The story
Named after John E. Bortle, who created the scale.
Etymology from Wiktionary, CC BY-SA 4.0.
Bortle scale
Today it means: A nine-level numeric scale that measures the night sky's brightness of a particular location. Full definition →
Today it means: A nine-level numeric scale that measures the night sky's brightness of a particular location. Full definition →
Named after John E. Bortle, who created the scale.
Etymology from Wiktionary, CC BY-SA 4.0.