This post is not intended as a debate.I am just curious because I don't know the answers and would like to know if some flat earth believer could supply the answers. You are certainly entitled to your beliefs.
Let me explain that I am what you would call a "round earther" and have had just enough education, training and experience to be familiar with the subject of the horizon.
I would be interested in seeing the flat earth definition of the horizon, where it is, etc. - flat earth facts.