Hausdorff Dimension

Scroll down from 0 to 3. The left column shows the Hausdorff dimension DH; the right column renders a custom mathematical geometry at that exact fractional dimension.

DH = log(N) / log(1/r)

0 ≤ D < 1 — Points & Fractal Dust

Totally disconnected sets: more than a point, less than a continuous line

Same dimension · 1 of 2
0.0000
log(1) / log(1/r) = 0

Isolated Point Set

A point has position, but no length, area, or volume. Even for a scatter of separate points, zooming in never splits a point into smaller pieces—each one remains a single dimensionless dot.

Same dimension · 2 of 2
0.0000
supₙ dim_H({1/n}) = 0

Harmonic Sequence {1/n}

Even an infinite sequence of points 1, 1/2, 1/3, 1/4, … crowding closer and closer toward zero still has Hausdorff dimension 0: every point remains isolated from its neighbors, taking up zero total length.

0.1000
log₁₀₀₀ 2 = 0.1000

Ultra-Sparse Cantor Dust

Splitting a bar and keeping only 2 tiny pieces at the far ends (scaled by 1/1000 each step) removes almost everything, leaving a sparse fractal dust of dimension log(2)/log(1000) = 0.1.

0.2000
α = 1 / 5

1D Lévy Flight Dust (α = 0.2)

A random walk that takes many tiny steps mixed with occasional giant leaps leaves behind tight clusters of landing points separated by wide empty gaps, with fractal dimension 0.2.

Same dimension · 1 of 2
0.3155
log₉ 2 = ½ log₃ 2

Sparse 1/9 Cantor Dust

Removing the middle seven-ninths of each bar and keeping only the 2 outer ninths (r = 1/9) leaves a sparse Cantor dust with exactly half the dimension of the classic Middle-Third Cantor Set.

Same dimension · 2 of 2
0.3155
log₉ 2 = ½ log₃ 2

Generalized 1/9 Devil’s Staircase Singularities

A continuous staircase curve that climbs from 0 to 1 while staying completely flat across the middle seven-ninths of every interval; all of its upward steps are concentrated on a Cantor dust of dimension log₉ 2 ≈ 0.3155.

0.4400
≈ 0.44

Kleinian Schottky Limit Set

Repeatedly inverting four mutually external circles into one another via Möbius transformations shrinks disks into a curving necklace of fractal dust inside the complex plane.

0.5000
1 / 2

Zeros of a Wiener Process

The instants where a 1D Brownian random walk crosses zero form a random, clustering dust on the time axis with exact Hausdorff dimension 1/2.

Same dimension · 1 of 2
0.5313
≈ 0.5312805

Gauss–Cantor Continued-Fraction Set (E₂)

Numbers in [0, 1] whose continued-fraction expansions use only the digits 1 and 2 are generated by repeating x ↦ 1/(1+x) and x ↦ 1/(2+x), carving a non-uniform Cantor dust of dimension ≈ 0.5313.

Same dimension · 2 of 2
0.5313
≈ 0.5312805

Ford Circles & Bounded-Type Diophantine Spectrum

Placing a tangent circle of radius 1/(2q²) above every simplified fraction p/q packs the line with mutually tangent circles; the irrational gaps that avoid all large circles with digits above 2 share the exact same dimension ≈ 0.5313.

0.5380
≈ 0.5380

Feigenbaum Attractor

As the growth rate r of the logistic map x ↦ rx(1 − x) approaches the onset of chaos (r∞ ≈ 3.56995), its period-doubling branches split infinitely many times and land on a universal fractal dust of dimension ≈ 0.5380.

Same dimension · 1 of 2
0.6180
1 / φ = (√5 − 1) / 2

Golden-Conjugate Cantor Set

Keeping 2 copies scaled by r = 2^(−φ) ≈ 0.3258 at each step produces a symmetric Cantor dust whose Hausdorff dimension is the exact golden ratio conjugate 1/φ ≈ 0.6180.

Same dimension · 2 of 2
0.6180
1 / φ = (√5 − 1) / 2

Fibonacci Cut-and-Project Quasicrystal

Selecting 2D grid points inside a tilted strip of golden slope 1/φ and projecting them onto the strip’s baseline creates an aperiodic chain of Long and Short intervals whose diffraction spectrum lives on a fractal support of dimension 1/φ.

0.6309
log₃ 2

Middle-Third Cantor Set

Repeatedly removing the open middle third of every interval leaves N = 2 copies at scale r = 1/3: uncountably infinite points, yet zero total length.

