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The Kid Should See This

How can a straight metal rod pass through a curved hole?

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Imagine how you might pass a straight metal rod through a curved hole. How does that work if neither bends? Is it impossible? This demonstration at the Science Museum in Valencia, Spain shows that it’s absolutely possible with some creative thinking: Motion changing where objects intersect over time. Gif via Reddit:

straight rod curved hole

Update: We want to build our own! Here’s a great example of how some paper, a toothpick, some tape, and a straw can recreate this excellent science project. There are also instructions for a stronger wood version at

In the archives: more spinning and more geometry, including a few Eames films from Mathematica: A World of Numbers… and Beyond.

via Neatorama.

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