Do plants do maths? Has the Internet made us all more intelligent? Why did my milk freeze? Why do my hands get cold, but not my face? How did people realise Earth is round? What's red shifting? Why does squinting make it easier to see things? Why is water unreactive when hydrogen and oxygen are? What makes red shifting happen? Dr Chris answers more top science questions from South Africa... Like this podcast? Please help us by supporting the Naked Scientists