Sunday20 August 2017

Ultimate architecture: Cern's partical detector

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To celebrate today's success of the 'Big Bang' experiment at Cern, read again Charles Jencks' look at the the world’s most powerful particle detector.

Architects, like scientists, thrive on cheap thought experiments which they then pay for in the field. This inclination to try out ideas in the mind first leads to a few breakthroughs and some pretentious jargon, but it is essential to the profession for sharpening concepts and taking risks.

Reyner Banham could be counted on to throw up such speculations. A Home Is Not A House, his 1965 Gedankenexperiment, was based on the unlikely proposition that the contemporary abode already contained so many pipes and gizmos it could easily evolve into something more extreme: a see-through plastic bubble plus all the necessary services.

Thus he had himself photographed in the nude sitting inside one of these transparent Gedankens, gesticulating at the high altar while its electronic wizardry churned out the delights of the day. The sixties’ “standard-of-living package” contained all the stimuli one would guess — food, music, old movies — and as drawn by François Dallegret, it looked like the ultimate hardware.

Physical theory

It was an extreme idea, but it became the fundamental thought behind hi-tech, Archigram and the Lloyd’s building. I was reminded of this concept, so close to the idea of “invisible architecture” put forward in the eighties, when invited to go to Cern, the European Organisation for Nuclear Research, to do a podcast with Brian Cox, one of the key British physicists at work there.

The pretext was the near-completion of the ultimate hi-tech mechanism, Atlas, by far the most powerful particle detector ever built. When it starts working in 2008, physicists hope to complete their picture of how the universe hangs together.

It is hoped that this large hadron collider will reveal the basic architecture of matter and the elusive Higgs particle that, like a keystone, holds it all together. This is the final stage in an ancient quest going back to 500BC, to Democritus’s postulation of the tiniest object in the universe as the “atomos”, that is, the “uncuttable element.” His conclusion was “that everything is made from atoms and the void”. This remains an uncanny insight, with the proviso that the uncuttable atom has been split into parts — protons and neutrons — and then further subdivided into quarks, electrons and a few other short-lived particles.

But the logic paid off, and today, by understanding these basic building blocks, we may have reached the end of a 2,500-year search. If these are indeed rock bottom, it will be the culmination of the longest and most heroic research project in the reductionist programme. And even if it is not, the theory known as the Standard Model of particle physics is one of the most successful ever constructed — tested to destruction in billions of carefully measured explosions.

The Standard Model, a description of basic nature formulated in 1967, is really a conceptual piece of architecture, built up through theory, mathematics and countless experiments. From a mathematical viewpoint, it is often described as beautiful because of the minimal and elegant way its parts hang together. It is based on internally consistent symmetries, and since it underpins everything else, is especially relevant to architects — after all, it explains the primary building blocks. Vitruvius wrote that the architect must “learn the fundamental principles of physics”, and that his art depended on “order and symmetry” among other things. But it may be the elegant logic of the Model that architects find most appealing.

By the late 1960s its predictive power had been demonstrated repeatedly, but researchers subsequently failed to find the most important piece of the elegant puzzle. Where was the Higgs particle, the one that gives everything mass?

It is named after an unusually modest scientist from Edinburgh, who showed its necessity. Physicists long to have particles named after them, but this self-effacing man referred to it as “the so-called Higgs”. How appropriate! The particle is as elusive as its namesake, and it is now the most sought-after unit of the universe. If it is not found by the atom smasher at Cern, the Standard Model will have to be rethought. Physicists say they won’t mind this refutation, even though the search has cost the public £25 billion over 40 years.

Each end of the huge Atlas cylinder sports a particle detector. Particles race through the central tube to crash at speeds near to that of light.
Credit: Cern/pa Archive and Cern
Each end of the huge Atlas cylinder sports a particle detector. Particles race through the central tube to crash at speeds near to that of light.