0.6700
≈ 0.67

Disconnected Fatou Dust Julia Set

When the complex constant c = −0.76 + 0.28i lies outside the Mandelbrot set, the Julia set shatters from a connected loop into a swirling cloud of disconnected Cantor dust.

0.6942
log₂ φ

Asymmetric Golden Cantor Set

Splitting each interval into a left piece of scale r₁ = 1/2 and a right piece of scale r₂ = 1/4 satisfies r₁^D + r₂^D = 1, yielding the golden ratio exponent.

0.7500
≈ 0.75

Hofstadter’s Butterfly (Quantum Hall Spectrum)

Electrons moving through a 2D crystal lattice in a magnetic field can only occupy specific energy bands; plotting allowed energies against magnetic flux reveals a self-similar butterfly made of Cantor-set slices.

0.7875
≈ 0.7875

Minkowski’s Question-Mark Curve ?(x)

Mapping each Farey mediant fraction (p₁+p₂)/(q₁+q₂) to the midpoint between its parents builds a continuous staircase curve whose growth is concentrated on a fractal dust of dimension ≈ 0.7875.

0.7925
log₄ 3

Four-Quarter Cantor Set

Dividing each bar into 4 equal quarters and removing the third quarter leaves 3 copies at scale r = 1/4, producing an asymmetric Cantor dust of dimension log(3)/log(4) ≈ 0.7925.

0.8500
2 log(2) / log(1/λ)

Smale Horseshoe Strange Saddle

Stretching a square vertically, folding it into a horseshoe, and intersecting its forward vertical strips with backward horizontal strips traps an invariant 2D Cantor dust at the saddle points.

0.8700
≈ 0.8700

Arnold Tongues & Circle Map Mode-Locking Spectrum

When a rotating oscillator is periodically driven, rational frequency ratios p/q lock into flaring V-shaped resonance tongues; along the critical top line where the tongues first touch, the remaining unlocked frequencies form a universal Cantor dust of dimension ≈ 0.8700.

0.9240
≈ 0.924

Zaslavsky Quasicrystal Stochastic Web

A harmonic oscillator periodically kicked at 5-fold rotational resonance (α = 2π/5) weaves a pentagonal quasicrystal skeleton of chaotic filaments and resonant island chains in 2D phase space.

0.9542
log₁₀ 9

Kempner Missing-Digit Set (No Digit 9)

Omitting a single decimal digit in base 10 keeps N = 9 intervals of scale r = 1/10 at every step: although its total length is zero, its Hausdorff dimension log₁₀ 9 ≈ 0.9542 makes it nearly indistinguishable from a solid 1D line.

1 ≤ D < 2 — Curves, Boundaries & Dendrites

Rough paths, self-similar coastlines, and branching trees that crinkle into the plane

Same dimension · 1 of 2
1.0000
lim log(2ᵏ) / log(1/rₖ) = 1

Smith–Volterra–Cantor Set (Fat Cantor Dust)

Removing a shrinking middle slice (length 1/4^k at step k) from every interval leaves a disconnected dust that still keeps half of the original bar’s total length, giving it full Hausdorff dimension 1.

Same dimension · 2 of 2
1.0000
2 + log₂(1/2) = 1

Takagi Blancmange Curve

Adding together a stack of triangle waves where each wave has twice the frequency and half the height of the previous one creates a curve that is crinkled at every scale and has no tangent anywhere, yet still has Hausdorff dimension 1.

1.0380
≈ 1.038

Quasi-Fuchsian Bers Slice Limit Loop

Deforming a Fuchsian circle group into complex Kleinian space twists its invariant circle (D = 1) into a nowhere-differentiable Jordan loop ("quasi-circle") separating two hyperbolic domains.

1.0812
≈ 1.0812

Cauliflower Julia Set (z² + 1/4)

Sitting directly at the parabolic cusp c = 1/4 of the Mandelbrot cardioid, this Julia set has no hyperbolic bulbs—only a billowing, scalloped chain of parabolic petals of dimension ≈ 1.0812.

1.0934
≈ 1.0934

Rauzy Tribonacci Fractal Boundary

Projecting the Tribonacci substitution (1 ↦ 12, 2 ↦ 13, 3 ↦ 1) onto its complex contracting eigenplane tiles the plane with three self-similar spiral lobes whose fractal boundary has dimension ≈ 1.0934.

1.1180
≈ 1.118

Golden-Mean Siegel Disk Julia Set

Tuning f(z) = e^(2πi/φ²) z + z² to the golden-mean rotation angle traps a neutral Siegel disk filled with smooth invariant orbits, ringed by a self-similar chain of pre-image tadpole basins.

