So here I am, my affections torn between a postal service that never feeds me but can tackle a challenge and one that gives me free tape and prompt service but won't help me out when I can't remember a street name. The lesson to draw from this, of course, is that when you move from one country to another you have to accept that there are some things that are better and some things worse, and there is nothing you can do about it. That may not be the profoundest of insights to take away from a morning's outing, but I did get a free doughnut as well, so on balance I guess I'm happy.

Disassemble the cells of a sponge (by passing them through a sieve, for instance), then dump them into a solution, and they will find their way back together and build themselves into a sponge again. You can do this to them over and over, and they will doggedly reassemble because, like you and me and every other living thing, they have one overwhelming impulse: to continue to be.

Think of a single problem confronting the world today. Disease, poverty, global warming... If the problem is going to be solved, it is science that is going to solve it. Scientists tend to be unappreciated in the world at large, but you can hardly overstate the importance of the work they do. If anyone ever cures cancer, it will be a guy with a science degree. Or a woman with a science degree.

I really enjoy going to a library and spending the day doing research - to me that is the most pleasurable part of writing the science book.

Britain still has the most reliably beautiful countryside of anywhere in the world. I would hate to be part of the generation that allowed that to be lost.

There is no such thing, incidentally, as one kudo.

Anyone who has read my books will know that I don't tend to use guides when I am travelling. It's not a pride thing, but it is certainly a fact.