Mathematicians discover shape that can tile a wall and never repeat
newscientist.com
newscientist.com
Direct link to PDF on ArXiv (89 pages) https://arxiv.org/pdf/2303.10798.pdf
I mean obviously it'd be too much cost and hassle, since you need at least 5 different tiles to tile a plane, but I'm still curious how it would actually turn out on a real floor or wall, with an interesting pattern on the tiles.
While you need multiple Wang tiles, at least they can be square rather than a rather awkward polygonal shape. So there's that...
[1]: https://grahamshawcross.com/2012/10/12/wang-tiles-and-aperio...
SAN FRANCISCO--(BUSINESS WIRE)--The Transbay Joint Powers Authority (TJPA) has received approval from Dr. Roger Penrose, the eminent British mathematical physicist, to incorporate his groundbreaking geometrical pattern in the design of the exterior walls of the future Transbay Transit Center (TTC) designed by Pelli Clarke Pelli Architects (PCPA). Dr. Penrose and PCPA are working in tandem to incorporate Dr. Penrose’s elegant design, known as the Penrose Rhombus Tiling, in the skin of the TTC. The design is remarkably simple but unique because it can be extended infinitely without repeating itself. The Penrose system is ideal for the perforations in the metal panels that will form the curved exterior of the Transit Center.
https://www.businesswire.com/news/home/20130711006350/en/Rog...
Outdoor mall
Mall alone being the 80s style indoor walkable variety. A 'strip mall' usually a single (often deformed to some degree) line of stores along a sidewalk next to a huge parking lot, also often with an island restaurant or small store that wants to stand out closer to the street edge of said lot.
https://nps.gov/nama/index.htm
Also, sometimes cars,
https://www.royalparks.org.uk/parks/st-jamess-park/things-to...
http://www.tessellations.org/real-materials-tessellations-16...
There's girih tiles. It's like 5 tiles that you can do a bunch of stuff with. Invented by some based geomystics like 1000 years ago.
And there's kisrhombille. Lots of options there.
The long string of horizontal yellow diamonds and upside down blue "darts" in this image: https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Wa...
Or the red "dominoes" in this image: https://grahamshawcross.files.wordpress.com/2012/10/13tiling...
Humans like patterns or randomness, we sort of hate quasi-versions of either (See: our disdain for blurry pictures).
The way you construct a set of Wang tiles determines how many you'll need. The first link in my previous post shows how to construct them for various set sizes.
The actual topic of the article was impressive, but this little fact about the meaning of "ein stein" was pretty interesting as well. TIL.
(I was once hearing someone talk about privacy and how people like Tsucabuc are destroying it. I never heard about him but apparently he is one of the owners of a large social media company. Then he mentioned Facebook and I realized he was pronouncing Zuckerberg in German.)
I just love this
From the preprint. It is definitely possible to lay the tiles so that they do not tile anymore.
https://tilings.math.uni-bielefeld.de/
examples:
https://tilings.math.uni-bielefeld.de/substitution/domino-va...
I can't believe NewScientist left that out of their headline.
I'm not clicking that, I don't trust I'll be able to come back.
But I could see this making a "psychedelic" experience a bit more interesting.
https://cs.uwaterloo.ca/~csk/hat/app.html
I just wished one could turn off the colors.
The colors really distract me from trying to see the patterns the shape itself creates. For me, the beauty here is that each piece is exactly the same. Colorizing them differently takes away from that.
main { filter: saturate(7) grayscale(10) contrast(3); }
It's not too hard to scrape the JavaScript out of the page. You could figure out where they set the colors and change that part.
I also wonder if you can do that on https://mathigon.org/polypad/8kVqVH2Mor6JTQ
There's also https://cs.uwaterloo.ca/~csk/hat/, but sadly I didn't see anything like a github link to the above demo.
And I wouldn’t know whether trivial multiples that still tile the plane non-periodically exist. Once you pick a multiple, even the claim that any of these basic structures in the plane is part of the multiple you picked doesn’t seem to have an obvious, trivial (1) proof to me, let alone the additional requirement that you can find non-overlapping ones.
(1) I’m trying, likely unsuccessfully, to dodge the problem of triviality in mathematics (https://en.wikipedia.org/wiki/Triviality_(mathematics)) here
>> The hat is one member of a continuous family of shapes that are all aperiodic, and that all tile the plane in the same way.
You could make a 2D diagram of the integers with they prime factorizations, which is aperiodic, but nearly periodic, but requires an infinite set of different "tiles".
