Cartesian Diver

The Cartesian diver is a classic scientific toy that demonstrates the principles of buoyancy and pressure, making it an excellent educational tool for teaching science concepts.

Principles

The Cartesian diver operates based on Archimedes' principle and Pascal's principle:

• Archimedes' Principle: An object immersed in a fluid experiences a buoyant force equal to the weight of the fluid it displaces.
• Pascal's Principle: A change in pressure applied to an enclosed fluid is transmitted undiminished throughout the fluid.

How It Works

1. When the Cartesian diver is placed in a large container of water, it floats on the surface due to the air inside it.
2. Squeezing the large container (such as a plastic bottle) increases the pressure inside the bottle. According to Pascal's principle, this pressure is transmitted to the water and then to the diver.
3. The increased pressure compresses the air inside the diver, reducing its volume and increasing its density.
4. When the diver's density becomes greater than the water's density, it sinks.
5. Releasing the bottle reduces the pressure, the air inside the diver expands back to its original volume, decreasing its density, and the diver floats back up.

Educational Value

The Cartesian diver can be used to teach the following scientific concepts:

• Buoyancy: Understanding why objects float or sink in water.
• Pressure: Understanding how pressure affects objects in a fluid.
• Gas Compression: Observing how gas changes volume under pressure.

How to Use

1. Prepare a plastic bottle filled with water.
2. Place the Cartesian diver model inside the bottle and cap it tightly.
3. Squeeze the bottle to control the diver's movement up and down.
   浮沉子介紹

浮沉子是一種經典的科學玩具，也被稱為卡地納浮沉子（Cartesian Diver）。這個玩具展示了浮力和壓力的基本原理，非常適合作為科學教育的工具。

原理

浮沉子的原理基於阿基米德原理和帕斯卡原理：

• 阿基米德原理：物體在流體中受到的浮力等於其排開流體的重量。
• 帕斯卡原理：在封閉流體中的壓力變化會傳遞到整個流體。

運作方式

1. 當浮沉子放入大容器中的水中時，它會因為內部的空氣而浮在水面上。
2. 當你擠壓大容器（如塑膠瓶），這會增加瓶內的壓力。根據帕斯卡原理，這個壓力會傳遞到瓶中的水，進而作用在浮沉子上。
3. 增加的壓力會壓縮浮沉子內的空氣，使其體積變小，從而增加浮沉子的密度。
4. 當浮沉子的密度大於水的密度時，它會下沉。
5. 釋放瓶子時，壓力減小，浮沉子內的空氣恢復原狀，浮沉子再次浮起。

教育價值

浮沉子可以用來教導以下科學概念：

• 浮力：了解為何物體在水中會浮或沉。
• 壓力：理解壓力如何影響流體中的物體。
• 氣體壓縮：觀察氣體在壓力下如何改變體積。

使用方式

1. 準備一個裝滿水的寶特瓶。
2. 將浮沉子模型放入瓶中並鎖上瓶蓋。
3. 擠壓瓶身即可操縱浮沉子的上下移動。