Join the world’s coolest science lesson in Geneva

On the outskirts of Geneva, straddling the Swiss and French border, the processes that created our universe are being probed and prodded in the world’s largest laboratory. Over 17,000 of the world’s best minds work at the European Organization for Nuclear Research, more commonly known as CERN. And just as the scientists arrive for work each day at this two-square-mile science city, so too do curious visitors.

In many ways, CERN is a huge museum — and it’s surprisingly accessible. The lab complex welcomes around 400,000 visitors every year on tours and there’s plenty to see, despite some areas being off-limits. There are more than 600 buildings in total — including a hospital and a hotel for visiting scientists — and many of the ones open to the public have hands-on exhibits.

All that’s required to visit on a regular tour is advance registration. However, it’s also possible to go with a specialist tour operator and explore the facility with a bona fide particle physicist. Want to play scientist for a day? Do it at CERN, where it’s possible to peer behind the curtain of the world’s most pioneering work on particle physics.

What’s CERN’s story?

CERN was established in 1954 after a handful of the world’s top scientists made an impassioned plea for the creation of a world-class physics research facility in Europe. These scientists were motivated by several factors, including a wish to stop the post-Second World War brain drain — when many of Europe’s brightest minds headed to America — as well as the desire to create an institution that could double as a force for unity in post-war Europe.

The work done by scientists at CERN is so monumentally important that it’s said Tim Berners-Lee invented the World Wide Web here in 1989 out of a motivation to share the lab’s data. A plaque outside one office visitors pass by marks the spot — but CERN has many other claims to fame. Not least, that three decades later it was here that the Higgs boson — or ‘god particle’ — was discovered.

The centrepiece of the campus is the Large Hadron Collider (LHC), a ring 17 miles in circumference that sits up to 175 metres below ground, where subatomic particles are sped up and smashed together. It’s off-limits to visitors, but that doesn’t quell the thrill of being on the site of the world’s largest and most complex machine. Its purpose? To try to reproduce conditions that occurred a tenth of a billionth of a second after the Big Bang.

Later this century, CERN will get a new toy; a 56-mile-circumference Future Circular Collider (the successor to the Large Hadron Collider — more sophisticated, more complex) is due to be built by around 2040. This and other aspects of the lab’s evolution are explained to visitors in an exhibition hall that’s open to all. It contains CERN’s first particle accelerator and — alongside displays of enormous spanners once used by workers — black-and-white photos depict the supersized parts, manufactured in various European countries, being dragged along country lanes on flatbed trucks in the 1950s, when construction of CERN began.

Where do you start?

Things get interesting at CERN before visitors even begin their tour. Grassy areas around the campus are dotted with physics-themed sculptures and retired pieces of equipment, including a huge replica of a dipole magnet, used to accelerate particles. Lego models in the lobbies of the most accessible buildings depict that building’s layout, and its location within CERN.

Regular tours focus on a number of areas designed with education in mind. A highlight is the Science Gateway, which incorporates hands-on labs, interactive exhibits and an auditorium, all in a space designed by Italian architect Renzo Piano — famed for building Paris’s Pompidou Centre. The most popular exhibit here allows visitors to learn about the invisible properties of heat with infrared cameras.

Going behind the scenes

But the real fun is what visitors get to see on the behind-the-scenes tours led by a professor of particle physics, who will walk you through the pioneering work done on site. While the LHC is off-limits, the next best thing is the ATLAS HQ. It’s the hub for the 5,000 scientists who study particles created by the LHC’s 7,000-tonne ATLAS particle detector — in a nutshell, a camera that detects and records the movements of the planet’s tiniest particles.

Visitors can peer through windows at ATLAS scientists working away behind banks of computers. Some have rubber ducks perched on top of them, which, your guide will tell you, is because the scientists are encouraged to solve problems by talking to their ducks.

Scientist-led tours also explore the Antimatter Factory, where CERN scientists are learning how to harness the potential of antimatter. To visit this area, guests are asked to wear small radiation detectors around their necks to comply with health and safety protocols — though your guide will explain that you’re actually exposed to more radiation during a flight than while touring CERN. When exiting the building, guides read out the digital display as proof of the infinitesimal amounts of exposure during a visit.

At the factory’s heart is the Antiproton Decelerator: a 182-metre-circumference ring of magnets and electric fields that’s designed to stabilise, then slow, notoriously unruly antiproton particles to produce antimatter — the opposite to matter, the subatomic particles that make up our universe. Visitors view the invention on raised gantries, allowing a view down into the decelerator’s tangle of wires and pipework, accessible only to employees who enter via an airlock in which retinas and retinal blood vessels are scanned.

A light-hearted antidote to time spent trying to wrap your head around antimatter is the tour of the offices used by research scientists from all over the world. The building in which they’re housed was constructed around the 1960s, and it’s quite a contrast to some other parts of the complex. The wood-panelled corridors feel vaguely like student halls with their slight mustiness, tatty walls stickered with flyers for social gatherings, and various flags hanging in the windows.

And just like a student — after hours spent mulling the most complex principles of the universe — visitors can take a coffee break at CERN’s Big Bang Café, sit down for lunch alongside research scientists, or kick back with a beer in the on-site canteen. The latter is a fitting tipple for physicists: your guide might explain that the late legendary physicist Donald A Glaser — who received the 1960 Nobel Prize in Physics and whose work became a lynchpin of CERN’s particle physics research in the 1960s and 70s — was prompted to conduct his research into fluid dynamics after studying the bubbles in a glass of beer.