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1 Large Hadron Collider

WHAT IS IT? The biggest and most powerful particle accelerator in the world.

SIZE: The ring-shaped tunnel is 27 kilometres long, so it would take more than 4 hours to stroll the whole way around. You could squeeze Bermuda, Monaco and four Vatican Cities into the area bounded by the LHC.

LOCATION: Buried over 80 metres underground, straddling the border between France and Switzerland at the CERN particle physics laboratory near Geneva.

WHAT’S IT FOR? Probing the fundamental nature of matter by recreating the conditions that existed shortly after the big bang, and looking for the hypothesised Higgs particle. The LHC will accelerate protons to within a whisker of the speed of light and collide them head on at an energy of up to 14,000 billion electronvolts. That’s seven times as much as the energies achieved in today’s most powerful accelerator, the Tevatron at the Fermi National Laboratory in Illinois.

WHY SO BIG? Actually, you should ask why LHC is so small. The answer is to keep the cost down. Rather than dig an expensive tunnel to house the new collider, physicists decided to rip out LEP, the electron and positron accelerator previously housed at CERN, and replace it with the 50,000 tonnes of equipment needed for LHC.

Powerful electric fields ramp up the energy of two proton beams as they travel in opposite directions around the ring. With each lap, the particles gain more energy.

Keeping such high-energy beams on track requires enormous magnetic fields, which are generated by superconducting electromagnets chilled to less than two degrees above absolute zero.

WHO’S WORKING ON IT? 600 scientists and engineers from around 30 countries.

STATUS: Over a third of the magnets have arrived at CERN. Expect the champagne corks to pop when the first protons collide in summer 2007.

COST: 3.2 billion Swiss francs, about $2.5 billion

MONSTER OFFSPRING: Even though the LHC is still being built, that hasn’t stopped physicists thinking about the next big particle accelerator. Top of their wish list is a 30-kilometre-long machine that will smash electrons and positrons together at energies of at least 500 billion electronvolts.

WHAT THE BOOKIES SAY: For a short while, Britain’s largest off-track bookmaker, Ladbrokes, is taking bets on the LHC and other experiments. Bookies’ odds are not straightforward probabilities – instead they take into account how much the company can afford to lose if it has to pay out. Ladbrokes spokesman Warren Lush puts the odds of finding the Higgs by 2010 at 6/1.

2 Earth Simulator

WHAT IS IT? The world’s fastest supercomputer.

SIZE: Earth Simulator occupies the same area as four tennis courts and uses more than 5000 computer processors connected by 2800 kilometres of cable.

LOCATION: Yokohama Institute for Earth Sciences in Japan.

WHAT’S IT FOR? Simulating complex physical systems. Earth Simulator’s main job is to make the most detailed models of Earth’s climate in the world. It calculates the interplay between the oceans and atmosphere, constantly running a massive digital mock-up of our planet’s weather and climate. Earth Simulator can even fast-forward the action to produce climate-change predictions 50 years into the future. What’s more, the supercomputer models earthquakes, the dynamics of the Earth’s core and the geomagnetic field.

Beyond earth science, physicists use the machine to predict the properties of new materials, understand the interactions between subatomic particles and model the flow of fuel in rocket engines.

WHY SO BIG? It takes a lot of computer power to process the signals from thousands of ground and ocean-based monitoring stations and weather satellites worldwide. Earth Simulator’s most recent simulation of the atmosphere was calculated using pixels measuring just 10 square kilometres.

WHO’S WORKING ON IT? 700 researchers from six countries.

STATUS: Earth Simulator was switched on in April 2002 and soon clocked 35,600 billion calculations per second, making it five times as fast as the previous record holder. Two years on, it has twice topped world supercomputer rankings and still far outruns its nearest rival, the Thunder supercomputer at Lawrence Livermore National Laboratory in California.

COST: About $430 million.

MONSTER OFFSPRING: Oak Ridge National Laboratory in Tennessee is planning to build a supercomputer capable of 50,000 billion calculations per second by 2007.

3 Cassini-Huygens Probe

WHAT IS IT? The largest planetary spacecraft in operation.

