Empirical Earth · Test It Yourself
The claim
“We shone a laser across miles of open water and it hit the target at the same height it left, with none of the drop a globe requires. The water is flat.”
What is measured
At ten kilometers a handheld laser beam is wider than the curvature drop it is meant to measure, so hitting the target proves nothing either way. The same experiment done with survey instruments, many targets and refraction solved from the data returns a sphere of about 6,371 km.
What would show this is wrong
Falsifiable by a laser test that reports its beam divergence, its launch and target heights, the distance, and the height of the beam center on arrival, and finds the drop absent with a residual smaller than the predicted curvature. The published tests that report those numbers find the drop.
Sources
This is one card from Empirical Earth, a free reference that states each flat-Earth claim at its strongest and then answers it with sourced measurements. Nothing is for sale and there are no advertisements.