PPO stands for "Permanent Paranormal Object". A PPO is something which could only be made using paranormal abilities. In other words, the very existence of a PPO would be tangible, persistent proof that paranormal powers exist.

This theme has been explored by various writers who handle paranormal subjects. If we find it hard to say how an object was made, how readily should we resort to paranormal explanations? When should we say, 'This must be of paranormal origin', and when should we say, 'I cannot figure out how this was made' ?

Some people take this view: 'Just because I can't figure out how it was made, that doesn't mean there isn't a way of making it'. Is this unduly sceptical? On the other hand, some take this view: 'Even if we figure out a clever way to make it, that doesn't mean we should dismiss the "paranormal origin" theory.' Is this unduly credulous?

I find the notion of a PPO fascinating. Suppose one sees a flat ring of paper, and a flat ring of silver foil, which are permanently inter-linked. There are no cuts, joins or seams to be found - both are intact. How could such rings be made? Must paranormal forces be involved? Well, I have a set. I do know how they were made, and there was nothing paranormal about it. And what about these two inter-linked rolls of "Sellotape" or "Scotch" tape? Nothing paranormal - just the exceptional creative ingenuity of Angus Lavery. What about this spoon that changes shape?

I am pleased to note that some people have used my Wow Cards as handy illustrations of the same theme. (They are nice and portable, and can slip inside any wallet or purse.) It has become very clear that the cards generate a wide range of responses.

Some people initially see nothing difficult or 'impossible' about Wow Cards. However, if they are gently invited to 'unfold the card in your mind', they gradually see the counter-intuitive nature of the cards' construction.

Other people need no such coaxing. They are immediately struck by the difficulties inherent in making the cards, and enjoy the mental challenge of trying to discover the folding process by 'reverse-engineering'.

"Ian, those 'things' you make, the Wow cards, are indeed clever, nearly impossible, and beguiling."
- James Randi