Speed of Light Testing Apparatus (Fizeau)

At this time (2019) flat Earth theorists have devised two wide-spread theories about what causes "gravity", or at least what causes the effect that we call gravity. The first theory, which is fading among the older flat-earthers, is that the flat earth is accelerating upwards which causes a downward force on the surface of the earth. The second is density theory. We will address universal acceleration in this post.