven times more powerful than the LHC.

This monster collider could be used to settle the question once and for all, but it’s hard to imagine that such a machine will get the go ahead, especially if the LHC fails to find anything beyond the Higgs.

We are at a critical juncture in particle physics. Perhaps after it restarts the LHC in 2015, it will uncover new particles, naturalness will survive and particle physicists will stay in business. There are reasons to be optimistic. After all, we know that there must be something new that explains dark matter, and there remains a good chance that the LHC will find it.

But perhaps, just perhaps, the LHC will find nothing. The Higgs boson could be particle physics’ swansong, the last particle of the accelerator age. Though a worrying possibility for experimentalists, such a result could lead to a profound shift in our understanding of the universe, and our place in it.

Discover more about the Higgs boson and the world’s largest science experiment in our new exhibition, Collider, opening on 13th November 2013.

This article first appeared on The Conversation.

Celebrate the Nobel Prize at the Science Museum

Roger Highfield, Director of External Affairs at the Science Museum, celebrates the 2013 Nobel Prize for Physics ahead of the opening of our Collider exhibition next month.      

Congratulations to Briton Peter Higgs and Belgian François Englert, winners of the 2013 Nobel Prize for Physics “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider.”

A few minutes ago, after an unusual delay, the Royal Swedish Academy of Sciences announced the winners of the physics prize in Stockholm, ending this chapter of the quest for new elementary particles, the greatest intellectual adventure to date.

Ian Blatchford, Director of the Science Museum, comments: “That it has taken decades to validate the existence of the Higgs Boson illustrates the remarkable vision of the theoretical work that Higgs, Francois Englert and others did with pen and paper half a century ago, one that launched an effort by  thousands of scientists and inspired a staggering feat of engineering in the guise of the Large Hadron Collider.

What is the Higgs? Here’s all you need to know, in just 90 seconds, from Harry Cliff, a Cambridge University physicist working on the LHCb experiment and the first Science Museum Fellow of Modern Science

Although the identity of the winners has been a closely-guarded secret, many have speculated that those who played a central role in discovery of the long-sought Higgs, notably the emeritus Edinburgh professor himself, were leading contenders for a place in history.

The Science Museum has been so confident that the Large Hadron Collider would change our view of nature that we have invested more than £1 million, and worked closely with the European Organization for Nuclear Research, CERN, to celebrate this epic undertaking with its new exhibition, Collider: step inside the world’s greatest experiment, which opens to the public on 13 November. 

Here Higgs explains how the Large Hadron Collider works during a visit to what is now Cotham School, Bristol, where he was once a pupil.

In July 2012, two separate research teams at CERN’s £5 billion Large Hadron Collider reported evidence of a new particle thought to be the Higgs boson, technically a ripple in an invisible energy field that gives most particles their mass.

This discovery represented the final piece of the Standard Model, a framework of theory developed in the late 20th century that describes the interactions of all known subatomic particles and forces, with the exception of gravity.

Nima Arkani-Hamed, a leading theoretical physicist at the Institute for Advanced Study in Princeton who will attend the launch of Collider, bet a year’s salary the Higgs will be found at the LHC.

Another speaker at the Collider launch, the world’s most famous scientist, Prof Stephen Hawking, lost a $100 bet he made against the discovery (though he is adamant that Higgs deserves the Nobel Prize).

Higgs, who refuses to gamble, told me just before the LHC powered up that he would have been puzzled and surprised if the LHC had failed in its particle quest. “If I’m wrong, I’ll be rather sad. If it is not found, I no longer understand what I think I understand.”

When Higgs was in the CERN auditorium last year to hear scientists tell the world about the discovery, he was caught reaching for a handkerchief and dabbing his eyes.  On the flight home, he celebrated this extraordinary achievement with a can of London Pride beer.

The Science Museum hoped to have the can, now deemed a piece of history Alas, Higgs had dumped it in the rubbish before we could collect it. However, the museum does possess the champagne bottle that Higgs emptied with his friends the night before the big announcement.

