Caption: Pole Vault.
Does this pole vaulter feel his FitzGerald contraction during his approach?
Explanation of the FitzGerald contraction:
Proper length is an intrinsic property of an object unlike length in general that depends both on proper length and reference frame of length measurement.
If v = 0, L = L_0. If v = c, L = 0.
The pole's proper length is greater than the length of the shed.
But the pole vaulter runs very fast and in a ground-frame observer's observation the pole is contracted to be less than the shed proper length and the whole pole is inside the shed for some time interval.
The pole vaulter's frame perspective is that the shed was contracted.
Yes, the ends of the pole were inside the shed, but NOT at the same time in his/her reference frame.
However, many results depend on the FitzGerald contraction, and so it has been indirectly verified endlessly.
Also it's a basic result of special relativity, and so all of special relativity depends on it.