SIZE: Cassini is 6.7 metres high and 4 metres across. It weighs 5.7 tonnes including fuel, about the same weight as an adult male African elephant.

LOCATION: In orbit around Saturn.

WHAT’S IT FOR? Unlocking Saturn’s mysteries. Cassini-Huygens will spend four years orbiting the ringed planet. During that time, the orbiter will study Saturn’s atmosphere and magnetic field, as well as its famous rings and icy moons.

On Christmas Day, Cassini will release the wok-shaped Huygens probe on a 20-day journey towards Titan, Saturn’s largest moon. Titan’s surface is hidden by thick clouds, so astronomers still don’t know for sure if Huygens will crash-land on ice or splash down in an ocean of hydrocarbon oil. But they do know Titan’s atmosphere, rich in nitrogen and methane, has a similar composition to Earth’s atmosphere before life evolved 4 billion years ago.

WHY SO BIG? Cassini carries 18 scientific instruments designed to image, map and analyse Saturn, as well as the 320-kilogram Huygens probe. Dripping with instruments, Cassini qualifies as the most well-equipped planetary spacecraft ever flown. But more than 50 per cent of its launch weight was the fuel it needed to reach Saturn on a 3.5 billion-kilometre journey via Venus (twice), Earth and Jupiter. Launched in 1997, Cassini was the last in a line of mammoth and extremely well-funded NASA spacecraft.

WHO’s WORKING ON IT? 260 planetary scientists from 17 countries.

STATUS: Cassini arrived at Saturn on 1 July and Huygens is scheduled to reach the surface of Titan in January 2005.

COST: $3.27 billion.

MONSTER OFFSPRING: NASA is hoping to launch JIMO, a mission to explore Jupiter’s icy moons Europa, Callisto and Ganymede, as early as 2012. JIMO could turn out to be the biggest spacecraft NASA has ever contemplated, weighing up to 20 tonnes.

WHAT THE BOOKIES SAY: Ladbrokes offers odds of 10,000/1 that intelligent life will be found on Titan by 2010.

4 Joint European Torus

WHAT IS IT: The world’s largest fusion reactor.

SIZE: JET’s doughnut-shaped reactor is embedded in a vessel 15 metres across and about 20 metres high.

LOCATION: Culham Science Centre in Oxfordshire, UK.

WHAT’S IT FOR? Mimicking the fusion process that powers the sun. The idea behind JET is simple enough: heat a mix of hydrogen isotopes to temperatures above 100 million degrees to make the nuclei fuse, producing helium, neutrons and enormous amounts of energy.

Heating the fuel enough to trigger fusion – and keeping it hot – is fiendishly difficult. The JET team uses just a tenth of a gram of cold hydrogen fuel, which it squirts into the reactor torus and then heats using a combination of radio waves, electric currents, and blasts from a beam of particles. The hydrogen atoms soon shake off their electrons, creating a hot plasma of ions and electrons that gets hot enough for nuclei to fuse.

JET exploits the fact that charged particles are deflected by magnetic fields. Strong spiral-shaped magnetic fields prevent the plasma from banging into the reactor walls where it would cool, snuffing out fusion.

WHY SO BIG: Big machines are better at retaining heat. Insulating the plasma from the cooler reactor walls is vital for sustaining fusion. It takes longer for heat to escape from a big machine than from a smaller one.

WHO’S WORKING ON IT? 600 researchers from 20 countries.

STATUS: The reactor holds the world record for power achieved from fusion. But 13 years after first demonstrating fusion, JET has yet to reach the break-even point where the power extracted equals the power needed to heat the plasma.

COST: To rebuild JET today would cost €1 billion, about $1.2 billion.

MONSTER OFFSPRING: International fusion researchers are hoping to build a reactor called ITER that will be almost six times the volume of JET. If successful, ITER will be the world’s first fusion reactor, churning out 10 times as much power as it guzzles.

WHAT THE BOOKIES SAY: Ladbrokes calculates the odds of a fusion power station being built by 2010 at 100/1.

5 National ignition facility

WHAT IS IT? The world’s biggest laser.

SIZE: At 215 metres long and 120 metres wide, NIF is about the same size as the Colosseum in Rome.

