Now, physicists at the European Organization for Nuclear Research (CERN) on the Swiss-French border are restarting the collider with the aim of understanding more about the Higgs boson, other subatomic particles and the mysteries of dark matter — an invisible and elusive substance that can’t be seen because it doesn’t absorb, reflect or emit any light.
Consisting of a ring 27 kilometers (16.7 miles) in circumference, the Large Hadron Collider — located deep underneath the Alps — is made of superconducting magnets chilled to ‑271.3°C (-456 F), which is colder than outer space. It works by smashing tiny particles together to allow scientists to observe them and see what’s inside.
“When we do research we hope that we will find something unexpected, a surprise. That would be the best result. But of course the answer is in the hands of nature, and it depends on how nature answers open questions in fundamental physics,” said Fabiola Gianotti, CERN Director-General, in a video posted on CERN’s website.
“We are looking for answers to questions related to dark matter, to why the Higgs boson is so light and many other open questions.”
Understanding the Higgs boson
Physicists François Englert and Peter Higgs first theorized the existence of the Higgs boson in the 1960s. Physics’ Standard Model lays out the basics of how elementary particles and forces interact in the universe. But the theory had failed to explain how particles actually get their mass. Particles, or bits of matter, range in size and can be larger or smaller than atoms. Electrons, protons and neutrons, for instance, are the subatomic particles that make up an atom. Scientists now believe that the Higgs boson is the particle that gives all matter its mass.
In the latest round of experiments, CERN’s scientists will study the properties of matter under extreme temperature and density, and will also be searching for explanations for dark matter and for other new phenomena, either through direct searches or — indirectly — through precise measurements of the properties of known particles.