Coin Rotation Paradox
- Max Born
Our mind is in trouble, because:
Set the ratio to 1:1, set revolve on and move the green point C to 06:00 - clock-position.
- Then, watch the rolling outer circle: It is at the same horizontal position as starting at 12:00. Hence, it must have been turned around, it revolved completely around C.
- Then, envision the distance passed by (or rolled over) as a straight line: It's
And the solution is...
We compare the circular motion with the circular rotation: The outer circle is moving from 12:00 to 06:00, a fixed distance.
- [revolve Off] Circular motion: The segment LR stays orthogonally to line AC (g).
- [revolve On] Circular rotation: The segment LR rotates around C.
And the item learned is ...
- Rotation is not a relative motion.
- If you walk on a not straight line, you will turn yourself!