Comment by slightwinder
4 days ago
> The “20 years away” meme is stupid.
No, it's not. It's just a legit illustration of somethings state of development on fundamental levels. It simply means "we have no f**ing clue how we can do this, but future..". This is different from something we have already solved, and you just need to throw money on it to scale it to whichever level you need it.
> Cracking natural language comprehension with digital computers is an example from our field and it’s here.
That's the point, everything in research is always x0 years away, until the breakthrough happens and it's finished.
> This is different from something we have already solved, and you just need to throw money on it to scale it to whichever level you need it.
We can already do fusion, and by every metric it is scaling. Triple product is increasing, etc.
Fusion does not become a viable source of energy until it scales beyond a certain point, but there is no "leap" between here and there that we know about, just better and better containment. We are descending a gradient, not looking for one.
If we had never managed to get fusion outside, say, hydrogen bombs, then I'd agree that we have no idea how to do it, but we have -- using many methods. Tokamaks seem to be the best one for scaling it so far, but there's other possibilities that I wish we would research more.
That's not really how it works. We do know SOME ways to reach fusion, but they are not on the level we need. We haven't mastered fusion yet, we still need to research the foundations. We don't even know if scaling is all we need, and we don't know how to scale it to the level we seek.
Technology usually has a range of performance, what it can do and what not. And our technology for fusion-process is not in the range for a commercial reactor, so we still need a breakthrough in our understanding.
Hmm... in that case the analogy with AI is even better. This sounds like neural networks before things like deep learning and the transformer architecture -- before we figured out how to scale them. Turns out this did require some innovations. It wasn't just a matter of making a bigger model.
If reaching a sufficiently high triple product were enough, I'd agree with you.
But at some point the problem becomes not one of plasma physics, but of engineering and economics. Regardless of the plasma physics, the walls of the reactor can withstand only so much power/area and only so much cumulative neutron irradiation. Issues like this seem mundane and therefore easy, but they're perfectly capable of rendering a technology into a nonstarter.