Experimental setup. As a beam of beryllium comes in from the left, the deuteron Trojan horse intercepts it at the target and delivers its neutron soldier. This allows the decay products of the beryllium and neutron reactions to be captured by a curved array of six detectors on the right. Credit: Hayakawa et al. There is a significant discrepancy between theoretical and observed amounts of lithium in our universe. This is known as the cosmological lithium problem, and it has plagued cosmologists for decades. Now, researchers have reduced this discrepancy by around 10%, thanks to a new experiment on...