Have you got supernatural healing powers, seen a ghost, talked to your grandma in heaven, been saved by an angel or gone for a ride in a UFO? If you can prove it scientifically, James Underdown will give you $100000.Underdown is the executive director of the Centre of Inquiry, in Los Angeles, and a sceptic activist who exposes phonies. He was visiting Cape Town last week with his wife, South African writer Karen Briner.Underdown welcomes controversy. He is a powerfully built man with kind eyes set in a lived-in face like a worn wallet.He has been a truck driver, carpenter, bouncer and film-maker, and is lead singer of a rock 'n roll group, The Heathens."I live in LA, which is crammed with people with New Age ideas - water dousers, psychics, healers, clairvoyants, past-life regressors. It got to the point at which, instead of arguing, I thought: 'All this stuff is testable by science'. So I started a centre for inquiry."Now they don't have to jaw- flap with me any more. I just hand them my card. We have a $100000 prize for anyone who can prove what he's saying."The centre doesn't charge for testing people's beliefs and claims."The thing is, people do not like the idea that life is random and unfair. They form these myths to console themselves."Take healing: "I have investigated many but have never found anyone who has been healed by faith."A cancer client was told to soak himself in a tub of water full of red-hot peppers. The idea was to sweat the cancer out. Did it help? No, it shortened his life by two years."We tested someone in Boston. She said she could astral-project to us in LA and tell us what is on the table behind the curtain. She had 20 tries and got zero right."We always ask them, do you feel you were treated fairly? They blame 'the negative energy' in the room or it 'wasn't one of my days'."Underdown said the people tested sincerely believe in what they are doing.He reported on a medium who did a one-hour reading."Over the span of 55 minutes she made hundreds and hundreds of guesses and answers. She would say, 'I see him at a bench, he is looking very happy, his dog is with him, a big dog, maybe a collie, has he got a dog? Ah no, maybe a neighbour's'. It was so rapid and there were so many questions it was hard not to get something right."TV shows are another thing. "I saw a John Edwards TV show being taped. The raw performance was completely different to what they showed on TV. All the mistakes ended up on the cutting room floor. A TV psychic would be in big trouble without his editor."It can be hilarious. "I went to one reading. The woman wanted to talk about her dead husband. The psychic said: 'I am getting something about Jesus. Jesus, Jesus'. Finally the woman said, 'I don't know what you're talking about - we're Jewish'."According to Underdown, people tend to be much more forgiving of psychics and mediums than of other service providers: "Hey, you got half of them right." But if it were your doctor or your car mechanic you wouldn't be so cheery."Being sceptical is just thinking rationally and is part of critical thinking and should be taught in schools. Society should have standards about what is true and what is not. Much of the stuff we believe is untrue," he said.Non-critical thinking can kill people: "When your health minister says that Aids can be cured by a diet, that's dangerous."So far a lot of people have tried but nobody has won the $100000.E-mail junderdown@ centerforinquiry.net if you think you deserve the $100000..