R. Gaur

Plasma in a fusion reactor is like a swarm of fireflies that you need to keep inside an invisible jar. It used to be thought that the jar's walls had to be perfectly smooth, or the fireflies would find a crack and escape. New work shows that the jar can be glued together from pieces with noticeable seams, and the swarm will still stay inside.

Deep beneath Japan's Mount Ikeno sits a tank holding 50,000 tons of the purest water. Inside, it catches neutrinos — ghostly particles that zip through Earth as if it weren't there. When a star explodes in our galaxy, neutrinos arrive first, hours before the light.

Inside every atom lives a proton. For a long time, it was considered as eternal as matter itself. But theories that unify all forces of nature predict that, sooner or later, the proton will decay. The only question is how long we have to wait. In the Japanese detector Super-Kamiokande — a giant tank of ultra-pure water — physicists searched for signs of such a decay.