Scientists have made a breakthrough in fusion — but don’t get carried away

I’m going to go out on a limb with a year-end prediction. The old joke in the physics community is still true: Fusion is always 50 years away.

That detracts nothing from the news of an awesome scientific accomplishment from the Department of Energy’s Lawrence Livermore National Laboratory (LLNL). Using its massive, multibillion-dollar laser machine, the LLNL team finally blasted through the first milestone on the path to practical fusion.

For the first time, albeit briefly, they induced a fusion reaction that produced “net energy,” i.e., the reaction yielded more...