more jets in the air. The efficiency of combustion engines has been rising fast since James Watt launched the industrial age 250 years ago. The best external combustion engines were about 20% ...

The steam engine is another example of an external combustion engine. In order to create a microscopic version of a Stirling engine, the researchers sandwiched a tiny, 2.94 μm melamine bead in a ...

Before internal combustion engines won over the automotive industry, they had to fight off rival forms of propulsion like early electric drive tech, and even grandfathered-in steam engines.