Physicists at Wits University now have access to the world’s largest and most complex scientific instruments used to study “elementary particles” — the basic constituents of matter.
The university is part of the South African cluster of the European Organisation for Nuclear Research (Cern), one of the world’s largest and most respected “knowledge factories” for the generation of scientific research, and home to scientists who developed the World Wide Web.
Funding from Wits, the department of science and technology and the South Africa-Cern consortium now enables South Africans to participate in the generation of this cutting-edge science and technology.
We remain insatiably fascinated by the question of how the universe came to be and what happened just after the Big Bang occurred 13,7-billion years ago. Modern physicists attempt every day to find theories to explain how and why various phenomena occur, to discover new dimensions and to explore the invisible dark material (dark matter, dark energy, exotic particles) believed to make up the majority of the universe.
The instruments used at Cern, situated on the Swiss-French border, are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with one another or with stationary targets. Detectors observe and record the results of these collisions.
It is much like smashing a wrist watch into millions of parts with a hammer, observing what happens to each particle and then trying to rebuild it, just on a much larger scale. In doing so, we observe how the particles collide, while we learn more about the laws of nature.
One of the specialist facilities at Cern is a large, advanced particle accelerator known as the Large Hadron Collider (LHC), which is used to study the smallest known particles. Located in a 27km circular underground tunnel, the LHC can be described as:
- The largest machine in the world (it contains 9 300 magnets);
- The fastest racetrack on the planet (trillions of protons race around the ring at 11 245 times a second, travelling at 99.99% of the speed of light);
- The emptiest space in the solar system (particles travel in an ultra-vacuum);
- The hottest and coldest spot in the galaxy (when particles collide they create temperatures 100 000 times hotter than the sun but the accelerator ring is cooled at -271.3°C);
- The most sophisticated detectors ever built (they sample and record the results of up to 600-million proton collisions per second); and
- The most powerful supercomputers in the world (the data recorded by each of the big experiments at the LHC will fill around 100 000 dual layer DVDs every year).
My colleague, Dr Oana Boeriu, and I are the Wits team’s lead physicists — both of us relocated to South Africa to lead this world-class project. Our team includes several staff members and postgraduate students and post-doctoral scholars.
We are part of a team of 2 900 scientists from 172 institutions in 37 countries conducting and observing experiments on Atlas, a general-purpose detector at the LHC that weighs 7 000 tonnes. We have a permanent presence in Geneva in that we rotate our staff and students to observe our experiments on site but, through the world-class technology and advanced computer systems, we can monitor our experiments from almost anywhere in the world.
We are investigating a wide range of physics, including the search for the Higgs boson (the product of the theory that explains the origin of particle mass), extra dimensions and particles that could make up dark matter.
There are thousands of computers working all over the world analysing data recorded by the Cern detectors. In particular, Wits is expanding the Tier3 centre where we can store large chunks of the Atlas data and host the Monte Carlo simulation needed to perform our different search analyse.
Investment in basic science is a fundamental characteristic of any future knowledge economy. This is the breeding ground for innovation, for generating new discoveries and for training future scientists to work in global intellectual communities on the most sophisticated equipment in the world. Our participation in Cern puts South Africa on the scientific map globally.
Dr Trevor Vickey is a researcher in the Wits school of physics