YouTube video (just click the link and it will automatically fast-forward to the right time mark for you which is located at about 9 minutes 50 seconds)
More of an astonishing nature. Here is a cork stopper. Here is a cork stopper with a pin in it and there's the head of the pin. Here's another cork stopper with a pin in it and that's the point of the pin. And if I put these point to head in this position, if I can find that position here, and let go, obviously it will not stay stably. It will tip over.
I'm not sure what he exactly means by that.
Still picture from the video: