The South Korean artificial sun, which goes by the name KSTAR (Korea Superconducting Tokamak Advanced Research), has made an important scientific discovery concerning nuclear fusion by being able to sustain plasma in high-confinement mode for a period of 102 seconds while simultaneously managing to keep plasma temperature at 100 million degrees centigrade for 48 seconds. This development by the Korea Institute of Fusion Energy (KFE) is another move towards achieving clean fusion energy, whose ability to generate unlimited amounts of electricity with little to no carbon emission is promising.
Or moving one part opposite the direction of another, to create resistance.
There’s plenty of conversation to be had about efficiency, heat venting, gross productivity. But “you can’t capture energy from another moving body” is something billards disproved several centuries ago.