Physics behind the floating card trick

[zorro]

Is there any Physics law behind this-

http://www.youtube.com/watch?v=YVH7dVJfyqA"

Or is it just a trick? I can't find any strings around the card.

 

[Archosaur]

I think there's a string running from his mouth to the card and then from the card to some point off to the left. I think that for four reasons:
First, the motion of his hands wouldn't interfere with such a setup.
Second, the card wobbles about an axis that suggests such a setup.
Third, he never opens his mouth.
Fourth, the card descends only when he leans forward.

 

[zorro]

Third, he never opens his mouth.

Hahaha
Yes I can see that. He is holding the string from his mouth.

Fourth, the card descends only when he leans forward.

A very careful observation!
Its just a trick :|

 

[K^2]

Not to his mouth. There are two strings, and they are at chest level. Attached to the shirt, probably. There almost has to be a second person controlling the other end of the strings.

Very nicely done, but no levitation.

Edit: Hm. Maybe it is in his mouth after all. Seems unnecessary, though.

 

[pallidin]

Right, just a good trick, and I doubt that something "truly" levitating would so easily wobble. And the axis of wobble is such that, like said, would not cause his hand movements to interfere with the "invisible" string.
Still, good trick.