1.1292
2 log₇ 3

Gosper Island Boundary

Each edge of a regular hexagon is replaced by 3 segments scaled by 1/√7, creating a crinkly rep-tile coastline of dimension log(3)/log(√7).

1.1540
≈ 1.154

Herman Ring Rational Map Julia Set

Unlike simple quadratic maps z² + c, degree-3 rational maps can trap smooth rotating ring-shaped bands ("Herman rings") nested inside a fractal web of smaller inverted pre-image rings.

1.1615
≈ 1.1615

Basilica Julia Set (z² − 1)

For f(z) = z² − 1, the superattracting period-2 cycle 0 ↦ −1 ↦ 0 carves a symmetric chain of pinched cathedral domes whose boundary curve has Hausdorff dimension ≈ 1.1615.

1.1820
≈ 1.182

Airplane Julia Set (z² − 1.75488)

At the superattracting period-3 root c ≈ −1.7548777 on the real antenna of the Mandelbrot set, the Julia set forms a chain of winged airplane fuselages strung along the real axis.

1.2000
≈ 1.20

Dendrite Julia Set (z² + i)

Because c = i is preperiodic under z ↦ z² + c (i ↦ −1+i ↦ −i ↦ −1+i), its Julia set has empty interior and forms a pure branching lightning-bolt skeleton of dimension ≈ 1.20.

1.2083
3 log φ / log((3+√13)/2)

60° Fibonacci Word Fractal

Generated by reading the infinite Fibonacci word 01001010… and turning left or right by 60° at every "0".

1.2393
≈ 1.2393

San Marco Cathedral Julia Set (z² − 3/4)

At the parabolic neck c = −3/4 where the main Mandelbrot cardioid meets the period-2 bulb, the Julia set resembles St. Mark’s Basilica in Venice reflected across water.

Same dimension · 1 of 2
1.2500
5 / 4

Loop-Erased Random Walk (SLE₂)

Whenever a 2D random walk crosses its own trail, erasing the closed loop it just formed turns a tangled path into a simple, non-intersecting curve of exact Hausdorff dimension 5/4 = 1.2500.

Same dimension · 2 of 2
1.2500
5 / 4

Uniform Spanning Tree (Wilson’s Algorithm)

Connecting every point of a 2D grid into a random branching maze without closed loops (built from loop-erased random walks) makes the unique path between any two corners scale with dimension 5/4.

1.2610
1.261 ± 0.003

Hénon Strange Attractor

Repeatedly folding and stretching the plane via (x, y) ↦ (1 − 1.4x² + y, 0.3x) produces a strange attractor that is locally a smooth curve crossed with a Cantor dust.

Same dimension · 1 of 2
1.2619
log₃ 4

Koch Curve & Snowflake

Replacing the middle third of every line segment with an equilateral triangle peak creates N = 4 segments of scale r = 1/3.

Same dimension · 2 of 2
1.2619
log₃ 4

Four-Corner 2D Cantor Dust

Dividing a square into a 3×3 grid and keeping only the 4 corner sub-squares (r = 1/3) leaves a disconnected cloud of points with the exact same Hausdorff dimension as the continuous Koch Snowflake.

1.2850
≈ 1.285

Chirikov–Taylor Standard Map & KAM Cantorus

In a periodically kicked rotor at the critical threshold K ≈ 0.9716, smooth phase-space orbits break apart into a porous fractal chain of islands ("cantori") surrounded by a sea of chaos.

1.3057
≈ 1.305688

Apollonian Gasket

Inscribing mutually tangent circles inside every curvilinear triangular gap via Descartes’ theorem leaves a residual set of dimension ≈ 1.3057.

1.3280
≈ 1.328

Penrose Rhomb Aperiodic Fractal Gasket

Deflating a 10-fold decagonal wheel of golden Robinson triangles by scale 1/φ while excising one interior sub-triangle at every generation carves a five-fold quasicrystalline lace.

Same dimension · 1 of 2
1.3333
4 / 3

2D Self-Avoiding Polymer Walk (SLE₈/₃)

A random walk on a 2D grid that is forbidden from ever visiting the same site twice pushes itself outward like a long polymer chain, converging to a fractal curve of exact dimension 4/3.

Same dimension · 2 of 2
1.3333
4 / 3

Planar Brownian Frontier (External Hull)

Although a 2D Brownian walk crosses itself so densely that its interior fills an area (D = 2), its outer coastline accessible from the outside has exact Hausdorff dimension 4/3—matching a self-avoiding walk.

