A new system has just been developed that promises to cure the skies of light pollution. Termed the Darklight Anachromatic Refractive Collimator, or DARC, it relies on a well-known but rarely applied aspect of the physics of light. By carefully adjusting light sources in both the infrared and ultraviolet ranges of the spectrum, light can be made to undergo destructive interference in the intermediary visible range, specifically in the blue frequencies scattered by earth’s atmosphere. The upshot of this is that the resulting interference cancels out scattered visible light, allowing stars to be seen clearly for the first time in urban areas.
A company in Iowa, DARC Fabrication Inc. has released plans that they will start to manufacture 1 meter diameter DARC projectors later this year. The company spokesperson, Dr. Jeremy Mnong, has indicated that they hope to start installing the systems on the rooftops of major buildings in metropolitan areas as demonstration units. They envision these systems working a little like searchlights, sweeping the sky of scattered light every minute or so as the DARC projectors are turned on massive motor-driven mounts. It’s also possible that DARC systems will be able to be mounted on truck flat bed trailers, and moved from place to place to provide spot coverage of particularly bad areas of light pollution.
The individual DARC projectors are expected to retail in the range of $20,000 US per unit. DARC Fabrication Inc. thinks that they can reliably produce about 500 units per year in the first year of production.
© 2013, David Allan Galbraith