- Jan. 24, 2024, 4:00 pm US/Central
- Charles Clark, Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland
- Doğa M. Kürkçüoğlu
- Video
Dislocations in wave trains were manifest in the 1830s studies of ocean tides by William Whewell, who discovered “amphidromic points” in the sea, where there is no tidal motion. John Nye and Michael Berry’s 1970s investigations, of fine structure in radio echoes from the bottom of the Antarctic ice sheet, revealed wavefront dislocation as a generic phenomenon. It became a broad field of science in the 1990s, when “orbital angular momentum states” of light were produced, followed by similar realizations in beams of atoms, molecules. x-rays, electrons and neutrons. Robert R. Wilson’s “Tractricious” sculpture at Fermilab provides a good framework for visualizing the unity of these phenomena.