The champagne bottle Peter Higgs drank from, the night before the Higgs boson discovery was announced to the world. Credit: Science Museum

The champagne bottle Peter Higgs drank from, the night before the Higgs boson discovery was announced to the world. Credit: Science Museum

The modest 84-year-old  is now synonymous with the quest: the proposed particle was named the Higgs boson in 1972.

But there have been demands that the particle be renamed to acknowledge the work of others. Deciding who should share this Nobel has been further complicated because a maximum of three people only can be honoured (prompting many to question the criteria used by the Nobel committee).

The LHC, the world’s most powerful particle accelerator, is the cumulative endeavour of around ten thousand men and women from across the globe. In recognition of this the Collider exhibition will tell the behind-the-scenes story of the Higgs discovery from the viewpoint of a young PhD student given the awesome task of announcing the discovery to her colleagues (though fictional, the character is based on Mingming Yang of MIT who is attending the launch).

However, although one suggestion is to allow the two research teams who discovered the Higgs boson to share the accolade, the Nobel committee traditionally awards science prizes to individuals and not organizations (unlike the Nobel Peace Prize).

Instead, the Nobel committee honoured the theoreticians who first anticipated the existence of the Higgs.

Six scientists published the relevant papers in 1964 though, as Belgium’s Robert Brout died in 2011, there were five contenders (the Nobel Prize cannot be given posthumously).

In August 1964, François Englert from the Free University of Brussels with Brout, published their theory of particle masses. A month later, while working at Edinburgh University, Higgs published a separate paper on the topic, followed by another in October that was – crucially – the first to explicitly state the Standard Model required the existence of a new particle. In November 1964, American physicists Dick Hagen and Gerry Guralnik and British physicist Tom Kibble added to the discussion by publishing their own research on the topic.

Last week, Prof Brian Cox of Manchester University, who works at CERN, said it would be ‘odd and perverse’ not to give the Nobel to Peter Higgs, and also singled out Lyn ‘the atom’ Evans, the Welshman in charge of building the collider, as a candidate.

And the two likeliest winners were named as Peter Higgs – after whom the particle was named – and François Englert, according to a citation analysis by Thomson Reuters.

Today’s announcement marks the formal recognition of a profound advance in human understanding, the discovery of one of the keystones of what we now understand as the fundamental building blocks of nature.

Discover more about the Higgs boson and the world’s largest science experiment in our new exhibition, Collider, opening 13th November 2013.

Unboxing CERN

Content Developer Rupert Cole on unboxing objects from CERN for Collider, a new Science Museum exhibition opening in November 2013.

There are not many things that would persuade me to wait for a van in the rain at 7am; but this was not to be missed. For on this particular cold, wet and early morning at the Science Museum, our hotly-anticipated Collider objects were due to arrive from CERN.

8am. An hour on and the van was here. Evidently, good objects come to those who wait.

Unveiling the LHC crates. Credit: Harry Cliff

Unveiling the LHC crates. Credit: Harry Cliff

Maybe it was the fact we had been working with only object dimensions and tiny pictures, but the first sight of even just the crates, in their various sizes and shapes, suddenly made the exhibition feel all the more real and tangible.

Broadly there were two concerns. Was everything there? And how to shift a two-tonne superconducting dipole magnet, aka “the Beast”? Luckily, on hand to help with the latter was a forklift truck – naturally, delivered by a bigger truck.

One forklift truck. Credit: Harry Cliff

One forklift truck. Credit: Harry Cliff

Once the two-tonne Beast had been fork-lifted over to the Goods Lift (conveniently situated up a slope) there was the small matter of getting it in. At this stage, ascertaining whether everything had come relied on the skilful art of imagining which object might fit in which crate. Given the variety of objects, ranging from a 22-cm delicate crystal detector piece to a whopping 2-metre-long iron magnet, guessing according to the logic of packing was relatively straight forward.

