Question: Why is dry ice and liquid nitrogen so fun

Simon Brown answered on 14 Nov 2019:

We are used to frozen water and temperatures down to maybe -8C in the winter. But when you go down to -78C, the freezing point of carbon dioxide, it’s a different level of cold. CO2 is either a gas (warmer than -78C) or a solid (colder than -78C). This is called sublimation when the liquid stage is left out.
And then there is liquid nitrogen when it goes from a gas to a liquid at -196C. At that temperate, you can do some really cool stuff like hammer a nail into wood using a frozen banana, cool a flower so cold it acts like glass – until it warms back up. I love the stuff.