Some theories say that if the universe has extra hidden dimensions, gravity could be much stronger at tiny distances, and colliding protons hard enough could briefly make microscopic quantum black holes. Physicists at UC Santa Barbara, working with the CMS experiment at CERN, searched data from the Large Hadron Collider (collected in 2016 to 2018) for the kind of burst of particles such a black hole would give off when it evaporates.
They did not find any evidence of them. A result like this is still useful. It rules out some versions of those theories, and the team also reported a new machine-learning method that spots this kind of event better than earlier approaches.
Why it matters: “We looked and found nothing” is a real scientific result. Every search that comes up empty takes some possible explanations off the table and points researchers toward the ones that are left. To learn what an ordinary black hole is first, see our black holes lesson.