It's not meaningless if you know the context. Achieving 100M degrees is actually a significant milestone for this type of device. The reactor in the UK has this

It's not meaningless if you know the context. Achieving 100M degrees is actually a significant milestone for this type of device. The reactor in the UK has this planned for somewhere in the next year. I don't know SPARC's schedule, maybe it's a bit more secretive but when they achieve 100M it will be in the news as well. And even if you don't know the context, the article says it's the first in the world to achieve 100M for 20 seconds, good luck doing that in your microwave. And the specific temperature of 100M degrees might seem arbitrary because it's such a funny sounding amount, but it is actually the precise temperature at which the plasma theoretically starts becoming net positive. Whether it actually was net positive will obviously be the focus of the researchers for the next weeks, and even if they find the plasma generated energy consistently (which we'd surprised about if it didn't) it still doesn't mean the reactor was net positive as a whole because of inefficiencies. They will not have fried their expensive reactor intentionally, so if they did that will be sad news. The scale of the experiment is clearly visible from the video. It's a room sized spherical tokamak style device. I'm pretty sure the density of the plasma inside those is a given but I'm not 100% on the physics there.