Homer called salt a divine substance. Salt taxes built empires across Europe and Asia. They even sparked a revolution. In this hour of To the Best of Our Knowledge, why salt is no ordinary rock. We’ll tell you how it’s changed the course of history. Also, the...Read more







Scientists are launching one of the most audacious projects ever conceived: a detailed map of the human brain, neuron by neron, synapse by synapse. For some scientists...