Optical Filters in Nature
ank you for your recent
article about optical filters
in nature (February 2009).
Your readers might be
interested to know about
a related publication by
A.A. Michelson, titled
“Metallic Colors in Birds
and Insects.” It appears,
with color photographs
and graphs, as Chapter XV, pp. 167-74,
in his book Studies in Optics, which was
published by the University of Chicago
Press in 1927.
Also interesting from a historical
perspective: In Chapter XIV of this
book, which is titled “Relativity,” it
would seem that Michelson hasn’t given
up on the concept of ether. For example,
he writes, “It is to be hoped that the
(relativity) theory may be reconciled
with the existence of a medium, either
by modifying the theory, or, more
probably, by attributing
the requisite properties
to the ether...” And, after
describing the results of
an experiment, he writes,
“ is result may be considered as an additional
e vidence in favor of relativ-
ity—or equally as evidence
of a stationary ether.”
Fred Peet
fpeet@eidetic.bc.ca
British Columbia, Canada
THE AUTHOR REPLIES: I want to thank
Fred Peet for his comments. Although I
am familiar with Michelson’s work on
the speed of light, I had no idea that
he had written on the subject of color
in nature. is forced me to do some
research. Michelson’s first published
article on the subject, “On Metal-
lic Colouring in Birds and Insects,”
appeared in Philosophical Magazine,
FEEDBACK | LETTERS
vol. 21 (1911)— 16 years prior to the
publication of Studies in Optics.
Your historical reference to ether—
the idea that light was carried in a
luminiferous medium—was an interesting diversion. As you point out, Michelson didn’t completely give up on that
idea to explain some phenomena.
H.D. Wolpert
wolpert.bio-optics@dslextreme.com
Los Angeles, Calif., U.S.A.
CORRECTIONS
In the article on p. 9 of the April 2009
OPN (Scatterings,“Designing Better
Spiral Micro-lasers”), we misspelled
the last name of one of the researchers
mentioned—Tae-Yoon Kwon. The correct
spelling is Kwon. We regret the error.
Also, in our feature on the International Liquid Mirror Telescope in the April
issue, one of the references is incorrect.
The final reference on p. 33 should read:
Cosmology at Low Redshifts, Astronomy
& Astrophysics 404, 47 (2003). We
apologize for the mistake.
Prototype
