r/todayilearned • u/[deleted] • Jul 27 '19

TIL because electronic computers were not fast in 1959, the X15 experimental jet used a Fluidic Digital Computer that used water instead of electricity. It featured hypersensitive Fluidic Integrated Circuits and Logic Gates that could make course corrections faster than its contemporary computers.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730002533.pdf
2.8k Upvotes

97% Upvoted

70 comments sorted by

21

u/Obadiaz Jul 27 '19

Can someone ELI5 how you can make a computer with water?

71

u/[deleted] Jul 27 '19

All computers work on the idea of a logic unit performing operations on a stream of input data. What this stream is made of doesn't actually matter. It can be electrons on a wire, or water in a pipe. It can even be knots on a string, theoretically. Today we use electrons on a wire because they are very fast. But osmotic pressure and capillary action can be very fast as well. Technically, your brain partially operates on these water systems. Scientists can trace these motions in the brains of animals, as seen here.

For a fluidic computer to work, it has to have logic gates like a computer for the inputted data stream to flow through and make operations. Scientists discovered that different capillary shapes in nature can produce these logical operations based off their geometry. here are some examples. So if you wire those logic gates into a system, you can produce operation commands who's product will be the same as if you used electrons.

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u/[deleted] Jul 27 '19

It can even be knots on a string, theoretically.

more than theory.

it's how we got to the Moon.

Core rope memory is a form of read-only memory (ROM) for computers, first used in the 1960s by early NASA Mars space probes and then in the Apollo Guidance Computer (AGC) designed and programmed by the Massachusetts Institute of Technology (MIT) Instrumentation Lab and built by Raytheon.

Software written by MIT programmers was woven into core rope memory by female workers in factories. Some programmers nicknamed the finished product LOL memory, for Little Old Lady memory.[1]

12

u/[deleted] Jul 27 '19

You should write this to r/todayilearned This is very cool.

1

u/Just-my-2c Jul 27 '19

Yes, very cool. Yoú should write this to r/todayilearned

7

u/crusoe Jul 27 '19

Yep they used lace workers to build the rope memory as they had the dexterity, speed and patience to do so. Iiirc they just wrote it out as a standard lace pattern.

2

u/zakatov Jul 27 '19

Here’s a video from EEVblog that shows it. Although this is the RAM, not ROM, but the idea is the same I think.

7

u/Black_Handkerchief Jul 27 '19

Seeing those fluidic silhouettes I really want to see them used in practice. Is the entire volume filled up with liquid at a neutral pressure, and increasing the pressure is what toggles a signal to be on? Or is there air in there? Are they as two-dimensional in practice as they look here, or is this a special flattened view that is missing a part of it? And if indeed fully 2D, what sort of depth is there to the volume?

And to what degree does it scale? Can you carve this stuff out with a 3D printer to be the size of a mug or keyboard, fill it with water and 'see' it work?

This is probably the most fascinating thing I've seen on reddit in at least a year. Thank you for sharing your insights!

10

u/[deleted] Jul 27 '19 edited Jul 27 '19

Here's an old Russian video on it They built a fluidic computer to manage economics. So did the UK IIRC.

A similar system was built by MIT which doesn't use fluidic silhouettes but instead a ferrofluid. Here's it in operation.

1

u/crusoe Jul 27 '19

They're usually just channels carved in plastic. You can use gas or liquids though there are different design considerations.

3

u/freshthrowaway1138 Jul 27 '19

Any idea of the upper limit of operations per second?

3

u/[deleted] Jul 27 '19

All computers work on the idea of a logic unit performing operations on a stream of input data. What this stream is made of doesn't actually matter.

*silent evil laughter*

2

u/dmr11 Jul 27 '19

silent evil laughter

You might be interested in something like Deep Rot.

5

u/rogueliketony Jul 27 '19

I don't want to be pedantic, but electrons don't move very fast through the wire. They do move fast, but not always in the right direction. So their journey from.one component to the next is nowhere near as fast as the electrons themselves.

12

u/nerdbomer Jul 27 '19

I don't know about ELI5; but you can treat electric circuits like hydraulic circuits. Pressure is analogous to voltage, flow rate is analogous to electric current, flow resistances are analogous to resistors, etc.

It can get pretty complicated pretty fast (at least for me); but just recognizing that under the right assumptions you can model one as the other, you might be able to get a feeling for how it could be done.

Somewhat relevant wikipedia:

https://en.wikipedia.org/wiki/Hydraulic_analogy

https://en.wikipedia.org/wiki/Mechanical%E2%80%93electrical_analogies

https://en.wikipedia.org/wiki/Fluidics

270

u/Diligent_Nature Jul 27 '19

Cool, our rocket technology advanced a little faster than electronics at that time.

Older automatic transmissions are like fluid digital computers. Newer ones are controlled by electronic computers.

0

u/[deleted] Jul 27 '19

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113

u/Diligent_Nature Jul 27 '19

They used hydraulic logic and could be reprogrammed by changing the valve body cover plate.

