Book: Even more things that nobody knows

It turns out there are many things we do not understand. This is Hartston’s second volume, adding another 501 mysteries to the 501 catalogued in his first book, Things That Nobody Knows.

Some of the things we don’t know are slight, others heavyweight, still others are things that we didn’t even know we didn’t know – perhaps the “unknown unknowns” Donald Rumsfeld baffled us with during the Iraq war.

In the first volume, the questions included why are so many giraffes gay (who knew?). In this book, the Rumsfeld category includes questions you have almost certainly never considered, such as why crocodiles eat fruit and whether the great patriarch Abraham owned camels. (Archaeologists say it is impossible, as camels did not arrive on the scene between the Red and Dead seas until the 9th century. Theologists say they know better.)

You would possibly think that a book with 501 unanswerable questions would be a bit like those unsatisfying Discovery Channel specials, that set up a question to which there is no definitive answer, only to trail off after an hour into a shifty “dunno” non-answer.

This book is not like that, which is a tribute to Hartston. A mathematician, industrial psychologist and twice winner of the English chess championship, he runs competitions in creative thinking for the Independent newspaper and is the author of The Encyclopedia of Useless Information as well as writing the off-beat Beachcomber column for the British tabloid, the Daily Express.

His breezy, often playful style makes this book endlessly diverting. His adherence to real science to give a complete account of the hunches, deduction and guesstimates that are the sum of our knowledge so far is always diverting and enlightening.

There’s also the breadth of subjects covered – astronomy and cosmology, mathematics, biology, medical science, music, art and literature.

Some of the questions he asks this time around are: Do animals have a sense of humour? Why do we have five fingers? How long can humans live? What did Jesus do in his youth? Which speech did Lincoln deliver at Gettysburg? Is there an odd perfect number? What happened to the Neanderthals? Were giant kangaroos too big to hop?

It’s a wonderful, lighthearted tour of the oddball, the perplexing and the fascinating. It should be one of those books you dip into from time to time for a gem or two. In practice, though, once opened it is hard to put down.