LOCATION: Lawrence Livermore National Laboratory, Livermore, California

WHAT’S IT FOR? Creating similar conditions to those inside the sun and other stars. The sun’s core is so hot and under such immense pressure that hydrogen nuclei fuse to produce helium, releasing energy. NIF researchers hope their laser can pull off the same trick with heavy hydrogen on Earth. Lasers have been used to trigger fusion before, but NIF aims to be the first facility to beat the break-even point at which lasers create more power from fusion than they consume.

To do this, NIF will focus 192 laser beams on a target the size of a peanut containing heavy hydrogen fuel. Each laser fires pulses of ultraviolet light lasting about 3 billionths of a second and containing 1.8 million joules of energy – that’s 500 times more power than the output of all the power stations in the US. When the pulses smash into the target chamber, they will produce blasts of X-rays that will converge on a plastic capsule filled with heavy hydrogen fuel at the heart of the chamber. The NIF team predicts that the X-rays will heat the fuel to 100 million degrees and squeeze it hard enough for the heavy hydrogen nuclei to fuse. The energy released should be more than 15 times what went in.

But NIF is expected to do more than this. Its lasers are also capable of recreating the crushing pressures, searing temperatures and immense magnetic fields found in neutron stars, planetary cores, supernovae and nuclear weapons. California could be the place to which physicists will turn to test their theories of the most extreme places in the cosmos.

WHY SO BIG? Because it takes intense heat and pressure to keep fusion going. At NIF, researchers turn a beam about as powerful as a simple laser pointer into 192 separate beams with a combined energy 3 million billion times greater. The gain comes from shuttling the laser backwards and forwards between mirrors and passing it through 3000 slabs of phosphate glass, in which neodymium atoms amplify the beams.

WHO’S WORKING ON IT? 850 scientists and engineers at Livermore. About another 100 physicists are planning experiments there.

STATUS: Beaming. Four out of the 192 lasers have been working for over 18 months and have already fired the most energetic laser shots in the world. Construction at NIF has been delayed many times since the project began in 1994, but the latest aim is to achieve fusion in 2010 and eventually reach the break-even point.

COST: $3.5 billion to build and commission.

MONSTER OFFSPRING: The trouble with NIF is that its lasers can fire only once every few hours. But a better version called the Mercury Laser is already on the drawing board, though it won’t necessarily be bigger than NIF. Mercury’s goal is to shoot 10 pulses every second.

WHAT THE BOOKIES SAY: Ladbrokes reckons the odds of a fusion power station being built by 2010 are 100/1.

6 LIGO

WHAT IS IT? The longest gravitational wave detector.

SIZE: Each of LIGO’s L-shaped detectors has arms 4 kilometres long.

LOCATION: LIGO comprises two detectors, one near Livingston in Louisiana, the other 3000 kilometres away in Hanford, Washington.

WHAT’S IT FOR? Spotting gravitational waves as they pass through Earth. Einstein’s general theory of relativity predicts that colliding black holes or imploding supermassive stars will send shudders through the fabric of space-time, but no one has observed these gravitational waves directly. LIGO scientists hope to change that and shed light on the violent processes that shaped the universe.

Each LIGO detector is searching for minuscule displacements in space-time caused by the passage of a gravitational wave. To do this, the LIGO team bounces laser beams between mirrors suspended at the ends and intersection of an L-shaped vacuum tube. The light beams meet where the two 4-kilometre arms of the detector join. Here they interfere to produce bands of light and dark stripes that should shift if the length of the arms is altered by a passing gravitational wave. As the wave sweeps past, it should distort the surrounding space causing one arm of the L to stretch while shrinking the other.

WHY SO BIG? Because ripples in space-time are so weak. Gravitational waves stretch and squeeze space-time by just 1 part in 10,000 billion billion, so LIGO’s arms have to be very long to have any hope of detecting their effect. Even with a detector 4 kilometres long, the LIGO team is looking for changes in the detector of less than 10^-18 metres. That’s equivalent to measuring the width of an atom in the distance between Earth and Jupiter.

By having two detectors 3000 kilometres apart, the LIGO team hopes to weed out any false alarms. Both LIGO detectors would simultaneously experience the same distortion of space-time caused by a passing gravitational wave, while Earth tremors, the rumble of passing trains and aircraft, and even thunderstorms, should affect only one detector at a time.

