Every major war has a rude awakening where people find out their predictions about how modern war works are wrong. The Battle of the Frontiers in WW1 was much deadlier than expected. Iraq 1991 stunned the world with how much more powerful computerized militaries were than they had realized.

Consider aircraft. Anyone can look at a biplane, and then a Spitfire, and know how much better the Spitfire is. Then again for a Spitfire versus a jet. But, you put an F35 next to an F16 and it takes a vastly higher amount of knowledge to know the gap is almost as wide between them as the gap between the biplane and Spitfire. The point is that post Cold War technological progress might be tremendous – but you don’t necessarily feel it the same way. A 1991 Abrams and an 1991 T72 roughly feel about the same but 73 Easting shows the gap was in reality enormous.

There is currently a debate in physics over the potential invention of a room temperature superconductor LK99. It was inspired by a Soviet paper from roughly 1990 and can be made using century-old equipment. If it pans out, it shows a truly astonishing failure of imagination. If not, it at least serves as a handy metaphor.

Many people have argued that things like the aircraft carrier and tank are obsolete. This is not quite that thread. Instead, what technology is the world, as the youth say, sleeping on? Technologies that are present in the real world or close to it, that have not quite gotten the attention and ubiquity that they might deserve, due more to inertia or a failure of imagination than anything else?