We don’t know why the universe appears to be expanding faster than it should. New ultra-precise distance measurements have only intensified the problem.
In 2023, the ALICE experiment was ready for their best year yet, until a mysterious signal threatened everything. As the LHC wraps up its 2025 lead-ion run, physicists recall how they worked together to solve the puzzle.
For a little over a month this summer, a huge electromagnet slowly journeyed from New York to Illinois, offering great photo opportunities along the way.