I get what you're saying, but do you really need to "prove" it in this case? I mean, assume that the Earth is flat, and then think through the consequences. It

I get what you're saying, but do you really need to "prove" it in this case? I mean, assume that the Earth is flat, and then think through the consequences. It requires a long-running, global conspiracy at all levels of society. And all to hide the fact from... whom? Edit to clarify: even if you can't "prove" it directly, you can probably show that it would have effects you do not observe.