Neutrinos are having a moment. They’re speeding across Europe (just how fast is under review), they’re changing flavors in China and, now, they’re carrying rudimentary messages through bedrock in Illinois. A team of physicists encoded a short string of letters on a beam of neutrinos at Fermi National Accelerator Laboratory in Batavia, Ill., and sent the message to a detector more than a kilometer away. On the journey the neutrinos passed through 240 meters of solid rock, mostly shale. What was the word they transmitted in the preliminary demonstration? “Neutrino.” The experiment is described in a paper posted to the...