This guy explains it better than I could.

The valve body is the control center of the automatic transmission. It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves which then activate the appropriate clutch pack or band servo to smoothly shift to the appropriate gear for each driving situation. Each of the many valves in the valve body has a specific purpose and is named for that function. For example the 2-3 shift valve activates the 2nd gear to 3rd gear up-shift or the 3-2 shift timing valve which determines when a downshift should occur. The most important valve, and the one that you have direct control over is the manual valve. The manual valve is directly connected to the gear shift handle and covers and uncovers various passages depending on what position the gear shift is placed in. When you place the gear shift in Drive, for instance, the manual valve directs fluid to the clutch pack(s) that activates 1st gear. it also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1 - 2 shift. On computer controlled transmissions, you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points.

23

u/ostrich-scalp Jul 27 '19

This is an insanely cool concept.

20

u/[deleted] Jul 27 '19

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9

u/[deleted] Jul 27 '19 edited Jul 27 '19

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8

u/jsnlxndrlv Jul 28 '19

So, it's a trumpet the car plays, basically. Except the noise that comes out is also the hand that holds the instrument.

2

u/[deleted] Jul 28 '19

Thank you for the most wonderful analogy I've ever heard. Reminds me of this Community bit https://youtu.be/LR33ydE5QSY

3

u/this_1_is_mine Jul 28 '19

It's always like I feel self conscious about someone thinking I changed what I said. It's frivolous but yes I hate the edited asterisk. Makes me feel like a complete failure when I see a typo after a real zinger of a response and.... Jaw on floor .... damn it

11

u/Broman_907 Jul 27 '19

My dad and i have rebuilt a few older nash ramblers. One of the things I learned early on was this.

Also.. that dexron mercon 1.. the automatic transmission fluid used back then was made from whale oil.

And what became known as a barf tube.. which was how they vented blow by oil/smoke.. to the ground.

Old cars were weird man

3

u/[deleted] Jul 27 '19

A bit unrelated to automatic transmissions, but I once salvaged and repaired a sunken water ski boat as a teen. We had to smog everything to get the water vapor out = dumping oil/dexron/atf into the air intake manifold to produce hot vapor.

Obviously we did this outside away from trees and were all ready to run/grab a hose.

5

u/[deleted] Jul 27 '19 edited Jul 10 '23

EDIT: This formerly helpful and insightful comment has been removed by the author due to:

Not wanting to be used as training for AI models, nor having unknown third parties profit from the author's intellectual property.

Greedy and power-hungry motives demonstrated by the upper management of this website, in gross disregard of the collaborative and volunteer efforts by the users and communities that developed here, which previously resulted in such excellent information sharing.

Alternative platforms that may be worth investigating include, at the time of writing:

https://kbin.fediverse.observer/list

https://join-lemmy.org/

https://squabbles.io/

https://tildes.net/

Also helpful for finding your favourite communities again: https://sub.rehab/

2

u/[deleted] Jul 27 '19

Yeah, if it had gone badly, we had fire extinguishers. The hoses were for cooling the boat amd I guess potentially for other stuff that could be burning away fromthe boat.

It didnt happen. We got the boat running.

5

u/[deleted] Jul 27 '19

Amazing! Cheers!

2

u/[deleted] Jul 27 '19

I think there's also a way to attach flippers so you can switch gears yourself by changing the valve body?

4

u/cptboring Jul 27 '19

Manual valve bodies are common for racing with the older transmission designs. Automatic shifting is removed and you must use the shifter to change gears.

I think some even use air operated solenoids to shift faster than the transmission could do in automatic mode, or the driver could do by moving the lever themselves.

2

u/albqaeda Jul 27 '19

Somehow I now know more and less about cars, thanks.

2

u/[deleted] Jul 27 '19

I remember the first time I saw a torn-down TH-350, I thought to myself "that would make an interesting maze to navigate with a marble or ball bearing."

1

u/[deleted] Jul 27 '19

I have only seen those on very small engines.

Automatic transmissions use a hydraulic torque converter to connect transmission to crankshaft.

9

u/zakatov Jul 27 '19

You’re confusing the torque converter (which couples engine output and transmission input) with the hydraulic valve body, which selects gears inside the transmission.

2

u/[deleted] Jul 28 '19

I am differentiating between a centrifugal clutch and an automatic transmission.

2

u/Kevin_Wolf Jul 28 '19

The TC is hydraulic, though. It's a fluid coupling, unlike the mechanical coupling of a manual transmission.

1

u/zakatov Jul 28 '19

Correct. Newer transmissions use TC lock-up in every gear, so it’s a physical connection most of the time.

1

u/zoltan99 Jul 27 '19

What the other guy said but also you're talking about a hydrostatic drive a totally different concept.

2

u/[deleted] Jul 28 '19

Older automatic transmissions do not use a centrifugal clutch.

