I much prefer the proof that a fly can stop a moving train.
imagine a fly heading north at a few miles per hour collides directly with a train heading south at 100 miles per hour.
There has to be an instant in time at which the fly's velocity passes through zero as it reverses direction. If the fly is in physical contact with the train (i.e. splattered all over it like a coat of paint) at that instant when its velocity is zero then it stands to reason that the train must also be stationary at that instant.
trouble is that this only works if you think of the collision as an inelastic contact like that between two pool balls (yeah I know that is elastic too but what the heck)
In reality, the molecules of the train and the fly actually deform or even slightly pass through each other so while the fly is stationary it is somewhat inside the fast moving train.
Kind of make my head spin thinking about it
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