We are losing our heritage of starry nights. Artificial light in the night sky threatens to destroy the spectacular views the heavens offer.
Inefficient lighting wastes money.
Light that shines anywhere but where it's needed is wasted. Unshielded lights cause glare and glare is uncomfortable at best and possibly dangerous, blinding you when you need to see. The bright flood or spot lights used for security can cast harsh shadows, providing cover for the criminals we seek to keep at bay. This is not beauty, it's a travesty. An measurement John E. Bortle has spent nearly 50 years observing the heavens, and his experience led him to create a 9-point scale rating the quality of the nighttime sky.