Physicists have created the most fiendishly difficult maze
sciencealert.com
sciencealert.com
Why did they build a maze for the Minotaur with a possible escape route rather than just an ordinary prison? Why leave the possibility of escape open?
Well see, the Minotaur was arbitrarily strong. No material could build a wall strong enough that he couldn't bash through nor a door that he couldn't break down. But, he wouldn't try and break down anything if there was obviously a path right there he could use to go around it normally. By putting him in a maze, he will always keep trying the next path thinking it might be the exit, never attempting to break any wall. The puzzle is harder than any material they could have used to build a prison, as it cannot be bent by the Minotaurs brute force.
Computation (eg cryptography) can be "unbreakable" in a way that bank vaults and deposit boxes can't.
Because it was not a maze, the Minotaur lived in the center of a labyrinth. A labyrinth is a continuous path that leads to the center. The objective was to send people into it so they would end up in the Minotaur's lair and be devoured. The reason the monster stayed was that he had everything he needed there, especially food.
> Although early Cretan coins occasionally exhibit branching (multicursal) patterns, the single-path (unicursal) seven-course "Classical" design without branching or dead ends became associated with the Labyrinth on coins as early as 430 BC, and similar non-branching patterns became widely used as visual representations of the Labyrinth – even though both logic and literary descriptions make it clear that the Minotaur was trapped in a complex branching maze.
For the textual tradition: https://www.theoi.com/Ther/Minotauros.html
Some images of Roman labyrinths: https://www.labyrinthos.net/photopage02.html
It’s especially hard for modern people to conceive of a world before the printing press where information wasn’t easy accessible.
I grew up in Croatia, and there the word for both maze and labyrinth is "labirint"
If I lived in it for 20+ years, I probably wouldn't.
The reason I checked was in my native Swedish there is only one word (labyrint).
Was it really always two different things even in English? I looked the words up in Gutenberg's public domain Webster's Unabridged Dictionary (1890?) a labyrinth there was "an ornamental maze" ... "Labyrinth, originally; the name of an edifice or excavation, carries the idea of design, and construction in a permanent form, while maze is used of anything confused or confusing, whether fixed or shifting. We speak of the labyrinth of the ear, or of the mind, and of a labyrinth of difficulties; but of the mazes of the dance, the mazes of political intrigue, or of the mind being in a maze." And from the definition of maze: "A confusing and baffling network, as of paths or passages; an intricacy; a labyrinth". Did the meaning drift a bit since then or was it only in mathematics that the words began to be used in the way that they are often used now for branching vs non-branching mazes?
Your definition is wrong.
For example, this Wikipedia article[1] on labyrinth in Greek, which has the picture [2] of a maze and calls it a labyrinth.
[1] https://el.m.wikipedia.org/wiki/%CE%9B%CE%B1%CE%B2%CF%8D%CF%...
[2] https://commons.m.wikimedia.org/wiki/File:NAMA_Tablette_1287...
My algorithms prof once took us on a fun journey describing the median-of-medians variation of the SELECT algorithm, and had us play around with different partition sizes to see its effect on asymptotic running time. Turns out if you choose any other value than 5, you get superlinear running time.
This is probably the most random display of fatuousness I’ve encountered from mathematics. There should be absolutely no reason the number 5 - not 3, not 4 - has anything to do with recursively selecting a median, and yet here we are.
It makes me wonder. Maybe there are computational rules similar to gravity or conservation of energy, but similar to physical machines, there seem to be computational ones that can be built defy them.
Presently this line of thought is dead because quantum computers have demonstrated doing something that can't be done classically. So we know there's no theoretical reason not to have a quantum computer. But the thought that the laws of the universe might be underpinned by computation is still very much alive. Its just all qubits at the bottom rather than classical bits.
There's a cliche in the field. "Information is physical". Roughly it means, information only exists encoded on some form of physical medium, and all physical systems are reducible to the information encoded as the state. Physical things are information, information is a physical thing. Information is physical.
This is a great observation! I just hesitate to romanticize the applicability of modern concepts to classical situations.
Check this out:
Imposter Syndrome
I thought about this as well, after my first remark. I think this issue could be solved by building a secondary labyrinth of ventilation ducts to channel the fresh air into the dead ends, in a way that entices the Minotaur in very confusing ways. The ducts could even have baffles that open and close, just like real ventilation systems in houses with zone-control airflow.
