What should I ask Philip Ball?

Yes I will be doing a Conversation with him.  Here is Wikipedia:

Philip Ball (born 1962) is a British science writer. For over twenty years he has been an editor of the journal Nature, for which he continues to write regularly. He is a regular contributor to Prospect magazine and a columnist for Chemistry World, Nature Materials, and BBC Future.

Ball holds a degree in chemistry from Oxford and a doctorate in physics from Bristol University.

He has written more science books than I can count (see Wikipedia), on a wide variety of topics, and I very much liked his latest book How Life Works: A User’s Guide to the New Biology.  How many people have demonstrated a greater total knowledge of science than he has?

So what should I ask him?