The simple equation to debunk a flat earth troll is to have them prove to you they can break the following mathematical equations (distance calculated in feet, Very High Frequency, Line of Sight.) Get a compass or a radio (Wi-Fi 2.4GHz is also LoS) and prove this wrong while they stand beside you. Fags need to disprove with you onsite and no slight of camera tricks - the below equations are immutable.
1. Eyesight = 1.23√eye-height OR 2. VHF_LoS = 1.23√antenna-height