Seen in a certain light, at a certain width..?
March 4, 2023 7:52 AM Subscribe
What’s the name for the type of pattern that only appears when selecting the right width of a grid? And what are similar puzzles/concepts/explorations of seemingly chaotic patterns that leap to life and order when a certain parameter is tuned correctly?
Sometime on late 90s / early 00s internet, I remember some kind of puzzle on a website that involved changing the width of a grid of squares (say, going from 5x100 to 10x50 to 20x25). When you selected the “correct” width, a pattern appeared (maybe words?)
I’m having trouble searching for this concept - any ideas if this has a specific name?
More broadly, this is making me think about the concept of seemingly chaotic information that requires just the right parameter and then it’s deeply informative. I expect this actually shows up a bunch of places, like tuning a frequency?, and code breaking, but I’m wondering if there are other interesting/curiosity-evoking examples you can think of, whether in the logic puzzle domain, some kind of scientific principle, conceptual art, stories/real life examples, or any format that resonates with this principle.
Thank you!!
Sometime on late 90s / early 00s internet, I remember some kind of puzzle on a website that involved changing the width of a grid of squares (say, going from 5x100 to 10x50 to 20x25). When you selected the “correct” width, a pattern appeared (maybe words?)
I’m having trouble searching for this concept - any ideas if this has a specific name?
More broadly, this is making me think about the concept of seemingly chaotic information that requires just the right parameter and then it’s deeply informative. I expect this actually shows up a bunch of places, like tuning a frequency?, and code breaking, but I’m wondering if there are other interesting/curiosity-evoking examples you can think of, whether in the logic puzzle domain, some kind of scientific principle, conceptual art, stories/real life examples, or any format that resonates with this principle.
Thank you!!
A moiré pattern happens when parallel lines are overlaid.
posted by Jesse the K at 8:11 AM on March 4, 2023 [2 favorites]
posted by Jesse the K at 8:11 AM on March 4, 2023 [2 favorites]
Not exact, but this sounds like a digital version of magic eyes, those random, chaotic, colorful patterns that jump to life when you kind of cross your eyes a little and hold them at the right distance from your face.
posted by sillysally at 8:23 AM on March 4, 2023
posted by sillysally at 8:23 AM on March 4, 2023
Fore-edge painting (Wikipedia link) on the edges of book pages
posted by adventitious at 8:55 AM on March 4, 2023
posted by adventitious at 8:55 AM on March 4, 2023
The closest I can come is a scytale.
I think your idea is that there is a bunch of information in a grid, and only dimensions of the grid name the message appear.
Like... This is the worst example, but laying out the numbers 1-100 in a straight line (1x100) is kind of boring, but in a 10x10 grid you see that the last digits in each column are all the same.
posted by Acari at 9:27 AM on March 4, 2023
I think your idea is that there is a bunch of information in a grid, and only dimensions of the grid name the message appear.
Like... This is the worst example, but laying out the numbers 1-100 in a straight line (1x100) is kind of boring, but in a 10x10 grid you see that the last digits in each column are all the same.
posted by Acari at 9:27 AM on March 4, 2023
This shows up in knitting! The most basic version is "self-striping yarn", where the yarn is dyed to change colors at certain intervals. You have to get the size and tension of the knitting project right to get the changes to line up so the stripes work properly. The width of the grid here is the number of stitches (and each stitch also has to use the right amount of yarn).
The more complicated version is "self-patterning yarn", which works on the same principle but can create much more elaborate designs. These are things like vertical stripes (created by the stitches in different rows lining up correctly) and even images. If you got the grid size wrong these would not work! Here are some examples of patterns.
posted by earth by april at 10:07 AM on March 4, 2023
The more complicated version is "self-patterning yarn", which works on the same principle but can create much more elaborate designs. These are things like vertical stripes (created by the stitches in different rows lining up correctly) and even images. If you got the grid size wrong these would not work! Here are some examples of patterns.
posted by earth by april at 10:07 AM on March 4, 2023
I expect this actually shows up a bunch of places, like tuning a frequency?
In digital sampling (say, converting music to bits for a CD or MP3 file, or turning visual data to bits for a photo) if you don't design your sampler right you get audio or visual noise in the resulting file as a result of aliasing. That particular Wikipedia post seems somewhat readable to me; if you're good at higher level math you can try reading about sampling theory, but I cannot possibly attempt to explain it without introducing errors. A brief summary that may not be entirely wrong is that if you have an analog signal you'd like to convert into a digital signal, your sampler should run at no less than twice the frequency of the signal (a number known as the Nyquist Rate). In practical terms, with some math and engineering details I've forgotten or in fact never fully understood, this is how you get from "human hearing goes up to about 20 kHz" to "CDs have a sample rate of 44.1 kHz." You may also read reviews of high end digital cameras that talk about whether the sensor in any given camera has an anti-aliasing filter, which has the positive effect of reducing color noise in some situations, but the negative effect of reducing overall resolution which may be important in other situations. Again, this is a thing I kind of understand well enough to know I don't personally need to care about the details, but here's an article with a link to a video that may be informative?
posted by fedward at 11:10 AM on March 4, 2023
In digital sampling (say, converting music to bits for a CD or MP3 file, or turning visual data to bits for a photo) if you don't design your sampler right you get audio or visual noise in the resulting file as a result of aliasing. That particular Wikipedia post seems somewhat readable to me; if you're good at higher level math you can try reading about sampling theory, but I cannot possibly attempt to explain it without introducing errors. A brief summary that may not be entirely wrong is that if you have an analog signal you'd like to convert into a digital signal, your sampler should run at no less than twice the frequency of the signal (a number known as the Nyquist Rate). In practical terms, with some math and engineering details I've forgotten or in fact never fully understood, this is how you get from "human hearing goes up to about 20 kHz" to "CDs have a sample rate of 44.1 kHz." You may also read reviews of high end digital cameras that talk about whether the sensor in any given camera has an anti-aliasing filter, which has the positive effect of reducing color noise in some situations, but the negative effect of reducing overall resolution which may be important in other situations. Again, this is a thing I kind of understand well enough to know I don't personally need to care about the details, but here's an article with a link to a video that may be informative?
posted by fedward at 11:10 AM on March 4, 2023
See also interference patterns.
And, in passing, there’s a Melissa Scott SF novel with a use of this I love. I think it’s Trouble and Her Friends, but it might possibly be Burning Bright. My copies are inaccessible, maybe someone else remembers.
posted by clew at 11:19 AM on March 4, 2023 [1 favorite]
And, in passing, there’s a Melissa Scott SF novel with a use of this I love. I think it’s Trouble and Her Friends, but it might possibly be Burning Bright. My copies are inaccessible, maybe someone else remembers.
posted by clew at 11:19 AM on March 4, 2023 [1 favorite]
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posted by justkevin at 7:55 AM on March 4, 2023