Hour Re-Re-Re-Powered

Here’s a set of three lines:

Three lines


Now try replacing each line with a half-sized copy of the original three lines:

Three half-sized copies of the original three lines


What shape results if you keep on doing that — replacing each line with three half-sized new lines — over and over again? I’m not sure that any human is yet capable of visualizing it, but you can see the shape being created below:

Morphogenesis #3


Morphogenesis #4


Morphogenesis #5


Morphogenesis #6


Morphogenesis #7


Morphogenesis #8


Morphogenesis #9


Morphogenesis #10


Morphogenesis #11 — the Hourglass Fractal


Morphogenesis of the Hourglass Fractal (animated)


The shape that results is what I call the hourglass fractal. Here’s a second and similar method of creating it:

Hourglass fractal, method #2 stage #1


Hourglass fractal #2


Hourglass fractal #3


Hourglass fractal #4


Hourglass fractal #5


Hourglass fractal #6


Hourglass fractal #7


Hourglass fractal #8


Hourglass fractal #9


Hourglass fractal #10


Hourglass fractal #11


Hourglass fractal (animated)


And below are both methods in one animated gif, where you can see how method #1 produces an hourglass fractal twice as large as the hourglass fractal produced by method #2:

Two routes to the hourglass fractal (animated)


Elsewhere other-engageable:

Hour Power
Hour Re-Powered
Hour Re-Re-Powered

Tri Again (Again (Again))

Like the moon, mathematics is a harsh mistress. In mathematics, as on the moon, the slightest misstep can lead to disaster — as I’ve discovered again and again. My latest discovery came when I was looking at a shape called the L-tromino, created from three squares set in an L-shape. It’s a rep-tile, because it can be tiled with four smaller copies of itself, like this:

Rep-4 L-tromino


And if it can be tiled with four copies of itself, it can also be tiled with sixteen copies of itself, like this:

Rep-16 L-tromino


My misstep came when I was trying to do to a rep-16 L-tromino what I’d already done to a rep-4 L-tromino. And what had I already done? I’d created a beautiful shape called the hourglass fractal by dividing-and-discarding sub-copies of a rep-4 L-tromino. That is, I divided the L-tromino into four sub-copies, discarded one of the sub-copies, then repeated the process with the sub-sub-copies of the sub-copies, then the sub-sub-sub-copies of the sub-sub-copies, and so on:

Creating an hourglass fractal #1


Creating an hourglass fractal #2


Creating an hourglass fractal #3


Creating an hourglass fractal #4


Creating an hourglass fractal #5


Creating an hourglass fractal #6


Creating an hourglass fractal #7


Creating an hourglass fractal #8


Creating an hourglass fractal #9


Creating an hourglass fractal #10


Creating an hourglass fractal (animated)


The hourglass fractal


Next I wanted to create an hourglass fractal from a rep-16 L-tromino, so I reasoned like this:

• If one sub-copy of four is discarded from a rep-4 L-tromino to create the hourglass fractal, that means you need 3/4 of the rep-4 L-tromino. Therefore you’ll need 3/4 * 16 = 12/16 of a rep-16 L-tromino to create an hourglass fractal.

So I set up the rep-16 L-tromino with twelve sub-copies in the right pattern and began dividing-and-discarding:

A failed attempt at an hourglass fractal #1


A failed attempt at an hourglass fractal #2


A failed attempt at an hourglass fractal #3


A failed attempt at an hourglass fractal #4


A failed attempt at an hourglass fractal #5


A failed attempt at an hourglass fractal (animated)


Whoops! What I’d failed to take into account is that the rep-16 L-tromino is actually the second stage of the rep-4 triomino, i.e. that 4 * 4 = 16. It follows, therefore, that 3/4 of the rep-4 L-tromino will actually be 9/16 = 3/4 * 3/4 of the rep-16 L-tromino. So I tried again, setting up a rep-16 L-tromino with nine sub-copies, then dividing-and-discarding:

A third attempt at an hourglass fractal #1


A third attempt at an hourglass fractal #2


A third attempt at an hourglass fractal #3


A third attempt at an hourglass fractal #4


A third attempt at an hourglass fractal #5


A third attempt at an hourglass fractal #6


A third attempt at an hourglass fractal (animated)



Previously (and passionately) pre-posted:

Tri Again
Tri Again (Again)

Allus Pour, Horic

*As a rotating animated gif (optimized at ezGIF).


