Imagine Batman has a new hyper speed Batship that is the shape of his circular bat emblem. The ground has convenient square grid on it and when parked on the ground the ship is exactly the same length as a square on the grid and its shadow touches the four sides of a square. Mounted underneath the Batship is a series of powerful lasers pointing directly downward and when fired simultaneously they burn an image of the Batship on the ground that has the same profile as the shadow.(adsbygoogle = window.adsbygoogle || []).push({});

Now Batman takes off and passes low over the ground at a relativistic speed such that gamma = 2. It is high noon and the shadow projected on the ground is half the length of the squares on the ground grid. He fires his lasers briefly and simultaneously and burns an image of the craft on the ground. The burned image on the ground is twice the length of a square grid and 4 times the length of the cast shadow seen by an observer on the ground.

So, do you agree with this conclusion and do you see the "trick" that brings about this seemingly contradictory conclusion?

If that is too easy, try this. What is the length of the shadow and the burned image relative to the squares on the ground according to Batman as he flies past?

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# Relativistic Batman puzzle

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