The iconic African baobab tree can live up to several thousands of years, but recently there’s been an increase in the trees dying. Stephan Woodborne is the senior accelerator mass spectrometry scientist at iThemba Labs in Johannesburg and explains how they found this out. In Unscience this week, is it really possible that you could be brushing your teeth with a little part of the Sterkfontein caves? Later in the show, we find out what scientist have to say about water dowsing, the practice of finding underground water reserves by walking around with an egg or certain sticks.