A brief history of liquid computers (2019)

My favorite liquid computer is the Bosch Continuous Injection System (CIS) which is a fully mechanical fuel injection system for internal combustion engines. It is able to compute the fuel maps for my old porsche in any kind of weather at any altitude. It is a K-Jetronic (1973–1994) version which means there is no computer at all. The only electrical part is a few bi-electric strips that are used to run the engine rich until it gets up to temperature. I truly amazing system but when a little piece of dirt gets in the wrong place or a pressure if off by a few bar it falls flat on its face and strands you. fun times.

It's come up on here before, but re-link to the 200-acre Mississippi River Basin Model: https://en.m.wikipedia.org/wiki/Mississippi_River_Basin_Mode...

Not exactly a "computer", but certainly computing something that was far beyond the ability of 1950s electronic computation systems to calculate.

IMHO, a great example of solving a problem any way you can, without limiting yourself to technological advances.

Terence Tao published an idea that one could maybe prove ill posedness of the Navier Stokes equations by modeling a liquid computer… build a machine that focuses energy in such a way that the solution jumps out of a particular function space at a desired point in time.

https://www.quantamagazine.org/a-fluid-new-path-in-grand-mat...

There was a neat liquid computer called the MONIAC used to model the national economic processes of the UK.

Here's a video: https://www.youtube.com/watch?v=rAZavOcEnLg

Edit: Oh it was mentioned in the paper!

It's worth noting a large portion of cars from the late 40s into the early 90s also have a "liquid computer": the hydraulic relay logic controlled automatic transmission.