CH 2: The Experiment That Detects Nothing

Ninety per cent of the matter in the universe cannot be seen. It's called dark matter and it's gravitational effect can be observed in the motion of stars and galaxies. This chapter takes us deep into an abandoned iron mine in Northern Minnesota, where physicists are using the half-a-mile of rock above as a shield to help them search for particles that are thought to make up dark matter. It's a story of how dark matter was discovered, how physicists converged on the mostly likely explanation and of the painstaking search for what makes up the universe's unseen mass.