You know how magnets can repel each other? And if you've ever tried to push them together it's very hard. The forces keeping them apart are very strong.

That's the essence of nuclear fusion. Forcing two particles together and using the energy from that reaction. Up until now it's taken more energy to create fusion than what you get out of it. In fact, fusion is the way that our sun makes power.

So remember Monday, December 5, 2022. That's when the Lawrence Livermore National Laboratory in California (see image) achieved net energy, meaning the reaction generated more energy than was put in to initiate the reaction. 

It's a really big step because scientists have been at this for decades. But it's still a little step because it will take some time before humans can benefit from this achievement.