WHO’S WORKING ON IT? At least 400 scientists from 7 countries.

STATUS: Pulling through. LIGO started searching for gravitational waves in 2002 and hasn’t found any so far.

COST: $292 million to build, excluding running costs.

MONSTER OFFSPRING: LIGO is a mere pipsqueak compared with the next ambitious project. Physicists are hoping to put a vast gravitational-wave detector in space, where the length of the arms can be much, much longer and the equipment is free from ground vibrations. If all goes according to plan, NASA and the European Space Agency will launch the LISA gravitational wave detector in 2012. LISA will bounce laser beams between three spacecraft flying 5 million kilometres apart in a triangular formation. Because its arms are so much longer than LIGO’s, LISA will be able to spot many more sources of gravitational waves, and perhaps even primordial ripples wrenched into existence moments after the big bang.

WHAT THE BOOKIES SAY: Ladbrokes is offering 500/1 on LIGO detecting gravitational waves by 2010.

7 Pierre auger observatory

WHAT IS IT? The world’s biggest cosmic ray detector.

SIZE: Auger’s detectors cover 3000 square kilometres. That’s about three times the area of Hong Kong, slightly bigger than the Australian Capital Territory around Canberra and roughly the size of Rhode Island.

LOCATION: Mendoza, Argentina.

WHAT’S IT FOR? Solving the mystery of where cosmic rays come from. Earth is continually bombarded by high-energy particles from outer space, but no one is certain where these cosmic rays come from, or what winds them up to energies of 10²⁰ electronvolts, the same energy as a tennis ball moving at almost 85 kilometres an hour. It’s also 10 million times greater than what is possible with the most powerful man-made accelerator.

To find out, Auger studies the showers of particles produced when cosmic rays hit molecules in the upper atmosphere. Each collision can be violent enough to shatter a molecule into myriad fragments, each of which go on to hit other molecules, starting a huge cascade that spreads out over a large area and falls to Earth.

Auger is looking for two telltale signs. On clear, dark nights, 24 large telescopes pick up the faint blue glow given out as cosmic rays hit nitrogen molecules in the atmosphere. In addition, Auger has 1600 detector tanks dotted across the pampas, each filled with 12 tonnes of water. These pick up the twinkles of light produced when charged particles from the showers zip through the detectors faster than the speed of light in water. By combining information from many detectors, the Auger team can work out the direction of the original cosmic ray, and thereby pinpoint where it came from.

Researchers also hope to find out whether rays with energies above 10²⁰ electronvolts can reach Earth from distant galaxies. Einstein’s theory of special relativity says they can’t, because they should lose too much steam on their way by interacting with the microwave radiation left over from the big bang. Yet some experiments have reported seeing cosmic rays above the 10²⁰ electronvolt limit, and there is no obvious source for them in our galaxy. The reports are extremely few and far between, but if Auger confirms that such particles are coming from far across the universe, it could mean rethinking Einstein’s special theory of relativity, or it might be evidence for mysterious super-heavy particles of dark matter created shortly after the big bang.

WHY SO BIG? Because of the size and scarcity of high-energy cosmic showers. A 10²⁰-electronvolt cosmic ray should produce an avalanche of up to 100 billion particles spread over an area of 10 to 20 square kilometres. But such ultra-high-energy cosmic rays will be rare. With a detector measuring 1 square kilometre, for example, researchers would expect to catch just one per century. But by covering a much larger area, Auger should bag 30 ultra-high-energy particles every year.

WHO’S WORKING ON IT? About 350 physicists and engineers from 15 countries.

STATUS: Already catching some rays. A quarter of Auger’s 1600 detectors have been up and running since January, with the rest due to be completed by the start of 2006.

The Auger team has even seen a few ultra-high-energy cosmic rays, though researchers are keeping tight-lipped about the details until they are certain they understand how well their detectors measure energy.

COST: $47 million, down $5 million on the original price tag.

MONSTER OFFSPRING: Researchers hope to build an identical observatory in Utah or Colorado so they can study cosmic rays coming from galaxies visible from the northern hemisphere too.

