By Professor Chandra Wickramasinghe
The Large Hadron Collider (LHC), which cost 4.75 billion dollars to construct, consists of a 17 mile long donut shaped tube buried 330 ft deep under the Swiss/French border near Geneva. Within this giant tube, supercooled magnets accelerate charged particles to speeds approaching the speed of light. Collisions between streams of high energy particles (protons) will, it is hoped, eventually provide evidence of the ultimate building blocks of matter. The LHC has been in operation since August 2008. The total cost of the entire project up to the time when the discovery of the Higgs boson was announced stands at a staggering 13.25 billion dollars.
According to the so-called "standard model" of particle physics the Higg’s boson, the most fundamental building block of matter, came into existence within a trillionth of a second of the Big Bang origin of the Universe, 13.7 billion years ago. It is the heaviest of all the fundamental particles that have been predicted theoretically, but because it decays so incredibly fast its existence had proved difficult to confirm.
The Higgs boson has a mass equal to 130 times that of the hydrogen atom, and it interacts with other fundamental particles to endow them with mass (weight). Without the gift of mass from the Higg’s particle, ther particles will not be able to bind together to form atoms, molecules, stars, planets and even life. Without the Higg’s boson we would not exist: that is why it has been called the ‘God particle’.
The quest for the fundamental building blocks of the Universe has history stretching over thousands of years. The key question relates to what happens if we break up a piece of matter, say a rock, into smaller and smaller bits. Beyond a certain point the bits would become invisible to the naked eye, but we can still imagine further divisions under, say, the most powerful microscope. Where does the division process stop?
The word atom is derived from the Greek a-tomos meaning not divisible. The pre-Socratic Greek philosopher Democritus (460BC-370BC) argued that ultimate indivisible units of matter exist, and these he called atoms. The indivisible atoms were thought to move in space and combine into various forms and structures to make up everything we see around us. Democritus’ views appeared to have been fully vindicated in the early nineteenth century when John Dalton (1766-1844) showed that the division of matter leads to atoms or elements such as hydrogen, carbon, oxygen, nitrogen, phosphorus, silicon, iron, silver……each with characteristic atomic weights and properties. Combinations of these atoms produce substances with distinctive properties like rock, water, and life.
The sequential division process envisaged by Democritus did not stop with Dalton’s atoms, however. In the 19th and early 20th Centuries atomic physicists—notably J. J. Thomson (1856-1940) and E. Rutherford (1871-1937)—began the next major scientific revolution that led to theories of atomic and nuclear physics – exploring matter at ever deeper levels. Atoms such as uranium were smashed to reveal smaller units – electrons, protons, neutrons – and these were believed for a while to be the ultimate indivisible units of matter. It was the smashing the atom that led to the discovery of the atom bomb, and on the more positive side, to the invention of nuclear energy from which a large fraction of the world’s power is currently derived.
But, the attempt to go further down on the scale of smallness – below electrons, protons, neutrons - continued. The standard theory of fundamental particles that is currently in vogue was developed in the 1960s. According to this theory we have two broad classes of fundamental particles called fermions and bosons. The fermions (a total of 48 particles called quarks and leptons) may be thought of as matter particles. The bosons (a total of 13 which includes the Higg’s boson) may be thought of as force-carrying particles. The Higg’s particle was a theoretical prediction made by Professor Peter Higgs at the University of Edinburgh in 1964. Higg’s argued that its existence was necessary in order that mass is conferred on all other particles.
The Large Hadron Collider, located near Geneva, has accelerated protons to speeds close to the speed of light, and thus caused them to collide with each other in conditions that mimicked those that existed close to the Big Bang. The recent announcement reports the discovery of tracks of the extremely short-lived Higg’s boson, after sifting through enormous amounts of data using the fastest supercomputers. If this discovery is confirmed, it surely marks an important milestone in our understanding of the physical universe and, indeed, of our own origins.
In our modern money-oriented society it is often asked: Of what use is this or that discovery? How will it lead to a better life for the vast majority of humanity? Answers can only be given in an historical context. Humans appear to have an innate and insatiable curiosity to probe the world in which they live; it is an integral part of human nature. Societal benefits that accrue from such activity tend, in general, to be long term. It is worth noting that everything we take for granted in our modern technological world derives ultimately from discoveries that, at the outset, seemed of little or no relevance to society. When the 19th century pioneer of electromagnetism, Micheal Faraday (1791-1867), was asked by Prime Minister Gladstone what use his discovery would be, his response was: "I haven’t got a clue, but I tell you this, Mr. Gladstone, one day you will tax it."
Whether discovering the Higgs particle will produce taxes in the future remains to be seen – but we should reflect on the fact that without the Higgs particle life would not have come into being.
*Professor at Cardiff University; Honorary Professor and Director of the Buckingham Centre for Astrobiology at Buckingham University, UK