At some point in history we (the West) lost the technology for running water, indoor plumbing, and sewers, for centuries. So a bicycle, even a draisienne, is still pretty complicated in that context.

It’s an interesting exercise, that could have happened. Like a lot of other things. The battery could be another example.

Or like, the invention of the computer, if we count the Antikythera mechanism as a computer.

What bugs me more is logarithms. You just multiply a fraction over and over. It’s counting multiplications. Even the Babylonians had something called logarithms, but that used tables for some trigonometric identity, probably slower than longhand multiplication of several leading digits. (Or just one leading digit, since their number system was base sixty. Have fun memorizing that times table.)

Yet the modern form didn’t show up until 1617. Even that was almost accidental, developed as a kludge for solving a different trigonometric problem. Except that kludge was backwards, using base 0.999 etc in 1614. It took only three years for another mathematician to figure out base 10 would be massively simpler. By 1620 another mathematician had drawn that as a line and recommended a compass for easy math. By 1622 someone had slapped two of those together to form a modern slide rule. By 1630 those were everywhere.

We should’ve been finding those things all over antiquity. Even cultures that had never been taught with them would have occasional bright sparks pick one up, fiddle around, and go “Oh… oh! OH!” And yet: it simply never happened, until well into the age of sail. The Romans understood compound interest so well that it was strictly illegal. They had percentages; they’re where “per cent” comes from. And before them, there’s cuneiform tablets figuring out the square root of two. Arabic numerals, which openly invite what we call scientific notation, were developed in the late 800s, and by 1000 had spread to the god-dang Pope. And it still took six hundred years for someone to figure out you can scrunch up the digits around a circle, with pi almost at 180 degrees, and save so much time fiddling with your abacus.