Later, came the Christmas-esque joy of cracking open the crates and seeing the LHC treasures in the flesh. Looking at the cross-section cut of the dipole magnet, it was nice to see that even “the Beast” had a friendly face.

Dipole magnet cross section. Credit: Harry Cliff

Dipole magnet cross section. Credit: Harry Cliff

After the museum conservators have polished various nooks and crannies, and the workshop team have made some mounts, the objects will be installed into this empty gallery – and soon after that, the gallery will make its dramatic transformation into the world’s greatest scientific experiment.

Exhibition space ready for the Collider exhibition. Credit: Ali Boyle

Exhibition space ready for the Collider exhibition. Credit: Ali Boyle

Come and experience the sights and sounds of CERN at Collider, a new immersive exhibition opening this November at the Science Museum. Book tickets here

Beaming with Joy: LHC celebrates five years of not destroying the world

Content Developer Rupert Cole, and Science Museum Fellow of Modern Science Dr. Harry Cliff, celebrate the LHC’s 5th birthday for Collider, a new Science Museum exhibition opening in November 2013.

Five years ago, at breakfast time, the world waited anxiously for news from CERN, the European Organization for Nuclear Research. The first nervy bunch of protons were due to be fired around the European lab’s latest and biggest particle accelerator, the Large Hadron Collider (LHC), as it kicked into action.

Some “mercifully deluded people” – as Jeremy Paxman put it – feared the LHC would do no end of mischief. There was talk of planet-swallowing black holes, the transformation of the Earth into a new state of “strange” matter, and even the prospect of the obliteration of the entire universe. But for those of more sensible dispositions, the LHC’s first beam was an occasion for great excitement.

As the protons sped all the way round the 27km tunnel under the countryside between Lake Geneva and the Jura Mountains, thousands of physicists and engineers celebrated decades of hard work, incredible ingenuity and sheer ambition. Together they had created the largest-ever scientific experiment.

After the LHC was switched on, project leader Lyn Evans said, “We can now look forward to a new era of understanding about the origins and evolution of the universe.”

Operating a massive particle accelerator requires much more than flicking a switch – thousands of individual elements have to all come together, synchronised in time to less than a billionth of a second.

University College London’s physicist Jon Butterworth recalls a “particularly bizarre memory” from that day. Relaxing in a Westminster pub after an exhausting LHC event in London, Butterworth found he could follow live updates from his own ATLAS experiment on the pub’s TV.

Time for a rest. Credit: CERN

Particle physics continued to make news. The following fortnight’s joy turned to dismay as an accident involving six tonnes of liquid helium erupting violently in the tunnel – euphemistically referred to as “the incident” – damaged around half a mile of the collider, closing the LHC for a year.

Since then, besides the brief setback that was “baguette-gate”, a bizarre episode when the collider was sabotaged by a baguette-wielding bird, the LHC has been producing great work. Hundreds of scientific papers have been published by the CERN experiments, on topics as diverse as searches for dark matter candidates, the production of the primordial state of matter (known as quark-gluon plasma) and precision measurements of matter-antimatter asymmetries.

However, it was on July 4 last year, that the LHC snared its first major catch with the discovery of the Higgs boson – as one of the most significant scientific finds of the century. The Higgs boson was one of the longest-sought prizes in science – it was almost fifty years ago in 1964 that three groups of theorists laid the ground-work for what would become the final piece of the theory known as the Standard Model of Particle Physics. They proposed an energy field, filling the entire Universe that gives mass to fundamental particles.

This “Higgs mechanism” neatly explained why the weak nuclear force was so weak and why light is able to travel over infinite reaches of space. It also laid the groundwork for the unification of the weak and electromagnetic forces into a single “electroweak” force, in a coup similar to James Clerk-Maxwell’s unification of electricity and magnetism in the 19th century.

