In theory, it’s possible to shoot some energy at hydrogen and get even more energy back. The process is called thermonuclear fusion, and if we could ever get fusion power to work — a big if — we’d never have to worry about our energy problems again.
It’s not a completely crazy notion. Nuclear fusion already takes place in the sun’s core, after all. And the promise of fusion power has led researchers to try their best for decades upon decades. Occasionally, they even make some advances — as happened this past winter, when scientists got closer to fusion power than ever.
Trouble is, the scientific and technical hurdles ahead are still enormous — in fact, we still don’t have a full grasp on what all the hurdles might be. Still, the potential pay-off is so massive that countries have sunk billions and billions of dollars into fusion research.
So here’s a guide to how far humanity has come on thermonuclear fusion — and how far we still have to go.