Albert Einstein’s general theory of relativity has given us navigation through the Global Positioning System (GPS), working models of black holes and was instrumental in understanding how the Big Bang shaped the universe. And it is almost 100 years, to the day, that scientists first observed the effects of Einstein’s relativity in action. On May 29 this year is the centennial anniversary of a crucial expedition to Africa, led by English astronomer Sir Arthur Eddington. The expedition to the Island of Principe, West Africa, aimed to observe a mesmerising total eclipse of the Sun briefly turn day into night.