David Crawford (astronomer) in the context of "Kitt Peak National Observatory"

The Nicholas U. Mayall Telescope, also known as the Mayall 4-meter Telescope, is a four-meter (158 inches) reflector telescope located at the Kitt Peak National Observatory in Arizona and named after Nicholas U. Mayall. It saw first light on February 27, 1973, and was the second-largest telescope in the world at that time. Initial observers included David Crawford, Nicholas Mayall, and Arthur Hoag. It was dedicated on June 20, 1973 after Mayall's retirement as director. The mirror has an f/2.7 hyperboloidal shape. It is made from a two-foot (61 cm (24 in)) thick fused quartz disk that is supported in an advanced-design mirror cell. The prime focus has a field of view six times larger than that of the Hale reflector. It is host to the Dark Energy Spectroscopic Instrument. The identical Víctor M. Blanco Telescope was later built at Cerro Tololo Inter-American Observatory, in Chile.

DarkSky International, formerly the International Dark-Sky Association (IDA), is a United States–based nonprofit organization incorporated in 1988 by founders David Crawford, a professional astronomer, and Tim Hunter, a physician and amateur astronomer. The mission of DarkSky is "to preserve and protect the night time environment and our heritage of dark skies through quality outdoor lighting".

Light pollution is the result of outdoor lighting that is not properly shielded, allowing light shine into the eyes and night sky. Direct light that shines into the eyes is called glare, and light directed into the night sky above the horizon causes skyglow. Lighting can also cause light trespass when it enters areas where unwanted (e.g. a neighbor's yard and windows). DarkSky is the first and currently the largest organization in the dark-sky movement.