1.3496
2 log₃(λ_T) ≈ 1.3496

Terdragon Curve Boundary

Replacing every segment with three segments of length 1/√3 at angles +30°, −90°, +30° builds a three-fold symmetric dragon rep-tile whose crinkly outer perimeter has Hausdorff dimension ≈ 1.3496.

1.3750
11 / 8

Critical 2D Ising Spin-Cluster Interface

At the critical Curie temperature T_c = 2/ln(1 + √2) of a 2D ferromagnet, the domain walls separating spin-up and spin-down islands converge to conformal SLE₃ curves of exact Hausdorff dimension 11/8.

1.3800
log(4) / log(1 + φ⁻¹)

Symmetric 5-Fold Pentagram Star Fractal

Replacing every outer vertex of a regular five-pointed star with a child pentagram scaled by the golden ratio conjugate while leaving the central pentagon open carves nested five-fold star corridors.

1.3934
≈ 1.3934

Douady Rabbit Julia Set

The Julia set of f(z) = z² − 0.12256 + 0.74486i has a period-3 superattracting basin shaped like a fractal rabbit with boundary dimension ≈ 1.3934.

1.4150
≈ 1.415

Clifford Strange Attractor

Iterating the trigonometric map (x, y) ↦ (sin(ay) + c cos(ax), sin(bx) + d cos(by)) (with a = −1.4, b = 1.6, c = 1.0, d = 0.7) folds the plane into translucent, silk-like curtains with sharp density caustics.

1.4248
≈ 1.4248

Newton’s Method Fractal (z³ − 1 = 0)

Iterating z ↦ z − (z³ − 1)/(3z²) partitions the complex plane into three cube-root basins whose shared Julia boundary has the Wada property: every boundary point touches all three colored basins simultaneously.

1.4422
≈ 1.4422

Burning Ship Fractal Boundary

Taking absolute values of the real and imaginary parts before squaring—z_{n+1} = (|Re z_n| + i|Im z_n|)² + c—folds the complex plane along both axes, sculpting a fleet of jagged masts, rigging, and flames.

1.4649
log₃ 5

Vicsek Cross Fractal

Subdividing a square into a 3×3 grid and keeping only the 5 cross squares (center plus 4 cardinal neighbors) gives D = log(5)/log(3).

1.4780
≈ 1.478

Gumowski–Mira Particle-Accelerator Attractor

Formulated at CERN to model nonlinear transverse proton-beam instabilities in circular storage rings, the Gumowski–Mira map weaves a winged, marine-like strange attractor of resonant islands and filaments.

1.4850
≈ 1.485

Peter de Jong Trigonometric Strange Attractor

Iterating (x, y) ↦ (sin(ay) − cos(bx), sin(cx) − cos(dy)) (for a = 1.4, b = −2.3, c = 2.4, d = −2.1) folds the plane into twisted Möbius ribbons and sharp hyperbolic cusps.

Same dimension · 1 of 3
1.5000
log₄ 8 = 3 / 2

Minkowski Sausage (Quadratic Koch Curve)

Replacing every straight segment with N = 8 orthogonal links of scale r = 1/4 (a symmetric square wave that neither loses nor gains area) produces a self-similar curve of exact Hausdorff dimension log(8)/log(4) = 3/2 = 1.5000.

Same dimension · 2 of 3
1.5000
2 − H = 3 / 2

Weierstrass Nowhere-Differentiable Function

Adding cosine waves where each harmonic doubles in frequency while shrinking by 1/√2 in height creates a continuous curve that is rough at every magnification, with Hausdorff dimension 3/2.

Same dimension · 3 of 3
1.5000
1 + κ / 8 = 3 / 2

2D Gaussian Free Field Zero Contour (SLE₄)

Tracing the zero-elevation contour lines across a random 2D Gaussian Free Field landscape produces nested fractal loops of exact Hausdorff dimension 3/2.

1.5236
log₂(λ_D) ≈ 1.5236

Heighway Dragon Boundary

While the interior of the paper-folding Dragon curve fills 2D area, its intricate outer perimeter has fractal dimension ≈ 1.5236.

1.5479
≈ 1.5479

Ikeda Laser-Cavity Strange Attractor

Modeling laser pulses circulating inside a nonlinear optical ring resonator via z_{n+1} = 1 + 0.9 z_n exp(i(0.4 − 6/(1 + |z_n|²))) folds phase space into a swirling whirlpool of fractal filaments.

