After two years of upgrades, the world's largest particle accelerator is back and business. And it's already bashing subatomic particles together at higher energies than ever before to probe the most fundamental questions about the nature of the universe.
Shortly after the discovery of the Higgs boson particle in 2012, the Large Hadron Collider — a 27 kilometer racetrack of superconducting magnets physicists use to smash together trains of protons — was taken offline. Researchers at the LHC's CERN Control Center have spent the last two years upgrading the machine, and on the morning of June 3rd, the souped-up particle collider was officially up and running again.
What do the upgrades mean? For one, the LHC can now smash roughly a billion pairs of protons together every second, twice its previous rate, at a record-breaking energy of 13 TeV. (At the moment, the actual number of collisions taking place is fairly small, but physicists will be progressively increasing the LHC's output in the coming months).
When protons collide, part of their energy is converted to mass, creating showers of new particles. The extra power of the upgraded LHC could reveal new subatomic phenomena that don't fit within standard models of particle physics, offering insights into the nature of dark matter and the most elementary building blocks of the universe. Perhaps, in another three years, we'll have ourselves a beautiful, all-encompassing theory of everything.
But as Michael Kramer points out over at The Guardian, there's an awful lot going on behind the curtain here. In reality, the LHC is an enormously complex experiment, perhaps the most complex scientists have ever conceived. Physicists must rely on theoretical models and computer simulations both to guide their experiments and interpret the deluge of data the LHC collects. And this raises thorny questions about how indisputable its findings truly are. As an exploratory experiment, what happens if we explore the wrong places? What if the models guiding our experiments are flawed? What if the search for a simple, all-encompassing theory to describe reality is, itself, misguided?
I'm certainly not qualified to answer these questions. But if one thing's clear, it's that where the LHC is taking us, we're going to need philosophy as much as science.
Top image via Maximilien Brice, CERN