A Stirling engine is an external combustion engine that runs on the expansion and contraction of gas within a sealed system. In this video, we break down how it works, from heating and cooling cycles ...

A team of researchers including Princeton computer scientists has developed a new tool that simplifies the process of animating still images, such as this diagram of an external combustion engine.

The original concept of combustion engines as we understand them dates as far back as the late 1800s. And while they are more or less a solved science today, they definitely didn't start that way.