Tunnel of Eupalinos
en.wikipedia.org
en.wikipedia.org
The diagrams in the article show how they changed the lateral direction of both tunnels to ensure they would collide in the horizontal plane, and expanded the ceiling of one tunnel and the floor of the other to ensure they would also intersect in the vertical plane. The diagrams in the article are illuminating, with some thought you can see it’s a very robust error correction mechanism that requires only a fraction more digging effort, and only requires precise measurements of the length of each tunnel (much easier to precisely measure than the angle or level!). Fascinating stuff.
That taught me they had ice houses in Persia in 400 BCE (https://en.wikipedia.org/wiki/Yakhchāl)
starting a hole from two ends a kilometer apart and meeting within a few millimeters in any axis is phenomenal, would love to learn more about what they used to ensure this kind of accuracy
> 4 Techniques for measuring altitude : Altitude measurements seem to have been made with a chorobates, a primitive leveller with a vessel for water, or forerunners of this instrument. Eupalinos probably measured the south and independently the north entrances more than to check once his between results and to obtain a higher level of accuracy. He would have chosen a flat path around the mountain following a contour line not necessarily on the same level as the entrances. When the two parts meet in the tunnel after three km, the closing error of the levelling is small, only a few decimetres and the accuracy is still better at the entrances. Eupalinos had probably arranged two stone blocks at each entrance, with flat and levelled top surfaces, aligned with the tunnels, from which the level of the floor of the tunnel could be guided. Possibly a movable wooden pole was used to level it with the surface of the two outer stone blocks. Further into the tunnels lines on the walls seem to have taken over the role of the outer stones. Eupalinos himself seems to have expected a somewhat less precise result as he raised the ceiling of the north tunnel by 2.5 m and lowered the floor of the south tunnel by 0.6 m, when approaching the meeting point.
I guess "millimeters" in the article is in error. Decimeters is much more believable.
Many potential factors are clearly not relevant: was not a major population center like Egypt, was not particularly rich in resources, was not a serious military might like Persia (except, though, in maritime context), was not centralized (quarreling city-states). Economically it was based on slave labor like the entire region. It was an extrovert society (trading a lot, establishing seaside colonies all over the Med etc), but so were the Phoenicians.
Maybe in the end it was just a non-linear cascade that is hard to explain "linearly" after the fact. Maybe using their interactions to copy and cross-fertilize what all the pre-existing cultures had to offer created a domino effect where one thing led to another (eg. improved script -> better education -> smarter logistics -> more spare time -> more philosopher-scientists -> more mathematics, you get the picture).
Its equally important to understand what caused the eventual decline. The depressing fact that "progress" is not monotonic. Could we be heading toward a new middle ages?
It helps that the Greek world was close to Europe and has a large literary legacyy (partially because of continuity through Rome).
Compare that to ancient Mesoamerican or African or Indian civilizations, which have a relatively shorter period of intense study, but every decade we seem to come away more impressed.
For example, Nazca puquios are still a bit of a mystery but are extremely sophisticated tunnel and irrigation systems: https://en.m.wikipedia.org/wiki/Puquios
Then one big thing was the development of a philosophical perspective that treated math as the basis of reality. That was also re-emerged as a trigger of the scientific revolution. Attributed to Pythagoras—but he deliberately never wrote anything down. What’s nice about not having written doctrines is that they can more easily evolve. The Pythagoreans, btw, also apparently conducted the first hypothesis driven experiment — testing their mathematical model of musical consonance by generalizing it from stringed instruments (where small integer ratios of string length produce consonance) to bronze chimes (where they found small integer ratios or chime thickness also produced consonance).
The recognition that “all is number” corresponds with (but doesn’t necessarily cause) big leaps in collective cultural progress.
What things today will be used for 1100 years?
The AI will have to move goods, technology change will still need to move goods, civilisations will rise and fall and still need to move goods. Even if energy gets more expensive, trade will still occur.
AI takeover isn't well defined, and by extension it isn't assured to be sensible — if a narrow AI is made to optimise the heck out of [high contagious, short latency period, long incubation period, high lethality, can form stable reservoirs in other species], it can be good at that without any long term planning about what happens next.
Conversely, we can also consider one that solves Von Neumann replication, and then it's less than a century to disassemble the planet Mercury, and from there a week or two for each of Venus and Earth. Assuming it had that as a goal.