How to engineer a reverse explosion
Observe safety rules when working with heating devices.
- empty aluminum can;
- heating device;
- bowl of cold water;
- heat-resistant gloves;
- 10mL water.
Pour 10mL water into an empty aluminum can. Place the can on a heating device, such as a small stove with a candle, and heat it until a large amount of steam is released. Put on a heat-resistant glove. Quickly put the can upside down in cold water. Observe as the can "explodes" inwards!
Such an inward explosion is known as implosion. When the can is heated, the air inside it expands, and some air is forced out. As the water in the can begins to actively evaporate, the forming vapor displaces even more air. The sum of the pressures of the remaining air and water vapor is equal to atmospheric pressure. When the can is cooled, the pressure inside falls and becomes lower than the outer atmospheric pressure, which crushes the can. This effect is enhanced by the condensation inside the can.