Bats and Butterflies

I’ve used butterfly-images to create fractals. Now I’ve found a butterfly-image in a fractal. The exciting story begins with a triabolo, or shape created from three isoceles right triangles:


The triabolo is a rep-tile, or shape that can be divided into smaller copies of itself:


In this case, it’s a rep-9 rep-tile, divisible into nine smaller copies of itself. And each copy can be divided in turn:


But what happens when you sub-divide, then discard copies? A fractal happens:

Fractal crosses (animated)


Fractal crosses (static)


That’s a simple example; here is a more complex one:

Fractal butterflies #1


Fractal butterflies #2


Fractal butterflies #3


Fractal butterflies #4


Fractal butterflies #5


Fractal butterflies (animated)


Some of the gaps in the fractal look like butterflies (or maybe large moths). And each butterfly is escorted by four smaller butterflies. Another fractal has gaps that look like bats escorted by smaller bats:

Fractal bats (animated)

Fractal bats (static)


Elsewhere other-posted:

Gif Me Lepidoptera — fractals using butterflies
Holey Trimmetry — more fractal crosses

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Holey Trimmetry

Symmetry arising from symmetry isn’t surprising. But what about symmetry arising from asymmetry? You can find both among the rep-tiles, which are geometrical shapes that can be completely replaced by smaller copies of themselves. A square is a symmetrical rep-tile. It can be replaced by nine smaller copies of itself:

Rep-9 Square

If you trim the copies so that only five are left, you have a symmetrical seed for a symmetrical fractal:

Fractal cross stage #1


Fractal cross #2


Fractal cross #3


Fractal cross #4


Fractal cross #5


Fractal cross #6


Fractal cross (animated)


Fractal cross (static)


If you trim the copies so that six are left, you have another symmetrical seed for a symmetrical fractal:

Fractal Hex-Ring #1


Fractal Hex-Ring #2


Fractal Hex-Ring #3


Fractal Hex-Ring #4


Fractal Hex-Ring #5


Fractal Hex-Ring #6


Fractal Hex-Ring (animated)


Fractal Hex-Ring (static)


Now here’s an asymmetrical rep-tile, a nonomino or shape created from nine squares joined edge-to-edge:

Nonomino


It can be divided into twelve smaller copies of itself, like this:

Rep-12 Nonomino (discovered by Erich Friedman)


If you trim the copies so that only five are left, you have an asymmetrical seed for a familiar symmetrical fractal:

Fractal cross stage #1


Fractal cross #2


Fractal cross #3


Fractal cross #4


Fractal cross #5


Fractal cross #6


Fractal cross (animated)


Fractal cross (static)


If you trim the copies so that six are left, you have an asymmetrical seed for another familiar symmetrical fractal:

Fractal Hex-Ring #1


Fractal Hex-Ring #2


Fractal Hex-Ring #3


Fractal Hex-Ring #4


Fractal Hex-Ring #5


Fractal Hex-Ring (animated)


Fractal Hex-Ring (static)


Elsewhere other-available:

Square Routes Re-Re-Visited

Square Routes Re-Revisited

This is a very simple fractal:


It has four orientations:


Any orientation can be turned into any other by a rotation of 90°, 180° or 270°, either clockwise or anticlockwise. If you mix orientations and rotations, you can create much more complex fractals. Here’s a selection of them:

Animated fractal

Static fractal


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Animated fractal

Static


Elsewhere other-posted:

Square Routes
Square Routes Revisited

Living Culler

When you replace a square with four smaller squares, each a quarter the size of the original, the smaller squares occupy the same area, because 4 * ¼ = 1. If you discard one sub-square, then divide each of the three remaining sub-squares into four sub-sub-square, discard one sub-sub-quare and repeat, you create fractals like those I looked at in Squaring and Paring. The fractals stay within a fixed boundary.

