MacTutor
23rd April
On this day in 1827, William R Hamilton presented a paper on optics, Theory of systems of rays, to the Royal Irish Academy while still a 21 year-old undergraduate. It is in this paper that Hamilton introduced the characteristic function for optics.
On this day in 2014 Google released a Planck doodle.
On this day in 2014 Google released a Planck doodle.