Gray Matter: In Which I Fully Submerge My Hand in Liquid Nitrogen
My hand is like a red-hot poker to the liquid nitrogen, but an insulating layer of nitrogen gas forms- a phenomenon known as the Leiden-frost effect- keeping my hand safe and warm for a fraction of a second.
I played with liquid nitrogen when I was an undergrad. I stuck my hand in it. Also, if you pour some on a tray, blobs are held together by surface tension. The interface with the tray is extremely low friction (as the Nitrogen is floating on a layer of gas that is boiling off). The little blobs skitter around in an extremely pleasing fashion. I also recal that, at the time, liquid nitrogen costed about the same as beer. So it was not bad value entertainment.