From New Scientist, Astronomy study proves mathematics theorem. As an astronomy and maths geek and teacher, this is the kind of story that makes me smile. The research concerns gravitational lens. This phenomenon occurs when the light from a very distant object is bent by the gravitational field of some objects between the distant object and the observer. This was a prediction of Einstein’s general theory of relativity. Depending on the mass and shape of the objects who’s gravitational field results in the lensing effect, multiple image of the distant object can be observed, this is where the mathematics comes in. It turns out that for a lens made of n stars, 5n – 5 is the maximum number images. It is not every day that The fundamental theorem of algebra is mentioned in the media, even in New Scientist 🙂 This is an example of how Pure Mathematics that is developed without any direct practical application can be vital to work at some later time. Another example is the applications of number theory to cryptography.