It's possible. Though it would be constrained to analog data transmission, where each step in pressure is a different analog value (0-255 instead of digital's 0/1). Of course, it will be slow.
BUT! You don't do things like this for efficiency, you do them because they are interesting and fun
Two parallel systems, one going each direction. One end produces the pressures, the other senses it. It won't be a beginner project by far, but it'd even be possible with an Arduino, some motors, some sensors, and the tubes and cylinders.
Plus it'll work as pneumatic (air) or hydraulic (fluid)!
Sure. This is kind of how altimeters work. Capacitor with thin film that responds to changes in pressure.
If you can rig one side of a tube to change the pressure in the tube, and the other side to measure changes in pressure, you've got a one way physical layer.
You could probably build something to detect pressure changes by putting a Wheatstone Bridge over a flexible membrane, which you'd then seal to/over one end of the tube.
It is but I'm pretty sure the data would transmit at the speed of sound instead of light, same as that one experiment with pushing a very very long pole
Do you know how I could look up that experiment? Because one of their claims is that it would transmit data at the speed of light. But their reasoning is related to gravity in a way that I don’t follow.
Yes, in fact, some of the earliest computer memory worked this way! It used mercury since sound travels quickly in it. A transducer in one end adds data, and one on the other end receives it. Then the circuit loops back to add the data that just fell off the tube! Always looping.
Effectively this is what analogue modems did, you sat the handset in a coupler and the sound from the earpiece was picked up by a microphone. Air pressure.
Easier to do in enclosed fluids than gas in open environment.
Find yourself a drilling engineer and be prepared to learn more than you ever wanted to know about how down hole sensors send data to surface via pressure waves in drilling mud. Key term for web search is “mud pulse telemetry”
Probably the easiest one to do is doing speech recognition on like a raspberry pi (plenty of tutorials for this)
You could go a bit deeper and do like note identification from a piano or something but you’d need to use an fft to figure out the frequencies and that’s probably way too advanced
This is a pretty good ELI5 explanation of how the signal processing for something like this works. She’d probably be able to get it with not too much help from a parent (I learned this in my 2nd year of ME)
Yup, the bits you're looking for are called "transducers", and they're made for the specific medium you're looking to communicate in (air, liquid, etc). I can explain more tomorrow :)
Think like analog radio waves. Not saying this is how you'd build it (this is a rather Rube Goldberg-esque example), but just as a thought experiment establishing possibility:
Build some sort of air chamber and vary the pressure in it. Have some device that can measure air pressure and can be hooked up to an oscilloscope to display measurements.
(which I'm not well read on, but if it's just superimposed sinusoids, then why not?), then it's a matter of outputting the electrical signal to some device that knows how to take analog EM waves as input, which already exist.
If the question is: could you broadcast data via air pressure in an unbounded medium like public airspace?, probably not.
But if you had some sort of bounded air chamber for short range use (like say within a single building), that doesn't sound impossible to me on its face.
(The limitations will come in with mechanical concerns like how quickly you can vary the air pressure in the chamber, by how much, and that would depend on the physical design.)
Comments
BUT! You don't do things like this for efficiency, you do them because they are interesting and fun
Plus it'll work as pneumatic (air) or hydraulic (fluid)!
If you can rig one side of a tube to change the pressure in the tube, and the other side to measure changes in pressure, you've got a one way physical layer.
https://physics.stackexchange.com/questions/21122/if-i-move-a-long-solid-stick-can-i-send-message-fastest-than-light
She kinda already has one in her throat...
Find yourself a drilling engineer and be prepared to learn more than you ever wanted to know about how down hole sensors send data to surface via pressure waves in drilling mud. Key term for web search is “mud pulse telemetry”
I mean theoretically you could use ultra-high or ultra-low frequencies but it's still sound
It would be awesome to rebuild something like this as a project
You could go a bit deeper and do like note identification from a piano or something but you’d need to use an fft to figure out the frequencies and that’s probably way too advanced
https://youtu.be/zb1r_uKOew4?si=hc0h0Vl8ieL96-xH
https://www.atlasobscura.com/articles/capn-crunch-whistle
https://youtu.be/spUNpyF58BY?si=mN0m6C9PcPhi2jj2
(You can do it using hydraulics, but unless it's in something constraining the air - like a hose - it's not gonna be easily decodable.)
(Although, communicating data through a room slowly by varying its air pressure slowly, that'd also work.)
Think like analog radio waves. Not saying this is how you'd build it (this is a rather Rube Goldberg-esque example), but just as a thought experiment establishing possibility:
If you can make waves similar to radio waves--
But if you had some sort of bounded air chamber for short range use (like say within a single building), that doesn't sound impossible to me on its face.