No text, but a visual code

[-JKP-]

I doubt that in the Middle Ages it was known that twinkling is atmospheric disturbance. Putting that modern concept on a medieval man is an anachronism...

Huh?

I wasn't imposing 21st century concepts on the Middle Ages, I was taking exception with YOUR 21st-century contention that planets don't twinkle. They do if they are at a level that has different atmospheric disturbance.