Live data from Hacker News

Can water solve a maze? [video]

youtube.com

61–70 of 133 posts

Re: Can water solve a maze? [video]

#61

The thing that I found most interesting was actually the little side discussion about all mazes being two pieces. Something that I had never considered, but seems fairly self evident (assuming only one path exists through the maze). Also makes me wonder what a proof would look like.

> Also makes me wonder what a proof would look like. Start with the simplest possible maze (i.e. one square with a start and a finish) which will be in two pieces. Then show that all possible additions will not add further pieces except for when you "cut" into an existing piece to make a separate non-solution route (i.e. a looped route that takes you back to the same point). (Having any loops in the maze would break…

> (Having any loops in the maze would break the condition of there being only one solution as you could take a detour round the loop as many times as you like and thus have an infinite number of "solutions")

The loop could be somewhere inaccessible from the starting point. Perhaps your logic holds if you insist that all pathways in the maze are connected, though.

Re: Can water solve a maze? [video]

#62

Earlier quoted context omitted.

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.

The presence of a creator does not change anything. Who created the creator?

That’s the point - something completely beyond our notions of causality or the arrow of time has to be at the foundation of it.

Re: Can water solve a maze? [video]

#63
post #42

Earlier quoted context omitted.

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?

water has a fair number interesting properties

https://www.chemistryworld.com/features/the-weirdness-of-wat...

Re: Can water solve a maze? [video]

#64
post #61

Earlier quoted context omitted.

> Also makes me wonder what a proof would look like. Start with the simplest possible maze (i.e. one square with a start and a finish) which will be in two pieces. Then show that all possible additions will not add further pieces except for when you "cut" into an existing piece to make a separate non-solution route (i.e. a looped route that takes you back to the same point). (Having any loops in the maze would break…

> (Having any loops in the maze would break the condition of there being only one solution as you could take a detour round the loop as many times as you like and thus have an infinite number of "solutions") The loop could be somewhere inaccessible from the starting point. Perhaps your logic holds if you insist that all pathways in the maze are connected, though.

Or define that the "maze" is the collection of all the reachable areas from the start position. Then, it doesn't matter what you do in inaccessible areas as they're not part of the maze.

Re: Can water solve a maze? [video]

#66

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…

How does that reconcile with the syphon principle? You'd figure that once the water is flowing out of the end, even if the tank was below some of the water's path, the flow would continue until all the water was gone.

Re: Can water solve a maze? [video]

#67

Earlier quoted context omitted.

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.

The presence of a creator does not change anything. Who created the creator?

The creator remains without a creation. The notion that most schools of thought have is, the creator is unborn and born at the same time and has always existed. Creator does not have a point of creation, not even death because those rules only apply to the materialistic universe.

Re: Can water solve a maze? [video]

#69
post #38

Earlier quoted context omitted.

You can make a maze with only one path (other than paths that double back on themselves), but has three pieces: https://i.imgur.io/R4j6TH3_d.png I think this is basically a flaw in the intuitive definition (or maybe only my intuitive definition) of "doubling back".

Except that this maze clearly has at least two solutions. Straight through the corridor, or via the loop. And that's assuming you don't wander around the loops n times.

Three solutions if you want to be nitpicky. You can go around the clockwise, and counter-clockwise :)

Re: Can water solve a maze? [video]

#70

> [2:39] ... Actually a maze becomes very easy to solve if you colour the two parts separately. Breezing through that example like he didn't just blow my mind, wow. It makes so much intuitive sense.

Unless you are the maze constructor, coloring the maze pieces is at least as hard as solving it.
Post reply on HN