FoundationalConceptsNeuroscience

11.4). The electromagnetic spectrum of radiation encompasses an
enormous range of energy, from very high-energy gamma rays and x-
rays to moderately high-energy ultraviolet radiation, to visible light,
to infrared radiation, to microwaves, and finally to relatively low-
energy radio waves. High-energy gamma rays and low-energy radio
waves differ by more than eighteen orders of magnitude (a factor of
1018 ora million million million = a quintillion) in energy. Within
this huge spectrum of energy, a narrow band spanning less than a sin-
gle order of magnitude comprises the sensitivity range of the human
visual system. This is “visible light,” so called because it is visible to us
humans, and to many other animals, too.
Not all that long ago it was widely believed that only we humans
had the ability to see the world in all its richness of color—that other
animals could only see things in black, white, and shades of gray.
Consider honeybees, insects that spend their lives visiting flowers,
gathering nectar and pollen, and transferring pollen between plants,
contributing to plant fertility. Though little in nature rivals the ex-
traordinary variety and exuberance of colors in flowers, it was not
generally believed that honeybees could see color. After all, they were
merely simple insects.
Then, in the early twentieth century, Karl von Frisch (1886-
1982), through years of careful observation and experimentation,
conclusively demonstrated that honeybees have color vision. This
may seem like an obvious fact today—now that we appreciate that
many animals have excellent color vision—but at the time it was a big
discovery, so much so that it contributed to von Frisch receiving the
Nobel Prize for Physiology or Medicine in 1973 (together with Konrad
Lorenz and Nikolaas Tinbergen, for their work in other aspects of ani-
mal behavior). Von Frisch began his Nobel Prize lecture: