John Dilday came to Robbins Monday to shed a little light on light.
"We sometimes think the more light, the better," he said. "But really, having the right amount of light is best. Too much light can mean you actually see less. Too much light is what we call glare."
Dilday was meeting with town and community leaders who will be planning Robbins area local support for this year's Mid-Atlantic Star Party (MASP), an annual gathering of astronomers.
MASP 2006 is moving from the Occoneechee Scout Reservation to a new site closer to town. The clubhouse and campground operated by a 26-year-old motorcycle club, Brothers of the Horizon, will host these stargazers this year.
As preparation, Dilday was explaining astronomers' need to have dark places where they set up their observation stations.
Astronomers don't hate light, Dilday told the gathering at the Robbins Area Public Library.
Mayor Mickey Brown, along with Commissioners Mark Garner and Lynn Loy as well as Debra Cockman, town clerk and finance officer, joined Ronnie and Pam Williams and others from the club attended.
"We love light, actually," Dilday said. "Light is what we are looking for. It's what we come to see."
The human eye developed over time in such a way as to respond in different ways to differing levels of light intensity. The eye can actually see different things in dim light than it can in bright light.
"We are lucky to have been raised by parents who knew to put shades over their lamps," he said. "Lights that shine directly into our eyes are blinding. Reading, where black letters lie on white paper, benefits from brighter light. Other activities benefit from much lower light."
He told of a painter whose works demonstrate this phenomenon. Forests in her paintings change as light is increased or reduced.
"You really see more trees at low levels," Dilday said. "When the light goes up, those trees go away."
Dilday showed an aluminum dish, a parabolic reflector made to go over a typical backyard light of the kind often used in rural areas for security.
"This redirects the light that otherwise would go up and be wasted," he said. "It shapes it to put that light where you want it to go."
By using covers, the area beneath can be three times a bright. Conversely, a bulb only a third the wattage needed without a reflector can be used. A 50-watt lamp does the same job as a 150-watt bulb.
Shaping the lighted area is more effective in another way. Reducing the glare in eyes makes everything easier to see.
Because bright light is commonplace, many people don't experience their own ability to adjust to dim light. Dilday showed a tiny one-cell flashlight, glowing a faint red.
"Once your eyes adjust, this is all you would need (at the star party) to get around," he said, moving it to cast a red glow against his palm. "I can ever read by it."
In low light, the eyes' pupils open wide. Things unseen come into view. Stars overhead that were too faint before can be seen peppering the sky. An ordinary pair of binoculars turns into an astronomical telescope.
White light takes the longest recovery time, red the least (though all light has some persisting effect).
"It can take half an hour for your eyes to recover," he said. "Sometimes even an hour. If a car shows up suddenly without turning off headlights, you'll hear somebody shout 'Light!' and soon everybody will be shouting 'Lights! Lights! Light!' People who really care will quickly turn away, close their eyes, until somebody can get the driver to kill their headlights."
There may be a detour during the Oct. 16 to 21 run of MASP that will take Lakey Siding Road traffic farther away from the observation area. People coming to visit who have to leave at night will park further away and walk in. Visitors are welcome, however, and first-timers are strongly encouraged to come before dark to get the lay of the place.
Flashlights should be small, their lenses covered in red. Plastic shopping bags, red in color, do quite well, Dilday said.
Some modern car headlights stay on all the time. Cockman told how to turn them off.
"Just pull up the emergency brake a little way," she said.
There will be plenty to see, and getting around will not be hard once eyes adjust. White lines, like those on football fields, will mark paths.
"You can see them easily, even by starlight," Dilday said. "Just look for a telescope where people are lined up. Get in line, and ask 'What are we looking at?' They'll tell you. It might be the crab nebula, or a cluster in Hercules. It'll be something to see."
On the hill, everybody waits for night to fall. All the MASP astronomers are waiting for a certain moment that traditionally signals the time to close gates and end in-and-out auto traffic. That's the twilight moment when a night's stargazing begins.
"It's when they see the first star," Dilday said.
John Chappell can be reached at 783-5841 or by e-mail at email@example.com.
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