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.
About 90% of us over the age of 12 fail to get as much exercise as we should. This is almost certainly not because we don’t believe in those benefits. Instead, it looks like at least part of the reason may be that some of us are genetically programmed to hate exercise.