youngsub can't <ctrl>C <ctrl>P
I have done it for him . . .
If the Flat Earth proponents want to criticize the NASA conspiracy they should also criticize other conspiracies 2000 or 3000 years ago.
We have seasons because the axis of rotation of the Earth is not perpendicular to the orbiting plane of the Earth. It is tilted 23.4 degrees with respect to the perpendicular direction.
However, according to the Flat Earth theory, we have seasons because the Sun is above the Tropic of Cancer at the summer solstice, and above the Tropic of Capricorn at the winter solstice like this:
N means the Tropic of Cancer, E means the eqautor and S means the Tropic of Capricorn.
According to the standard round Earth theroy, the angle between the lines connecting the Sun’s two positions at the two solstices is always 46.8˚(=23.4˚+23.4˚), as long as the Sun is visible (i.e., not below the horizon) at the two solstices.
However, this is not true for the Flat Earth theory.
In any flat earth model, this angle θ must be always less than 46.8˚, unless the observing point is at the equator. (θ in such a case is 46.8˚). My quick calculation shows that θ can be as small as 20.4˚ at the Polar Circles. So, how can we measure θ?
By measuring the lengths of a pole and its shadow at the two solstices. It is as simple as that. Actually, many have measured θ since ancient times. The half of θ gives the angle the axis of the Earth tilted.
However, as you can see the value of θ/2 (the angle tilted) in the following document, θ has been measured since 3000 years ago, but it was never below 46.8˚.
1979A&A....73..129W Page 129
Actually half of θ has been consistently decreasing from 23.8˚ 3000 years ago to 23.4˚ now. Notice that there is this consistency dispite the fact that not all of them (actually, I guess none) were measured at the equator.
Thus, if the Flat Earth believers want to complain of the NASA conspiracy, they should also complain of the fabrication of these ancient people.