A flower-shaped brooch produced by Jewelarama, with a diffracting disc at the flower’s center. [etsy.com/shop/MermaidSistersStudio]
The first recorded effort to construct a diffraction grating was in 1785 by scientist David Rittenhouse of the University of Pennsylvania, USA. It was made in response to a query from New Jersey politician David Hopkinson, who wanted to know why his handkerchief looked very peculiar when he held it close to his eyes. Rittenhouse created a model of the horizontal threads of the handkerchief by winding a wire between the threads of a very fine screw. (See “Diffraction, the Silk Handkerchief, and a Forgotten Founder,” OPN, October 2010.)