[roelschroeven]

I know some people who tap a can of Coke before they open it, because "that prevents it from spilling". Each time they do that, they are more convinced that their hypothesis is correct.

But is it correct? To find out, we need to try to invalidate it. Try opening the can without tapping it first. If the Coke doesn't spill, the hypothesis is clearly wrong. It the Coke does spill now, it's quite strong evidence in favor of the hypothesis.