In 1970 a scientist named Ray Davis filled the bottom of a gold mine in South Dakota with 100,000 gallons of cleaning solution. Why? He was trying to catch a mysterious object known as a neutrino.
A neutrino is a tiny particle that gets spat out when one element turns into another one through the process of radioactive decay. In the time it takes to read this sentence, you’ll be bombarded with a few billion neutrinos. Fortunately for you, these loners of the subatomic world rarely bump into anything. In fact, neutrinos traveling through a light year of lead only have a 50/50 chance of bumping into anything. For scientists like Roy, this makes it hard to study neutrinos. Hence his elaborate setup.
Ray’s work in the mine—later dubbed the Homestake Experiment– supported the idea that the sun is constantly shooting out billions of neutrinos. Later work would show that dying stars also emit bursts of neutrinos.
But why should we care about neutrinos? One idea is to use them for communication. Because neutrinos can pass through just about anything unfazed, they have a distinct advantage over the electromagnetic waves that carry our radio and cell phone signals, which can get blocked by objects like mountains. Hence, neutrinos might one day be carrying your Snapchats straight through the center of the earth. Making this loner particle the unwitting carrier of social messaging all over the planet.