Mark Thomson, a professor of experimental particle physics at the University of Cambridge, has secured one of the most sought-after roles in global science. Yet, from a certain perspective, it’s hard not to wonder if he’s made a personal sacrifice for the greater good.
On January 1, Thomson will become the director general of CERN, the Nobel prize-winning nuclear physics laboratory near Geneva. It is here, deep underground, that the Large Hadron Collider (LHC)—the largest scientific instrument ever built—recreates conditions from the first moments after the Big Bang.
The LHC earned its place in history by discovering the elusive Higgs boson, whose associated field acts like a cosmic glue that gives particles mass. However, one of Thomson’s first tasks will be to shut down the collider for major engineering work. It won’t restart until his term is nearly over.
In his office at the Cavendish Laboratory, past a model of the DNA double helix discovered in Cambridge over 70 years ago, Thomson is far from dismayed by the shutdown. In fact, he is looking forward to the next five years.
“The machine is performing brilliantly, and we’re collecting vast amounts of data,” he says. “There will be plenty to analyze during this period. The physics results will keep coming.”
Thomson’s background is not traditionally academic: he attended a comprehensive school in Worthing, West Sussex, and developed an interest in physics only after reading a popular science book about CERN in his early teens. “It kind of set my direction,” he recalls. “I wanted to understand how the universe works.” He was the first in his family to attend university, studying physics at Oxford.
The LHC accelerates protons—the nuclei of hydrogen atoms—to nearly the speed of light inside a 27-kilometer ring beneath the French-Swiss countryside. At four points around the ring, protons traveling in opposite directions are collided. The energy from these impacts creates a shower of new particles, which are recorded by the LHC’s detectors. Following Einstein’s famous equation, E=mc², more energy produces more massive particles.
Starting in June, the shutdown will pave the way for the High-Luminosity LHC, a major upgrade involving powerful new superconducting magnets to focus the proton beams, making them brighter. This will increase the number of collisions tenfold. The detectors are also being enhanced to better capture the subtle signs of new physics. “It’s an incredibly exciting project,” Thomson says. “It’s more interesting than just running the machine as usual.”
If successful, the upgrade will allow for more precise measurements of particles and their interactions, potentially revealing flaws in current theories that could lead to new discoveries. One lingering mystery is the Higgs boson itself. While elementary particles acquire mass from the Higgs field, why their masses differ remains unknown. Even how Higgs bosons interact with each other is unclear. “We could see something completely unexpected,” Thomson notes.
Overseeing the High-Luminosity LHC will be a central focus of Thomson’s five-year term. But he must also address a larger and more contentious project: planning for what comes after the LHC, which is set to end its life around 2041. The leading candidate is a colossal machine called the Future Circular Collider (FCC).
According to CERN’s feasibility study, the FCC would be over three times the size of the LHC, requiring a new 91-kilometer circular tunnel dug up to 400 meters underground. The project would be built in two stages, with the first phase beginning in the late 2030s.In the 2040s, the plan is to collide electrons with their antimatter partners, positrons. Then, around the 2070s, that machine would be replaced by a new collider designed to smash protons at seven times the energy of the Large Hadron Collider (LHC). The initial phase is estimated to cost 15 billion Swiss francs, or about £14 billion.
The engineering itself is ambitious, but the Future Circular Collider (FCC) faces broader challenges. CERN’s member states, who will vote on the project in 2028, cannot cover the entire cost, so additional international contributors are needed. At the same time, a debate continues over whether this is the best machine for making new discoveries. There is no guarantee it will answer the big questions in physics, such as: What is the dark matter that clumps around galaxies? What is the dark energy driving the universe’s expansion? Why is gravity so weak? And why did matter prevail over antimatter when the universe formed? Without a clear, guaranteed breakthrough, Mark Thomson’s task of rallying support will be more difficult.
Yet CERN has always been about more than just science. Thanks to the laboratory, Europe is the global leader in particle physics, attracting tens of thousands of researchers and driving the development of new technologies. However, other countries, notably the United States and China, are advancing their own plans for next-generation colliders. Whether CERN retains its pre-eminence depends on the success of the LHC’s successor.
“We haven’t reached a point where discoveries have stopped, and the FCC is the natural next step. Our goal is to understand the universe at its most fundamental level,” says Thomson. “And this is absolutely not the time to give up.”
Frequently Asked Questions
Of course Here is a list of FAQs about the statement The man taking charge of the Large Hadron Collider is doing so only to shut it down
Beginner General Questions
1 What is the Large Hadron Collider
The LHC is the worlds largest and most powerful particle accelerator Its a 27kilometer ring of superconducting magnets buried underground near Geneva Switzerland at CERN Scientists use it to smash protons together at nearly the speed of light to study the fundamental building blocks of the universe
2 Is it true that a new person is taking charge just to shut the LHC down
No that is not true This is a misunderstanding or a piece of fiction The LHC is a critical scientific instrument New directors or project leaders are appointed to manage its operations upgrades and future research goals not to terminate it
3 Why would anyone think someone wants to shut it down
This idea might come from science fiction a misunderstanding of scheduled maintenance or confusion about budget debates The LHC periodically undergoes long shutdowns for upgrades and repairs which someone might misinterpret as a permanent closure
4 Who is actually in charge of the LHC
The LHC is managed by CERN the European Organization for Nuclear Research A team of scientists engineers and a project leader oversee its daily operations Leadership roles change over time as part of normal career progression
5 Can one person even decide to shut down the LHC
No The LHC is an international project funded and operated by a collaboration of many countries Any major decision like a permanent shutdown would require complex consensus among member states and the scientific community not a single individual
Intermediate Operational Questions
6 Does the LHC ever get shut down
Yes but only temporarily It runs in multiyear runs followed by scheduled Long Shutdowns These periods are for essential maintenance upgrades to increase its power or sensitivity and to install new detectors
7 What happens during a scheduled Long Shutdown
Teams perform thousands of maintenance tasks reinforcing electrical connections upgrading computing systems installing new beam pipes and improving detector components Its like a massive pit stop to make the machine even better
