How CERN Works

A CERN worker cruises past a painted representation of the LHC’s ATLAS experiment on Dec. 13, 2011, in Geneva, Switzerland.
A CERN worker cruises past a painted representation of the LHC’s ATLAS experiment on Dec. 13, 2011, in Geneva, Switzerland.
Harold Cunningham/Getty Images

If Albert Einstein were alive on July 4, 2012, I'd like to think that he would have grinned when researchers ecstatically announced that they had found what they believed was the Higgs boson.

More than 40 years before, British theoretical physicist Peter Higgs and his colleagues had proposed that this particular elementary particle and its associated field were the reasons why matter has mass. When scientists confirmed Higgs' theory in the 21st century, it opened a window as to how the universe works, which Einstein and many others have devoted their lives to studying.

The discovery represented a triumph of science. Yet, researchers made the find not by looking through a telescope, analyzing data collected from a spacecraft or even performing one of Einstein's famous thought experiments. They found Higgs through decades of painstaking research at colliders around the world, notably CERN in Geneva, Switzerland. CERN stands for the Conseil Européen pour la Recherche Nucléaire (or the European Center for Nuclear Research).

Their research was painstaking because the life of the Higgs boson is infinitesimally short. It breaks into smaller particles in much less time than it takes to blink. Scientists had to be on their toes to detect Higgs. Through trial and error, euphoria and despair, scientists at CERN spent $10 billion over the decades chasing the elusive particle [source: Overbye].

The discovery put CERN on the front page. Yet, most people still have no idea what the scientists at CERN actually do. We can help with that.

Inside CERN

CERN has been around since the 1950s. Recall that at the end of World War II, Europe was a mess and its scientific community a shambles. Scientists in the United States, which included many plucked from Europe, had taken the lead in physics. In 1949, French quantum physicist Louis de Broglie proposed that Europe try to recapture its scientific glory by creating a multinational atomic physics laboratory.

A few years later, CERN was born and built just outside Geneva. The 12 founding states included Belgium, Denmark, France, West Germany, Greece, Italy, the Netherlands, Norway, Sweden, Switzerland, the United Kingdom and Yugoslavia. As of January 2014, 21 countries, including Israel, Poland and Finland, are CERN members, and each one gets two spots on the CERN council, the decision-making body, but a single vote on such decisions. CERN's Director-General, Rolf Heuer in 2014, essentially functions as the leader.

The United States is not a member but an observer state, that is, one that can attend meetings and get info but not vote on CERN matters [source: CERN]. (Speaking of the U.S., it contributed $531 million for the construction of several LHC components.)

CERN's job was to find out how the universe worked. No big deal, right? Scientists decided the best way to accomplish this monumental task was to build giant machines that slammed subatomic particles into one another. The hope was that these so-called atom smashers would give researchers a glimpse back to the time just after the universe came into being. Accordingly, CERN started building its very first accelerator in 1957, the Synchrocyclotron, which crashed and smashed its way toward 33 years of service. CERN now operates several accelerators and one decelerator in a building complex that straddles the Swiss and French border. The cost of the experiments is spread over the member states [sources: Exploratorium, CERN].

By 2014, 2,400 full-time employees and 1,500 part-timers, were working at CERN, while more than 600 institutes and universities were allowed to use its facilities to start unraveling a variety of mysteries, such as antimatter, black holes, and the events that occurred a split second after the Big Bang. Moreover, 10,000 scientists from 113 countries — half of all the particle physicists on planet — stop by CERN for research each year. And it's not just scientists either. People work at a variety of jobs including engineers, experimental physicists and even accountants. Scientists from member states get first crack at a position, although senior scientists from other countries are always considered [sources: Exploratorium, CERN].

The Hadron (Collider) at the Heart

Do you want to push those buttons as badly as we do?
Do you want to push those buttons as badly as we do?
© Denis Balibouse/Reuters/Corbis

At the heart of CERN is the world's largest and most powerful particle accelerator, an atom smasher called the Large Hadron Collider (LHC). (It's so big that it has its own article.) The LHC is made of a 17-mile (27-kilometer) ring of superconducting magnets and a series of accelerators that shoots high-energy particles through the apparatus like a bullet through a gun. Located 328 feet (100 meters) below ground, the collider blasts a beam of protons in one direction, while another beam travels in the opposite direction.

