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Steve Mould 12 Sep 2025 45 here now

Nature’s Optical Illusion

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3D zoetropes based on the golden ratio were first invented and designed by John Edmar

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3:13 Slowed down the video to 0.25 to see the seed distribution in slow motion. At that speed, watching and listening to Steve is hilarious. 😂
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Watching this makes me feel like I'm on shrooms
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@riggocalle From YouTube ↗ 22 Sep 2025 12
A warning for flashing lights at 0:50 could be of use for light sensitive people.
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I discovered this effect through the work of artist John Edmark. He has made a set of strobe sculptures called “Bloom”, similar to the flowers at 0:01 and 1:44. He has other work based on spirals and mathematical principles too. Worth checking out!
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@filipsperl From YouTube ↗ 22 Sep 2025 126
The reason why golden ratio works nicely is actually simpler than you think.

Imagine turning around a rational part of the circle every time you "spit out" a new seed. Steve did 2/5 in the video, which resulted in 5 lines coming from the center. You could try a seemingly better angle like 7/22, which will result in 22 lines, but there will stil be areas where no seeds go to. There's always space between the lines, even if you make a lot of lines (especially the further you go from the center). The point is, no mater what the rational angle is, if you turn enough times, you will always come back to the stating direction and therefore spit out a second seed in that same direction, which eventually turns into a line of seeds once you spit in the same direction a few more times.

The only way to prevent cirling back like this, is by using an irrational number, like the golden ratio, sqrt(2) or pi. It works because no matter how many times you turn, for example a 1/sqrt(2) of a circle, you won't ever get back a rational number, so there is no way to come back to 0, aka the starting direction.

Why the golden ratio works the best is a slightly different topic, about why it's the "most i
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The Algorithm always recommends the last video you made, which I already watched. It's like when I order a product online and then get ads all day for the thing I just bought. They should just recommend your merch and not try to be clever, that's your job
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2:11 at the beginning of this sentence I thought for a second that you were saying there’s genuinely nobody on earth who has figured out the answer to those two questions and, for a brief moment, my mind was blown. Then came the phrase “better than”. Lol
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@JH-lo9ut From YouTube ↗ 22 Sep 2025 7
By the way, on some vinyl record players, there is a pattern of dots on the rim of the turntable. These are there to calibrate the speed of rotation.
There is a little stroboscope (flashing light) built in to the player, (usually it looks like a little column with a glass "window" on the side).
When you turn on the strobe, in a dark room, you will see the illusion of those dots moving. You are supposed to adjust the speed of the turntable so that it looks like the top row of dots are moving steadily to the right, the bottom row should be moving steadily to the left and the middle row should appear to be perfectly still.

The speed of the player may be inaccurate, because it is driven by a simple electric motor via belt and pulley. Lots of factors will affect the speed of this system, like the stability of voltage, the condition of the bearings and even the temperature in the room wich affects the stiffness of the rubber drive belt.
The stroboscope is controlled by a quartz clock, so it is not affected by ambient factors.
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1:23 wait those records are awesome though
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The algorithm has failed to predict what I like - surprise, I’m a CD player enthusiast now
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@elbiggus From YouTube ↗ 22 Sep 2025 41
This sort of thing always reminds me of the SMBC comic "Math Translations":

Fractals are everywhere! (Sometimes a little thing grows on a big thing.)
The Golden Ratio is everywhere! (Sometimes one thing is about half as big as another thing.)
The Fibonacci Sequence is everywhere! (Sometimes things grow exponentially.)
The Harmonic Series grows to infinity unless you throw out numbers with a 9 in their denominator! (Sometimes th..What? What? But how in the? What the balls?)
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I watched viharts doodling in math class video on the Golden ratio over a decade ago now, and the understanding I gained from it as a kid then is still cemented in my mind. Those videos raised a generation, and got kids like me interested in maths beyond algebra. This video was a throwback for me, because I knew the answer but taking the journey again as an adult was nostalgic.
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An old use of this effect is with engine timing. You can put a mark on the flywheel damper, fit plate with marks, and sync a strobe light to cylinder 1. Then you can adjust the timing to fractions of a degree. The strobe creates a stationary line you adjust to the fixed plate.
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It's also a great pattern for rocket engine injectors because it packs the elements in tightly but doesn't have repeating patterns that can support combustion instability.
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@zsoltsz2323 From YouTube ↗ 22 Sep 2025 122
"It never crashes because it lives in the browser." As a web developer, I might be slightly weeping.
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That poor cactus is DIZZY!
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@xliquidflames From YouTube ↗ 22 Sep 2025 1000
2:50 Over the next several videos, we begin noticing sprouts and then trees growing out of Steve's floor.
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@drewtetz From YouTube ↗ 22 Sep 2025 2000
hey, i designed all those zoetrope records! always excited to know that other people are also staring at rotating circles thinking about numbers :) super fun & informative!
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@hsmoscout From YouTube ↗ 22 Sep 2025 438
"this is just a cactus spinning on a cd" i've seen enough perfect video thank you
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@SteveMould From YouTube ↗ 22 Sep 2025 875
3D zoetropes based on the golden ratio were first invented and designed by John Edmark. You can find his fascinating work here: www.johnedmark.com/ and on his instagram: www.instagram.com/john.edmark