But to me that feels different than saying that inventions where sufficiently small steps away from a general engineer's education that you could "simply" explain them and not be met with wonder.
The atom nucleus was discovered by counting how many alpha particles bounced off the nucleus of a piece of gold foil and how many simply passed through it. The bounce rate was incredibly low and therefore the nucleus must have been orders of magnitude smaller than the gap between the next nucleus.
Personally I think you could tell a GE engineer in 1912 that their company would be building a radiation-powered electrical plant and they'd be keen to find out how, not baffled at the very concept. No way of knowing for sure, of course. Just that, this was an era when radioactivity and (what became) nuclear research was very much something the educated were reading about in their monthly magazines.
On the one hand the idea for nuclear fission was still fairly far off in 1912, since even in the 30's many physicists were still skeptical that radioactive energy could be released more rapidly than it normally is in natural substances. On the other hand a couple of major factors leading to it were already known in 1912: the fact that radioactive decay released large amounts of energy and Einstein's discovery of mass-energy equivalence.
As for jet engines the situation is clearer since a pulsejet was already patented in 1906.
I think in 1912 these technologies would seem like semi-plausible science fiction, but not magic.