I have recently (yesterday) performed an experiment, the results favor a Spherical model.
I am attempting to measure the dip to the horizon and the accosiated distance to prove a globe model.
An observer close to Earths surface can only see a limited area, bounded by a circle centered on the observer. This circle is called the horizon.
In the spherical Earth model a point on this circle is slightly below the plane drawn through the observer and perpendicular to a line from the observer to the center of the Earth. The angle between this plane and the line from the observer to a point on the horizon is called the dip of the horizon.
In a FE model, many FEers claim that the horizon raises to eye level. (Impossible)
I decided to get hold of a theodolite and make some measurements across a bay in south wales The area has some costal cliffs, And a set of ramps/steps down to the beach . I had a theodolite, and Altimeter, a 10m tape measure and I am measuring the angle the horizon is below the theodolite and the distance that the horizon is away.
The results I am going to show almost certainly show that the Earth is (approximately) a sphere:
Experement 1
Measure the dip to the horizon at altitudes of 2,5,10,15, 20, 30 and 40 meters altitude
Theodolite set to standard atmosphere for all readings above 5m and sea level (1/7) setting for on the ground at the waters edge and 2 meter reading. remember we have to also allow for refraction, which was visually low on the day.
sea level = 0.01- 0.03 degrees (reading unstable)
2 m = 0.04 degrees
5 m = 0.07 degrees
10 m = 0.11 degrees
20 m = 0.17 degrees
30 m = 0.24 degrees
40 m = 0.32 (Horizon contrast not clear enough for accuracy as hazyness was present)
Experement 2
Measure the Distance to the Horizon in Kilometers from a known altitude
2m = 4.67
5m = 8.03
10m = 11.36
20m = 16.05
30m = 19.64
40m = 22.10
Extra
Measure the elevation angle of Polaris
Result: 51.42 degrees
Of course this will be ignored, or called fake.
More results to come soon, along with Pictures of ships over the horizon complete with measurements, two synchronized videos of sunsets from 2m and 30m altitude and other fun stuff!
Quick question to ponder. If I measured between 3 points in a triangle, why would the measured angles add up to more than 180 degrees?