WHAT THE BOOKIES SAY: Ladbrokes calculates the odds of physicists understanding the origin of cosmic rays by 2010 at 4/1.

8 AMANDA

WHAT IS IT? The world’s largest neutrino telescope

SIZE: AMANDA is made of more than 700 sensors arranged in a cylinder about 1 kilometre tall and 200 metres across.

LOCATION: 1400 metres under the ice near the Amundsen-Scott station at the South Pole.

WHAT’S IT FOR? Mapping the neutrino sky. Neutrinos stream out from the most violent events and objects in the universe, such as gamma-rays bursters and active galaxies with supermassive black holes at their centres. Their feeble interaction with matter makes them ideal astronomical messengers. Unlike light or charged particles, they travel across the cosmos without being absorbed by dust or deflected by magnetic fields, giving an unhindered view of objects that might otherwise be hidden.

A tiny fraction of neutrinos crash into oxygen nuclei in the Antarctic ice, sending atomic wreckage flying. Most of this debris is absorbed, but some particles carry on for hundreds of kilometres, giving out a glow that travels through the clear Antarctic ice to AMANDA’s sensors, which hang suspended on strings from the ice cap.

Because the AMANDA team is looking at the neutrino sky for the first time, there is a chance the researchers might spot something completely new to astronomy.

WHY SO BIG? Neutrino interactions are few and far between. Only 1 in a million neutrinos passing through AMANDA produces a signal. But the huge detection volume massively increases the odds of spotting neutrinos.

WHO’S WORKING ON IT? About 120 physicists from six countries

STATUS: Catching neutrinos since 2000. So far the team haven’t seen any evidence for neutrino sources in deep space.

COST: $31 million to design and build the detectors, excluding the cost of transporting them to the South Pole.

MONSTER OFFSPRING: Researchers have started building a bigger version of AMANDA at the South Pole. Known as IceCube, the detector will comprise 5000 sensors buried in a cubic kilometre of ice and should be complete in 2009. Before then, NASA will fly a balloon for 30 days over the South Pole equipped with a neutrino detector called ANITA. The detector will monitor 1 million cubic kilometres of ice, looking for telltale pulses of radio waves given off by neutrinos streaking through.

9 ATLAS

WHAT IS IT? The biggest particle physics detector ever built.

SIZE: ATLAS is 46 metres long, 25 metres high and weighs 7000 tonnes. That makes it 1.5 times as long as an adult blue whale, the longest creature ever to live on Earth.

LOCATION: Surrounding a segment of the giant underground ring-shaped LHC experiment (see page 27).

WHAT’S IT FOR? Probing the matter from which we’re made by creating the most energetic particle collisions ever seen on Earth.

ATLAS is built from many chambers surrounding the collision point of two beams of particles. Particles produced in the collision are logged as they leave a trail or dump their energy in one of the chambers. By piecing together their energy and momentum, researchers reconstruct the immediate aftermath of proton collisions, and deduce what particles were fleetingly created.

One aim of ATLAS is to look for the Higgs, the final missing piece of our standard picture of matter. Seeing super-heavy particles could be the first evidence for supersymmetry, a theory in which all the forces of nature are united. And because ATLAS will study the most energetic collisions ever seen, there is a chance it could discover something completely unexpected and surprising about matter.

WHY SO BIG? High-energy particles pack a huge punch. ATLAS needs to be able to capture and sort through the billion proton collisions that will happen every second at the LHC. And that’s no mean feat: each collision will send hundreds of particles flying into the detector.

WHO’S WORKING ON IT? More than 1700 physicists from 34 countries.

STATUS: Going underground. The vast support structure is already in place in the ATLAS cavern. Above ground, detector components are being assembled all round the world and will be shipped to CERN by the end of 2006. ATLAS should measure its first proton-proton collisions in summer 2007.

COST: Excluding running costs, 550 million Swiss francs, or about $430 million.

MONSTER OFFSPRING: Doubtful. Though particle physicists are planning a future particle accelerator, it will smash lower-energy particles and so the detector is unlikely to be as large as ATLAS.

WHAT THE BOOKIES SAY: Ladbrokes puts the chances of finding the Higgs by 2010 at 6/1.