I like Richard Feynman’s puzzles, because they are easy to state and understand, they give lots of food for thought, and they can be hard to solve.
Try to solve each of the following puzzles on your own first, then watch the videos.
Puzzle #1 : The Train
What keeps a railroad train on the tracks?
Physicist Richard Feynman explains how a train stays on the tracks.
Puzzle #2 : The Mirror
When one looks into a mirror, one see an image of himself…. When raising one’s right hand, the image raises its left. When raising one’s left, the image raises its right. So, why is it that the mirror reverses left and right, but not top and bottom? Why does a mirror appear to invert the left-right directions, but not up-down?
Puzzle #3 : The Sprinkler Problem
You have an S-shaped lawn sprinkler-an S-shaped pipe on a pivot-and the water squirts out at right angles to the axis and makes it spin in a certain direction. Everybody knows which way it goes around; it backs away from the outgoing water. Now the question is this: If you had a lake, or swimming pool-a big supply of water-and you put the sprinkler completely under water, and sucked water in, instead of squirting it out, which way would it turn? Would it turn the same way as it does when you squirt water out into the air, or would it turn the other way?
Watch the experiment…