The Dent Dipleidoscope, a Sundial by Another Name.
Our local star has provided time-keeping for millennia but the Industrial Revolution led to increased demand for time accuracy that simple sundials could not provide. The sun, celestial mechanics and innovation provided a simple, inexpensive device that allowed setting clocks in the mid-1850's by the layman with an accuracy of just a few seconds. This presentation will discuss the history, science, design and use of the Dent Dipleidoscope and several working units will be displayed.
Larry McDavid has long been interested in the history and design of sundials and is a long time member and Sundial Registrar for the North American Sundial Society. Larry often travels to give presentations on the science and construction of sundials. He is also a deep sky observer and maintains a permanent telescope pad at the Orange County Astronomers dark sky site at Anza. Larry chases eclipses and has traveled to distant locations to observe six solar eclipses.
Larry is active in the Microscopical Society of Southern California and uses compound and stereo microscopes as a hobby and to support his interests in home shop machining and electronics. He holds an Extra class amateur radio license and has been active on the HF and VHF ham bands for over 55 years. Larry builds much of his own equipment using a small home electronics shop and precision metal machine shop.
Larry is a retired electromechanical engineer and worked as Engineering Manager for Beckman Instruments, TRW and Molex for over 30 years. Larry has managed the development of Martian life detection instruments, Earth-orbiting instruments that detected the Antarctic ozone hole, medical monitors that enhanced the survival rate for very premature babies and automotive air bag crash sensors.
Astronomical science with your consumer-type digital camera
The common DSLR camera - when properly used - can be a remarkably accurate scientific instrument.
Robert K. Buchheim
Mr. Buchheim has been an avid amateur astronomer for over 30 years. His particular joys are introducing children to the night sky, and encouraging amateur astronomers to participate in small-telescope research projects. His book, "The Sky Is Your Laboratory" is a manual for the research-oriented amateur astronomer.
Mr. Buchheim has been a visual observer, telescope maker, CCD astrometrist and photometrist. He has published deep sky observations, presented papers at astronomy conferences, given presentations to amateur astronomy clubs, and published research papers on asteroids, variable stars, and double stars. He is a Trustee of the Orange County Astronomers (in southern California), a Board member of the Society for Astronomical Sciences, and proprietor of the Altimira Observatory (in his backyard). In 2010 he was awarded the G. Bruce Blair award for noteworthy contributions to amateur astronomy, by the Western Amateur Astronomers. His professional background is in engineering and manufacturing management; in that role has published a few technical papers in peer-reviewed journals. He received a BS in Physics from Arizona State University, and is a graduate of the Defense Systems Management College and the UCLA Executive Management program.
"What's Up?" in this month will be presented by Steve Condrey
Monthly General Meeting
The OCA has a general meeting held on the second Friday of every month* at Chapman University.
These meetings are free and open to the general public.
The meetings take place in The Irvine Lecture Hall with seating for approximately 250 people.
The Irvine Lecture Hall (located adjacent to the Hashinger Science Center) is near the south east corner of the campus
and the nearest cross street is East Palm Ave and North Center Street.
The meetings start promptly at 7:30 PM.
The basic agenda, with approximate times, is as shown below.
7:00 PM - 7:30 PM Pre-meeting Slide Show
Arrival of audience. This presentation includes recent astronomical photographs taken by OCA members.
7:30 PM - 7:45 PM Club Announcements
Usually presented by the OCA Secretary, Bob Buchheim.
7:45 PM - 8:15 PM "What's Up?"
Usually presented by OCA Member and Space Artist, Chris Butler.
8:15 PM - 9:15 PM Main Talk
Speakers are often from JPL/Caltech and other major educational and astronomical institutions.
The level of the talks are usually appropriate for anyone who has an interest in this hobby.
9:15 PM - 9:30 PM Refreshments
Break Donuts, coffee, soda are available for a small donation.
9:30 PM - 10:00 PM "Ask an Astronomer"
Anyone can stay behind and ask a panel of experts any burning question related to this hobby.