Peter Higgs at CERN’s public announcement of the Higgs Boson, 4 July 2012. Credit: CERN

However, like air, the Higgs field itself is invisible; the only way to know if it is there is to create a disturbance in it, like a breeze or a sound. It was Peter Higgs who first suggested that if the field existed, it would be possible to create such a disturbance, which would show up as a new particle. Hence, the boson was named after him, much to the irritation of some of the other five theorists responsible for the theory.

The LHC’s discovery of the Higgs closed a chapter in the development of fundamental physics, placing the keystone into the great arch of the Standard Model. The LHC is currently being upgraded so that in 2015 it will reopen at almost double its previous energy. What every scientist is now aching for is a sign of something new, physics beyond the Standard Model, and most probably beyond our wildest aspirations.

This article was originally published at The Conversation (original article).

Through the past, present and future, follow the compelling drama, the amazing achievements and the inspirational hopes of the LHC at Collider, a new exhibition opening this November at the Science Museum.

The Conversation

Click and zoink – it’s your birthday!

Ahead of November’s opening of the Collider exhibition, Content Developer Rupert Cole takes a look at the story behind the Geiger counter

“The excitement is growing so much I think the Geiger counter of Olympo-mania is going to go zoink on the scale!”

Thus spoke Boris Johnson in his London Olympics opening speech a little over a year ago. The author of several popular histories including Johnson’s Life of London, is it conceivable Mayor Boris knew the Olympic summer coincided with the 104th birthday of the Geiger counter…?

On this day, 105 years ago, Hans Geiger and Ernest Rutherford published their paper on a revolutionary new method of detecting particles.

Geiger and Rutherford at Manchester, 1912. Credit: Science Museum / SSPL

Geiger and Rutherford at Manchester, 1912. Credit: Science Museum / SSPL

The first generation of Geiger counters did not produce the characteristic click we know and love today. Instead, an electrometer needle would suddenly jump, indicating an alpha particle had been detected.

They worked by picking up electric signals given off by electrons, which had been stripped from gas molecules by passing alpha particles. The beauty of them was that they provided another way to measure radiation, verifying the laborious and blinding method of counting light scintillations.

Once the technology improved, Geiger-Muller counters (as the later ones were called) became extremely nifty particle detectors, essential hardware for any cosmic-ray physicist. They are now used for many different purposes, from airport security to checking the levels of radioactivity in certain museum objects.

One of Geiger’s own counters made in 1932. Credit: Science Museum / SSPL

One of Geiger’s own counters made in 1932. Credit: Science Museum / SSPL

For a long time the device was just a tool used by researchers of radioactivity, an innovation that made Geiger’s task of counting by eye emissions of alpha particles from radium a little easier.

This is not to deny Geiger’s eyes were very effective counters of tiny flecks of light – produced by individual alpha particles as they hit a fluorescent screen. As Rutherford said at the time:

“Geiger is a demon at the work of counting scintillations and could count for a whole night without disturbing his equanimity. I damned vigorously and retired after two minutes”.

Arriving in Manchester in 1907, the German-born Geiger clearly was responsible for the nitty gritty side of the research. Ernest Marsden, a twenty-year old undergraduate, joined the pair the following year. The young student may not at first have realised that he was contributing to one of the most remarkable discoveries of the century.

In a darkened lab, Geiger and Marsden would take turns to count the sparkles of alpha particles as they hit a screen, having been fired straight through a sheet of gold leaf.

As the particles were much smaller than the gold atoms, it must have seemed slightly barmy when Rutherford suggested to move the counting screen behind the radium source and look for scintillations there.

The near-blind researchers hit gold, so to speak, and found the odd alpha particle had bounced back. Rutherford declared it the most incredible event of his life, “as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.”

The team discovered the atoms had a nucleus – a miniscule core that caused the occasional alpha particle to rebound. Rutherford would soon come up with an entirely new picture of atoms, which depicted electrons orbiting around this central nucleus.

Model of hydrogen atom, according to the theory of Ernest Rutherford and Niels Bohr. Credit: Science Museum.

Model of hydrogen atom, according to the theory of Ernest Rutherford and Niels Bohr. Credit: Science Museum.

