On the latest editon of the Naked Scientist - Antimatter, the rules of physics say there should be at least as much antimatter in the Universe as there is matter, the material that we are made from. But scientists can't find it, suggesting either that we've got something wrong, or something else very exciting and important must be happening. Also, why the hand you type with can affect how you feel. As well as a look at some of this week's other leading science breakthroughs