Performativizing Paronomasticity

The title of this incendiary intervention, which is perhaps my most contrived title yet, is a paronomasia on Shakespeare’s “Alas, poor Yorick!” (Hamlet, Act 5, scene 1). “Allus” is a northern form of “always”, “pour” has its standard meaning, and “Horic” is from the Greek ὡρῐκός, hōrikos, which strictly speaking means “in one’s prime, blooming”. However, it could also be interpreted as meaning “hourly”. So the paronomasia means “Always pour, O Hourly One!” (i.e. hourglass).

A Seed Indeed

Like plants, fractals grow from seeds. But plants start with a small seed that gets bigger. Fractals start with a big seed that gets smaller. For example, perhaps the most famous fractal of all is the Koch snowflake. The seed of the Koch snowflake is step #2 here:

Stages of the Koch snowflake (from Fractals and the coast of Great Britain)


To create the Koch snowflake, you replace each straight line in the initial triangle with the seed:

Creating the Koch snowflake (from Wikipedia)


Animated Koch snowflake (from Wikipedia)


Now here’s another seed for another fractal:

Fractal stage #1


The seed is like a capital “I”, consisting of a line of length l sitting between two lines of length l/2 at right angles. The rule this time is: Replace the center of the longer line and the two shorter lines with ½-sized versions of the seed:

Fractal stage #2


Try and guess what the final fractal looks like when this rule is applied again and again:

Fractal stage #3


Fractal stage #4


Fractal stage #5


Fractal stage #6


Fractal stage #7


Fractal stage #8


Fractal stage #9


Fractal stage #10


I call this fractal the hourglass. And there are a lot of ways to create it. Here’s an animated version of the way shown in this post:

Hourglass fractal (animated)


Hour Re-Re-Powered

In “Hour Power” I looked at my favorite fractal, the hourglass fractal:

The hourglass fractal


I showed three ways to create the fractal. Next, in “Hour Re-Powered”, I showed a fourth way. Now here’s a fifth (previously shown in “Tri Again”).

This is a rep-4 isosceles right triangle:

Rep-4 isosceles right triangle


If you divide and discard one of the four sub-triangles, then adjust one of the three remaining sub-triangles, then keep on dividing-and-discarding (and adjusting), you can create a certain fractal — the hourglass fractal:

Triangle to hourglass #1


Triangle to hourglass #2


Triangle to hourglass #3


Triangle to hourglass #4


Triangle to hourglass #5


Triangle to hourglass #6


Triangle to hourglass #7


Triangle to hourglass #8


Triangle to hourglass #9


Triangle to hourglass #10


Triangle to hourglass (anim) (open in new tab to see full-sized version)


And here is a zoomed version:

Triangle to hourglass (large)


Triangle to hourglass (large) (anim)


Hour Re-Powered

Pre-previously on Overlord in terms of the Über-Feral, I looked at my favorite member of the fractal community, the Hourglass Fractal:

The hourglass fractal


A real hourglass for comparison


As I described how I discovered the hourglass fractal indirectly and by accident, then showed how to create it directly, using two isosceles triangles set apex-to-apex in the form of an hourglass:

Triangles to hourglass #1


Triangles to hourglass #2


Triangles to hourglass #3


Triangles to hourglass #4


Triangles to hourglass #5


Triangles to hourglass #6

[…]

Triangles to hourglass #10


Triangles to hourglass #11


Triangles to hourglass #12


Triangles to hourglass (animated)


