Original Math Designs
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diffgeom.com
Original Math Designs
@diffgeom.com
600 followers 510 following 280 posts
The online shop Differential Geometry, at www.diffgeom.com, run by Andrew D. Hwang.

"Hwang" rhymes with "song" more or less, he/him: Freelance mathematician, mathematical artist (no machine learning), author, difficult to summarize
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Particularly looking forward to coffee tomorrow!

store.elkement.art/en-eur/pages...

#SciArt #MathArt #PhysicsArt
Right-hander's view of white ceramic coffee mug decorated with elkement's hand-drawn ellipsoids. Left-hander's view of white ceramic coffee mug decorated with elkement's hand-drawn ellipsoids.
November 8, 2025 at 11:10 PM
diffgeom.com
Another new nylon earring design: Swirl depicts an angle-preserving flow on the sphere.

www.diffgeom.com/product-cate...

#MathArt #Jewelry #3DPrinting
Green 20mm nylon earrings in the shape of a sphere with five bands swirling diagonally around the poles. Red 20mm nylon earrings in the shape of a sphere with five bands swirling diagonally around the poles.
November 6, 2025 at 11:55 PM
diffgeom.com
There are new nylon earring designs in my online math shop! Anemone is a stylized representation of the complex 2/7-power.

To celebrate, all my original nylon designs are at a special price, which includes shipping to the US.

www.diffgeom.com/product-cate...

#MathSky #MathArt #Jewelry #3DPrinting
Pink 20mm nylon earrings in the shape of knotted bands having 7-fold rotational symmetry. Purple 20mm nylon earrings in the shape of knotted bands having 7-fold rotational symmetry. Red 20mm nylon earrings in the shape of knotted bands having 7-fold rotational symmetry.
November 6, 2025 at 1:00 PM
diffgeom.com
I have mathematical greeting cards (original designs, no AI, boxes of 10) in stock!

www.diffgeom.com/product-cate...

Price includes shipping within the US.

Browse the whole shop:
www.diffgeom.com/shop

#MathSky #MathArt
A virtual evening scene depicting a Georgia O'Keeffe-like enameled orb over a silhouetted range of mountains under a winter sky, dusted with five-pointed stars.
November 1, 2025 at 1:25 PM
diffgeom.com
A new version of z = -(1-x^2)(1-y^2), with most of the struts parallel rather than the two families split equally.

#MathSky #MathArt
Isometric perspective photograph of a 6.5-inch model made from a 2x19 array of laser cut fiberboard struts. The model is bowl-shaped in the middle, and supported by four legs where the corners bend downward.
October 30, 2025 at 10:05 PM
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Free Online Math Materials

A blog post on linear algebra, taken from the students' preface to my free (gratis) book, with links to interactive software for matrix multiplication and exploring the geometry of linear transformations.

www.diffgeom.com/blogs/about-...

#MathSky #ITeachMath
A screenshot of an interactive program for exploring the geometry of plane linear transformations, showing a 2x2 matrix, the action of the linear transformation T having that standard matrix, and the eigenspace(s) of T.
October 27, 2025 at 11:19 PM
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My popular Harmonia pendant is available in sterling silver for the first time!

www.diffgeom.com/product/harm...

Browse all my jewelry designs at Differential Geometry:

www.diffgeom.com/product-cate...

#MathArt #Jewelry #SmallBusiness
Photograph of Harmonia, a shiny silver pendant in the looping shape of a stylized flower with six petals, on black background.
October 24, 2025 at 9:05 PM
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Yesterday's post reminded me of this model (ca. 1988), hand-plotted and hand-cut on sketch paper. The graph is
Re[(x+iy)^4] = x^4 - 4x^2y^2 + y^4.
Used it a few times over the years when teaching multivariable calculus, but it's too fragile to pass around.

#MathSky #MathArt #ITeachMath
Photograph of a cross-slotted white paper model of a 2-variable "dog saddle" graph, made from an 11x11 array of vertical planes, each cut into the shape of a cross section. The model sits on a reddish glazed tile surface. Photograph of the same paper model folded flat on a reddish glazed tile surface. The cross sections look like two humps interpolated by a two variable graph.
October 23, 2025 at 6:45 PM
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The graph z = -(1-x^2)(1-y^2), in suitable units.

#MathArt
Isometric perspective photograph of a 6.5-inch model made from a 7x7 array of laser cut fiberboard struts. The model is bowl-shaped in the middle, and supported by four legs where the corners bend downward. Oblique diagonal photograph of a 6.5-inch model made from a 7x7 array of laser cut fiberboard struts. The model is bowl-shaped in the middle, and supported by four legs where the corners bend downward.
October 22, 2025 at 7:36 PM
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Matching silver pendant and earrings (sold separately) at Differential Geometry. The knotted band is a stylized representation of the complex 2/7-power function.

www.diffgeom.com/product/anem...
www.diffgeom.com/product/anem...

www.diffgeom.com/product-cate...

#MathSky #MathArt #Jewelry
Photograph of a flower-like mirror-polished sterling silver pendant, about 1.2in/30mm across, with seven-fold rotational symmetry. Photograph of flower-like mirror-polished sterling silver earrings, about 0.8in/20mm across, torus knots with seven-fold rotational symmetry.
October 20, 2025 at 7:50 PM
diffgeom.com
I design and sell mathematically-accurate jewelry inspired by differential and algebraic geometry, and topology, and invite you to browse!

www.diffgeom.com/product-cate...

#MathSky #MathArt #Jewelry #3DPrinting
A gallery of 15 photographs of shiny mathematical pendants and earrings at Differential Geometry.
October 19, 2025 at 3:26 PM
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#PortfolioDay I'm Andy, a mathematician (complex differential geometry) who left academia in 2023 with the aim of cultivating love of math while earning a modest living selling original images and objects created with GPL tools and my own software.

www.diffgeom.com

#MathArt #Jewelry #3DPrinting
Untitled: Photograph of a 3D printed nylon "(2,3,5) trig pyramid" about 70mm corner to corner. https://www.diffgeom.com/blogs/about-math/trig-pyramids/ Pulse: Photograph of a black T-shirt with a wavy surface mesh. https://www.diffgeom.com/product/unisex-tee-pulse/ Core: A digital image of a nested-spherical structure with a red-gold nucleus and an outer shell dotted with purplish slots edged in glowing gold. https://www.diffgeom.com/product/poster-core/ Anemone 7,2: Photograph of a gold-plated brass pendant, about 40mm across, in the shape of a twisted band with seven-fold rotational symmetry. (Sold, but see https://www.diffgeom.com/product/anemone-52-necklace/)
October 14, 2025 at 4:15 PM
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The interesting part of a parabolic cyclide -- a product torus in the 3-sphere stereographically projected to 3-space from a point on the torus -- about 85mm across, prospectively a brass desktop model.

#MathSky #MathArt #3DPrinting
Photograph of a 3D printed symmetrical white nylon surface shaped like a saddle with a topological handle.
October 11, 2025 at 4:30 PM
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Six new poster/wall decor designs at Differential Geometry:

www.diffgeom.com/product-cate...

#MathSky #MathArt
A gallery of six mathematical posters: A sphere resembling an underwater life form with a glowing nucleus; A purple and green conformal hexagon tiling of a torus, seen from inside; A white wireframe torus casting a shadow on a virtual calm tropical sea; A dramatic side-lit red and black form resembling a melted heart; A blue mollusk shell with a gold coordinate grid looming in a twilit sky; A field of sky-blue foreground-background arrows masking underlying reality.
October 9, 2025 at 7:51 PM
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A new blog post, hopefully accessible to anyone who has seen cosine and sine, illustrating and explaining trig nets ("Lissajous figures"), trig pyramids (3D printed model shown), and other fun with 4- and 6-D geometry:

www.diffgeom.com/blogs/about-...

#MathSky #MathArt #ITeachMath #3DPrinting
Another photograph of the white 3D-printed nylon model looking like a radiator-finned pyramid wrapping arms around itself. Photograph of a white 3D-printed nylon model looking like folded fingers or a (2,3) trig net.
October 2, 2025 at 5:30 PM
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A friendly reminder not to mistake reflections -- words and concepts of narcissists, the screen you are staring at this very second -- for reality.

#MathSky #MathArt
Multiple turns of a blue spiraling surface, shaded orange-gold as if lit by firelight, partly immersed in and reflected from a vertical mirror.
September 26, 2025 at 3:09 PM
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Three original pendant/earring designs at Differential Geometry. Links and mathematical descriptions are in the alt text. I invite you to browse all my designs here:

www.diffgeom.com/product-cate...

