The Earth's orbit of the sun opens up lots of questions that FET can not explain. There is the Doppler shift in starlight, the apparent backward motion of mars across the night sky. the transit of Venus, sidereal time, the delay of the rise and set times for the moons of Saturn and Jupiter, the yearly movement of the stars, trigonometric measurement of the astronomic unit and the size of the planets orbits, the time taken for an orbit of the moon is not the same as a lunar cycle, there is more but flat earthers cant mentally time share so more than one thought at a time hurts their heads.