You can see in the sidebar that you can traverse the industries in time (Preceded by and Followed by links). Amazingly, these span _species_, since stone tools were in use before Homo sapiens were on the scene.
It's really incredible that at that point humans(or whatever homo species) could 1) invent novel techniques for tool making and 2) train others, who could train others, etc etc until the technique traveled flawless across the accessible world.
The weirdest part for me though is how flawless transmission of the techniques happened over a relatively short period of time, but (1) was so infrequent that each technique lasted for tens or hundreds of thousands of years. Yet not so infrequent that it never happened, or it only happened once.
There's an argument that some technologies only make sense in a particular context and so if you invent that technology without the context it dies out.
IIRC Writing died out several times, some specialists would see the value in recording language "permanently" and embrace the invention but nobody else did, then circumstances result in this group dying out or at least being dispersed and the ability is lost again.
There are some edge cases too. The invention of radio almost doesn't make sense, because they didn't yet understand enough about electromagnetism to make anything resembling a modern radio transmitter. The "spark gap" radio transmitter invented was totally crazy (in modern terms it's basically a broadband jammer and thus illegal), but if nobody else has a radio transmitter then it's all you've got. If that technology was slightly worse (say the maximum range is a hundred times worse or getting the transmitter working is not merely tricky to learn but such an art that few can do it reliably even with practice) it wouldn't be useful and would have gone nowhere until the electromagnetic theory gets better and valves are invented.
The Alexanderson alternator was an intermediate technology between the spark gap transmitters and tubes. Unlike the spark gaps transmitters, it produced a more spectrally clean waveform, but only at modest frequencies (up to 600 kHz, according to the Wikipedia page).
The other thing this article made me think of: the stone tools get stored in a cave and forgotten (the small band of users get wiped out for some other reason), then another band finds the cave (because of a rainstorm) and the tools and the broken bones nearby. They figure it out and “own” the cave and the tools for a few years/generations until history repeats. Over the 200,000 year use of the cave, maybe it sat dormant for 1-5,000 years at a time. Imagine finding a cave in a mostly empty land, and finding useful artifacts inside.
Check out https://en.wikipedia.org/wiki/Oldowan
You can see in the sidebar that you can traverse the industries in time (Preceded by and Followed by links). Amazingly, these span _species_, since stone tools were in use before Homo sapiens were on the scene.