1.5500
≈ 1.55

Barnsley Fern (Affine IFS Attractor)

Four contractive 2D affine maps—a stem map, a main successively smaller frond map (85% probability), and left/right pinna maps—drive the Chaos Game onto a self-affine botanical frond of Hausdorff dimension ≈ 1.55.

1.5650
≈ 1.565

Berry–Goldberg Curlicue Fractal (Quadratic Weyl Sum)

Adding unit steps whose angle turns by n²√2 π at step n coils a single chain into nested Cornu spirals where every spiral arm is built out of smaller spirals.

Same dimension · 1 of 2
1.5850
log₂ 3

T-Square Fractal Boundary

Placing a half-scale square on every exposed corner spawns 3 new outward corners at scale r = 1/2 at each step, giving its fractal boundary exact dimension log(3)/log(2) ≈ 1.5850.

Same dimension · 2 of 2
1.5850
log₂ 3

Sierpiński Triangle Gasket

Every triangle splits into N = 3 corner sub-triangles at half the linear scale (r = 1/2), yielding D = log(3)/log(2) ≈ 1.5850.

1.6000
≈ 8 / 5

Ballistic Deposition & KPZ Crystal-Growth Horizon

Particles raining vertically onto a substrate and sticking upon first contact with an occupied neighbor build a porous columnar crystal forest whose roughened upper horizon obeys Kardar–Parisi–Zhang (KPZ) scaling.

1.6180
φ = (1 + √5) / 2

Golden Dragon Curve

Replacing every segment with two unequal legs scaled by r₁ = (1/φ)^(1/φ) ≈ 0.74274 and r₂ = r₁² ≈ 0.55167 satisfies r₁^φ + r₂^φ = 1/φ + 1/φ² = 1, giving a curling asymmetric dragon of exact Hausdorff dimension φ.

1.6309
1 + log₃ 2

Pascal’s Triangle Modulo 3

Coloring the entries of Pascal’s triangle not divisible by 3 packs 6 sub-triangles into every 3×3 block: log(6)/log(3) = 1 + log₃ 2.

1.6379
3 log φ / log(1 + √2)

90° Fibonacci Word Fractal

Tracing the infinite Fibonacci substitution word 01001010… with 90° orthogonal turns at every "0" transforms the 60° snow-crystal curve (1.2083) into a dense, self-similar labyrinth of dimension ≈ 1.6379.

1.6588
≈ 1.6588

Harter–Heighway Twindragon & Dragon Tiling

Joining two Heighway dragon curves head-to-tail forms the central-symmetric Twindragon rep-2 tile, which tessellates the entire plane with interlocking dragon territories.

1.6826
1 + log₅ 3

Pascal’s Triangle Modulo 5

Coloring the entries of Pascal’s triangle not divisible by the prime p = 5 packs p(p+1)/2 = 15 sub-triangles into every 5×5 block: log(15)/log(5) = 1 + log₅ 3 ≈ 1.6826.

1.7000
≈ 1.70 ± 0.02

Diffusion-Limited Aggregation (DLA)

Brownian particles wandering randomly until they stick to a seed crystal grow into branching lightning-like dendrites with dimension ≈ 1.70.

1.7227
4 log₅ 2

Conway’s Pinwheel Fractal

Subdividing a 1 : 2 : √5 right triangle into 5 congruent sub-triangles of scale r = 1/√5 and removing the central tile at each step produces an aperiodic fractal whose triangles rotate through infinitely many irrational angles.

1.7268
log₃ 20 − 1

Diagonal Hexagonal Slice of the Menger Sponge

By Marstrand’s slicing theorem, cutting a 3D Menger Sponge (D = log₃ 20 ≈ 2.7268) along the diagonal plane x + y + z = 0 reduces its dimension by 1 and reveals six-pointed hexagonal stars instead of squares.

Same dimension · 1 of 2
1.7500
7 / 4

Critical Percolation Hull (SLE₆ Boundary)

While the interior of a 2D critical percolation cluster has dimension 91/48 ≈ 1.8958, its outer coastline (including deep fjords whose necks have not yet pinched shut) is a fractal curve of exact dimension 7/4 = 1.7500.

Same dimension · 2 of 2
1.7500
≈ 1.75

Hele–Shaw Viscous Fingering (Saffman–Taylor Instability)

Injecting a low-viscosity fluid into a high-viscosity fluid confined between two parallel glass plates triggers repeated Laplacian tip-splitting instabilities, forming a radial Hele–Shaw rosette of dimension ≈ 1.75.

