Autumn brings out the birdwatcher in many of us. Migrant birds are moving all around the northern hemisphere, often in great flocks, making amazing spectacles. Among them are the humble starlings. Cheeky, chatty little blue-black birds that go largely unnoticed for most of the year. A murmuration of starlings, as

It’s not often that you can say that one picture changed the world, or at least the way that we see it. But one image that fits this description was John Snow’s cholera map. In 1854, Dr John Snow was trying to work out what was causing an outbreak of