Optical connections: How Thomas Young decoded the world

It was a French demolition squad that found the object 215 years ago. Fortunately, they realised the importance of the stone covered with engravings of text in three different scripts built into an ancient wall in the Egyptian village of Rashid (Rosetta). With the Napoleonic Wars turning in favour of the British, the Rosetta Stone ended up in the British Museum where it has remained on display since 1802, apart from a short excursion to Paris in 1972. It took a mind that first described astigmatism and the mechanism of accommodation, and performed experiments demonstrating the nature of light and colour vision, to reveal its secrets.