Читать книгу What on Earth is Going On?: A Crash Course in Current Affairs - Arthur House - Страница 12
ОглавлениеWhat does it stand for?
Conseil Européen pour la Recherche Nucléaire, or the European Organisation for Nuclear Research. When it was founded in 1954, the cutting edge of theoretical physics was concerned with investigating the nucleus of the atom, hence the word ‘nuclear’ in the title. Today CERN’s research focuses on the sub-atomic particles at a much deeper level than the nucleus; for this reason
it is sometimes also referred to as the European Laboratory for Particle Physics. CERN makes a strong claim to be the greatest experiment ever undertaken by humankind, remarkable for its scale, number of scientists and countries involved, technological expertise and sheer ambition.
Where is it?
CERN’s research centres are spread across a number of sites in France and Switzerland. Its flagship site is the Large Hadron Collider (LHC) near Geneva, a gigantic particle accelerator which spans the Swiss-French border at a depth of 100 metres underground. The main component of the LHC is a 27 km ring of superconducting magnets, each chilled to—271°C, around which trillions of charged subatomic particles—either lead ions or hadrons (bundles of quarks)—are accelerated in opposite directions in a near-perfect vacuum. When they have reached 99.99999999% of the speed of light the particles are collided, generating temperatures 100,000 times hotter than the sun’s core and recreating the conditions in the thousandths of a nanosecond following the Big Bang.
There are 10,000 scientists and engineers from 100 different countries working on the LHC, and six separate experiment teams analysing the data from these collisions, each of them focusing on different particles with their own set of specialised equipment. The LHC took 13 years to build and cost around £4.5 billion, and was officially switched on on 10 September 2008, sending its first particle beams successfully around the circuit. Unfortunately, an electrical fault only nine days later caused a helium leak and damage to some of the magnets, requiring lengthy repairs and delaying the atom-busting action until mid-2009.
What’s the point of it?
In short, the CERN scientists are trying to discover more about the basic building blocks of the universe. Theoretical physicist Dr Subodh Patil uses this culinary analogy to explain it in layman’s terms: ‘Imagine you have some really exquisite quiche and you want to find the recipe, except that the person who made it won’t tell you a thing. So you throw it around the room against other stuff, like fruit or custard pies, and hope that the crap that flies out gives you some hint of the fine herbs and spices used.’ Over the past few decades, the Standard Model of particle physics has been developed to explain many of the observable features and interactions of the universe. It identifies twelve types of sub-atomic particle out of which all matter is made; six quarks (the up, down, charm, strange, top and bottom quark) and six leptons (the ε-neutrino, electron, μ-neutrino, muon, τ-neutrino and tau particle). It also recognises the effects of three fundamental forces (the strong, weak and electromagnetic forces) on these particles, resulting from the exchange of force carrier particles called bosons (gluons, photons and W and Z bosons).
However, the Standard Model is incomplete, because it fails to reconcile the theory of general relativity (Einstein’s theory of gravity, which phrases gravity as nothing more than the effects of matter and energy curving spacetime to make us feel gravitational forces) with quantum theory, which is used to describe goings-on at a sub-atomic level. Recreating the conditions just after the Big Bang should give scientists a more coherent idea about the universe’s workings as well as providing insights into such mysteries as: the origins of mass (why some particles weigh more than others, and why some particles seem to have no mass at all), the nature of antimatter, dark matter, dark energy and the ‘primordial soup’ that the universe consisted of immediately after the Big Bang (quark-gluon plasma, apparently), and whether multiple dimensions exist beyond the four that we currently know about.
What is the Higgs boson?
The so-called ‘God particle’ is a force-carrier particle theorised by English physicist Peter Higgs to explain why matter has mass. His theory supposes that all particles had no mass immediately after the Big Bang, but an invisible force field (the ‘Higgs field’) condensed as the universe cooled, and any matter that interacted with it was given a mass via the Higgs boson. This, however, may be completely wrong, and if they can’t find this elusive particle at CERN (or at Fermilab, a rival American particle accelerator trying to beat them to it) the boffins will have to come up with a different theory altogether.
What is antimatter?
Antimatter was first proposed by physicist Paul Dirac in 1928. For each particle of matter that exists, there exists a corresponding particle of antimatter, with the same mass but the opposite electric charge. This idea was confirmed in 1932 when positrons (antiparticles to electrons) were found to be naturally occurring in cosmic rays, and since then anti-particles have been produced in labs (including the first anti-atom at CERN in 1995). Because matter and antimatter annihilate when they come together, and the Big Bang produced equal amounts of each, scientists don’t understand why any matter still exists, or, if the antimatter’s somehow disappeared, where it’s all gone.
What are dark matter and dark energy?
It turns out that the majority of the universe consists of these invisible and poorly understood substances. According to the latest observations, dark matter accounts for 22% of it, and although it cannot be seen its density can be measured because it has a gravitational field which bends light. Dark energy makes up around 74% of the universe, is evenly distributed through space and time and has a repulsive effect on the universe as a whole, which accelerates its expansion. The remaining 4% of the universe is made of matter—3.6% of which is intergalactic gas, leaving 0.4% for the stars, planets, etc.
Is the Large Hadron Collider going to destroy the world?
No. As Brian Cox—formerly the keyboardist with pop band D:Ream and now a professor at the University of Manchester—put it eloquently last year, ‘anyone who thinks the LHC is going to destroy the world is a twat’. Despite this and many other assurances to the contrary from the scientific community, some people still think it might. One group, which included a few scientists (but no particle physicists), lodged a lawsuit at the European Court of Human Rights in September 2008, claiming that CERN had not properly considered the danger to human life that the experiment posed. They feared that the collisions in the LHC could create a microscopic black hole which would grow uncontrollably and suck the earth inside out within four years. Earlier in the year two Americans pursued a similar claim at a federal court in Hawaii, worrying not only about black holes but also about the possibility of the LHC emitting ‘strangelets’, hypothetical objects made of up, down and strange quarks which might turn the entire planet into a dense lump of homogenous ‘strange matter’. Both of these lawsuits were dismissed.
A modest proposal
In 1989, Englishman and CERN employee Tim Berners-Lee drafted a document entitled ‘Information Management: A Proposal’. His supervisor’s response to it was ‘vague, but exciting’, and he gave Berners-Lee the go-ahead to develop his idea. A year later the World Wide Web was born.
