>>521101984
Physics research stalled because we pushed the limits of our knowledge down to smaller and smaller scales until we got so far that we're now butting up against some hard technological limits.

In order to research subatomic particles, you have to actually be able to do experiments on them. The smaller a particle is, the more energy you need to break it apart and see what's inside it, and the more sophisticated your equipment needs to be to measure the results. A little over a century ago you could do meaningful research with just an electron gun and a sheet of gold foil, now you need a 27km long particle collider that costs billions just to eke out a few more data points.

Yeah, the US did decide to dial back on theoretical research a few decades ago. You know who didn't? The Europeans. They actually went and built the the fuck-off big collider when the Americans wouldn't. You know what all those billions got them? A few Nobel prizes, but nothing of any practical value whatsoever. The Americans don't have any hidden theoretical research locked away; the kind of people who can do that kind of research are incredibly rare and part of a very small community, everyone would notice if large numbers of them were disappearing into government labs. The American government just took a look at the cost-benefit analysis and decided it wasn't worth it.

Progress in theoretical physics stalled because it's really hard do work out what the fuck is going on down in the subatomic world with the data we have, and we don't have the technology to do the experiments needed to give us more data.

Well, that and the traditional interpretation of Quantum Mechanics is completely wrong and has been leading researchers down dead ends for decades. But honestly I don't think even overcoming that would help.