system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the new nuclear fusion breakthrough and why is it a big deal?
gpt
The new test generated the same amount of energy that was required to start/sustain it.

This still isn’t useful, but it’s an improvement from previous attempts that consumed more energy than they generated.

Of course to be economically viable a fusion generator must produce far more energy than it consumes, but we’ve at least shown that such a thing is theoretically possible.

Whether it can be economically scaled up to an industrial process at any useful efficiency remains to be seen.  Don’t buy any hype just yet, we’ve been writing wishful articles about fusion energy being a decade off for 70 years.