What’s the earliest someone could have made a phonograph if they’d understood the basic principles involved? Quite early, ChatGPT says:
A screw-cutting lathe drawn in 1483 shows that late-medieval instrument makers already had a leadscrew, treadle/hand-crank drive, and slide rest accurate enough to carry a stylus slowly along a rotating cylinder.
With beeswax — ubiquitous and soft enough to take fine impressions — and thin metal or animal-skin diaphragms coupled to a simple horn, every physical element of Edison’s 1877 tinfoil phonograph was within reach; nothing required steam power, electricity, or metallurgical advances later than the 15th century. Wax itself was later used in commercial cylinders.
So, had someone grasped the “vibrate-stylus-in-groove” idea, a crude yet understandable recorder-player could have been built in Western Europe around the end of the 15th century — almost four centuries before Edison.
There are many such cases of this. I would be surprised if there were not, hidden away in one or more dark labs somewhere, some infinite-energy engines that can run on water or draw energy from the æther or something. And lest you think that, if such a thing existed, “we” would know about it, know ye that, were I to develop such a device, I’d never tell you, either.
More importantly, let’s all take a moment to reflect on how Absolutely Fucking Insane that a computer can now respond like this.
There was a foot-pedal powered machine gun in Scientific American in the 1950s; Poul Anderson used it in his Maurai stories. Buildable since the invention of the potter’s wheel. Bible stuff about ‘broken on a potter’s wheel’ might…
I’ve discussed ideas behind their time before.
There are filters other than lack of concept/looking this way, however.
The Romans had mobile artillery, but faced few worthwhile targets for it.
The Greeks before them invented things like taxi meter and steam turbine. But without units and measures worked out, more complex things like steam turbines could not easily become more than expensive-to-maintain toys, and that’s not even starting on cheap slave labor.
The measures are a separate story. Mostly only the empires like Roman or Chinese were able and willing to establish a consistent system of standards & measures at all — creating, enforcing, and keeping up long enough to make it stick.
Obviously, whatever the Romans established as a matter of consistent policy was doomed to go down soon after them. In the conditions when feudal organization became necessary because nobody could pay taxes in money, measures swiftly degraded via petty fraud.
https://slatestarcodex.com/2017/03/16/book-review-seeing-like-a-state/
On the other end, «The whole Confucian sea-board had standardized the lee-board. And hauled it up or dropped it as they choosed». But anything less immediately useful…
Or remember LK-99? We’re probably well behind the time of a real one.