Now, here’s an even simpler way to create the hourglass fractal, starting with a single vertical line:

Line to hourglass #1


Line to hourglass #2


Line to hourglass #3


Line to hourglass #4


Line to hourglass #5


Line to hourglass #6


Line to hourglass #7


Line to hourglass #8


Line to hourglass #9


Line to hourglass #10


Line to hourglass #11


Line to hourglass (animated)


Hour Power

Would it be my favorite fractal if I hadn’t discovered it for myself? It might be, because I think it combines great simplicity with great beauty. I first came across it when I was looking at this rep-tile, that is, a shape that can be divided into smaller copies of itself:

Rep-4 L-Tromino


It’s called a L-tromino and is a rep-4 rep-tile, because it can be divided into four copies of itself. If you divide the L-tromino into four sub-copies and discard one particular sub-copy, then repeat again and again, you’ll get this fractal:

Tromino fractal #1


Tromino fractal #2


Tromino fractal #3


Tromino fractal #4


Tromino fractal #5


Tromino fractal #6


Tromino fractal #7


Tromino fractal #8


Tromino fractal #9


Tromino fractal #10


Tromino fractal #11


Hourglass fractal (animated)


I call it an hourglass fractal, because it reminds me of an hourglass:

A real hourglass


The hourglass fractal for comparison


I next came across the hourglass fractal when applying the same divide-and-discard process to a rep-4 square. The first fractal that appears is the Sierpiński triangle:

Square to Sierpiński triangle #1


Square to Sierpiński triangle #2


Square to Sierpiński triangle #3


[…]


Square to Sierpiński triangle #10


Square to Sierpiński triangle (animated)


However, you can rotate the sub-squares in various ways to create new fractals. Et voilà, the hourglass fractal appears again:

Square to hourglass #1


Square to hourglass #2


Square to hourglass #3


Square to hourglass #4


Square to hourglass #5


Square to hourglass #6


Square to hourglass #7


Square to hourglass #8


Square to hourglass #9


Square to hourglass #10


Square to hourglass #11


Square to hourglass (animated)


Finally, I was looking at variants of the so-called chaos game. In the standard chaos game, a point jumps half-way towards the randomly chosen vertices of a square or other polygon. In this variant of the game, I’ve added jump-towards-able mid-points to the sides of the square and restricted the point’s jumps: it can only jump towards the points that are first-nearest, seventh-nearest and eighth-nearest. And again the hourglass fractal appears:

Chaos game to hourglass #1


Chaos game to hourglass #2


Chaos game to hourglass #3


Chaos game to hourglass #4


Chaos game to hourglass #5


Chaos game to hourglass #6


Chaos game to hourglass (animated)


But what if you want to create the hourglass fractal directly? You can do it like this, using two isosceles triangles set apex-to-apex in the form of an hourglass:

Triangles to hourglass #1


Triangles to hourglass #2


Triangles to hourglass #3


Triangles to hourglass #4


Triangles to hourglass #5


Triangles to hourglass #6


Triangles to hourglass #7


Triangles to hourglass #8


Triangles to hourglass #9


Triangles to hourglass #10


Triangles to hourglass #11


Triangles to hourglass #12


Triangles to hourglass (animated)


Tri Again (Again)

I didn’t expect to find the hourglass fractal playing with squares. I even less expected it playing with triangles. Isosceles right triangles, to be precise. Then again, I found it first playing with the L-triomino, which is composed of three squares. And an isosceles triangle is half of a square. So it all fits. This is an isosceles right triangle:
isosceles_right_triangle

Isosceles right triangle


It’s mirror-symmetrical, so it looks the same in a mirror unless you label one of the acute-angled corners in some way, like this:

right_triangle_chiral_1

Right triangle with labelled corner


right_triangle_chiral_2

Right triangle reflected


Reflection is how you find the hourglass fractal. First, divide a right triangle into four smaller right triangles.

