Light doesn't only let us see things, it can also reveal what exactly they're made of. Everything from the composition of stars, to the difference between a healthy cell and a cancerous one. Robert Thompsom 'shines a light' on the wonders of spectroscopy, as well as organic electronics (the future of tech!) and how to make your very own spectrometer with only a cereal box and a CD. Plus our weekly science news and a particularly firey Fieldwork Faux Pas.