Imaging sub-millimeter features from 250m away using only a hard disc as a lens. The Aragosope is a simple diffractive telescope achieving high resolution imaging without mirrors or lenses. NASA funded an exploration of the concept for a giant space telescope back in 2014, but when I set out to make a practical experiment in 2018 there was only one other example I could find on the internet. I will give an introduction to what diffraction is, how it can be used in optics to do useful things like form images, why NASA might be interested, and how I made the experimental setup. I will also perform a live demonstration during the talk of both a simple aragoscope setup and some other diffractive optics (including rainbow chocolate, holograms and a camera that uses 35mm film as the lens! After the talk (and more importantly after dark!) I will also replicate a full demonstration of my Aragoscope experiment if weather allows.
Speakers: Simon Jelley