Scientists Create a Prototype 'Air Plasma' Engine That Works Without Fossil Fuels

A prototype jet engine can propel itself without using any fossil fuels, potentially paving the way for carbon-neutral air travel.

There's a long way to go between a proof-of-concept prototype and installing an engine in a real plane. But the prototype was able to launch a one-kilogram (2.2-pound) steel ball 24 millimeters (almost one inch) into the air. That's the same thrust, proportional to scale, as a conventional jet engine.