Abstract

This paper aims to develop an understanding of a peculiar hourglass-shaped caustic that can be observed if a partially filled wine glass is illuminated by parallel light. The light pattern is first described in terms of an idealized model of the liquid volume only: the sum of the parametric projection curves obtained by light refraction through liquid cones of varying wall inclinations in the framework of geometrical optics. Within this analysis, analogues to two specific refraction ice halos, the circumzenithal and the Parry arc, will prove to be helpful. The analysis is supplemented by ray tracing simulations that further elucidate the origin of the hourglass caustic when the glass is added to the refraction scenario.

© 2018 Optical Society of America

Ice analog halos

Zbigniew Ulanowski
Appl. Opt. 44(27) 5754-5758 (2005)

Halo in the box: a macroscopic crystal arrangement to project mosaic halos

Markus Selmke and Sarah Selmke
Appl. Opt. 57(29) 8614-8623 (2018)

A general setting for halo theory

Walter Tape and Günther P. Können
Appl. Opt. 38(9) 1552-1625 (1999)

Geometry of halo formation

Walter Tape
J. Opt. Soc. Am. 69(8) 1122-1132 (1979)

Analytic foundations of halo theory

Walter Tape
J. Opt. Soc. Am. 70(10) 1175-1192 (1980)