Marvelous Motion

Mobile Science Museum · Mathematics

Operation: 1. Turn the handwheel and observe the motion trajectory of each light spot; 2. After the glass becomes transparent, observe the internal structure of the exhibit. Function Overview: The exhibit consists of a circular aperture made of 8 LED lights, a transmission gear set, liquid crystal glass, a rotating handwheel, and a display stand. When the handwheel is turned, you will see that the motion trajectory of each gradually lighting LED is a straight line, forming a uniform rice-shaped pattern; after the liquid crystal glass is powered and becomes transparent, the internal transmission mechanism can be seen. Scientific Principle: Why is the motion trajectory of each light spot a straight line when the circular aperture composed of 8 light spots rolls internally tangent to a large circle? This is a mathematical problem. In the exhibit, the large circle is fixed, and the small circle rolls along the inner side of the large circle. The trajectory of any point on the small circle is called a hypocycloid. When the diameter of the small circle equals the radius of the large circle, the trajectory of any point on the small circle is a straight line. The 8 light spots are evenly distributed on the edge of the small circle and move together with it. Observe any light spot carefully, and you will find that its motion trajectory is actually a straight line. After power is turned on, the glass becomes transparent. Please observe carefully: is the diameter of the small circle in the exhibit equal to the radius of the large circle? You can make several circular discs of different sizes from hard cardboard, cut out a larger circle from another piece of hard cardboard, and use a pencil to trace the hypocycloid. See if the trajectories are the same?

Options

• China Science and Technology Museum Standard Edition CSTM Standard Edition
  Dimensions (unit: m): 0.75×0.68×1.01 Brand: KexMall Model: PopsciCat-Mobile-107 1. Materials: ① Display stand: flame-retardant ABS injection molding, thickness ≧4mm ② Tabletop: compact laminate, thickness ≧12mm ③ Instruction sign: acrylic UV printing ④ Tabletop fixing parts: standard triangular lock ⑤ Protective cover: transparent acrylic + colored acrylic 2. Main Configuration: ① Electrical control: electrical logic control system, equipped with KexMall® K1 type PLC controller with protection specially for science exhibits ② Switching power supply: AC-DCS-60-12/24 input AC100-240V, 50/60Hz, output power 60W ③ Button: self-reset 22mm stainless steel metal button with ring light ④ Switchable glass: tempered glass 3. Energy Requirement: AC100-240V, 50/60Hz 500W

  Operation: 1. Turn the handwheel and observe the motion trajectory of each light spot; 2. After the glass becomes transparent, observe the internal structure of the exhibit. Function Overview: The exhibit consists of a circular aperture made of 8 LED lights, a transmission gear set, liquid crystal glass, a rotating handwheel, and a display stand. When the handwheel is turned, you will see that the motion trajectory of each gradually lighting LED is a straight line, forming a uniform rice-shaped pattern; after the liquid crystal glass is powered and becomes transparent, the internal transmission mechanism can be seen. Scientific Principle: Why is the motion trajectory of each light spot a straight line when the circular aperture composed of 8 light spots rolls internally tangent to a large circle? This is a mathematical problem. In the exhibit, the large circle is fixed, and the small circle rolls along the inner side of the large circle. The trajectory of any point on the small circle is called a hypocycloid. When the diameter of the small circle equals the radius of the large circle, the trajectory of any point on the small circle is a straight line. The 8 light spots are evenly distributed on the edge of the small circle and move together with it. Observe any light spot carefully, and you will find that its motion trajectory is actually a straight line. After power is turned on, the glass becomes transparent. Please observe carefully: is the diameter of the small circle in the exhibit equal to the radius of the large circle? You can make several circular discs of different sizes from hard cardboard, cut out a larger circle from another piece of hard cardboard, and use a pencil to trace the hypocycloid. See if the trajectories are the same?

• Optimized Popular Edition Optimized Edition
  Dimensions (unit: m): 0.75×0.68×1.01 Brand: KexMall Model: PopsciCat-Mobile-107 1. Materials: ① Display stand: flame-retardant ABS injection molding, thickness ≧4mm ② Tabletop: compact laminate, thickness ≧12mm ③ Instruction sign: acrylic UV printing ④ Tabletop fixing parts: standard triangular lock ⑤ Protective cover: transparent acrylic + colored acrylic 2. Main Configuration: ① Electrical control: electrical logic control system, equipped with KexMall® K1 type PLC controller with protection specially for science exhibits ② Switching power supply: AC-DCS-60-12/24 input AC100-240V, 50/60Hz, output power 60W ③ Button: self-reset 22mm stainless steel metal button with ring light ④ Switchable glass: tempered glass 3. Energy Requirement: AC100-240V, 50/60Hz 500W

  Operation: 1. Turn the handwheel and observe the motion trajectory of each light spot; 2. After the glass becomes transparent, observe the internal structure of the exhibit. Function Overview: The exhibit consists of a circular aperture made of 8 LED lights, a transmission gear set, liquid crystal glass, a rotating handwheel, and a display stand. When the handwheel is turned, you will see that the motion trajectory of each gradually lighting LED is a straight line, forming a uniform rice-shaped pattern; after the liquid crystal glass is powered and becomes transparent, the internal transmission mechanism can be seen. Scientific Principle: Why is the motion trajectory of each light spot a straight line when the circular aperture composed of 8 light spots rolls internally tangent to a large circle? This is a mathematical problem. In the exhibit, the large circle is fixed, and the small circle rolls along the inner side of the large circle. The trajectory of any point on the small circle is called a hypocycloid. When the diameter of the small circle equals the radius of the large circle, the trajectory of any point on the small circle is a straight line. The 8 light spots are evenly distributed on the edge of the small circle and move together with it. Observe any light spot carefully, and you will find that its motion trajectory is actually a straight line. After power is turned on, the glass becomes transparent. Please observe carefully: is the diameter of the small circle in the exhibit equal to the radius of the large circle? You can make several circular discs of different sizes from hard cardboard, cut out a larger circle from another piece of hard cardboard, and use a pencil to trace the hypocycloid. See if the trajectories are the same?

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