Saturday, 29 August 2009

Seeing Through Illusions – Richard Gregory ***

Oxford University Press has a long and distinguished history of producing popular science books that sound as if they are going to be brilliant, but turn out to disappoint. Often this is because the author is a scientist who knows his subject, but doesn’t really know how to communicate it to the general reader. Seeing Through Illusions is a classic case of this phenomenon. The premise is superb. Using optical illusions and what they reveal to explore the workings of human sight and perception. But sadly it is a wasted opportunity.
It’s revealing that the first actual optical illusion in the book doesn’t come to the colour plates have way through. There’s page after page of context and explanation without ever showing us an optical illusion – the reader is desperately wanting to see one and we just keep getting comments on them without the actual things. When they do crop up they are little more than listed, with plenty of jargon but little relevance to the structure of the text.
It would have been so much better to have built the structure around the illusions, allowing them to gradually reveal the theory and ideas, rather than piling in all the theory in text form first, then finally throwing in illusions.
A few specific issues. Richard Gregory can be a bit fuzzy when off his subject. He tells us that Einstein won his Nobel Prize for his paper on Brownian motion – in fact it was his paper on the photoelectric effect that won him the prize. And the text is often overladen with jargon. Take this caption for an illusion: ‘Ponzo illusion. The basic perspective illusion. The upper horizontal line appears expanded by constancy scaling, normally compensating shrinking of the retinol (sic) image with increased distance.’ Is that clear?
Just occasionally there are moments of real interest where something is revealed about the way our complex visual systems fool us in the way they produce an apparent image of what we see. But this could have been an absolutely wonderful book, and it is, in practice, hard to recommend it for the general reader. What a pity.
Review by Brian Clegg