Throughout the long years, it was not only family and friends who grew up with children, but also many seemingly insignificant toys.
The gyroscope unearthed at the Hemudu site is about 7,000 years old and is arguably one of the oldest surviving toys in the world.
The small gyro is a symbol of the love that parents have for their children despite the limited conditions.
They still do their best to make toys to safeguard their children's happy childhood.
Today, with the rapid advancement of technology, innovative gyros of various materials and shapes have emerged, and their uses are becoming more and more widespread.
Some are fitted with colored lights, emitting brilliant colors to attract the eye.
Some are hollowed out to make a beeping sound when spinning, and some are "fattened up" to over 100kg to compete with each other for strength.
After the old wooden gyro, the use of electricity gave it a 'boost' and the electric gyro gradually emerged in Japan, where it has been popular ever since.
It adds cooler styles and functions to traditional ones, such as intelligent sensing.
This, coupled with the anime associated with it, has deepened its popularity among Japanese teenagers.
The gyro's characteristic is that it is dynamic.
When a gyro spins at high speed, the central axis of the gyro appears to be rotating around a vertical pole, a phenomenon called progression.
This is because when the gyro is subjected to the moment of gravity for the fulcrum, the vectorial direction of the angular momentum traces a cone as the gyro rotates, according to the angular momentum theorem.
In fact, due to the tidal forces exerted by the Sun and the Moon, our Earth is constantly and slowly moving, and the long term becomes the age difference.
In our everyday life, we often see this movement, for example, when a bicycle is moving.
If it is slightly skewed, it is balanced by turning the front end slightly to the other side.
This is the result of gravity creating a moment of advance on the pivot point of the tyre, which causes the bike to regain its balance.
The gyroscopic effect is the effect of a spinning object acting like a gyroscope.
A gyroscope has two characteristics: it is dynamic and it has a fixed axis.
When a gyroscope spins at high speed and encounters an external force, the direction of its axis does not change with the direction of the external force, but rather the axis moves around a fixed point.
If you have ever played with a gyroscope you will know that the shaft twists and turns as the gyroscope spins on the ground, this is the in-feed. Simply put.
The gyroscopic effect is that a spinning object has the inertia to maintain its direction of rotation (the direction of the axis of rotation).
When a force is applied to a rotating object at a certain point, the effect of the force will appear to be 90 degrees along the direction of rotation and the rotating object will have a tendency to remain in its original state and resist the external force, i.e. the axis of the rotating object will try to remain in the direction it is pointing.