Square replaced with four smaller squares, each ¼th the size of the original


Animated fractal


Static fractal


This time I want to look at a slightly different process. Replace a square with nine smaller squares each a quarter the size of the original. Now the sub-squares occupy a larger area than the original, because 9 * ¼ = 2¼. If you discard — or cull — sub-squares and repeat, the resultant fractal grows beyond the original boundary. Indeed, sub-squares start to overlap, so you can use colours to represent how often a particular pixel has been covered with a square. Here is an example of this process in action:

Square replaced with nine smaller squares, each ¼th the size of the original


Animated fractal


Static fractal #1


Static fractal #2


Here are the individual stages of a more complex fractal that uses the second process:

Stage 1


Stage 2


Stage 3


Stage 4


Stage 5


Stage 6


Stage 7


Stage 8


Stage 9 (compare Fingering the Frigit and Performativizing the Polygonic)


Stage 10


Animated version


Static version #1


Static version #2


And here are some more of the fractals you can create in a similar way:


Static version #1

Static version #2


Static version #2

Static version #2

Static version #3





Various fractals in an animated gif


Squaring and Paring

Squares are often thought to be the most boring of all shapes. Yet every square holds a stunning secret – something that in legend prompted a mathematical cult to murder a traitor. If each side of a square is one unit long, how long is the square’s diagonal, that is, the line from one corner to the opposite corner?

By Pythagoras’ theorem, the answer is this:

• x^2 = 1^2 + 1^2
• x^2 = 2
• x = √2

But what is √2? Pythagoras and his followers thought that all numbers could be represented as either whole numbers or ratios of whole numbers. To their dismay, so it’s said, they discovered that they were wrong. √2 is an irrational number – it can’t be represented as a ratio. In modern notation, it’s an infinitely decimal that never repeats:

• √2 = 1·414213562373095048801688724209698…

A modern story, unattested in ancient records, says that the irrationality of √2 was a closely guarded secret in the Pythagorean cult. When Hippasus of Metapontum betrayed the secret, he was drowned at sea by enraged fellow cultists. Apocryphal or not, the story shows that squares aren’t so boring after all.

Nor are they boring when they’re caught in the fract. Divide one square into nine smaller copies of itself:


Discard three of the copies like this:

Stage 1
Retain squares 1, 2, 4, 6, 8, 9 (reading left-to-right, bottom-to-top)


Then do the same to each of the sub-squares:

Stage 1


And repeat:

Stage 3


Stage 4


Stage 5


Stage 6


The result is a fractal of endlessly subdividing contingent hexagons:

Animated vesion


Retain squares 1, 2, 4, 6, 8, 9 (reading left-to-right, bottom-to-top)


Here are a few more of the fractals you can create by squaring and paring:

Retain squares 1, 3, 5, 7, 9 (reading left-to-right, bottom-to-top)


Retain squares 2, 4, 5, 6, 8


Retain squares 1, 2, 4, 5, 6, 8, 9


Retain squares 1, 4, 6, 7, 10, 11, 13, 16


Retain squares 1, 3, 6, 7, 8, 9, 10, 11, 14, 16


Retain squares 2, 3, 5, 6, 8, 9, 11, 12, 14, 15


Retain squares 1, 3, 5, 7, 9, 11, 15, 17, 19, 21, 23, 25


Retain squares 1, 3, 7, 8, 11, 12, 14, 15, 18, 19, 23, 25


Retain squares 1, 5, 7, 8, 9, 12, 14, 17, 18, 19, 21, 25


Retain squares 2, 3, 4, 6, 7, 9, 10, 11, 15, 16, 17, 19, 20, 22, 23, 24


Retain squares 1, 2, 5, 6, 7, 9, 13, 17, 19, 20, 21, 24, 25


Previously pre-posted (please peruse):

M.i.P. Trip

He Say, He Sigh, He Sow #44

H. Rider Haggard describes fractals:

Out of the vast main aisle there opened here and there smaller caves, exactly, Sir Henry said, as chapels open out of great cathedrals. Some were large, but one or two — and this is a wonderful instance of how nature carries out her handiwork by the same unvarying laws, utterly irrespective of size — were tiny. One little nook, for instance, was no larger than an unusually big doll’s house, and yet it might have been a model for the whole place, for the water dropped, tiny icicles hung, and spar columns were forming in just the same way. — King Solomon’s Mines, 1885, ch. XVI, “The Place of Death”.

