In the beginning time stood still and matter rested with emptiness long cast, darkness deep in its shadow. As neither a void that existed nor an abyss that prevailed, this ‘nothingness’ was a perpetual absence of space and time that occupied neither, being the sum negative of any record of existence.
From this unknowable nihility, a single point of origin, rushing out exponentially, emerged, spewing out matter and space in a birth violent and cataclysmic commonly known as the Big Bang. As this genesis beat upon the currents of creation, time began, assuming its count. In those first moments, the very essence of what reality would be existed as sort of a cosmic haze, a nebulous aggregate of particles and plasma. From this churning cauldron would emerge the Universe as we know it today, an ineffable expanse of matter as stars and planets and mountains and oceans and indeed humanity itself.
For the universe to have existed, the very moments after the Big Bang, when particles like quarks, anti-quarks, gluons, protons, electrons, neutrons and a whole menagerie of subatomic species were created, remain a critical and indeed crucial point.
By general estimates, these events lay far back in a primordial past, some 13 billion years ago, where the shape and structure of matter and space were decided, the laws of physics determined and reality incepted. It was the very seconds, minutes and hours of these moments that set the course for things to come, and if an understanding of the present were to be sought, it would be found in the past, where the veritable ‘Hows?’ and ‘Whys?’ would be possibly answered.
Of course, as an event in pre history, the Big Bang remains well out of our ken despite certain ‘echoes’ of it still being felt but this has not stopped scientists from trying to understand it, with many attempts to try and recreate, on a very small scale, those decisive moments after the Big Bang in order to study the fundamental building blocks of the Universe. Chief among these initiatives had been the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, a particle collider that smashes protons together to observe their decays and what they might produce.
As the most powerful particle collider ever built, the LHC itself, with its six distinct detectors, is a modern day wonder, occupying a 27 kilometer ring beneath the Franco-Swiss border and consuming just about as much electricity as the whole of the residential area of Geneva. Having taken a decade to be built, involving thousands of scientists and engineers from all over the word, the LHC is on the forefront of particle and high-energy physics and since it began experimenting in 2008, it has lived up to its billing, having produced unprecedented science. Last year alone, the LHC and its two experiments, ATLAS and CMS were able to find or thereabouts the elusive Higgs Boson, dubbed the ‘God Particle’, a particle of inestimable importance.
PIQUE’s exclusive interviews with Dr. Jean-Philippe Tock and Dr. Heather Gray
Large Hadron Collider (LHC)
Being possibly one of the most expensive experiments in history, and an engineering marvel, what did CERN hope to achieve by building the Large Hadron Collider?
Dr. Jean-Philippe Tock, SMACC (Superconducting Magnets And Circuits Consolidation) project leader: In the spirit that is animating CERN since its creation in 1954, the main goal of the LHC is to extend our understanding of the Universe. Presently, the so-called Standard Model, a collection of theories of our current understanding of fundamental particles and forces. According to the theory, quarks are the building blocks of matter and forces act through carrier particles. Even if this theory, confirmed by many experimental evidence, is very powerful, it cannot explain some phenomena such as dark matter and the absence of antimatter in the Universe. It also does not explain the origin of mass. According to the Brout-Englert-Higgs mechanism, the whole space is filled with a “Higgs field” and particles acquire their masses by interacting with it.
One thing that is particularly striking about the LHC is it size, why was it conceived on such a grand scale? Does the size itself enable the kind of science you are doing? And if so, would something even bigger be possibly better?
The maximum reachable energy in a circular collider is proportional to its size and to the strength of the dipole magnetic field that curves the trajectory of the proton. To explore new territories, this energy has to be the maximum possible so the larger, the better. For the LHC, the existing tunnel of the LEP (Previous CERN accelerator standing for Large Electron Positron collider) was reused. It is a 27-km long tunnel built at a mean depth of 100 m. It has to be noted that to achieve this unprecedented collision energy, superconducting magnets were used to produce the dipole magnetic field curving the protons trajectory. If conventional resistive magnets had been used, the tunnel would have been at least 4 times longer and the electrical power consumption 40 times higher.
What does an undertaking like the LHC and CERN itself require in terms of resources and manpower?
Already in the early 80s, people at CERN were already thinking of the long-term future and proposed the successor of the Large Electron Positron collider. The first paper mentioning LHC dates back from 1984. It was approved in December 1994 by the CERN Council. The first particles circulated in the LHC in September 2008. This gives an idea of the extent in time of such a project. The LHC machine itself cost about 4.6 billion CHF.
Thousands of physicists, engineers, technicians, students at CERN and in collaborating institutes have worked for more than 30 years to turn the LHC into a real and working machine. It’s worth noting that the annual budget of CERN is no larger than that of a large university, so it represents very good value for money!
