The Zhou Bi Suan Jing (The Arithmetical Classic of the Gnomon and the Circular Paths of Heaven) is an ancient Chinese mathematical text that dates from the period of the Zhou Dynasty (1046 – 256 BCE). It is an anonymous collection of 246 mathematical problems, each with detailed steps and answers. It contains one of the first recorded proofs of the Pythagorean Theorem, to which a later Chinese mathematician, Chou Kung, provided an accompanying diagram (below) that is for me one of the simplest ways to see how the area of the square of the hypotenuse equals the sum of the areas of the squares of the other two sides. If you have even a rudimentary grasp of this most popular of school maths topics, you should be able to see how it works from the diagram.

My second topic is what I hope is a measured response to some criticism I received in the press recently. A year ago I wrote an article in the Telegraph about a 9th century scholar from Baghdad who had come up with some crude evolutionary ideas. The article (as well as another in the Guardian) was my way of testing the water ahead of a Royal Society lecture I gave as well as the filming of my BBC series and the book. Basically, if I was to be getting stuck in to this subject I was keen to see the public’s reaction. It clearly provoked, albeit a whole year later, an acquaintance of mine, Steve Connor, science correspondence for the Independent newspaper.

I have worked with Steve before and know him well and I do not want this to look like we are locking horns on this. Steve wrote a piece in which he says:

Professor Jim Al-Khalili, a physicist at Surrey University, has been a vocal supporter of al-Jahith, and will no doubt be bringing him in to his rather good series Science and Islam on BBC 4.

“Environmental factors influence organisms to develop new characteristics to ensure survival,” al-Jahith wrote. “Animals that survive to breed can pass on their successful characteristics to offspring.”
Al-Khalili says that this qualifies as a theory of natural selection, but any scholar of Darwinism will point out that this could just as easily describe another, discredited evolutionary mechanism, known as Lamarckism. Sorry Jim, from what little we know of al-Jahith and his ideas on evolution, he can’t hold a candle to Darwin and Wallace.

In fact, al-Jahith did not even get a mention in my TV series – there were plenty more even greater scientists to talk about than him. Steve seems to think I was literally claiming that al-Jahith discovered the theory of evolution before Darwin and that I was somehow belittling Darwin’s achievement. Nonsense. Darwin is for me one of the top five greatest scientists of all time (Newton, Einstein, Aristotle and Archimedes are the others – order them as you see fit). All al-Jahith did was suggest that animals might be influenced by their environment and that they could pass on these acquired characteristics to their offspring. This is of course, at best, Lamarckism, not Darwinism, and the two are very different. But even the now discredited Lamarck should not be too concerned, for al-Jahith’s writing (in his “Book of Animals”) is littered with superstition and mythology (like God reverse evolving (is this devolution?) a race that he is unhappy with back to apes! His notions should not be taken too seriously as scientific.

No, my point was rather that here was a Muslim scholar over a thousand years ago prepared to come up with outlandish theories in order to describe the world around him. It may not have been proper science as we would define it today but this rationalist outlook and sense of enquiry is often missing in many religious societies today (just check out the recent opinion polls about evolution theory in two highly religious countries (the US and Turkey) and be very afraid! If I were wishing to provoke, it would not have been Darwinists – for I am a dyed-in-the-wool Darwinist myself – but rather as a wake up call to those theists, particularly young Muslims who should feel very proud of the achievements of medieval scholars like al-Jahith, who have such a problem with it.

So, no Steve, I wasn’t dissing Darwin. But we are celebrating the 200th anniversary of his birth this year, so I guess now is a great time to be engaging in debate on evolution, one of the greatest discoveries (some would argue the greatest) in the history of science. And you and I are most definitely on the same side here.