These sounds are a common occurrence when metal touches dry ice because room temperature metal is much warmer than the surface of the block of dry ice (-110 degrees Fahrenheit), the heat it holds causes the block to rapidly sublimate. As the gas expands, it is trapped under the metal and struggles to break free, resulting in a variety of sounds. This behavior can be reproduced with a few fun experiments using dry ice and metal. Check out this video involving dry ice and a quarter:
Without pressure applied like the knife in the first video, the gas is able to move the coin to escape, resulting in the coin “dancing” and making less noise. In both experiments, as the metal comes to an equilibrium temperature, the visible and audible reactions decrease significantly. If you need a quick refresher on dry ice safety, print out our handy guide and give it a read. Don’t forget to use our store locator to find out where to buy dry ice near you! We hope you enjoy these fun experiments! If you have an idea for a similar scientific exploration, we would love to see it!