1.7712
log₃ 7

Hexaflake

Replacing every regular hexagon with N = 7 hexagons at scale r = 1/3 carves negative-space voids shaped like Koch snowflakes.

1.7848
log(4) / log(2(1 + cos 85°))

Cesàro Torn Square Fractal (85° Sweep)

Replacing all four sides of a square with inward-pointing 85° Koch spikes (scale r = 1/[2(1 + cos 85°)] ≈ 0.4599) carves four-way diagonal lightning fissures that almost touch across the interior.

1.8110
≈ 1.811

Indra’s Pearls (Kleinian Circle Limit Set)

When Kleinian circle generators become mutually tangent at parabolic cusps, their limit set transforms from disconnected Schottky dust (0.4400) into interlocking spiral chains of glowing circles.

1.8340
≈ 1.834

Nutrient-Limited Bacterial Colony Rosette

When colony growth is governed by local nutrient diffusion and surface-tension tip splitting, competing lobes thicken into a dense coral rosette sitting between thin DLA (1.7000) and critical percolation (1.8958).

1.8550
≈ 1.855

Optimal River Drainage Network (Hack’s Law Basin)

Erosion-driven competition between tributaries carves a dendritic watershed where channel width scales with upstream catchment area (A^0.45) and the space-filling river network reaches dimension ≈ 1.855.

1.8617
log(6) / log(1 + φ)

Golden Pentaflake

Replacing every regular pentagon with N = 6 pentagons scaled by r = 1/(1 + φ) = (3 − √5)/2 carves nested five-pointed golden stars into the negative space.

1.8928
log₃ 8

Sierpiński Carpet

Subdividing a square into 9 sub-squares of scale r = 1/3 and punching out the middle one leaves N = 8 copies: log(8)/log(3) ≈ 1.8928.

1.8958
91 / 48

2D Critical Percolation Cluster

At the critical site occupation threshold p_c ≈ 0.592746 on a 2D square lattice, the incipient spanning cluster forms a scale-invariant fractal archipelago of exact conformal dimension 91/48.

1.9120
≈ 1.912

Self-Avoiding Moore Maze Loop

Arranging four rotated Hilbert curves into a closed ring that leaves narrow non-touching corridors between branches winds a single loop through the square with fractal dimension ≈ 1.912.

1.9340
≈ 1.934007

Lévy C Curve

Replacing each segment with two 45° legs scaled by 1/√2 builds a self-overlapping canopy whose intricate outer boundary has dimension ≈ 1.9340.

1.9650
≈ 1.965

Peano–Gosper Flowsnake Curve

Replacing every directed segment with 7 segments on a triangular grid winds a single crinkly path through every sub-hexagon of the Gosper Island, packing the plane just shy of the D = 2 space-filling limit.

1.9700
≈ 1.97

Planar Dielectric Breakdown (Lichtenberg Figure)

In high-voltage planar dielectric breakdown with weak Laplacian screening (η < 1), branching discharge channels feather out across every angular sector to nearly fill the 2D disk.

2 ≤ D < 3 — Strange Attractors, Surfaces & Sponges

Sheet-like chaotic attractors, crumpled surfaces, and porous 3D cages

Same dimension · 1 of 3
2.0000
dim_H(∂M) = 2

Boundary of the Mandelbrot Set

By Shishikura’s theorem, the filaments along the perimeter of the Mandelbrot set branch so densely that its 1D boundary has full Hausdorff dimension 2.

Same dimension · 2 of 3
2.0000
log₂ 4 = 2

3D Sierpiński Tetrahedron (Tetrix)

Subdividing a 3D regular tetrahedron into N = 4 half-scale corner tetrahedra (r = 1/2) and excising the central octahedron produces a 3D polyhedral sponge whose Hausdorff dimension is exactly log₂ 4 = 2—a three-dimensional object with the scaling weight of a flat plane.

Same dimension · 3 of 3
2.0000
log(2) / log(√2) = 2

Pythagoras Tree (a² + b² = c²)

Branching each square into two child squares along the legs of a right triangle (scales r₁ = cos θ and r₂ = sin θ) satisfies r₁² + r₂² = 1 directly from the Pythagorean theorem, giving exact Hausdorff dimension 2.

2.0130
≈ 2.013

Rössler Strange Attractor

Driven by a single quadratic nonlinearity z(x − c), the Rössler ODE spirals outward in a flat 2D disk before kicking upward along z and folding back onto itself, creating a folded-band strange attractor of dimension ≈ 2.013.

