Pretty common one is this idea that you can see the curvature of the Earth from an airplane. Often used to suggest one can only be an FE proponent if you've never traveled via one. As we've discussed a number of times here, while the curve left to right is technically more than it is on the ground, it's still a matter of pixels and not discernible with the naked eye from standard commercial airliners' windows, as is often claimed. Even a high quality camera requires the image to be carefully looked at in order to find even the potential for a curve to exist, and it's likely at least some of these are the result of confirmation bias.