#MathArt #Jewelry #3DPrinting
Six photographs of matching silver pendant and earring sets. "Intimo" is a trefoil knot on a conformally-parametrized torus, resembling linked rings, symbolizing eyes filled with positive regard. https://www.diffgeom.com/product/intimo-necklace/ https://www.diffgeom.com/product/intimo-earrings/ "Vivace" is a lively, spiraling, climbing minimal surface. https://www.diffgeom.com/product/vivace-necklace/ https://www.diffgeom.com/product/vivace-earrings/ "Anemone" resembles two intertwining bands, though on closer gaze there is only one, eternally joined. https://www.diffgeom.com/product/anemone-silver-necklace/ https://www.diffgeom.com/product/anemone-silver-earrings/
September 25, 2025 at 3:40 PM
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Although my online shop Differential Geometry is a primary source of income, I maintain (on a static html site) a list of other creators' mathematical online shops:

www.diffgeom.org/misc/math_sh...

I hope you will browse and support us all!

#MathSky #MathArt #ITeachmath #SmallBusiness
A deep blue mottled annulus surrounds a black hole, or the moon's disk during a total solar eclipse. On closer gaze, silver ant-like shapes follow each other endlessly around a torus. The torus is tiled with a golden hexagonal grid. Each ant is isolated in its own cell.
September 21, 2025 at 2:38 PM
diffgeom.com
Differential Geometry is an online shop and blog devoted to math appreciation, education and outreach. All designs I sell are my own. I invite you to drop by and browse!

www.diffgeom.com
www.diffgeom.com/product/post...

#MathSky #MathArt #ITeachMath #SmallBusiness
"Core," a nested spherical structure resembling a cell, deep-sea creature, or abstract portrait of each of us. The inner shell radiates warmly, the outer is made of purplish spots that glow with inner light.
September 20, 2025 at 5:40 PM
diffgeom.com
I design and sell mathematically-accurate jewelry inspired by differential and algebraic geometry, and topology, and invite you to browse!

www.diffgeom.com/product-cate...

#MathSky #MathArt #Jewelry #3DPrinting
A gallery of 15 photographs of shiny mathematical pendants and earrings at Differential Geometry.
September 17, 2025 at 4:56 PM
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#MathSky #MathArt
An abstract nautilus shell, deep blue with a bright gold coordinate grid, glowing in the center, looms in a virtual twilit sky.
September 15, 2025 at 4:59 PM
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A more formal snapshot/portrait of a commercially printed 3.5in (90mm) black nylon model of Costa's minimal surface. The contours on the planar end are artifacts of the SLS process, but visually pleasant and mathematically meaningful.

#MathSky #MathArt #3DPrinting
A monochrome photograph of a black nylon "abstract soap film" surface on a white background. The model has flared round openings (catenoid ends) at top and bottom and a circular skirt (planar end) in the middle. Features of the topology -- the surface is a torus with three punctures -- can be seen as holes interpolating the catenoid and planar ends.
September 7, 2025 at 2:14 PM
diffgeom.com
I design and sell mathematically-accurate jewelry inspired by differential and algebraic geometry, and topology. Pieces shown are still available. I invite you to browse, and to email if there are shapes you'd like to see!

www.diffgeom.com/product-cate...

#MathSky #MathArt #Jewelry #3DPrinting
A gallery of 15 photographs of shiny mathematical pendants and earrings at Differential Geometry.
September 6, 2025 at 5:20 PM
diffgeom.com
An oblique view of Trinity, a 3-1/2in (90mm) unpolished brass piece made in 2023 by Shapeways from an original design.

This photo was a pleasant hard drive find. Although the piece is not visibly symmetric, there are curves I better appreciate now than 2.5 years ago.

#MathSky #MathArt #3DPrinting
Photograph of a rounded, shiny brass surface comprising a twisted band, against a reddish tile background. One edge of the band is a circle; the other edge wraps three full turns about the circle in a normal plane as that plane sweeps around the circle.
September 2, 2025 at 2:51 PM
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The plotting/drawing software ePiX is also suitable for laying out pieces for slotted models such as Pulse.

www.diffgeom.com/products/pul...

www.diffgeom.com/blogs/free-o...

#MathSky #MathArt
Photograph of a sinuous model in the shape of an abstract wave form made from laser-cut aluminum struts, seen obliquely, sitting on a glazed tile table.
August 30, 2025 at 4:54 PM