…the limits at which… illumination is sufficient, under good weather conditions, for terrestrial objects to be clearly distinguished.
US Naval Observatory
At 6° under speak only with kindness,
At 12° trust buoys to gather the port.
At 18° swing doubt though its usual cold orbit.
Let a scratch in a song be love’s cough in the dark.
Who arched the bridge to this island of flare-ups?
Which is the key to the hotel of dismay?
Nests blunt the junctions between river and ocean.
I suppose we have done with our mutual heat.
As horizons melt into more vivid disclaimers
or choose from a shoreline’s stubbed-out streets,
let go the gold ways you thought nothing then nothing.
Think nothing forever when you get to my name.