Geiger recalled the glory moment: “One day (in 1911) Rutherford, obviously in the best of spirits, came into my room and told me that he now knew what the atom looked like”.

You will have the chance to see up close Rutherford and Bohr’s atomic model, and discover the objects that helped shape modern physics in Collider, a new exhibition opening this November.

If Particle Physics Did Parties…

With the Collider exhibition now open, Content Developer Rupert Cole explores some famous physics parties of the past. 

As it happens, Carlsberg did do particle physics. The Danish beer giant was an unlikely benefactor of the Niels Bohr Institute – one of the great centres of theoretical physics research.  

And Bohr himself even lived at the brewery’s “Honorary Residence” after winning the Nobel Prize, complete with a direct pipeline supplying free Carlsberg on tap! Just imagine what untold influence lager had on those groundbreaking discussions of quantum theory during Bohr’s thirty-year stay…

Niels Bohr’s luxury mansion at the Carlsberg Brewery, 1963. Credit: CERN

Niels Bohr’s luxury mansion at the Carlsberg Brewery, 1963. Credit: CERN

After my last blog about bubble chambers and beer, I thought, since it’s the festival season, why not go the whole hog and explore a few partying highlights from the history of physics.

The first Cavendish Laboratory Dinner, 1897

During the Christmas Holidays of 1897, the staff and students of Cambridge’s Cavendish Laboratory had a memorable dinner party at the Prince of Wales’ Hotel.

It was a “rollicking affair”. JJ Thomson, Professor of the Laboratory, was remembered by a student to be “as happy as a sand-boy”. Thomson, of course, had been very busy that year discovering the subatomic world. Another physicist, Paul Langevin, sang La Marseillaise with such fervour that a French waiter embraced him.

That night was the beginning of a Cavendish tradition: singing physics through the medium of light opera. Lyrics about atoms and ions were put to Gilbert and Sullivan tunes, long before Tom Lehrer. The next day, Thomson remarked that “he had no idea that the Laboratory held such a nest of singing birds”.

It must have been quite a noise, as the Proctors of the University came to enquire at the hotel what the “proceedings” were about. Fortunately, they did not enter the room – “being,” Thomson supposed, “impressed, and I have no doubt mystified, by the assurance of the landlord that it was a scientific gathering of research students”.

JJ Thomson and his Cavendish students, 1897. Credit: Cavendish Laboratory

JJ Thomson and his Cavendish students, 1897. Credit: Cavendish Laboratory

The first dinner was such a hoot that it became an annual occasion. The merry songs that emerged at these events were soon immortalised in regular published editions of The Post-Prandial Proceedings of the Cavendish Society.

Feynman’s entire anecdotal oeuvre

“There’s so much fun to be had”

Not many Nobel prize-winning physicists can say they’ve played the frying pan in a samba band at Rio’s Carnival; made complex calculations on napkins in strip bars; or spent a sabbatical on the Copacabana drinking themselves teetotal and seducing air-hostesses. A raconteur of almost mythic proportions, Richard Feynman had a natural aptitude for partying.

Costume parties really brought out the showman in Feynman. He was very versatile, boasting a clothing repertoire that ranged from a Ladakhi monk to God. But it was on one April Fools’ Day that Feynman surpassed himself. Sat primly on a chair, looking regally and nodding graciously to other guests, Feynman was the very image of Queen Elizabeth II – wig, white hat, green dress, purse and gloves. At the end of the evening, he performed his royal finale: a striptease!

We must unfortunately cut short of the entire Feynman backlog of anecdotes, so instead click here for a video of Feynman playing “orange juice” on the bongos.

Higgs’ champagne moment, 2012

On a Saturday night in Sicily, Peter Higgs was dining with friends when the phone rang. Fellow physicist John Ellis had called to tell Higgs to come to CERN. Swiftly, travel arrangements were made and another bottle of white ordered. History was being written.

