They were right all along! 😱

Hate to be nitpicking, but the level measures if a surface is horizontal, not if it is flat. Two different things.

It's just on the level

That's a pretty stunning sort of allegorical representation of their perspective.

Sadly, some people probably think this is a good argument.

No. Actually is a proof that Earth is round. Like the glass in the spirit level.

How about: “The local tangent to the earth’s surface is flat”.

Explain this

a lake with mountains in the background and a mountain reflected in the water

ALT: a lake with mountains in the background and a mountain reflected in the water

There is the evidence. I'll live better now. :) :) :)

I wonder why that little bubble is all spherical and what not? Maybe it illustrates a larger concept.