2.0600
2.06 ± 0.01

Lorenz Strange Attractor

Crossing past dimension 2 into 3D phase space, the chaotic butterfly trajectory weaves an infinite stack of two-dimensional sheets.

2.0800
≈ 2.08

Chua’s Double-Scroll Strange Attractor

Generated by Chua’s nonlinear electronic circuit with a piecewise-linear negative-resistance diode, trajectories wind around two flat coplanar vortex rings linked by a twisted 3D bridge.

2.1300
≈ 2.13

Thomas’ Cyclically Symmetric Attractor

Driven by cyclically symmetric sine-wave feedback across x, y, and z, chaotic trajectories braid through a 3D lattice cage of three mutually perpendicular vortex tubes.

2.1500
≈ 2.15

Dadras Four-Wing Butterfly Strange Attractor

While the Lorenz attractor has two wings and Halvorsen has three, the 3D Dadras system couples quadratic cross-terms across all three axes to spin trajectories through four symmetric butterfly wings.

2.1800
≈ 2.18

Halvorsen Three-Wing Strange Attractor

Driven by three-fold symmetric quadratic coupling, trajectories spiral outward through three tetrahedral funnels before folding over into the neighboring wing.

2.1827
log₃ 11

3D Tetrahedral Koch Star Surface

Subdividing each equilateral triangle face into 9 sub-triangles of scale r = 1/3 and erecting a 3-sided regular tetrahedral spike over the central triangle replaces 1 face with N = 11 sub-triangles: log(11)/log(3) ≈ 2.1827.

2.2288
≈ 2.2288

Aizawa Torus-Sphere Strange Attractor

A 6-parameter 3D polynomial ODE weaves chaotic orbits across the latitudes of a glowing sphere before plunging vertically through its polar core like a planetary magnetic dynamo.

2.2619
1 + log₃ 4

Cartesian Product Fractal (Koch × Interval)

By the product dimension theorem D_H(A × B) = D_H(A) + D_H(B), extruding a Koch Snowflake curve (log₃ 4 ≈ 1.2619) along a 1D vertical interval (D = 1) forms a crinkly 3D prism wall of exact dimension 2.2619.

2.2920
≈ 2.292

Chen’s Double-Helical Tornado Attractor

As the topological dual to the Lorenz system, Chen’s attractor braids its two chaotic wings into a tall, tightly twisting 3D tornado column of dimension ≈ 2.292.

2.3219
log₂ 5

3D Fractal Square Pyramid

Subdividing a 3D square pyramid into N = 5 half-scale pyramids (4 at the base corners plus 1 at the apex) gives D = log(5)/log(2) ≈ 2.3219.

2.3297
log(20) / log(2 + φ)

3D Dodecahedral Polyflake

Replacing a regular dodecahedron with N = 20 sub-dodecahedra at its vertices scaled by r = 1/(2 + φ) ≈ 0.2764 builds a five-fold polyhedral cage of dimension log(20)/log(2 + φ) ≈ 2.3297.

2.3347
log₃ 13

3D Quadratic Koch Surface (Type 1)

Subdividing each square into a 3×3 grid and erecting a 5-sided cube turret over the middle square replaces 1 square with N = 13 sub-squares at scale r = 1/3: log(13)/log(3) ≈ 2.3347.

2.4022
log₃ 14

3D Cuboctahedral Space-Frame Truss

Subdividing a 3×3×3 cube and keeping the N = 12 edge-midpoint sub-cubes plus 2 opposite corner sub-cubes at scale r = 1/3 carves an open 3D diagonal space-frame truss of dimension log(14)/log(3) ≈ 2.4022.

2.4150
≈ 2.415

3D Mandelbox (Box-Fold & Sphere-Inversion Fractal)

Alternating cubic box-reflections across [−1, 1]³ with spherical inversions inside a ball of radius 1/2 (at scale s = −2.0) carves an architectural 3D sponge of struts, grilles, and recursive courtyards.

2.4739
≈ 2.473946

3D Apollonian Sphere Packing

Packing mutually tangent spheres into every tetrahedral gap between four base spheres leaves a residual 3D fractal foam of dimension ≈ 2.4739.

Same dimension · 1 of 2
2.5000
5 / 2 = 3 − H

Fractional Brownian Surface (H = 0.5)

A 2D random Brownian landscape has Hausdorff dimension 3 − H = 2.5, sitting halfway between a smooth 2D sheet and a 3D volume.