Deus ex machina

It may be the elegant logic of the Standard Model that architects find so appealing

Like that of the Standard Model, the physical architecture at the heart of Cern is also invisible, but because it is underground, not because it is conceptual. Atlas is a five-storey detection centre with 100 million silicon pixel detectors and many other measuring devices. I was lucky enough to see it in the rare state of being pulled apart so that a new section could be inserted, and it looked every bit as beautiful and complex as the cross-section of a rocket engine. This kind of beauty is what Le Corbusier described in Towards a New Architecture (1922) as “the engineer’s aesthetic”.

The machine or engineer’s aesthetic has been one staple of architecture ever since, and its problems are well known. Engineering may produce not just beautiful truths, but ugly compromise. But Atlas is the ultimate cross-section of the engineer’s aesthetic — truth is beauty this time, not a botch. If only one could see it from a distance! The problem is not just that it sits 100m underground, but also that it is viewed up close, from catwalks, and therefore obliquely.

An ideal city

We were lucky to see the ends of the huge cylinder, with their particle detectors, two fans of golden panels. With radial divisions like streets and avenues, they resemble an ideal city of the Renaissance. They focus on the centre, where the church would be, the place where particles race at each other near the speed of light, crash, and then release their hidden truths.

It is hard not to use religious metaphors when discussing the whole search for the Higgs, which is sometimes called the “God particle”. All this money spent over 80 years on colliders, each one grander and more expensive than the last, reminds one of the cathedral mania that afflicted Europe from 1150 to 1284, when building for the stars ended in tears at Beauvais with the collapse of the vaults.

It is true that there are many practical spinoffs for healthcare and society, but the heart of the search is spiritual— pure knowledge about the universe and how it is. In this sense there are amusing parallels with cathedral building and those attempts to decode the mind of God, to find out the arcane secrets of existence, to intrigue. It is no wonder that in the race for the Higgs some people suspect Fermilab in Chicago of supplying dud components, a huge magnet that ruptured a pipe, and no wonder that Dan Brown also got in on the act with his angels and demons, co-opting some anti-matter from Cern in a bogus plot to blow up the Vatican. The hard-to-see beauties of Atlas remind me of Ruskin’s “unvisible angels” at Rheims, those hidden sculptures that only God could perceive — or at least the adept on a ladder.

If you look and think hard about Atlas, if you study the cross-section and Google the animation, you can just about understand the inner and outer detectors, what the magnets are doing, how the different particles curve to release their meaning.

It takes a lot of work for the novitiate to reach the insight of the priesthood, and there are mind-boggling miracles to swallow along the way. At full-beam intensity, Atlas has to analyse one billion events per second and select 200 interesting results per second for later analysis. In one year this will lead to the equivalent of 15 million gigabytes of data, or a stack of bibles 7km high.

All right, it does not compare with Jesus transforming five loaves and two fishes into food for 5,000. Or does it? In a way these explosions are miracles of transformation, particles turning into energy or vice versa, matter disappearing into heat to re-emerge as information, basic stuff recreating situations that are very much like the universe was at the beginning of time. No wonder people fear Atlas might set off another Big Bang, and create a few mini-black holes.

But the priests tell us not to worry about being swallowed up, as every second the earth is hit by cosmic rays a billion times more powerful than the hoped-for baby black hole. Take this on faith — like much else at Cern, the world is paying a price to get it right.

In a way Atlas and the sleek, magnetic units that line the underground loop at Cern, all 27km of it, are versions of what Le Corbusier termed the “architecture of truth”, a phrase he applied to minimalist Cistercian buildings, where each stone was cut and dovetailed into its specific role. Again, it was more the polished pyramids than British hi-tech, but let that pass.

British obsession

What is not in doubt is that with this hard-to-see, five-storey detector a ne plus ultra of heavy metal architecture has been reached, way surpassing the best efforts of Richard Rogers and Morphosis. There will never be steel as thick as it is in the centre of Atlas, and never another explosion of such colourful hardware — at least in one place above ground.

All this money spent over 80 years on colliders reminds one of the cathedral mania that afflicted Europe from 1150 to 1284

In a way it is the culmination of a very British obsession, one that started its recent history with Brunel, and travelled through the Rolls-Royce engine, the Lloyd’s building, and Foster’s Hong Kong bank. Many British universities and physicists are involved with constructing and interpreting Atlas, which will come as no surprise for the architectural culture that produced James Stirling and Douglas Stephen’s sixties’ tome, British Buildings.

