Video of the day

Listened to a very cool Radiolab recently about the physics of a falling slinky.

The last week, I came across an Atlantic page on the same cool topic.  I like’s it’s embedded video better:

And some explanation:

 In the video below [I didn't embed], physicist Rod Crossexplains that the tension of the spring counters the pull of gravity (“equal and opposite forces”), holding the bottom end of the Slinky in place until it “gets the information that the tension has changed.” By the time the bottom end of the Slinky gets the memo, the top end has fallen to meet it. What’s true for Slinkies is also true in sports, including tennis rackets, according to Cross. Your hand doesn’t feel the impact of a tennis racquet hitting a ball until the ball “is well on its way.”

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