Light usually takes the fastest path from A to B, and the difference in speed between air and glass means that the shortest path in terms of distance may not be the fastest one. N is close to 1, while for glass it is about 1.5 - so light travels slower through glass than through air. In short, c is the speed of light in a vacuum, and v is the speed of light through the medium. Given the medium, mathematics can compute refractive index: The refraction displayed in the album cover is all to do with the speed at which a beam of light travels (depending on the medium) which could be glass, air or water. Sean Jamshidi, a PhD student at University College London, broke down the significant mathematical points of the album cover and found three parts to focus on. The refraction and dispersion explains why the rainbow and the incoming beam are not parallel, and how the white light splits up as it passes directly through the prism. It’s an example of an ‘optical phenomena’ known as refraction and dispersion, which may sound a little complicated, but it’s more understandable once you break it down. Whether you've seen it in its original vinyl form or on a t-shirt, it's hard to think of a more recognisable image in the music industry.Īnd - surprisingly - there’s a lot of mathematics behind the album cover, with its simple geometric design and rainbow pattern.Īs reported by Chalkdust Magazine, the album cover shows a beam of white light hitting a triangular prism splitting into ‘constituent parts’ (which is the rainbow).
Pink Floyd’s Dark Side of The Moon album is instantly recognisable - thanks in no small part to its iconic cover.