There, hi-tech details and the entire building are displayed in cutaway axonometrics for the adept to understand the real message. Elegant, thin-line drawings show how the building works and fits together; displaying the what and why of separate functions and different materials, they make a rhetoric of functional assemblage and use. The aesthetics of truth comes in several different flavours, like a quark, and the axon of Atlas explains beauties otherwise hidden to the eye. Again, they are Ruskin’s angels that only God sees and that we know.

Architects and the public will be frustrated by the invisibility below ground and the ugliness above. For an organisation that is so idealistic, so international and four years older than the EU, it is opaque in communicating its fundamental message — discovering the basic truths below nature, “zero nature”.

This failure is understandable and normal. Scientists want to get on with their jobs, unhindered by politics, aesthetics, planning boards and any consideration beyond the work at hand. When Cern had recently to accommodate an extra big magnet in Atlas, a three-storey hole was simply cut through the front facade of the surmounting block and the magnet bunged in. Cern above ground has all the qualities of backstage at a Hollywood studio, or a Heathrow airport roundabout.

There is one architectural expression, a three-quarter globe in wood called Le Palais de l’Equilibre that houses public exhibits, but except for this building, necessity rules. After 60 years of existence, perhaps a new approach will emerge?

The esoteric world of studying the fundamentals of nature by blowing it up is very unlikely and marvellous. The rest of nature refuses to give up its secrets this way, they have to be teased out with delicacy.

But at Cern it is particle acceleration, collision and then subtle detection that results in truth, many inferences aided by computer analysis.

It takes several months to utter the word “Eureka!” but when the tell-tale tracks are studied and the patterns recur, the certainty grows — we have got back to the beginning of time and captured a trace of the ultimate truth. I have always found these traces beautiful and fascinating, an object for a new aesthetic: of lines, curves and spirals, a matrix of filigree movement. They say the only way one can really understand the basics of nature — the atom or the cell — is to see them moving, not as a series of still frames as they are taught. Probably both frozen diagrams and animated videos are needed, the kind of thing one finds on YouTube.

But for architects and sculptors, who deal in frozen movement, there is a new language of expression lurking here waiting to be exploited, and it could make manifest the truths of “zero nature” on which the rest of it is built.

The path of the 27km-long underground collider tunnel (shown in red) on the Swiss border west of Geneva.
Credit: Cern/pa Archive and Cern
The path of the 27km-long underground collider tunnel (shown in red) on the Swiss border west of Geneva.

How will the atlas particle accelerator work?

If you’ve heard of Cern, chances are it’s because Tim Berners-Lee was working there when he and colleague Robert Cailliau invented the World Wide Web. But while the most famous invention to come out of the institution is a technological one, Cern’s day-to-day business is scientific discovery for its own sake.

To study subatomic particles, physicists make them collide with one another at high energy and watch what happens.

The particles travel in a vacuum chamber cooled to minus 270°C, where huge magnets pull them around in a circle and focus them into a beam. When the particles collide, detectors monitor the interaction — what new particles are created and how much energy is released — recreating the conditions scientists believe existed in the first millionths of seconds after the Big Bang. Eventually Cern hopes to detect the elusive Higgs boson, a particle which has never been observed.

The large hadron collider fills a 27km tunnel which runs underground across the France-Switzerland border near Geneva. Atlas, the first experiment to be carried out in it, is due to begin in May 2008.

The tunnel was previously used for Lep, the larger electron-positron collider, an earlier generation of particle accelerator.

Britain was one of the 12 founding members of Cern in 1954. There are now 20 European member states, and many other countries and organisations — including Unesco, the United States and Japan — have been given observer status.
The economics of building laboratories of this scale mean that more than half the world’s particle physicists are working on experiments which run at Cern.

BD reporter Marguerite Lazell did a three-month internship in the Cern press office in 1997 as part of her MSc.


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