Artificial light makes the modern world possible. But not all kinds of light are good for us. Electric light has fundamentally altered our lives, our bodies and the very nature of our sleep.
Like all mammals, the Neanderthals breast fed their babies. Scientists wanted to know: For how long? A team of researchers say they’ve answered that question by looking at the fossilized tooth of an eight-year old Neanderthal child discovered in a Belgian cave.