January 14, 2009 -
"Timelines" by Roger Bailey,
Walking Shadow Designs
Abstract: The sun is the essence of time. The daily rotation and annual orbit
of the earth determine our hours, day, seasons and year. A sundial provides a
true measure of time using a shadow to track the relative motion of the earth
and sun. Sundials were the first instruments developed by man to measure and
understand the universe. In the presentation "Timelines", Roger Bailey outlines
how our concept and measurement of time evolved through the use of sundials.
Different cultures used different concepts of time and carved different
timelines on their sundials. Many examples from around the world will be
presented. One example is the dial that Roger recently designed for the Missouri
Botanical Garden. This Ottoman sundial uses two gnomons to tell time in four
different systems: normal hours based on 12 noon, Babylonian hours based on
sunrise, Italian hours based on sunset and Moslem prayer times.
Bio: Roger Bailey is amazed by how much you can learn from the
shadow of a stick. His curiosity about sundial time has guided personal
explorations in astronomy, mathematics, history, religion, anthropology, art,
and crafts. Roger is interested in sharing this interest in sundials and
strongly supports the North American Sundial Society in appreciating sundials in
modern society. Roger has been an active member of NASS since 1995 and Secretary
Like most engineers, Roger likes to design and build things. His working career
as a Chemical Engineer was devoted to research and development of diverse energy
technologies including hydrogen isotope extraction and oil sands processing.
This research typically involved long development time horizons, large budgets
and teamwork management. Designing and building houses and sundials has provided
more immediate and personal satisfaction.
Roger Bailey graduated with an honours BASc in 1966 from Queen's University and
is a semi-retired Professional Engineer. As the principal of Walking Shadow
Designs, Roger is now offering consulting services on energy technologies and
His interests are indicated by membership in the North American Sundial Society,
the Royal Astronomical Society of Canada, and various hiking groups.