right_triangle_div4

Right triangle rep-tiled


Then discard one of the smaller triangles and repeat. If the acute corners of the smaller triangles have different orientations, one of the permutations creates the hourglass fractal, like this:

right_triangle_div4_1

Hourglass #1


right_triangle_div4_2

Hourglass #2


right_triangle_div4_3

Hourglass #3


right_triangle_div4_4

Hourglass #4


right_triangle_div4_5

Hourglass #5


right_triangle_div4_6

Hourglass #6


right_triangle_div4_7

Hourglass #7


right_triangle_div4_8

Hourglass #8


right_triangle_div4_9

Hourglass #9


right_triangle_div4_123_010

Hourglass animated


Another permutation of corners creates what I’ve decided to call the crane fractal, like this:
right_triangle_div4_123_001

Crane fractal animated


right_triangle_div4_123_001_static

Crane fractal (static)


The crane fractal is something else that I first found playing with the L-triomino:

l-triomino_234

Crane fractal from L-triomino


Previously pre-posted:

Square Routes
Tri Again

Square Routes

One of the pleasures of exploring an ancient city like York or Chester is that of learning new routes to the same destination. There are byways and alleys, short-cuts and diversions. You set off intending to go to one place and end up in another.

Maths is like that, even at its simplest. There are many routes to the same destination. I first found the fractal below by playing with the L-triomino, or the shape created by putting three squares in the shape of an L. You can divide it into four copies of the same shape and discard one copy, then do the same to each of the sub-copies, then repeat. I’ve decided to call it the hourglass fractal:

l-triomino_124

Hourglass fractal (animated)


l-triomino_124_upright_static1

Hourglass fractal (static)


Then I unexpectedly came across the fractal again when playing with what I call a proximity fractal:
v4_ban15_sw3_anim

Hourglass animated (proximity fractal)


v4_ban15_sw3_col

(Static image)


Now I’ve unexpectedly come across it for a third time, playing with a very simple fractal based on a 2×2 square. At first glance, the 2×2 square yields only one interesting fractal. If you divide the square into four smaller squares and discard one square, then do the same to each of the three sub-copies, then repeat, you get a form of the Sierpiński triangle, like this:

sq2x2_123_1

Sierpiński triangle stage 1


sq2x2_123_2

Sierpiński triangle #2


sq2x2_123_3

Sierpiński triangle #3


sq2x2_123_4

Sierpiński triangle #4


sq2x2_123

Sierpiński triangle animated


sq2x2_123_static

(Static image)


The 2×2 square seems too simple for anything more, but there’s a simple way to enrich it: label the corners of the sub-squares so that you can, as it were, individually rotate them 0°, 90°, 180°, or 270°. One set of rotations produces the hourglass fractal, like this:

sq2x2_123_013_1

Hourglass stage 1


sq2x2_123_013_2

Hourglass #2


sq2x2_123_013_3

Fractal #3


sq2x2_123_013_4

Hourglass #4


sq2x2_123_013_5

Hourglass #5


sq2x2_123_013_6

Hourglass #6


sq2x2_123_013

Hourglass animated


sq2x2_123_013_static

(Static image)


Here are some more fractals from the 2×2 square created using this technique (I’ve found some of them previously by other routes):

sq2x2_123_022


sq2x2_123_022_static

(Static image)


sq2x2_123_031


sq2x2_123_031_static

(Static image)


sq2x2_123_102


sq2x2_123_102_static

(Static image)


sq2x2_123_2011


sq2x2_123_201_static

(Static image)


sq2x2_123_211


sq2x2_123_211_static

(Static image)


sq2x2_123_213


sq2x2_123_213_static

(Static image)


sq2x2_123_033_-111


sq2x2_123_033_-111_static

(Static image)


sq2x2_123_201_1-11_static

(Static image)


sq2x2_200_1-11_static

(Static image)


sq2x2_123_132

(Static image)