This topic has been a big thorn in the side of my mind for a long time; and this is regarding the art of "pulling someone over without touching them".
I enjoy martial arts, and was interested in watching "Mind, Body and Kick ass moves" which aired on BBC 3 not so long ago. In various episodes Chris (I think) stands behind a person, and uses Chi/Ki to pull someone backwards (he also gives people weird sensations, all the while not touching them).
I was happy to accept that this was some weird martial arts effect...and that I'd have to develop my Chi Gung. Of course, the tables turned whilst watching Derren Brown in "Messiah". If you recall whilst posing as a radical Christian, "converting" people. He stands behind someone and pulls them backwards.
This leads me to believe that it (as well as a lot of martial arts demonstrations) are atleast in part a trick. (A lot of it is due to physics), but I can't get my head around this.
I can believe that Derren uses his mini-hypnotism (and by saying he will catch them, let what happen happen, and standing behind them. They are inevitably going to fall), but for the more detailed versions (pushing pulling, and doing other stuffs

Any help?
Edit [ I'm guessing you prob wont tell me, but a direction to a book, or a discussion about it would be interesting. I've been stewing about this for a while ]
(Some of Derren's stuff annoys me....because there doesn't seem to be any logical explanation. It's seems to be pure witchcraft....it's great!).