With a new year comes a whole new stack of science questions to challenge Dr Chris, Dr Dave and Dr Kat. This week they explain where the sand in the Sahara comes from, whether mirrors can reflect x-rays, if it is dangerous to live near a phone mast, and whether splitting water could solve our energy problems. We are also joined by the editor of Chemistry World, Dr Mark Peplow, who talks about labs the size of a postage stamp, nanoparticles in exhaust fumes, and why putting milk in your tea might not be such a good idea, and sticking with chemistry, Dave Ansell discovers which household liquids... Like this podcast? Please help us by supporting the Naked Scientists)