Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Can water solve a maze? [video]

youtube.com

Post reply on HN
Print view View original

41–50 of 133 posts

Re: Can water solve a maze? [video]

#41

Post by grupthink »

archerx wrote: post #29
zamadatix wrote: post #26

Earlier quoted context omitted.

If I launch a random cellular automaton there isn't as much a real reference I'm trying to compare it to as just seeing what cool things it does. Maybe I can coax it into something comparable if I want, e.g. pick rule 110 and set it up to run ChatGPT and write this comment, but the only "realness" requirement is it follow what logic allows not it has a real reference it's supposed to emulate and be compared to.

I wouldn't call that a simulation though, it's just a looping process with rules. A simulation implies imitation, so if it's not imitating anything is it a simulation?

It would be simulating causality. If you had a water maze that was large enough - with enough gates, switches, and circuits - then it would be turing complete and simulate its own universe. But the more likely scenario is that it doesn't compile into anything. The point is, given enough time, and space (it's going to be one large maze) it's capable of applying the same rules of causality, and calculating the same math across all universes. That said, if your quarks and neutrinos blip in and out of existence, you can blame it on the turbulent water maze(s) higher in our simulation stack. :)

Re: Can water solve a maze? [video]

#42

Post by Retric »

mnw21cam wrote: post #20

He's wrong about why that maze towards the end of the video doesn't empty out the supply tank. It's not surface tension, but rather it is the fact that the path goes up and down. The down parts of the path will be filled with air, and the up parts will be filled with water. Water is more dense than air, so the supply must have more pressure than the sum of all the heights of the up parts in order for water to flow. T…

Mostly, but surface tension in aggregate is meaningful.

Surface tension is doing two things, first it’s contributing to back pressure several times in the same way it’s just barely keeping water from over topping. Secondly it’s taking up volume in air pockets thus increasing the pressure of those pockets. So, if he added soap to reduce surface tension the tank wouldn’t empty but it would end up lower. My guess is roughly an inch but it’s worth testing.

Re: Can water solve a maze? [video]

#43

Post by User23 »

AltruisticGapHN wrote: post #17
grupthink wrote: post #8

A computer is a computer, and our universe is a computer. So, it's possible we're living in a simulation but not one that was intentionally constructed by a higher life form, but rather, a simulation that emerged from nature (e.g. electrons whizzing along the surface of silica rock on a desolate planet). Our universe could recursively be computers all the way down.

The simulation theory simply postpones the hard problem of consciousness. It's like a magician trick, pulling wool over the eyes, moving your attention away from the real problem long enough, so that you stop thinking about it.

The simulation theory is literally a species of creationism, which I find quite amusing.

Re: Can water solve a maze? [video]

#44

Post by docandrew »

quickthrower2 wrote: post #27
AltruisticGapHN wrote: post #17

Earlier quoted context omitted.

The simulation theory simply postpones the hard problem of consciousness. It's like a magician trick, pulling wool over the eyes, moving your attention away from the real problem long enough, so that you stop thinking about it.

Even without consciousness, the existence of the universe faces the same causality issues.

All the talk of simulations, multiverses, etc is IMO expending a lot of effort to avoid facing the possibility of a Creator - the “uncaused cause” or something existing outside of time and space.

Re: Can water solve a maze? [video]

#45

Post by GistNoesis »

Inspired by Steve mould, I had some fun doing something quite similar a while ago experimenting with Bell Siphon, 3d printing, and numerical simulation. If this interest someone here I just pushed it to Thingiverse now https://www.thingiverse.com/thing:5948252 https://www.youtube.com/watch?v=S748mcM0MSg

As Steve showed, it's particularly important to take into account both air and water.

There is still some work needed to make it Sim2Real and optimize the design automatically.

The ambitious end-goal, is to have a cascading siphon (not so dissimilar than the flushing mechanism in your toilet) that can reliably be switched on by a single additional drop of water. (Currently I achieve this goal using a Shishi Odoshi fountain to arm the siphon very reliably but it still has one moving part, but that's a story for another day).

Quite fun, messy and time-consuming rabbit-hole to go down to, cause you need to get the details right.

Re: Can water solve a maze? [video]

#46

Post by PartiallyTyped »

_v7gu wrote: post #35

So it's basically A* with higher scores when going towards gravity, very cool. Another physics problem analogue I really like is the problem of fastest travel from point A to point B when you have to cross a river. One approach to solve is is to treat it as a minimization problem by writing down everything, another one is to realize light beams have already solved this problem for you, and the problem becomes much si…

Assuming the heuristic follows triangle inequality, then it is A*.

Re: Can water solve a maze? [video]

#47

Post by mywacaday »

Retric wrote: post #42
mnw21cam wrote: post #20

He's wrong about why that maze towards the end of the video doesn't empty out the supply tank. It's not surface tension, but rather it is the fact that the path goes up and down. The down parts of the path will be filled with air, and the up parts will be filled with water. Water is more dense than air, so the supply must have more pressure than the sum of all the heights of the up parts in order for water to flow. T…

Mostly, but surface tension in aggregate is meaningful. Surface tension is doing two things, first it’s contributing to back pressure several times in the same way it’s just barely keeping water from over topping. Secondly it’s taking up volume in air pockets thus increasing the pressure of those pockets. So, if he added soap to reduce surface tension the tank wouldn’t empty but it would end up lower. My guess is rou…

What's great about this video and the discussion is that something as familiar as water can have new and non intuitive things to learn about it. Are there any other examples of common things that have non obvious behaviour from every day experience?

Re: Can water solve a maze? [video]

#48

Post by willis936 »

s-macke wrote: post #4

If you are using a gas rather than a liquid, it is even simpler. Just set a high pressure at the beginning and a low pressure at the end. The gas will automatically follow the steepest part of the pressure gradient. The static solution can be calculated by solving the Poisson equation. In [1] you can see a small implementation of the idea. [1] https://simulationcorner.net/maze/

Some if Buls Berglund's recent videos about waves in mazes made me realize this.

Funnily enough he uploaded a video two hours ago that shows what it looks like.

https://youtu.be/lBLlYmM6tjU

Re: Can water solve a maze? [video]

#50

Post by thih9 »

bilsbie wrote: post #49

Not sure if mazes are np complete but if so could we map other problems into maze designs and the water can solve problems for us?

I thought we decided to use electricity and silicon mazes instead?

But there were attempts to use water too, e.g. MONIAC: https://en.m.wikipedia.org/wiki/MONIAC

Post reply on HN