Extreme experiments: The laboratories that are pushing science to its limits

By Kath Nightingale

Published: Thursday, 07 July 2022 at 12:00 am

Scientists go to extraordinary lengths to expand our understanding of radical phenomena in the most extreme labs on Earth.

The deepest (and cleanest)

SNOLAB, Ontario, Canada

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© Science Photo Library

Even a Bond villain might consider SNOLAB too remote for an underground lair. Earth’s deepest and cleanest lab is two kilometres underground, part of a nickel and copper mine in Ontario, Canada.

The deep layer of rock between the 5,000m2 lab and the Earth’s surface shields it from the cosmic radiation that would otherwise interfere with its sensitive experiments. The lab searches for solar neutrinos (extremely small subatomic particles produced by the Sun) and dark matter, the estimated 27 per cent of matter in the Universe which remains a mystery to us.

But situating a sparkling clean lab in a mine comes with its downsides. As well as a 1.5km walk from the lift to the lab, researchers and support staff must undergo a lengthy cleaning process involving showers, hosed-down boots and lab-laundered clothes to make sure that no mine dirt or particles make it into the facility.

The lab also contains the world’s deepest underground flushing toilet.

The loudest

NASA Reverberant Acoustic Test Facility, Ohio, USA

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© NASA/GRC

Launching rockets is a noisy business, and scientists need to make sure that payloads can withstand the extremely loud sounds involved in take-off and ascent into space.

NASA’s Reverberant Acoustic Test Facility carries out part of a suite of testing that complex and sensitive hardware must undergo before being deemed clear for take-off, by submitting them to noises of up to an eardrum-bursting 163 decibels.

In order to make the necessary sounds, NASA’s Reverberant Acoustic Test Facility uses 36 huge horns, which are powered by the change in pressure as liquid nitrogen turns into gas. Each of the horns – which can produce volumes equal to thousands of home speakers – emit different frequency ranges, so the noise can be tailored to suit the necessary requirements.

The brightest

Extreme Light Laboratory, Nebraska, USA

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© University of Nebraska-Lincoln

Another lab that needs to keep an eye on its cleanliness is responsible for producing the brightest light ever known on Earth. The Extreme Light Laboratory at the University of Nebraska-Lincoln broke records in 2017 by generating a light a billion times brighter than the surface of the Sun.

The light is produced by focusing a laser beam extremely intensely and then using it to bombard a single electron with short, powerful laser pulses, each only a fraction of a second but with more power than a trillion light bulbs.

You might think such an extreme light would require a huge machine, but in fact the equipment is small enough to fit into an ordinary laboratory. Researchers wear safety glasses, hair nets and other protective clothing to keep the equipment safe from dust.

The highest

Pyramid Lab, Khumbu Valley, Nepal

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© Getty Images

Nestled in Nepal’s Khumbu Valley, just over 5,000m above sea level in the Sagarmatha National Park, is the Pyramid Lab. Located 7.2km from Everest Base Camp, the 8.4m-high glass, aluminium and steel pyramid generates its own power from solar panels.

The Pyramid Lab project was the result of a scientific race between two research teams – one American and one Italian – to establish whether Mount K2 in Pakistan was in fact taller than Everest. From the Italian collaboration came the idea of a research station to house high-altitude research and replace the tents and unreliable generators upon which researchers had previously depended.

The laboratory was opened in 1990 and has been used by hundreds of scientists to conduct high-altitude environmental, geological and health research. Sadly, funding for the lab was frozen in 2015, closing it to researchers and endangering the data from its varied environmental monitoring instruments.

The coldest

Fallturm, Bremen, Germany

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© ZARM/University of Bremen

Rising 146m above the University of Bremen, the Bremen drop tower, or Fallturm, looks a little like Rapunzel’s tower. But its appearance hides some innovative machinery, used by scientists to perform near-zero gravity experiments by dropping them inside the tower to reach weightlessness.

Some experiments focus on how equipment destined for space will perform, others use the lack of gravity to explore phenomena that are not detectable in normal gravity. One such project produces ‘Bose-Einstein condensates’, low-density clouds of gas that are cooled to near absolute zero. At such low temperatures, all the atoms coalesce and begin to act like a single atom, allowing researchers to study quantum mechanics.

In 2021, researchers producing these condensates achieved a temperature 38 trillionths of a degree warmer than absolute zero, for a total of two seconds. Previously, the coldest temperature identified anywhere in the Universe was the Boomerang Nebula, located 5,000 light-years from Earth. At -272°C, it is 1°C warmer than absolute zero.

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© ZARM/University of Bremen

The quietest

Orfield labs, Minneapolis, USA

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© Alamy

It’s not unusual to long for peace and quiet, but some places can be too quiet. That’s said to be the case for the Anechoic (‘no echo’) Chamber at Orfield Labs in Minneapolis, once dubbed ‘the quietest place on Earth’.

Sealed off from the rest of the world by layers of steel and concrete, and lined with thick fibreglass shapes, the walls of the chamber absorb 99.9 per cent of sound. The chamber measures -9 decibels (around 0 decibels is the quietest sound a human can hear). It’s a great place for manufacturers to test their products – how their loudspeaker is performing, or whether a new gadget makes too much noise, for example – but it’s less great to hang out in.

We’re used to sounds reflecting off surfaces, so anyone in the chamber quickly becomes uncomfortable due to the eerie sound quality. In the absence of any other sounds, they begin to hear the functions of their own body – such as the blood pulsing in their brain – and can become disorientated without the usual auditory signals that root us in place.

The largest

CERN, France/Switzerland

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© CERN

The world’s biggest laboratory is probably also the most famous: CERN. Housing the Large Hadron Collider (LHC), which was used to find the theorised Higgs boson in 2012 (a detection which bagged its discoverers a Nobel Prize), CERN’s home in the countryside outside Geneva covers 550 hectares (1,360 acres) across Switzerland and France and is host to more than 12,000 scientists.

The LHC is also the biggest machine in the world. Located almost 100 metres below ground, its 27km ring of superconducting magnets works with a number of other structures to accelerate subatomic particles, colliding them into each other and monitoring the results in an attempt to recreate conditions of the Big Bang, and unlock the secrets of how the Universe was formed.

After a three-year break, during which time it was revamped to become more powerful and include more experiments, the LHC beam has started up again, and scientists are excited to see what will be discovered next.

The hottest

Relativistic Heavy Ion Collider, New York, USA

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© Brookhaven National Laboratory

Sticking with colliders, researchers using the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory in New York State have achieved the hottest temperature recorded on Earth.

The RHIC specialises in colliding larger, heavier particles such as gold ions (gold atoms which have lost electrons). By smashing gold ions into each other in the RHIC’s 3.8km collider ring at near light speed, a temperature of four trillion degrees Celsius – about 250,000 times hotter than the middle of the Sun – was produced for a fraction of a second.

The collision ‘melts’ the protons and neutrons in the gold ions, releasing their component quarks and gluons and forming a quark-gluon plasma. But it’s not just about breaking records. It is thought that this plasma filled the Universe shortly after the Big Bang, so studying it could tell us more about the Universe’s first seconds.

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