Editing Ladder paradox (section)

==Paradox==
The simplest version of the problem involves a garage, with a front and back door which are open, and a ladder which, when at rest with respect to the garage, is too long to fit inside. We now move the ladder at a high horizontal velocity through the stationary garage. Because of its high velocity, the ladder undergoes the relativistic effect of [[length contraction]], and becomes significantly shorter. As a result, as the ladder passes through the garage, it is, for a time, completely contained inside it. We could, if we liked, simultaneously close both doors for a brief time, to demonstrate that the ladder fits.

So far, this is consistent. The apparent paradox comes when we consider the [[symmetry]] of the situation. As an observer moving with the ladder is travelling at constant velocity in the [[inertial reference frame]] of the garage, this observer also occupies an inertial frame, where, by the [[principle of relativity]], the same laws of physics apply. From this perspective, it is the ladder which is now stationary, and the garage which is moving with high velocity. It is therefore the garage which is length contracted, and we now conclude that it is far too small to have ever fully contained the ladder as it passed through: the ladder does not fit, and we cannot close both doors on either side of the ladder without hitting it. This apparent contradiction is the paradox.

{|
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| [[File:Ladder Paradox Overview.svg|thumb|266px|left|Figure 1: An overview of the garage and the ladder at rest]] || [[File:Ladder Paradox GarageFrame.svg|thumb|150px|Figure 2: In the garage frame, the ladder undergoes length contraction and will therefore fit into the garage.]] || [[File:Ladder Paradox LadderFrame.svg|thumb|150px|Figure 3: In the ladder frame, the garage undergoes length contraction and is too small to contain the ladder.]]
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