Fun post for Friday.
Researchers at Nanyang University demonstrate the refractive qualities of Calcite to make a post it note ‘disappear.’
[youtube=http://www.youtube.com/watch?v=U5APMyTGrFg]Researchers at Nanyang University demonstrate the refractive qualities of Calcite to make a post it note ‘disappear.’
Erasmus Bartholin was the first to note the double refraction of iceland spar (Calcite) in 1669. You can get his Experimenta crystalli Islandici disdiaclastici quibus mira & insolita
refractio detegitur as a free ebook.
Isaac Newton also experimented and reported on the phenomenon.
But the folks at Nanyang University got it posted to Youtube
Obvious applications include defense, organized crime, smuggling, and advertising.
Open clusters