Do you think we will see practical applications of the discoveries you have made? And in the same vein do you think, much like with atomic research, this comes with a slight apprehension? Of possibly being misused?
To achieve our goal, we need new tools that are sometimes exceeding what is available in the industry. So, in close collaboration with industries, sharing our expertise, we are developing what is needed.
There are examples in medicine, engineering, information technology (obviously the World Wide Web). These applications are usually not imagined from the start.
CERN’s mission as stated in the Convention that established it clearly says: “The Organization shall have no concern with work for military requirements and the results of its experimental and theoretical work shall be published or otherwise made generally available”
And this reflects in the laboratory. Every laboratory is open to visit and a climate of exchange of information is present.
Dr. Heather Gray, CERN Staff member and ATLAS team researcher:
Higgs Boson
By unlocking the door into the atom and far beyond, just what are we looking for and trying to understand?
What we’re trying to do by looking into the atom and beyond, to discover the building blocks of reality and understand the fundamental properties of how things work. That’s what the LHC was built for and that’s what we’re trying to do.
With its mandate of studying areas of physics such as particle and quantum research, testing the Standard Model etc, do you think the LHC has limitations in what it can do and unearth?
Yes and no. The LHC is designed to answer very specific questions such as the very important question of the origin of mass. As such the LHC has been well designed successfully answered this question. In terms of which of the more general questions the LHC can answer, it is limited in terms of its energy, with the LHC presently operating at 8TeV. More energy would mean that we’d be able to study particles with a higher mass and probe ever deeper into the atom.
2012 was a particularly fruitful year for CERN in that the Higgs Boson was for all purposes discovered or at least a particle resembling it. To a layman what is the Higgs Boson and why has it been so important?
Well there are a number of analogies commonly used to try to illustrate what the Higgs boson means but I personally am not big fan of them. The Higgs Boson was a missing piece in the Standard Model, a missing piece in that we had a model in which particles had mass, yet the theory told us that the particles were massless. The Higgs boson was the key missing piece with which the theory remains consistent and the particles have mass.
One analogy that has been used is that the Higgs Boson is like a glue, binding things together, would you agree with that? And what about is description as the ‘God Particle’?
I wouldn’t really say the Higgs is a kind of a ‘glue’ because that would imply it was a force of some kind, like the existing forces that we know, magnetic, or a weak nuclear force etc. But the Higgs itself is responsible for giving particles mass, so while it is not a force, it still remains an essential component. I’m not particularly fond of the title ‘God particle’; to be honest it started off as joke and seems to have been taken up from there. A phrase like the ‘God Particle’ means that it is somehow beyond our understanding but, in reality, we know a great deal about the particle and its properties. The Higgs is of course a very important particle but I think the phrase overstates it somewhat.
The ‘particle’ discovered in the tests last year was said to be either the Higgs Boson or a new specie altogether, so if it wasn’t the Higgs, what else could it possibly be?
At the moment that’s exactly what we’re up to, trying to understand and interpret the data that we have. We’ve done some measurements, trying to determine the properties of the particle, such as its spin, its width etc that was discovered last year and to see if this is consistent with our understanding of the Higgs Boson. So far we’re pretty confident that the particle is what we’re looking, or at least is a Higgs Boson even if we’re not quite sure its the Higgs Boson.
To the uninitiated how would you explain the results obtained, that is that a statistical significance of 5 sigma had been achieved but more was required.
So the thing is this is all about statistics and probability, our findings have to have a certain reliability before we can say that we’re really sure about something. So we have conventions in terms of the probability of the result being a background fluctuations for when we use the term evidence (3 sigma) or observation (5 sigma). The results we obtained last year, that is 5 sigma mean that we had an ‘observation’ of a particle. If you compare a 5 sigma result to a 3 sigma result the higher the sigma means you can add more ‘9s’ to a 99.99...result not being a background fluctuations. Of course it’s not possible to get a 100% result as we’re always dealing with probability and statistics.
Since the announcement last year, has any further work been conducted?
Yes, very much so, we’re not even remotely done with our work or all the measurements using the data we’ve taken. As I said before, the measurements are working on are to measure each of the properties of a particle and so there’s a lot of data that we’re going through and analysing. When the LHC is up and running again in 2014, we plan to conduct more measurements and with its increased energy of 14TeV, nearly double of what it is now, we expect to get more exciting measurements and improved precision.
The LHC is looking into the very fabric of the universe as well, trying to ascertain the existence of dark matter and dark energy, what has CERN been able to find so far?
While there are dedicated experiments being conducted on this elsewhere, CERN and the LHC is looking into discovering Super Symmetry and by that super symmetrical particles. If we were to find such particles then they could potentially be excellent candidates to explain dark matter. So far we have not been able to find any clues of super symmetrical particles but we’re working on it.
The writer is a journalist based in Islamabad.
