I wish I could adjust my voice, but it's just what's happened to me. It's because I've lived abroad for a long time, and my wife is English and my kids all have English accents, and every voice I hear is English. I've never intentionally changed my accent at all.

Coming back to your native land after an absence of many years is a surprisingly unsettling business, a little like waking from a long coma. Time, you discover, has wrought changes that leave you feeling mildly foolish and out of touch.

Physics is really nothing more than a search for ultimate simplicity, but so far all we have is a kind of elegant messiness.

There is something about the momentum of travel that makes you want to just keep moving, to never stop.

Cheapness is a great virtue.

Every atom you possess has almost certainly passed through several stars and been part of millions of organisms on its way to becoming you. We are each so atomically numberous and so vigorously recycled at death that a significant number of our atoms-up to a billion for each of us, it has been suggested-probably once belonged to Shakespeare. A billion more each came from Buddha and Genghis Khan and Beethoven, and any other historical figure you care to name.

No one knows, incidentally, why Australia's spiders are so extravagantly toxic; capturing small insects and injecting them with enough poison to drop a horse would appear to be the most literal case of overkill. Still, it does mean that everyone gives them lots of space.