That's simply false. When I use the word assumption, I'm talking about a number that does not come from empirical evidence.
Eratosthenes assumed the earth was spherical in his experiment. Without that assumption, his experiment proves nothing. That was an earlier point, and the claim is 100% true.
Gravity itself is an assumption.
And yes, our distance to the sun is calculated using assumptions.
If the earth were flat, Eratosthenes would have found the sun to be directly overhead at both places. There would be no calculation of the circumference of the earth or of its radius. The distance to the sun and moon involve measuring parallax.
He assumed that all sun rays come in parallel with one another. He assumed the sun was incredibly far away.
We know for certain that all sun rays do not come in parallel with one another. Heliocentrists argue that is 100% due to refraction. FE claims the sun is not 100,000,000 miles from Earth.
As I stated before, the experiment can be replicated with beer bottles and a flashlight. It doesn't prove curvature.
Math isn't some source of objective truth. Math is a tool for describing a set of circumstances. Those circumstances don't have to be reflective of reality. You can still solve for whatever variable you want to, in the end.
Simple measurements on the ground and trigonometry are all you need. No assumptions whatsoever.
That's simply false. When I use the word assumption, I'm talking about a number that does not come from empirical evidence.
Eratosthenes assumed the earth was spherical in his experiment. Without that assumption, his experiment proves nothing. That was an earlier point, and the claim is 100% true.
Gravity itself is an assumption.
And yes, our distance to the sun is calculated using assumptions.
If the earth were flat, Eratosthenes would have found the sun to be directly overhead at both places. There would be no calculation of the circumference of the earth or of its radius. The distance to the sun and moon involve measuring parallax.
Of course, all of this assumes you can do math.
He assumed that all sun rays come in parallel with one another. He assumed the sun was incredibly far away.
We know for certain that all sun rays do not come in parallel with one another. Heliocentrists argue that is 100% due to refraction. FE claims the sun is not 100,000,000 miles from Earth.
As I stated before, the experiment can be replicated with beer bottles and a flashlight. It doesn't prove curvature.
Math isn't some source of objective truth. Math is a tool for describing a set of circumstances. Those circumstances don't have to be reflective of reality. You can still solve for whatever variable you want to, in the end.
You "know" a lot things that just aren't so.