The ventilation ducts could also work to confuse and terrify any humans who were sent into the labyrinth. They’d carry sounds allowing the human to hear the heavy breathing and bellowing of the Minotaur in ways that make it sound like he’s always just around the corner!
The more interesting case is that Sisyphus can contemplate the nature of the system, and reason toward an out that involved undermining Hades power over the Underworld. If he could pause and do experiments, discover the limits of the enchantment, and work around them, that would be ideal. However such an option would also be an excellent way for Hades to extend and deepen the severity of the punishment. A god's arbitrary power is arbitrarily powerful, after all.
Perhaps what all those Greek epics taught me, is that once someone condemns you to a destiny, then that’s it. No other destiny can open up.
E.g. this:
+-- -+----+----+----+----+
| | | | | |
| | |
+-- -+-- -+----+----+-- -+
| | | | | |
| | | |
+-- -+----+-- -+----+----+
| | | | | |
| | |
+-- -+----+-- -+-- -+-- -+
| | | | | |
| | | |
+-- -+-- -+-- -+----+----+
| | | | | |
| | | |
+----+----+----+----+ +
Is just this, with extra wall material in each cell, reducing the aperture of the passages: + +----+----+----+----+
| | |
| | |
+ + +----+----+ +
| | | |
| | | |
+ +----+ +----+----+
| | |
| | |
+ +----+ + + +
| | | |
| | | |
+ + + +----+----+
| | | |
| | | |
+----+----+----+----+ +The first solution was immediately plain. I did not think about it. I did not read about it. I just looked at it because my eyes were drawn to it, and and the solution was simply present for me.
I did think about the second one (the allegedly-simpler one) for a very brief moment.
And then, I read the words.
But it took me longer to read and parse "is just this with extra wall material in each cell" than either of those two maze-interpretation events consumed.
(I do not think that I am a particularly slow reader.)
Hence, the remark.
I don't think I've seen this maze building technique, even though it seems simple.
But does anyone know a good metric for maze difficulty? Or what the study of maze difficult would really look like? The classic maze solving algorithm (right hand rule/DFS) is deterministic anyway.
I didn't, but found this [1] 2001 paper without much difficulty. Getting much out of it is more difficult. As I understand it, the complexity measure they propose is somewhat related to the difference of arctans of turns to take "forward" vs turns to take "backward", summed up for every fork and scaled with some length measurement. There are definitely plenty of other complexity measure though (e.g. number of forks, number of incorrect paths, etc) -- correlating that to practical difficulty is less straightforward.
[1] https://archive.bridgesmathart.org/2001/bridges2001-213.pdf
https://en.wikipedia.org/wiki/Micromouse
For example: https://swati-mishra.com/wp-content/uploads/2020/02/advanced...
I think there are a bunch of problem-definition details that would need to be hammered out first, ex:
1. Is this solving the maze with perfect knowledge of its layout--a bird's eye view from above--or does it require gradual exploration to fill out the contours?
2. If it requires exploration, how far can you see? Do you need to actually spend a move to enter a square to know whether it is a dead end, or can you tell from N squares away? Is the viewer constrained by trigonometry, where they can only uncover partial knowledge about nearby rooms and small geometric quirks can have a big effect on exploration progress? Is there a distance limit to vision?
3. If it requires exploration, is there a cost to backtracking, or--like DFS--can you simply teleport between all places you've already been without a cost?
4. Is a "difficulty" rating across mazes based on a single algorithm, or the best-possible choice for that particular maze from a set, or does it represent the average expected effort expended by a particular population of different people/algorithms?
____
Interestingly, you don't always actually have to _have_ an actual solution - it can be possible to determine run-time bounds (that tell you how hard your problem is at least) just on theoretical grounds. This could be, e.g., by comparing it in complexity to another problem that has already been studied and whose complexity is thus known.
Since solving mazes is however (also) something to be enjoyed by humans, it’s possible that perceived maze difficulty could be dependent on factors that wouldn’t really matter for a straightforward algorithm. For example, a very “jagged” maze could feel more difficult for humans because it’s harder to follow with your gaze, while an optimal maze solution finding algorithm wouldn’t be impacted.
In cases like this, formulating difficulty can be more of an art than an optimization problem.
EDIT: See also andrew_eu’s reply (which I only saw now), where multiple “interesting” notions of “difficulty” are proposed.