Perhaps you could take an irrational or transcendebtal number, and take its multiples or powers mod 1, to get an aperiodic nearly periodic sequence.
So we have a serious "infinite chaos out of plain order" situation here. Which I call impressive.
We have like 10 different chaoses, depending on how you do your first tile. What would a superposition look like?
And it's pretty easy to organize, given that it's based on the chunkykisrhombille.
Hmmm. What powers would it give us, bigstructurewise?
Very interesting. There are specific regions that repeat, but the overall image does not.
https://www.google.com/search?q=%22Clark+Richert%22+Art&tbm=...
[1] https://commons.m.wikimedia.org/wiki/File:Comparison_of_trun...
Still, can one prove this is aperiodic from geometry alone? It seems rather difficult to actually prove that fact. Feels intuitive that there must be a period somewhere, however large it may be, on the infinite 2D plane.
For example, consider rectangles with sides of 1 and 3 units: they can cover the plane periodically (e.g. in a simple rectangular grid), but also aperiodically, because you can form a square grid of square 3 by 3 units "metatiles", each encoding one bit of information in the vertical or horizontal orientation of the narrow rectangles; then it's easy to break symmetry by orienting metatiles so that for all integers m and n some metatile differs from the metatile m rows and n columns away, so the period cannot be m rows and n columns.
So, it has "islands" of repenting combinations of tiles, but these islands do not repeat / translate in a regular way.
So, there are "patterns" (as a matter of fact, the elementary tile is repeated infinitely on the tiling) but you cannot fill the plane with mere translations of one.
See: https://personal.math.ubc.ca/~cass/courses/m308-02b/projects...
There's not a way to do that sort of grouping for these tiles.
Compare pi. I can find the numbers representing my name in ascii an infinite number of times in the digits of pi, but if i find it once, there's no information in where to find it again, i can't just move forward n digits to find it, then another n digits to find it again, and ao on.
However, they might match in small patches, just never across the entire infinite plane.
cuz it would be mind blowing if you made a copy and it wasn't a copy... pauli whackamole exclusion tiling
Kind of, though, right? One could also look at it as they've found two shapes that happen to be reflections of each other.
That excludes affine transformation.
[0] : https://www.cnn.com/videos/health/2023/01/09/monty-python-si...
https://tilings.math.uni-bielefeld.de/substitution/penrose-r...
https://tilings.math.uni-bielefeld.de/substitution/fibonacci...
https://tilings.math.uni-bielefeld.de/substitution/semi-deta...
In addition, the dragon curve is a fractal -- mathematically, it's defined as the limit that the substitution process converges to as the details get "infinitely small", which means that in a sense, the true dragon curve (as opposed to the approximation that you can draw on a computer) has a boundary with no straight line segments at all. On the other hand, an aperiodic tiling is composed of finite, fixed-size tiles that extend outwards to infinity.
Funnily enough, the dragon curve is a space-filling curve that tiles the plane periodically.
They say they have "a new kind of geometric incommensurability argument", and there are many statements about the related undecidability of related tiling classes.. but not really grokking this.
Anyone know?
Would be extremely curious if patterns like the one described exist in math.
https://en.wikipedia.org/wiki/Penrose_tiling#Kite_and_dart_t...
[0]: https://www.chiark.greenend.org.uk/~sgtatham/puzzles/js/loop...
http://www.fleen.org/generative_art_project/i0_quartersize.p...
Of course individual tiles will repeat, but never in an infinite periodic pattern.
Edit: a novelty of this paper is that their shape is "truly" aperiodic, which means no matter how hard you try, you will end up with aperiodic tiling. Existing one-shape aperiodic tilings had to add constraints on how to put two shapes next to each other to ensure aperiodicity.
What does this mean? How can an individual tile "repeat"?
It's very probable (I did not read the paper, only their website page) that the tile only occupies a finite amount of orientations in the tiling and therefore at least (and probably more if not all) one orientation will also be present an infinite amount of times.
However this does not imply periodicity of the tiling.
Side: This is an amazing tattoo idea.
https://aperiodical.com/2023/03/an-aperiodic-monotile-exists...
Most people would call that pattern obviously repeating (in the shape itself).
--veritasium
101001000100001... is aperiodic but doesn't contain every finite string.
But you could say that becaus it contains an infinite set of distinct finite substrings, it can be put in bijection with any countable set of objects. That's not a "picture" in common parlance, via any sort of structured encoding, it's just an index.