To find out how the universe truly works, scientists have for decades worked on the standard model of particle physics. When the Higgs boson was found at the Large Hadron Collider almost a decade ago, it was supposed to be the final piece in the jigsaw at the smallest, subatomic scale. Yet this week came the news that there may be new particles or forces that aren’t accounted for in the standard model.
What these might be is a mystery hidden, say researchers at Fermilab in the US, within muons, a bulkier relative of electrons, one of the building blocks of matter. Scientists at Cern in Geneva also think they have picked up something unexpected in muon-electron interactions, contrary to standard model predictions. Do they possess differences besides their mass? The answer might be yes. There are holes in the standard model. It does not account for gravity and does not explain dark matter, which makes up two-thirds of reality, nor why nearly all the anti-matter created in the big bang has disappeared. And it has little about the “dark energy” to which we ascribe the accelerating expansion of the universe.
Whatever is missing from the standard model might explain these phenomena. Science is still progressing. Humility demands that we accept that there are scientific riddles that no one can unlock right now. But by being curious and building on what we know, we can discover more answers all the time. Whereas Einstein’s general relativity looked at enormous scales, the standard model concerned itself with the very tiny – where measurement is hard to make accurately. The latest discrepancies may be a statistical fluke. What scientists cannot say is that they have made a discovery. But for the moment the thrill is that experiment appears ahead of the theory.