Nautical twilight is a period in the morning and evening when the sun is between six and 12 degrees below the horizon. The horizon and the brighter stars are usually visible, making it possible to navigate at sea. The sky is dim and bluish, and artificial light is needed for detailed activities. Nautical twilight is the second twilight phase, after civil twilight and before astronomical twilight.
Basically "dark as night". That's 6-12 degrees below the horizon.
Here's another deceptive graphic. Those markings are NOT drawn to scale. I put a red square at the 45 degree mark -- I used a protractor overlay to get it precise. I had to scale the protractor down, so the numbers are blocky, but it still works perfectly for the job. The red square is the halfway point, or FORTY-FIVE degrees. They show about 32 degrees and label it "18 degrees". At their scale, you'd have about 24 of their degrees before you'd find yourself actually at the 45-degree mark! Insane.
Maybe it's a widespread issue that too much of the earth is lit up at once for the globe model? I didn't know that, but having barely dug below the surface I found not one but TWO images that are completely doctored to convince people that it's normal/expected for more than 1/2 the earth to receive sunlight at once.
By the way, as a man who spends LOTS of time outside, I'm here to tell you: at the 6 degree point, about 25 min. after "sundown", you can't do any work outside without a flashlight. If you dropped a 50 dollar bill on the ground, you wouldn't be able to find it without artificial lighting. You basically can't find weeds in a garden. It's when I say "time to go inside". And that's just 6 degrees below the horizon.
In other words, the only appreciable "daylight" is the first kind of twilight, Civil Twilight. End of list. The others are basically night, night-er, and pitch black.
Topic: 99% of world population in daylight - WHAT? (Read 16770 times)