Changes

MO: Amazed actually. When my science Q&A column started in 1994 we thought it might run for five years before the questions dried up. Now they are getting better and better. Who would think of asking ''How fat do you need to be to be bulletproof''? More amazingly is the fact that our readers had the answer to hand (it's 100-stone, or 60 cm of fat around your vital organs). Brilliant! And I knew they'd be able to answer it - I have great faith in the readership. And children observe more keenly than adults (especially in the things that interest them, like bodily emissions). One of the more enduring things I'm asked in interviews is why is snot green? It was first asked a by a child 15 years ago and people still dig it out (if you'll forgive the pun).