Kaboom! Kablam! Splat!

Use any exclamation you want. At top speed, the particles smash into each one at 99.9999991 percent the speed of light [source: CERN]. Every time the protons smash into one another, it creates a complex spray of other particles. Many of those particles last for less than a second but leave a trail of subatomic bread crumbs that scientists can follow. To follow that trail, scientists rely on two highly complex detectors, which allow them to see the elementary building blocks of our universe.

One of those detectors is ATLAS. The machine, which is about 148 feet (45 meters) long and 82 feet (25 meters) high, helped find the Higgs boson. ATLAS is half as large as Notre Dame (the cathedral, not the university) and weighs as much as the Eiffel Tower (the one in Paris, not Las Vegas). CERN scientists use ATLAS and the other detectors (ALICE, CMS, LHCb, LHCf) to study stuff you read about only in sci-fi books, such as whether other dimensions exist; what type of unifying force might be in the universe; and if there's evidence of dark matter. Only two detectors, ATLAS and CMS, were devoted to solving the Higgs boson mystery. All experiments at the LHC are distinct and run by a worldwide collaborating team of scientists [sources: ATLAS, CERN].

Analyzing CERN Data: Now That's a Big Job

Smashing particles together at nearly the speed of light is one thing; interpreting the data from those collisions is another. Particles collide in the LHC nearly 600 million times a second [source: Sakai]. The information spewing out of those crashes can tell us volumes about the inner workings of the atom and the forces that hold the atom together, but we certainly can't record all of the information from the detectors. If CERN did, ATLAS, for example, could fill 100,000 CDs with data every second. Instead, ATLAS, like the other detectors, can record only a "smidgen" of info, roughly enough to put on 27 CDs per minute [source: ATLAS].

While that number is only a portion of the available information, it's still an overwhelming amount. The detectors transfer what they find to the CERN Data Center, where technicians and researchers use computers to digitally reconstruct each collision. During reconstruction, scientists put their theories of how particles behave to the test. They compare computer-simulated collisions to the actual collisions. A disparity between the two might signify new science, something that had gone unexplained [source: Sakai].

Each day, the data center processes one petabyte of information. It would take 223,000 DVDs to hold all the information in a petabyte [source: McKenna]. To make things more difficult, scientists pore through 30 petabytes each year, which makes new science incredibly difficult to find [sources: CERN, McKenna].

Given those staggering numbers, CERN's data hub can't crunch such numbers all by itself. Instead, scientists rely on the planet's largest computing network, the Worldwide LHC Computing Grid, an association of 170 computer centers in 40 countries. The grid is touted as the "most sophisticated data-taking and analysis system ever built for science." It runs more than 2 million jobs a day and can transfer 10 gigabytes of data from its servers every second. Without the grid, the Higgs boson might have gone undiscovered [source: WLCG].

As for Einstein, he'd be rocking in the grave if he knew what was happening at CERN — that is, if his friends hadn't spread his ashes on the Delaware River in 1955.

Author's Note: How CERN Works

I reference Einstein not because I understand even a grain of what he's taught the world, but because today's scientists pretty much try to build upon Einstein's work. One of the things Einstein spent a lot time studying was how atoms and light behaved. His theories ultimately led to the existence and discovery of the Higgs boson.

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  • ATLAS Experiment, CERN. "What is ATLAS?" (July 25, 2014)
  • European Center for Nuclear Research (CERN). "Birth of the Web." (July 24, 2014)
  • European Center for Nuclear Research (CERN). "Computing." (July 25, 2014)
  • European Center for Nuclear Research (CERN). "FAQ: LHC The Guide." (July 30, 2014)
  • European Center for Nuclear Research (CERN). "The History of CERN." (July 24, 2014)
  • European Center for Nuclear Research (CERN). "The Large Hadron Collider." (July 25, 2014)
  • Exploratorium. "The Heart of the Matter: Inside CERN, the world's largest particle accelerator." (July 25, 2014)
  • Holmes, Nigel. "What Is the Higgs?" The New York Times. (July 24, 2014) CERN-searched-for-physics-most-elusive particle.html?adxnnl=1&view=Game_of_Bumps&ref=higgsboson&adxnnlx=1385219691-CQT+Ibo61fcAqjfVSynO+A&_r=1&
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