Watch glass objects disappear and learn about the index of refraction

Has anybody out there actually been to the Exploratorium out in San Francisco? I assume it's a great science museum, but I've never actually been to San Francisco.

The video above shows an experiment comparing the index of refraction of pyrex (borosilicate glass - the rods that disappear) to that of, I assume, soda lime glass (the rod that stays visible). Pyrex has a nearly identical index of refraction as does corn or vegetable oil (and mineral oil, too). Because of that, Pyrex 'disappears' when soaked in corn oil.

For a slightly more theatrical presentation, check out Steve Spangler's take on the same experiment.



The demo also works with ghost crystals...


I've also heard that it works with colorless gelatin, but I haven't found a video of that, and I haven't tried it at home...yet...