Today is the sixty-first anniversary of the death of the great scientist Albert Einstein but despite this his legend still lives on. He is widely regarded as the most famous scientist ever, Einstein’s name is synonymous with problem solving and a genius-like intellect. With his shock of white hair and bushy moustache, he is instantly recognisable, but for all this it is one small equation that has ensured his legacy lives on. In 1905, the German published his now famous theory of special relativity – E=mc2. It is an equation that is known all around the world and one that adorns posters, t-shirts and has even been turned into tattoos. But what is it, how does it help us today and what does it actually mean?