Clear skies greeted 235 visitors to Western University’s Cronyn Observatory Summer Public Night, Saturday, July 7th, 2018, 8:30—11:00 p.m. RASC London Centre member Henry Leparskas presented the “Einstein’s Equivalence Principle” experiment, which consisted of a metre long stick topped by transparent plastic sphere containing a cup with a ball attached to a spring. Henry showed how, when the stick is held vertically and tossed in the air (or dropped), gravity is cancelled out in free fall, enabling the spring to pull the ball into the cup—since the ball experiences zero gravity—thus demonstrating Einstein’s “Equivalence Principle” that gravitational force is indistinguishable from acceleration. Henry circulated the device among some of the visitors to try the experiment themselves. There were 43 visitors in the lecture room by 8:15 p.m.
Professor Pauline Barmby made 2 presentations of her digital slide presentation “The Gemini Observatory” and fielded questions. Graduate student Megan Tannock was initially at the door doing “crowd control” before going downstairs into the “Black Room,” around 8:30 p.m., to do the “Transit Demonstration” and “Spectroscopy Demonstration.” RASC London member Bob Duff took over the visitor count which came to 235 people by the end of the evening.
Megan Tannock spent most of the evening downstairs in the “Black Room” where she did the “Transit Demonstration” with the “Transit Demo” model—showing how the transit detection method worked for finding extra-solar planets—and the “Spectroscopy Demonstration,” with the visitors putting on diffraction grating glasses to view the spectra of 4 gas discharge lamps, including hydrogen, helium, neon and mercury.
Henry Leparskas spent the evening in the downstairs history rooms, showing visitors the“1940s Period Room,” a recreation of Dr. H. R. Kingston’s 1940 office, with his brass refractor and the Sotellunium—a mechanical eclipse demonstration model built by W. G. Colgrove—on display; and the “1967 Period Room,” recreating the early control room of the Elginfield Observatory to celebrate the 150th anniversary of Confederation—Canada 150. The newly created “W. G. Colgrove Workshop Period Room” was also open for visitors to inspect. The 3 “Period Rooms” were designed by RASC London Centre member Mark Tovey.
RASC London Centre was represented Everett Clark, Henry Leparskas, Steve Imrie, Dale Armstrong, Heather MacIsaac, Bob Duff, Steve Gauthier, Peter Jedicke and Mike Flegel. Everett made ready the big 25.4cm refractor (Meade 28mm Super Wide Angle eyepiece, 157X) in the dome and directed it towards Venus, although it was not visible in the bright early evening sky. Graduate student Hadi Papei arrived and was telescope operator for the evening, showing visitors Venus and Jupiter through the 25.4cm refractor (Meade 28mm SWA eyepiece, 157X). Peter Jedicke gave 3 short talks in the dome to visitors who were lined up all the way down the stairs to view through the big 25.4cm refractor. Mike Flegel answered some questions. Everett talked to visitors and gave out 2 “Star Finder” planispheres.
On the observation deck outside the dome, Steve Imrie directed the London Centre’s home-built 30.5cm Dobsonian towards the wind turbine on the Engineering building and then showed visitors Venus (17mm Nagler eyepiece, 88X). He was soon joined Steve Gauthier and they took turns showing people Jupiter and Saturn through the 30.5cm Dobsonian (17mm Nagler eyepiece, 88X), later swapping in the 12.5mm Ortho eyepiece (120X) for a better view of Saturn. Steve Gauthier answered questions from visitors. Dale set up and operated the observatory’s Meade 8-inch (20.3cm) Schmidt-Cassegrain for the evening and began by showing visitors Jupiter (12.5mm Ortho eyepiece, 160X). He later swapped in the 15mm Sky-Watcher UltraWide eyepiece (133X) and then the 26mm Plossl (77X) to show them globular cluster M13. Heather MacIsaac set up her Celestron NexStar 90SLT 90mm Maksutov-Cassegrain and showed visitors Venus, Jupiter and Saturn, using the 17mm Plossl eyepiece (73.5X).
The visitors were gone by 11:00 p.m., after an interesting and enjoyable evening with the slide presentation “The Gemini Observatory,” the “Transit” and “Spectroscopy” demonstrations, tours of the history rooms, and observing Venus, Jupiter, Saturn and M13 through telescopes. The 25.4cm refractor was directed towards Mars, rising low in the southeastern sky, around 11:30 p.m. after the visitors had gone, and Dale installed the No. 25 Red planetary filter on the Meade 28mm SWA eyepiece (157X) to try and highlight features on the planet’s surface.