I've long been fascinated with the Pilatus PC-9:
It's a turboprop sold as a trainer but also as a light attack aircraft - it's the closest thing to a modern-day WW2 fighter. The performance figures are actually less impressive than late-war aircraft but I assume it's cheaper, lighter, more reliable, and probably a lot more capable in the air-to-ground role. My hunch is that WW2 designers almost reached the upper limit of what you could do with a propeller aircraft, and if jets had never been invented most innovations post-WW2 would have been incremental.
A while back I read Richard Rhodes'
The Making of the Atomic Bomb, and that gave me a renewed respect for what people could do in the first half of the century. Atomic physics essentially began with people shining radiation sources through pieces of gold foil with slits cut in them, and looking at tiny particles with microscopes. The early experiments were unbelievably primitive by modern standards.
The thing that really struck me was the construction of Fat Man. That was an implosion-type bomb. The idea of packing explosives around a central core and detonating them at exactly the same fraction of a second - so that the shockwave forms a perfectly spherical implosion wave that travels through the uranium core - sounds hard enough but was fiendishly difficult with 1940s technology. It required input from a pool of explosives experts, in addition to the pool of chemical experts that developed the uranium refinery, plus the atomic experts.
It really brought home how hopeless the German and Japanese bomb-making projects were. They would never have been able to refine uranium and it would have taken years before they could assemble a bomb because they simply didn't have the mass of experts required (and their enrichment plants would probably have been bombed into oblivion).
I understand that fusion weapons are designed so that the interior of the case focuses the explosive shockwave of the fission stage so that it implodes the fusion stage, which again is extraordinary for the 1950s. Imagine the theory that went into designing a case that could - for a tiny fraction of a second - reflect the force of an atomic explosion, and the manufacturing precision required to not only construct one of these devices, but thousands of them.
And make them robust enough that the radiation doesn't fry the circuits, and shockproof enough that the ground crew can handle them. Also shockproof enough that they can be blasted into space on an ICBM and then withstand re-entry. Hard science! It's fantastic.
