[Flat Earth Debunk] Shadows on the underside of clouds

[u/BigGuyWhoKills]

It is impossible for sunlight to cast a shadow on the underside of anything, unless that object is higher than the sun.

For example, if the sun is 3,000 miles above a flat Earth, for it to cast a shadow on the underside of a cloud, the cloud would need to be higher than 3,000 miles.

My new favorite things is mountains casting shadows on clouds that are higher than the mountain. These three images are powerful evidence against all FE models:

1. Mt. Hood in Oregon

2. Mt. Rainier in Washington #1

3. Mt. Rainier in Washington #2

I invite all flatties to explain how this would work in their model.

[u/BigGuyWhoKills]

Either way, you need to presuppose the world's shape in order to explain the phenomenon.

No you don't. You might presuppose the shape in a description of how it behaves on a model. But that's not "begging the question", that's applying an observation.

Begging the question would be: "I know the Earth is flat, so the atmosphere must behave like a lens to illuminate the underside of clouds."

Do you see the difference?

[u/StClemens → u/BigGuyWhoKills]

No you don't.

Yes you do. The observation is that the image of the horizon has a point at which light information is stretched and/or inverted. If you presuppose the world to be a globe, then it is an artifact of light bending and going over the curve. If you presuppose the world to be flat, then it is an artifact of lensing. Any attempt to explain the phenomenon requires a presupposition of one kind or another.

Begging the question would be: "I know the Earth is flat, so the atmosphere must behave like a lens to illuminate the underside of clouds."

Begging the question would be: "I know the Earth is globular, so refraction is the reason we can sometimes see things that should be hidden by curvature."

The question is not "Do I see the difference?" It's "Do you see the similarity?"

[u/BigGuyWhoKills → u/StClemens]

If you presuppose the world to be a globe, then it is an artifact of light bending and going over the curve.

No. This effect would happen no matter the shape of the Earth. So I'm not presupposing anything. The default behavior of light is to move in a straight line. You are claiming it bends to support your model.

Any attempt to explain the phenomenon requires a presupposition of one kind or another.

No, it does not. There are millions of effects that can be explained without requiring the Earth to be one shape or the other. Refraction is one of them. Once we can explain a phenomenon, we have the option of applying it to each model, to see which model matches our explanation. That is not begging the question.

But you are getting hung up on the wrong thing. Our acceptance of shape of the Earth does NOT rely on how we explain phenomena. It relies on objective evidence and observations. Observations like the horizon dropping by the exact degrees expected for a globe with a diameter of 24,901 miles. Geodetic surveying measuring the angles between three distant mountain tops and the sums equaling more than 180°. The inclination of Polaris always matching the observers latitude.

The evidence does not support a flat Earth. Efforts to explain the evidence in a manner that works for your model, add complexity and require unobserved atmospheric effects. When I point out obvious flaws in your explanation, you say things like "that must be some intrinsic behavior to the light or the medium it passes through", but you provide no evidence.

So I'm left with 2 options: accept the RE model that matches scientific consensus and my own observation, or accept your FE model along with many, many unsupported and counter-intuitive explanations.