The host discusses the "Hui stick," a mysterious device that spins when a person rubs a stick against a notched surface and says a "magic word." The host explains that the device works due to the interplay between two torques: one caused by the person's finger pressing against the stick and the other by the person's hand steadying the stick. The host demonstrates that the direction of rotation can be controlled by adjusting the position of the finger on the stick. The host also experiments with a modified version of the Hui stick, called a "Hui stick comb," which applies a constant torque in a direction perpendicular to the up-and-down motion of the stick, preventing the stick from escaping the torque and thus preventing controllable rotation.
Here are the key facts extracted from the text:
1. The 11th Curiosity Box is currently shipping.
2. A Hui stick is a device that can make a propeller spin in a controlled direction.
3. The Hui stick consists of a rubbing stick and a propeller stick with notches on one side.
4. When the rubbing stick is rubbed across the notches, the propeller stick vibrates, causing the propeller to spin.
5. The direction of the propeller's spin can be controlled by applying pressure to one side of the propeller stick with a finger or thumb.
6. The propeller stick's vibrations are not purely vertical, but also have a horizontal component that causes rotation.
7. The rotation is caused by the interplay between two torques: one from the finger or thumb applying pressure, and one from the hand holding the back of the stick.
8. The direction of the rotation depends on the location of the finger or thumb on the propeller stick, with the upper right quadrant producing counterclockwise rotation and the upper left quadrant producing clockwise rotation.
9. The same principle applies to the lower quadrants, with the lower right quadrant producing clockwise rotation and the lower left quadrant producing counterclockwise rotation.
10. If a force is applied to the propeller stick that cannot be escaped by the vibrating stick, the rotation direction is not controllable.
11. A Hui stick comb can be used to apply a torque directly to the propeller stick, but this does not allow for controllable rotation.
12. The shirt worn by the host comes in box eleven and features a design related to cardinal and ordinal numbers.
13. The smallest transfinite cardinal is Aleph-Null, which represents the number of whole numbers, integers, even numbers, and odd numbers.