World Science Scholars

### 11.4 The Dynamite Pole in the Barn Paradox

Discussions
• Consider a version of the Pole-in-the-Barn ‘paradox’ in which a bundle of dynamite is hooked up to explode if the pole fits inside the barn. Does this complicate the proposed resolution? Do we now have to deal with a more urgent paradox in which observers at rest with respect to the barn say it’s been blown to pieces while those at rest with respect to the pole say it hasn’t? Explain your answers.

• That’s funny because that’s exactly the thought I had after watching your video. As you explained before, it can’t be the case for the one person the barn explodes, while for the other it doesn’t. The bundle of dynamite explodes when the pole if fully inside the barn, but from which perspective? I think we must define that first.
If we say it explodes when the whole pole is inside the barn from the perspective of the barn (or someone at rest relative to the barn), the bundle will explode, even though the person running along the pole will say the pole did not fit inside the barn. It’s not his perspective that is deciding for whether the explosion will occur, but rather the perspective of the barn, and the barn says the pole did fit inside it.
If however we say the dynamite explodes when the pole is inside the barn form the perspective of the pole (or someone running along the pole), the bundle will not explode, even though the barn will say the pole fit inside it.
So saying ‘the bundle of dynamite will explode if the pole fits inside the barn’ is not a clear statement, since we must define from whose perspective the pole must fit inside the barn first.
Of course the above is only true if the speed of the pole relative to the barn is high enough that the pole fits inside the barn from the perspective of the barn. Otherwise the pole won’t fit in from any perspective and the dynamite won’t explode either way.
Anyway, that’s my thoughts on the problem. Please correct me if I’m wrong or missed something 🙂

• What would happen if there is a mechanism in the barn that only when the ends of the pole touch the ends of the barn, it closes an electric circuit that causes the barn to explode? Would the barn explode? 🤷‍♂️💥

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