A few evenings later, Higgs was in Ellis’ Geneva home sharing a bottle of champagne with family and friends – that day he had read a note that confirmed the particle he had predicted to exist 48 years ago had finally been found.

The following day, on 4th July 2012, CERN held a conference announcing to the world the discovery of the Higgs Boson. Emotions running high in the packed lecture hall, Higgs likened the experience to “being at a football match when the home team has won”. Fittingly then, on the Easyjet flight home to Edinburgh, he turned down more champagne in favour of a can of London Pride.

See JJ Thomson’s 1897 cathode-ray tube, Peter Higgs’ champagne bottle, and experience more great moments of discovery at Collider, a new exhibition at the Science Museum.

The Art of Boiling Beer: 60 years of the Bubble Chamber

Ahead of November’s opening of the Collider exhibition, Content Developer Rupert Cole explains how beer was used for cutting-edge particle physics research. 

Late one night in 1953, Donald Glaser smuggled a case of beer into his University lab. He wanted to test out the limitations of his revolutionary invention: the bubble chamber.

Previously, Glaser had only tried exotic chemical liquids in his device. But now his sense of experimental adventure had been galvanised by a recent victory over the great and famously infallible physicist Enrico Fermi.

Donald Glaser and his bubble chamber, 1953. Credit: Science Museum / Science and Society Picture Library

Donald Glaser and his bubble chamber, 1953. Credit: Science Museum / Science and Society Picture Library

Fermi, who had invited Glaser to Chicago to find out more about his invention, had already seemingly proved that a bubble chamber could not work. But when Glaser found a mistake in Fermi’s authoritative textbook, he dedicated himself to redoing the calculations.

Glaser found that, if he was correct, that the bubble chamber should work with water. To make absolutely certain he “wasn’t being stupid”, Glaser conducted this curious nocturnal experiment at his Michigan laboratory. He also discovered that the bubble chamber worked just as well when using lager as it had with other chemicals.

There was one practical issue however, the beer caused the whole physics department to smell like a brewery. “And this was a problem for two reasons,” Glaser recalled. “One is that it was illegal to have any alcoholic beverage within 500 yards of the university. The other problem was that the chairman was a very devout teetotaler, and he was furious. He almost fired me on the spot”.

On 1st August 1953, 60 years ago this Thursday, Glaser published his famous paper on the bubble chamber – strangely failing to mention the beer experiment.

Glaser’s device provided a very effective way to detect and visualise particles. It consisted of a tank of pressurised liquid, which was then superheated by reducing the pressure. Charged particles passing through the tank stripped electrons from atoms in the liquid and caused the liquid to boil. Bubbles created from the boiling liquid revealed the particle’s path through the liquid.

Particle tracks produced by Gargamelle indicating the discovery of the neutral currents, 1973. Credit: CERN

Particle tracks produced by Gargamelle indicating the discovery of the neutral currents, 1973. Credit: CERN

One of Glaser’s motivations for his invention was to avoid having to work with large groups of scientists at big particle accelerators. Instead, he hoped his device would enable him to study cosmic rays using cloud chambers in the traditional fashion; up a mountain, ski in the day, “and work in sort of splendid, beautiful surroundings. A very pleasant way of life – intellectual, aesthetic, and athletic”

Ironically, as the bubble chamber only worked with controlled sources of particles, it was inherently suited to accelerator research, not cosmic rays. Soon the large accelerator facilities built their own, massive bubble chambers.

Design drawings for CERN’s Gargamelle bubble chamber. Credit: CERN

Design drawings for CERN’s Gargamelle bubble chamber. Credit: CERN

Between 1965-1970 CERN built Gargamelle – a bubble chamber of such proportions that it was named after a giantess from the novels of Francois Rabelais (not the Smurfs’ villain). Gargamelle proved a huge success, enabling the discovery of neutral currents – a crucial step in understanding how some of the basic forces of nature were once unified.

This November you’ll have the chance to see up close the original design drawings for Gargamelle, and much more in the Collider exhibition.