Session 2: The "Rachet mechanism" that converts random motion into propulsion
A Mechanism That Advances in Irregular Motion
The movement of exchange rates often appears as unpredictable, random motion. When you think it will go up, it goes down, and when you think it will go down, it goes up. Even within such irregular motion, is it possible to create a mechanism that progresses in one direction?
The hint lies in the "ratchet mechanism." This mechanism, which converts random forces into one-way motion, is widely applied in nature and physics, and even in our familiar tools. In this article, using examples of witch grass (cat’s-tail), Maxwell's demon, and a ratchet wrench, we will explain this mechanism in detail.
What is the Ratchet Mechanism?
Definition of the Ratchet Effect
A ratchet mechanism is,a system that permits movement in a specific direction from random motion while restricting movement in the opposite direction.
With this, one can extract one-directional energy from random motion.
Origin of the Ratchet Wrench
The word "ratchet" is also used for tools like the ratchet wrench. This wrench restricts rotation to one direction and prevents force from acting in the opposite direction, allowing efficient tightening of screws with minimal motions.
This mechanism—allowing only one-directional movement and blocking the reverse direction—is the essence of the ratchet.
Concrete Examples of the Ratchet Mechanism
1. Upside-Down Hold of Cat's Tail
As a familiar example, consider gripping the spike of the cat's tail (chimpweed) upside down and moving it. This movement exhibits the ratchet mechanism.
Details of the Mechanism
- Gripping action:
When you grip the cat's tail, it is pushed in the direction of its bristling, causing the whole plant to rise. - Releasing action:
When you release, the protrusions of the inverted bristles prevent it from falling, thereby maintaining position. - Result:
Repeating this “grip and release” causes the cat's tail to gradually move upward.
Key Points
- Grip: Ensure movement in the desired direction.
- Release: Restrict movement in the opposite direction.
2. Maxwell's Demon
Another example is Maxwell's demon, proposed by 19th-century physicist James Clerk Maxwell. This thought experiment explains a mechanism that selects random motion to produce a one-directional outcome.
Details of the Mechanism
- Random molecular motion:
Molecules move randomly at high and low speeds inside a box. - Demon's selection:
A small door is placed; the "demon" opens the door for fast molecules coming from right to left and closes it for slow molecules. - Result:
Fast molecules accumulate on the left, creating a temperature (energy) difference.
Key Points
- A mechanism that sorts random molecular motion to create unidirectional energy (temperature difference).
- In physics, this is discussed in relation to energy conversion efficiency and thermodynamic principles.
Summary of the Ratchet Mechanism
Common to the examples of cat's tail, Maxwell's demon, and the ratchet wrench is the idea of “choosing movement in the desired direction while restricting movement in the opposite direction.” Understanding this mechanism reveals how to effectively utilize random motion.
Next Time
What would happen if we could apply this mechanism to the foreign exchange market? Even in a fluctuating market, there is a possibility of turning random motions into one-way “profit.”
Next time, using probability theory of random walks, we will explore how prices move and how to identify opportunities for profit. Let’s think together about how to realize the ratchet mechanism in the market!