x Abu Dhabi, UAETuesday 25 July 2017

On course for a collision with the beginning of time

The Large Hadron Collider promises to solve some of the greatest mysteries in physics. Scientists hope the structure's ultra-high energy impacts will help explain the Big Bang, dark matter and the elusive Higgs boson.

Spectators look at the Atlas detector designed to measure the broadest possible range of particles within the Large Hadron Collider at the Centre Europeen de Recherche Nucleaire (Cern) near Geneva, Switzerland.
Spectators look at the Atlas detector designed to measure the broadest possible range of particles within the Large Hadron Collider at the Centre Europeen de Recherche Nucleaire (Cern) near Geneva, Switzerland.

The largest scientific instrument ever created will soon be switched on. Designed to pummel subatomic particles into each other at speeds a whisker from the speed of light, the Large Hadron Collider (LHC) is intended to replicate the extreme conditions that existed a few trillionths of a second after the Big Bang. Scientists hope the US$8 billion (Dh29.36bn) collider will unlock the deepest secrets of the universe if, that is, the experiments pencilled in to begin in August proceed without a hitch.

Experiments involving high-powered particle collisions or nuclear energy have always sparked talk of doomsday scenarios. In the early days of nuclear physics, Dr Enrico Fermi offered wagers on whether the first experiments with atomic weapons would destroy the universe. This experiment is no different. A sceptical minority has warned that the primordial extremes generated in the collider could create a tiny black hole that would feed its voracious appetite by sucking up everything within gravitational pull - including us, the Earth, and all of creation as we know it.

Assuming the disaster-scenario is as groundless as the Millennium Bug, the particles will barrel their way around the collider's 27-kilometre circumference deep in the ground at the Franco-Swiss border near Geneva. Coaxed by the world's most powerful magnets, "the protons will go around the circuit around 11,000 times per second", said Dr Mohammad Yousif, assistant professor of physics at the University of Bahrain, and an expert in high-energy physics.

No less than 10,000 of the brightest minds in particle physics will spend years sifting through the mountain of data from the LHC, which is based at the European Centre for Nuclear Research (Cern). "We are returning back to the Big Bang, at that point everything was unified and fundamental. We are going to change theories. It will be a 'new physics'," Dr Yousif said. It's easy to understand the how scientists will make new discoveries from the extreme conditions. To make the magnets work more efficiently, the near-perfect vacuum that exists inside the chamber will be cooled with liquid nitrogen to about minus 271C, which is only two degrees higher than absolute zero, the temperature where molecular motion ceases.

Beams containing billions of subatomic particles such as protons will be launched around the ring in opposite directions. Each beam will contain the same amount of energy as a car travelling at 1600 kph. When the beams cross, only a tiny percentage of the particles will collide, but will generate temperatures more than 100,000 times hotter than the centre of the Sun. These ultra-high energy collisions will smash the particles into their constituent parts, and building-sized detectors will scan the debris to see what emerges.

The particles produced by the collisions could be used to solve some of physics' biggest riddles, including the nature of dark matter - the mysterious material that cosmologists suspect makes up more than 95 per cent of the mass in the universe. Researchers will also look into the existence of other dimensions. Our physical experience is limited to three but physicists have speculated that other dimensions exist that can help explain the way atoms function.

"But the main thing is Higgs," Dr Yousef said, referring to the The Higgs field - a ubiquitous field that theoretically permeates the whole universe and reacts with particles that move through it, endowing some of them with mass. It might be hard to believe, but until now, the world's greatest scientists have not been able to prove why some particles have mass and others do not. "If you imagine a field full of snow, and you are trying to plod through it in your boots, you can only move slowly. You're a heavy particle. If you have skis, you can glide over it. You're a light particle. We're trying to shake particles out of this field to see if it exists," said Dr James Gillies, a spokesman for Cern.

The so far undiscovered particle related to the Higgs field is known as the Higgs boson. It is the only particle predicted by the "standard model" that has yet to be discovered. The standard model is a unified theory describing the interaction of forces and particles. The Higgs boson is one of the last pieces of its puzzle. It is of such importance it has been dubbed "the God particle" and some scientists speculate it could be the key to unravelling the mystery of gravity.

Newton famously described gravity and explained how the planets were held in orbit. But the gravitational force was of no use in understanding the otherworldly realm of particles. Scientists discovered the "strong" and "weak" nuclear forces that dictate how atoms are held together and how they decay. While these two forces are billions of times stronger than gravity, they are only effective over the minuscule distances involved with atoms. The fourth fundamental force is electromagnetism.

The standard model incorporates three of the four fundamental forces but "it has a serious shortcoming, it doesn't include gravity", Dr Gillies explained. "The Higgs is the last part of the standard model to be tested. It might be a step on the way to understanding gravity." The result could be the elusive "theory of everything" which would explain all the forces in the universe, from the gravitational attraction between galaxies, to the smallest molecular bond.

Of course, until the giant magnets are switched on and the experiments analysed, nobody knows if the Higgs field will be discovered, or what to do with it if it is. "From pure science, you won't find anyone who will tell you what you can do with the Higgs, but you won't find anyone who will say you can't do anything. History shows us advances come from curiosity driven research," Dr Gillies said.

The technological spillover from experiments at Cern has already had a huge impact. Not only is the technology of the particle accelerator used at many hospitals, in 1990 the world wide web was created there by Tim Berners-Lee, to facilitate information sharing between scientists all over the world. And what's the official line on the speculation that the experiment could tear up the universe? A body of 20 physicists, including a Nobel laureate, were commissioned to study the fears and determined that "there is no basis for any concern".

As Dr Gillies said, "Protons smash into the atmosphere at higher energies than we will produce. We bring naturally occurring conditions into the laboratory. You can speculate that the LHC might produce microscopic black holes, but the bottom line is that we are not producing anything that isn't produced naturally." @Email:jcalderwood@thenational.ae