How do ice cubes cool a drink?

Answering a 12-year-old's question for the Curious Kids series, a physicist explains that ice cools a drink through heat transfer: hot liquid molecules collide with colder ice molecules, transferring thermal energy until temperatures equalize, melting the ice in the process. The explanation walks through the distinction between temperature and energy, noting that a small cup of hot tea has less total energy than a large, colder iceberg despite being hotter.

The piece traces the process through the laws of thermodynamics, explaining that energy only flows from hotter to colder substances, and that ice absorbs energy first by warming to 32 degrees Fahrenheit, then by melting, before the whole mixture settles at a uniform chilly temperature.

The full dispatch is available from the source below.