I had the same thought. you see yourself at the bottom of a bowl with ridges above you yet you know the surface is flat. If you take away the gravity then there

I had the same thought. you see yourself at the bottom of a bowl with ridges above you yet you know the surface is flat. If you take away the gravity then there is no wicked climb, ergo no mountain: the world suddenly appears flat. I know little physics but I think you're right! If true then your insight is greater than the authors.