Trinity Physics – The Discovery of Conical Diffraction

The 19th century was a very exciting time for Irish physics. The grounds of Trinity College Dublin were walked by some of the greatest Irish physicists in history. This story involves two of them, William Rowan Hamilton and Humphrey Lloyd.


In the early 19th century, William Rowan Hamilton mathematically predicted a curious phenomenon called conical refraction and Humphrey Lloyd was the first person to demonstrate the effect experimentally. This achievement was a strong argument for the wave theory of