An astonishing proportion of the Japanese tourists who visit Cambridge want to be photographed against the backdrop of the apple tree in front of Trinity College. Wonder if this is because of the legend about Newton and the apple? (His rooms overlook the lawn on which an apple tree stands.)

Which reminds me of one of my favourite cartoons. It shows Newton sitting under the tree, rubbing a bump on his head. He is looking meditatively at the offending fruit lying at his feet and saying: “Now comes the difficult bit — getting a research grant to write it up”.