Simply Change Settings
to Familiar Units
example:
Distance to the object to: miles
Eyesight level to: inches
Distance to horizon: miles
Obscured object part: feet
You've been taught your entire life, this is how the world is shaped.
However when easy math is applied, it becomes clear our reality and what we have been taught, do not align.
In this experiment:
Distance to object is 6 miles.
The Eyesight level is 18 inches
Image 1 shows how the curvature should be hiding the entire boat and flag under the horizon 13.5 feet.
Image 2 shows what is seen in reality, no curvature,
with entire boat and flag in full view of observer.