Same dimension · 2 of 2
2.5000
≈ 2.50

3D Diffusion-Limited Aggregation (3D DLA Cluster)

Extending Brownian particle aggregation from 2D (D ≈ 1.70) into three-dimensional space raises the cluster dimension to D ≈ 2.50, forming a 3D dendritic coral bush screened by the 3D harmonic potential.

2.5290
log((√7 − 1) / 2) / log(√2 − 1)

Jerusalem Cube

Drilling Jerusalem-cross tunnels scaled by the silver ratio r = √2 − 1 through every face leaves 8 corner cubes of scale r and 12 edge cubes of scale r², satisfying 8r^D + 12r^(2D) = 1.

2.5819
log(12) / log(1 + φ)

3D Icosahedral Golden Polyflake

Replacing a 20-face regular icosahedron with N = 12 sub-icosahedra at its twelve vertices scaled by r = 1/(1 + φ) ≈ 0.3820 completes the 3D Platonic fractal family at dimension log(12)/log(1 + φ) ≈ 2.5819.

2.5850
log₂ 6 = 1 + log₂ 3

3D Octahedron Fractal

Replacing a regular octahedron with N = 6 half-scale octahedra at its six cardinal vertices carves octahedral cavities that project along the axes into Sierpiński gaskets.

2.6309
log₃ 18 = 1 + log₃ 6

Mosely Snowflake Sponge

Removing the 8 corner sub-cubes and the central sub-cube from every 3×3×3 block leaves N = 18 sub-cubes at scale r = 1/3, sculpting a 3D crystalline snowflake polyhedron of dimension log₃ 18 ≈ 2.6309.

2.6667
8 / 3

3D Turbulent Vorticity Filament Tangling

In the β-model of intermittent high-Reynolds-number fluid turbulence, vortex stretching concentrates energy dissipation into a braided 3D tangle of vortex tubes and hairpin eddies of dimension ≈ 8/3.

2.7268
log₃ 20

Menger Sponge

Drilling tunnels through every face of a 3×3×3 cube removes 7 sub-cubes and leaves N = 20 sub-cubes at scale r = 1/3: zero volume, infinite surface area.

2.7650
≈ 2.765

3D Cortical Sulci & Gyri Buckling Surface

Tangential expansion of a 2D cortical sheet constrained inside a 3D cranial sphere buckles into nested convoluted ridges (gyri) and deep branching fissures (sulci) with surface fractal dimension ≈ 2.765.

2.7950
≈ 2.795

Romanesco Golden-Angle Cone Fractal

Arranging self-similar 3D paraboloid buds at the golden divergence angle Δθ = 2π/φ² ≈ 137.5077° generates interlocking Fibonacci parastichy spirals where every bud is a miniature cone of smaller buds.

2.8350
≈ 2.835

3D Kleinian Schottky Sphere Foam

Lifting Möbius circle inversions into three-dimensional space across six octahedral generator spheres packs nested 3D spheres inside spheres into a volumetric Kleinian foam.

2.8550
≈ 2.855

3D Quaternion Julia Set (q ↦ q² + c)

Slicing the 4D hypercomplex Julia set of q ↦ q² + c (for quaternion c = −0.2 + 0.6i + 0.2j + 0.2k) across 3-space reveals a sculpted fractal body of folded ribbons and self-similar tendrils.

2.8800
≈ 2.88

3D Mandelbulb (Power-8 Spherical Map)

Lifting z ↦ z⁸ + c into spherical coordinates (r, θ, φ) ↦ (r⁸, 8θ, 8φ) produces a 3D fractal body adorned with recursive crown-like bulbs, canyons, and spirals whose boundary approaches dimension ≈ 2.88.

2.9250
≈ 2.925

3D Multi-Scale Gyroid Minimal-Surface Sponge

Layering triply periodic Schoen gyroid minimal surfaces across nested spatial scales forms a curved 3D labyrinth of channels that packs surface area densely into volume.

2.9700
≈ 2.97

3D Space-Filling Bronchial Tree

Mammalian lung airways and vascular networks bifurcate across ~23 generations with Murray’s scaling factor r ≈ 2^(-1/3), creating a 3D canopy whose terminal surface packs 3D volume with dimension ≈ 2.97.

D = 3 — Space-Filling Volume

A 1D curve folded so densely that it visits every point of three-dimensional space

3.0000
log₂ 8 = 3

3D Hilbert Space-Filling Curve

Folding a 1D curve into N = 8 sub-cubes at half scale (r = 1/2) visits every voxel of three-dimensional space, reaching D = log(8)/log(2) = 3.