Optics & Photonics News - September 2011

This display of
ice-crystal halo
effects around the
sun, photographed
at the South Pole,
includes at least
a dozen effects,
some of which have
been recorded by
sketches over the
past few centuries.
The mechanisms for
many of them have
only been under-
stood for the past
few decades. All are
formed due to the
interaction between
light and airborne ice
crystals in the shape
of hexagonal plates
or columns.

Marko Riikonen

ack in the 19th century and earlier—in the days of Rayleigh, Tyndall, Maxwell and Snell— science was often conducted by natural philosophers—generalists whose primary tools were their own eyes.

The subjects of their curiosity were everyday phenomena such as the blue sky, white clouds, the flattened horizon sun, haloes and mirages.

Every few years, a diverse group of scientists carries on this tradition when they gather for the international “Light and Color in Nature” conference. The meetings cover anything having to do with naked-eye optical phenomena, including rainbows, halos, reflections in water, etc. In this forum, curiosity—not job security or advancement—reigns supreme.

Participants include physicists, meteorologists, mathematicians, computer scientists, astronomers, biologists, geologists, teachers and even artists. You don’t need to belong to any scientific organization to attend, and there are no vendors, workshops, parallel sessions or town hall meetings.

Although most presentations are quite technical and wind
up in refereed journals, the conference is relaxed and friendly.
There’s free beer and no one takes themselves too seriously:
The conference’s highest (and only) award is the Lord Rayleigh
Prize, a small plastic toy truck emblazoned with the words
“Fresh Milk from Lord Rayleigh’s Farm.”
Begun in 1978 at the initiative of OSA Fellow David Lynch,
the Light and Color in Nature meeting takes place every three
or four years. The most recent one took place in St. Mary’s,
Md., U.S.A., in 2010, and the next will occur at the University
of Alaska Fairbanks in August 2013. Although recent meetings
have been arranged independently of any organization, OSA
played a key role in launching these conferences: The first few
were sponsored as OSA topical meetings.

Bob: It is interesting to consider the connection between these gatherings and the very origins of optics, which were based on individuals’ attempts to understand the world around them. The motivation was often simple curiosity. Of course, as understanding began to yield practical benefits, other incentives arose. This conference is an attempt to get back in touch with the idea that simple curiosity can be a powerful motivator for scientific discovery.

In 1954, the astronomer Marcel Minnaert inspired many optical scientists with his book The Nature of Light and Colour in the Open Air, a paperback translation of his original Dutch work published in 1937. The book explores optical phenomena in the sky, sea and water, and the author’s constant message is to look with questioning eyes at the world around us. To this day, it remains a text that many of us refer to and treasure.