Could our universe have more dimensions than the three of space and one of time that we experience?

Recent results from the Dark Energy Spectroscopic Instrument (DESI) have renewed interest in whether our current picture of the universe is complete. Some theories suggest that extra dimensions could help explain three of the greatest mysteries in physics: the nature of dark energy; the invisible influence of dark matter; and why gravity is so much weaker than the other fundamental forces.

From string theory to braneworlds, the search for extra dimensions pushes the boundaries of science and could reveal that the reality we experience isn’t all there is.

Mark Thomson is the newly appointed director general of CERN near Geneva, Switzerland. CERN is the world’s biggest particle physics laboratory, and its Large Hadron Collider (LHC) smashes particles together at almost the speed of light to understand the fundamental nature of the universe. CERN has been responsible for groundbreaking new physics, most notably the discovery of the Higgs boson in 2012, and is a world leader in antimatter research. However, in order to probe even deeper, it must run at higher energy levels. We catch up with Thomson at an important juncture, as the LHC is due to shut down for two years for upgrades, paving the way for even more exciting physics. But is there anything left to discover? And are large particle accelerators the future of particle physics?

“There are really big questions that we don’t know the answer to,” says Thomson. “Big questions like dark matter. Is the Higgs boson a fundamental particle? Does the Higgs boson interact with the dark matter? At some point, we are going to find answers to some of these really, really big questions.”

Read more: The experiments that could finally explain gravity

Deep beneath the planet’s surface at the Sanford Underground Research Facility in South Dakota, scientists are waiting for something that may never happen – the interaction of weakly interacting massive particles, or WIMPs. This is LUX-ZEPLIN, the most sensitive dark matter detector on Earth.

WIMPs are a leading contender for dark matter and could answer one of the biggest mysteries in cosmology: where is the missing matter that makes up the universe? The detector is filled with 10 tonnes of ultra-pure liquid xenon and is so sensitive that even a single gram of dust would skew its results. A single collision could reveal what most of the universe is made of, or prove that decades of physics may be pointing us in the wrong direction.