Phrallic Frolics

It’s a classic of low literature:

There was a young man of Devizes
Whose balls were of different sizes:
     The one was so small
     ’Twas no use at all;
But t’other won several prizes.

But what if he had been a young man with balls of different colours? This is a core question I want to interrogate issues around in terms of the narrative trajectory of this blog-post. Siriusly. But it’s not the keyliest core question. More corely keyly still, I want to ask what a fractal phallus might look like. Or a phrallus, for short. The narrative trajectory initializes with this fractal, which is known as a pentaflake (so-named from its resemblance to a snowflake):

Pentaflake — a pentagon-based fractal


It’s created by repeatedly replacing pentagons with six smaller pentagons, like this:

Pentaflake stage 0


Pentaflake stage 1


Pentaflake stage 2


Pentaflake stage 3


Pentaflake stage 3


Pentaflake stage 4


Pentaflake (animated)


Pentaflake (static)


This is another version of the pentaflake, missing the central pentagon of the six used in the standard pentaflake:

No-Center Pentaflake stage 0


No-Center Pentaflake stage 1


Stage 2


Stage 3


Stage 4


No-Center Pentaflake (animated)


No-Center Pentaflake (static #1)


No-Center Pentaflake (static #2)


The phrallus, or fractal phallus, begins with an incomplete version of the first stage of the pentaflake (note balls of different colours):

Phrallus stage 1


Phrallus stage 1 (monochrome)


Phrallus stage 2


Phrallus stage 3


Stage 4


Stage 5


Stage 6


Stage 7


Stage 8


And there you have it: a fractal phallus, or phrallus. Here is an animated version:

Phrallus (animated)


Phrallus (static)


But the narrative trajectory is not over. The center of the phrallus can be rotated to yield mutant phralloi. Stage #1 of the mutants looks like this:

Phrallus (mutation #1)


Phrallus (mutation #2)


Phrallus (mutation #3)


Phrallus (mutation #4)


Phrallus (mutation #5)


Mutant phralloi (rotating)


Here are some animations of the mutant phralloi:

Phrallus (mutation #3) (animated)


Phrallus (mutation #5) (animated)


This mutation doesn’t position the pentagons in the usual way:

Phrallus (another upright version) (animated)


The static mutant phralloi look like this:

Phrallus (mutation #2)


Phrallus (mutation #3)


Phrallus (upright #2)


And if the mutant phralloi are combined in a single image, they rotate like this:

Mutant phralloi (rotating)


Coloured mutant rotating phralloi #1


Coloured mutant rotating phralloi #2


Square Routes Revisited

Take a square, divide it into four smaller squares, and discard the smaller square on the top right. Do the same to each of the subsquares, dividing it into four sub-subsquares, then discarding the one on the top right. And repeat with the sub-subsquares. And the sub-sub-squares. And the sub-sub-sub-squares. And so on. The result is a fractal like this:

sq2x2_123_1

Stage 1


sq2x2_123_2

Stage 2


sq2x2_123_3

Stage 3


sq2x2_123_4

Stage 4


sq2x2_123

Animated fractal


sq2x2_123_static

Final fractal (static)


It looks as though this procedure isn’t very fertile. But you can enrich it by rotating each of the subsquares in a different way, so that the discarded sub-subsquare is different. Here’s an example:

Stage 1


Stage 2


Stage 3


Stage 4


Stage 5


Stage 6


Stage 7


Animated fractal


Final fractal (static)


Here are more examples of how rotating the subsquares in different ways produces different fractals:

Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Animated fractal

Static fractal


Previously pre-posted:

Square Routes — first look at this kind of fractal

Corralling Chaos

All the best people brood incessantly on the fact that a point inside a square jumping half-way towards a randomly chosen vertex will not create a fractal. Inside a triangle, yes: a fractal appears. Inside a pentagon too. But not inside a square:

Point jumping half-way towards a randomly chosen vertex


Instead, the interior of the square fills with random points: it crawls with chaos, you might say. However, fractals appear inside a square if the point is restricted in some way: banned from jumping towards a vertex twice in a row; banned from jumping towards the second-nearest vertex; and so on. Those restrictions are what might be called soft, because they take place in software (or in the brain of someone following the rule as a game or piece of performance art). Here’s what might be called a hard restriction that creates a fractal: the point cannot jump towards a randomly vertex if its jump passes over any part of the red upright cross:

Point cannot pass over red lines


I call this a barrier fractal. It’s obvious that the point cannot jump from one corner of the square towards the opposite corner, which creates bare space stretching from each vertex towards the tips of the upright cross. Less obvious is the way in which this bare space “cascades” into other parts of the square, creating a repeatedly branching and shrinking pattern.