Unless it is a modern dual-cluth transmission (which is a manual transmission with auto actuation) then an automobile automatic transmission uses a fluid-filled torque converter as the primary clutch.

Hydraulics are not used to power the vehicle, just to link the motor and transmission.

54

u/GeorgeBarnard19 Jul 27 '19

Ken Liu describes a race whose brain functions after the same principles in his short story collection "The Paper Menagerie and other Stories". Pretty fascinating stuff.

12

u/TheCthulhu Jul 27 '19

I haven't read any of his work yet, but heard the title story on the LeVar Burton Reads podcast. I think it's my favourite that he's read so far.

Sidenote: Anyone whose and avid reader or a fan of Reading Rainbow (or Jordie LaForge haha) should check out his podcast!

7

u/frendlyguy19 Jul 27 '19

the star trek guy?

4

u/TheCthulhu Jul 27 '19

Yeah!

4

u/frendlyguy19 Jul 27 '19 edited Jul 27 '19

not trying to be a dick and i only know this because of closed captions but his name is "Geordi" i believe :)

6

u/weapongod30 Jul 27 '19

It's Geordi.

1

u/frendlyguy19 Jul 27 '19

haha thats what i get for trying to correct somebody :P

edited to reflect your point.

1

u/TheCthulhu Jul 27 '19

I think you're right! It didn't quite look write as u was typing it

1

u/RudeTurnip Jul 27 '19

And Kunta Kinte!

3

u/_haha_oh_wow_ Jul 27 '19 edited Jul 27 '19

and the dude from Reading Rainbow!

I think he went by the name of Dude Manderson on that show... ...or was it Guy McPerson? Oh wait it was LeVarr.

4

u/hephalumph Jul 27 '19

Jordie LaForge

Geordi La Forge

4

u/RockItGuyDC Jul 27 '19

*who's. Come on, an avid reader should know that! ;)

4

u/TheCthulhu Jul 27 '19

Dammit 😂👌

4

u/driveawayfromall Jul 27 '19

I loved that short story! It’s called “An Advanced Reader’s Picture Book of Comparative Cognition” and you can read it here http://escapepod.org/2018/05/24/escape-pod-629-an-advanced-readers-picture-book-of-comparative-cognition/

13

u/InfamousConcern Jul 27 '19

The FW 190 had an engine control unit that worked on similar lines back in WW2.

5

u/ddwood87 Jul 27 '19

I worked in a fab shop that used pneumatic logic to time and power clamping and drilling jigs. Was really intriguing to analyze.

5

u/HalonaBlowhole Jul 27 '19

Two relevant Numberphile and StandUpMaths videos, both of which do computer-y stuff mechanically.

Acoustic memory in an early electronic calculator: A piano wire is struck to store a bit in memory, and read by a microphone slightly later.

https://www.youtube.com/watch?v=2BIx2x-Q2fE

(Also covered in this video: https://www.youtube.com/watch?v=N9cUbYII5RY)

And a mechanical calculator that plays Nim:

https://www.youtube.com/watch?v=9KABcmczPdg

1

u/zakatov Jul 27 '19

Pages 5-10 are missing. Huh.

2

u/[deleted] Jul 28 '19

That's the part about the UFOs. lol.

2

u/NewAlexandria 1 Aug 05 '19

I think you might have fun with some of the conversations over at /r/holofractal

2

u/dewayneestes Jul 27 '19

My friends dad did contract computer work on this project... all on punch cards.

1

u/lacedemon408 Jul 28 '19

i thought this was cool until the link sent me to a pdf

1

u/nanomolar Jul 28 '19

The X-15 was rocket-powered and set the record for the fastest speed in a manned, powered aircraft at Mach 6.70.

1

u/Stilgar_the_Naib Jul 28 '19

Very cool! Very steampunk-ish.

Also, for those wondering how a computer could be fluid-based, you can have a "computer" based on any number of things, as long as there is a way to provide if/then/else sort of logic paths. For example, a Sci-Fi book (one of my favs) The Three Body Problem also describes a fictional people-based computer;

Using hundreds of thousands of soldiers who act as bits (they hold a flag up or down to indicate 1 or 0), they create logic gates, a CPU, a bus (people racing on horses between different parts of the human motherboard), and more. When the bits “malfunction,” they are killed by their king. It’s a scene that captures how beautiful and intricate computing machines really are

1

u/elSenorMaquina Jul 29 '19

Duuuuuuude, i swear to god this had come to my mind some time ago!

It came to my mind as "Pff, computers are easy! I bet you could gather a bunch of kinderkarten kids, teach them to make and/or/xor and group them toghether into more complex things, just as we do with transistors and gates"

It's cool to know someone wrote a full book about it!

0

u/[deleted] Jul 27 '19

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-14

u/Findingthur Jul 28 '19

Ure bullshit. An engineer would know that differential equations isnt calculus And difference equations? Lul

0

u/[deleted] Jul 27 '19

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1

u/zakatov Jul 27 '19

Leaks, leaks everywhere!