Thank you. I remember when I took physics in college about a million years ago, the professor said it was an unsolved problem but I immediately just wrote it off as atmospheric distortion. How wrong could I be when a simple experiment with a small pebble proves it’s an illusion? You chose your screen name well, Moonman62, you chose your screen name well. :-)
But the question remains... Is the Sun’s apparent size on Mars’ horizon also an illusion?