A. James Mallmann

Milwaukee School of Engineering · Milwaukee School of Engineering

In the entertainment world, people usually like, and find memorable, novels, short stories, and movies with surprise endings. This suggests that classroom teachers might want to present to their students examples of surprising facts associated with principles of physics. Possible benefits of finding surprising facts about principles of physics are...

For temperate latitudes, the assumed path of the Sun across the sky would suggest that the angle between the horizon and the Sun’s path at sunset would be much greater on the first day of summer when the Sun is high in the sky at noon than on the first day of winter when the Sun’s noon elevation is 47° lower. The angle that the Sun’s path makes wit...

Rays of sunlight that strike raindrops produce rainbows that provide information about the spectrum of sunlight. Rays of sunlight that strike airborne ice crystals produce halos, sun pillars, and many other patterns of light and color in the sky. Analysis of those patterns makes it possible to determine the types and orientations of the ice crystal...

The Physics Teacher 46(4), 196 (2008) DOI: http://doi.org/10.1119/1.2895662

Using a Monte Carlo method, we simulate the appearance of light pillars produced by nearby light sources and compare their appearance with simulations of Sun pillars. Photographs of light pillars are also compared with the simulations. We expand the idea of light and Sun pillars by examining the reflected-light patterns from several different known...

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Sometimes a vertical column of light can be seen either above or below the sun, usually when the sun is low in the sky.

When light from the sun reflects off the external faces of airborne ice crystals, patterns of light may appear in the sky. The parhelic circle and sun pillar are two specific examples. In this paper we present a discussion of the light pillars that are produced when ice crystals are illuminated by nearby light sources.

An attempt is made to describe the appearance of a rare anthelic arc. The appearance is misrepresented by a previously published photograph.

Ice crystals in the form of right hexagonal prisms have faces that form 90° prisms. Light rays were traced through these prism faces by computer calculation, and the light patterns that would be produced in the sky for a particular distribution of crystal orientations were simulated. Crystals with random orientations produce a 46° halo. Hexagonal p...

A computer simulation technique is used to investigate the origins of the arcs of Lowitz. The model explored consists of light passing through a hexagonal ice plate, spinning about a major diagonal axis that remains horizontal as the crystal falls.

The existence of hexagonal, pencil-shaped ice crystals that fall with their long axes horizontal is well established. We have used a computer simulation technique to examine the consequences of five mechanisms suggested in the literature to explain the origins of anthelic arcs. The results show that pencil crystals with horizontal axes may be respo...

Circumscribed halos which appear around the sun are simulated by a computer treatment of a simple model.