EDIT: Relatedly, humans use heuristics a lot. And there are many NP-hard problems where we can solve lots of “reasonable” points in the problem space in reasonable time (computers or humans alike), at the risk of having to time out, maybe try with another approach, and eventually just give up. Traveling salesmen are actually traveling the country after all. So worst case is not always a good measure for games. But I see you mentioned that already.
This has significant implications to search spaces that are very heavily branched with many deep dead ends but a relatively shallow goal.
The number of problems in general life matching that description is… huge.
This is just another way of saying the size of the search space is (b^d), and DFS "walks the tree" until it finds the exit, which means on average its going to iterate half the entire search space before getting there. Furthermore, unless there is some other information available which correlates with the correct path at a given intersection, there's no possible way to do better than testing the possible branches sequentially (as in DFS) and therefore no way to improve on searching half the entire space.
Look at a very simple maze, you will likely “intuitively” solve it immediately without performing an actual DFS. Implementing that as an actual computer algorithm would be insane since your algorithm would now rely on the computational needs of a human perception system, which decreases algorithmic efficiency by many orders of magnitude. But humans with their weird squishy brains have what they already have, and on the flip side are simply not optimized for algorithms on all but the smallest data structures. (You can very easily read even distorted text, but you have an extremely hard time balancing a simple red-black-tree in your head or even on paper.)
EDIT: Relatedly, humans use heuristics a lot. And there are many NP-hard problems where we can solve lots of “reasonable” points in the problem space in reasonable time (computers or humans alike), at the risk of having to time out, maybe try with another approach, and eventually just give up. Traveling salesmen are actually traveling the country after all. So worst case is not always a good measure for games.
[1]: https://mazes.co.uk/
Think of each free-standing section of wall as a node in a graph. The graph's edges connect free-standing wall sections which are adjacent. The task is to find (and circumnavigate) all the graph's nodes.
Yes, it could be very tedious to search this alternative representation of the maze for the exit node. Far more likely not - the description was "maybe 150 foot square", not "multi-acre corn maze".
*Assuming a two-dimensional maze, a finite number of free-standing wall sections, flat spacetime, and non-zero lower bound on the width of the maze's paths.
As an organizer, I'd be much more concerned about medical emergencies and inter-personal crime in the maze.
I guess "professional" mazes may have sprinkler systems. Still, it seems that even in buildings that do, a lot of value is put into maintaining escape routes.
> I will never go into another [plywood] maze again [...]
... without a marker.
[1] https://imgur.com/a/3paGJOk
I discovered a somewhat similar fractal-maze when playing around with the dragon curve[2], maybe I should publish that.
My mother has told me I would have them done within seconds, and I'd have a whole book before she'd finish putting the groceries away.
I've never thought much about it other then, 'I used to like doing mazes'; but I wonder if it was a special gift I could have developed.
I'd just relax and de-focus for a moment, keeping my eyes on a printed maze but not really looking at it. To me, the path never really looked any different visually -- it was just clearly and distinctly evident in ways that I cannot properly articulate.
Once the path revealed itself through no particular effort on my part, I could trace it out with a pencil or a crayon or whatever.
I could do this trace by starting from random points in the middle, drawing lines towards the outside, or start at one end or the other. It didn't really make a difference to me where I started the trace. To me, I was just tracing parts of a path that I knew to be correct -- it didn't matter at all to me what order I drew them in.
It was a rather unpopular trick. Other kids were sure that I was cheating (as if I had a catalog of solutions to all of the world's mazes in my head or something) or showing off (they may have been right about this last part).
Adults would proclaim (rather insistently) I must be doing it wrong somehow despite consistently and confidently, if unconventionally, arriving at the correct answer on the first try. They tended to make it very clear that they were unappreciative of this departure from normalcy.
Seems that you managed to train your neural networks to do a parallel search. Probably visual cortex neurons. GPU acceleration rocks.
Anyway, I always wondered how he could do it. To me he was just drawing lines everywhere, but there would eventually be a complete maze with only one solution.
Maybe it was a memorized algo--like a party trick basically.
These weren't hard to make as you just built out from the start and added random branches, or dead ended them occasionally.
> Quasicrystals are a form of matter only found very extremely rarely in nature.
;)
The closest I've found is a paper they reference for generating arbitrary rhombic tilings in arbitrary numbers of dimensions, based on the de Bruijn grid method: