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Showing posts from February, 2016

William Stein discusses open-source mathematical software in academia. I liked this quote:

William Stein discusses open-source mathematical software in academia.  I liked this quote:

We as a community overall would be better off if, when considering how we build departments, we put "mathematical software writers" on an equal footing with "algebraic geometers". We should systematically consider quality open source software contributions on a potentially equal footing with publications in journals.

I have some limited personal experience with this, in that I have done job market searching in areas related to academia, e.g. trying to answer whether it would be possible to get a job as a software developer for an astronomy facility.  (In my case, it was far from possible because I don't have a PhD.  That seems a must, weighted near infinitely higher than longtime software experience, industry or opensource.)

In any case, it's good to see William so devoted to his mission to "create a viable open source alternative to Mathematica".

Originally sh…

{7,3} Surfboard Part Deux

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{7,3} Surfboard Part Deux

The print on fiberglass cloth arrived today, and it is awesome!  I'm especially impressed with the black, and excited to see the finale.

This printing technology could surely be used for other artistic purposes besides surfboards.

For more, see {7,3} Surfboard Part 1:
plus.google.com/+RoiceNelson/posts/iSmtVvE7xTV

Awesome time-lapse.

Awesome time-lapse.  

This makes it look so easy, but I remember seeing posts for each mirror around once a day from James Webb Space Telescope (JWST) as it was getting assembled.

Originally shared by James Webb Space Telescope (JWST)

A brand-new time-lapse of #JWST's mirror being assembled!
https://youtu.be/1d1sHLkmNQI

Read more about the video: http://www.nasa.gov/feature/goddard/2016/new-nasa-time-lapse-shows-nasas-webb-telescope-primary-mirrors-complete-assembly
http://www.nasa.gov/feature/goddard/2016/new-nasa-time-lapse-shows-nasas-webb-telescope-primary-mirrors-complete-assembly

I spent the last two evenings making a small site to act as a portfolio of math viz projects.

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I spent the last two evenings making a small site to act as a portfolio of math viz projects. Let me know what you think!

roice3.org

It's easy to end up obsessing over these things. Time to pull myself away and sleep!

{∞,∞,∞} Honeycomb in Spherical Video

{∞,∞,∞} Honeycomb in Spherical Video

This time we are applying a loxodromic Möbius transformation to animate.  The two fixed points I chose are not antipodal on the viewable sphere, and they can be placed in the same view.  Can you find them?  We are zooming away from one and towards the other, and rotating everything about both.

This is not a looping animation, so I had to render a bunch more frames to make the video a reasonable length.  The 1800 frames took about 20 hours to render.

Aside:  I've noticed that every spherical viewer available gimbal locks at the poles, which is unfortunate.  It should be easy to avoid that with quaternion rotations (like MagicCube4D does).  Anyone know of a spherical viewer without that limitation?  My favorite desktop viewer for spherical video and images so far is KolorEyes.

Relevant Links

What is a {∞,∞,∞} Honeycomb?
arxiv.org/abs/1511.02851

KolorEyes spherical viewer
www.kolor.com/kolor-eyes

MagicCube4D
http://superliminal.com/cube/cube.htm
https://www.…

With just a little over 800 square feet in our home, Sarah and I could sure use this upgrade!

With just a little over 800 square feet in our home, Sarah and I could sure use this upgrade!

Originally shared by Henry Segerman

More spherical video trickery!: A two-fold branched cover of my apartment.
https://www.youtube.com/watch?v=UUW_ZU3_TQM

Hyperbolic Catacombs Carousel

Hyperbolic Catacombs Carousel

Take an immersive spin around the {3,7,3} honeycomb in the upper half space model.  See the paper Visualizing Hyperbolic Honeycombs to learn about this strange world.

arxiv.org/abs/1511.02851

This video came about from a fun evening of equirectangular projections with Henry Segerman and Vi Hart.
https://www.youtube.com/watch?v=GRo_FQm2KRc&feature=share

{7,3} Surfboard

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{7,3} Surfboard

For our tenth anniversary, Sarah Nemec-Nelson planned a perfect gift, a custom surfboard that I could decorate with mathematical art.  We've spent a lot of time in Galveston the last few years, and I've really enjoyed learning to surf.

I've been tuning a number of ideas, finally settling on this.  The surfboard deck will look like the left portion of the image.  The pattern used is on the right.  It is the {7,3} hyperbolic tiling in Vladimir Bulatov's band model, along with a gray outline of its {3,7} dual and a colorful Coxeter complex.  Like the Poincaré disk and upper half plane, the band model is a conformal model of the hyperbolic plane.  The coloring is based on ideas developed with Henry Segerman for our paper Visualizing Hyperbolic Honeycombs.

The surfboard will be shaped by James Fulbright of Strictly Hardcore Surf Specialties, and BoardLams will do the printing (on fiberglass).  I'm stoked!  I'll be sure to post pictures of the end result…

Is ∞ odd or even?

Is ∞ odd or even?

This question popped into my head yesterday, and had already been asked and answered nicely on math.stackexchange.  I liked Qiaochu Yuan's answer the best...

math.stackexchange.com/a/49045/300001

...as well as the related question/answer he linked to, "Is infinity a number?"

math.stackexchange.com/questions/36289/is-infinity-a-number

Great reading.  I find questions like this so interesting because they take some concept in one context and try to meaningfully extend it to another context.
http://math.stackexchange.com/questions/49034/is-infinity-an-odd-or-even-number#