Life Under the Sun

A collection of science essays
about how organisms sense and respond to the sun's radiation

by Peter A. Ensminger

Life Under the Sun is a book that represents my personal festschrift to organisms which sense and respond to the sun's radiation. The book will have about fifteen essays upon completion and will be published by Yale University Press. All the essays are written at a non-technical level and are directed toward readers interested in nature, science, or the environment. A table (Levels of Light on Earth and Some Associated Biological Responses) unifies many of the disparate topics covered in my book.

Some of the essays I have completed are:
A Novel Method of Weed Control
Farmers can dramatically reduce their dependence on herbicides by applying a new method to reduce the germination of photosensitive weed seeds. (Cover article in Biology Digest, January 1996).

A Burning Issue
Recent research has shown that long wavelength ultraviolet radiation (UV-A), formerly considered rather benign, can cause skin cancer and other health problems in humans. (Cover article in Biology Digest, May 1996).

Light and Beer
Light chemically excites certain chemicals derived from hops which can destroy the flavor of beer in the well known sun-struck reaction. (Cover article in Zymurgy, Autumn 1996).

Phycomyces - The Fungus that Sees
Physiological processes in the fungus Phycomyces and in the visual systems of humans allows adaptation to a 10 billion fold or more change in ambient light intensity.

The Five Percent Solution to Vision
The Eyeless Shrimp (Rimicaris exoculata) lives near hydrothermal vents, two miles deep in the Atlantic ocean, and has very rudimentary eyes which may allow it to actually see these deep sea geysers.

Turning on a Butterfly
The Japanese yellow swallowtail and many other butterflies have photoreceptors on their genitalia and light-excitation of these photoreceptors is necessary for copulation.

A More Delightful Vision
The mantis shrimp, which lives in tropical coral reefs, has eyes with more than a dozen different types of photoreceptors, many more than humans or any other species.

Vision at the Threshold
A rod cell in the retina of our eyes can sense the absorption of a single photon and absorption of photons by only about six different rod cells allows us to perceive a flash of light.

Peter A. Ensminger,
last updated July 7, 1998