When the barrier is a circle, a similar fractal appears:


If the point can also jump towards the center of the circle, this is what happens:

“Down through the aether I saw the accursed earth turning, ever turning, with angry and tempestuous seas gnawing at wild desolate shores and dashing foam against the tottering towers of deserted cities.” — “The Crawling Chaos” (1921), Winifred Jackson and H. P. Lovecraft.


Now here’s an upright cross with a gap in the middle:


Here’s an upright cross when the point can also jump towards the center of the cross:


A slanted cross with a central attractor:


And a single horizontal stroke:


A slanted stroke — note pentagons:


Even if the barrier is small and set on an edge of the square, it affects the rest of the square:


A more attractive example of edge-affects-whole:


Circles away from the edges


Detail of previous image






Here the point can also jump towards the center of the square’s edges:


A more subtle barrier fractal uses the previous jumps of the point to restrict its next jump. For example, if the point cannot jump across the line created by its previous-but-one jump, it moves like this:

Jump can’t cross track of last-but-one jump (animated gif)


The fractal itself looks like this:


Rule: on jump #3, cannot jump across the line created by jump #1; on jump #4, cannot cross the line created by jump #2; and so on.



And this is the fractal if the point cannot jump across the line created by its previous-but-two jump:

Rule: on jump #4, cannot jump across the line created by jump #2; on jump #5, cannot cross the line created by jump #3; and so on



Jumper to Jumper

Previously I’ve looked at fractals created by a point moving half-way towards the random chosen vertex of a polygon. But you can also choose an initial vertex, then choose a new vertex by adding a random number to that initial vertex. Then repeat. For example, if the polygon is a square and the initial vertex is v = 1, then choose v + 3 = 4 or v – 1 = 3, and so on.

You can then ban or un-ban the choice of vertex-jump as you can ban or un-ban direct choices of vertex. These two methods of random choice are effectively the same, but one can be simpler to program than the other. That’s why I’ve come across some new fractals by using vertex-jumps. Here they are:

vertices = 4, vertex-jump = (1,2,3,4), ban on same choice twice in a row


vertices = 4, vertex-jump = (1,2,3,4), ban on 2 in row (black-and-white version)


v = 4, vj = (1,2,3,4), ban on choice c + 2 from previous choice c


v = 4, vj = (1,2,3,4), ban c + 2 (animated gif)


vj = (1,2,3,4), ban c + 2 (black-and-white)


vj = (1,2,3,4), ban c + 0 at time t+1 unless c + 0 at time t-1


vj = (1,2,3,4), ban c + 0 at t+1, unless c + 0 at t-1 (black-and-white)


vj = (1,2,3,4,5), ban c + 0


vj = (0,1,2,3,4), ban c + 0


vj = (0,1,2,3,4), ban c + 0 (black-and-white)


vj = (1,2,3,4), ban c + 2 at t+1 unless c + 2 at t-1 (animated gif)


vj = (1,2,3,4), ban c + various at t+1 unless c + various at t-1 (animated gif)


vj = (1,2,3,4,5), ban c + 0 at t+1 unless c + 0 at t-1


vj = (-2,-1,0,1,2), ban c + 0


vj = (-2,-1,0,1,2), ban c + 0 (black-and-white)


vj = (0,1,2,3,4), ban c + va unless c + va


v = 5, vj = (1,2,3,4), ban c + 0


v = 5, vj = (1,2,3,4), ban c + 2


v = 5, vj = (0,1,2,3), ban c + 3


v = 6, vj = (0,1,2,3), ban c + 2


v = 6, vj = va, ban c + va (animated gif)