In deepest, darkest January, Adam Gopnik muses on light and dark.

Adam reminds us that - from the natural world of the ghost moth to the politics of today's America - although we live in a 'gloomy moment' we can 'adjust our eyes to the gloom.'

'Every little bit of light we make,' writes Adam, 'in every decent thing we do and every indecency we refuse to accept, illuminates some small corner of our universe. Even at night, after all, we still see light. The stars shine, too.'

Producer: Adele Armstrong Sound: Peter Bosher Production coordinator: Gemma Ashman Editor: Richard Fenton-Smith