An Improved CMB Map Colormap

Although a variety of colormaps have previously been specifically developed for displaying cosmic microwave background (CMB) maps, none of these have been designed with perceptual uniformity or color-vision-deficiency (CVD) accessibility in mind. To improve upon this status quo, in support of publications1 for the 2022 data release for the Cosmology Large Angular Scale Surveyor (CLASS), I used Matplotlib’s Viscm tool to develop a new diverging colormap that resembles the Planck colormap but is mostly perceptually uniform and is perceived similarly by both individuals with typical color vision and those with red or green color-vision deficiencies. The Q-band Stokes U map from the CLASS paper, which uses the new colormap, is shown below.

A CMB map in equatorial coordinates is shown under Mollweide projection. Data are shown for around 70% of the sky, and the Galactic plane is visible. The new colormap discussed in this blog post is used, starting from blue to a warm light gray and then to red. Continue reading

  1. Y. Li et al., “CLASS Data Pipeline and Maps for 40 GHz Observations through 2022”, arXiv:2305.01045.  

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Galaxy Pie

For the baking contest at this year’s Center for Astrophysics barbecue, I made a blackberry pie containing a spiral galaxy made from a coconut pudding.1 The pie ingredients were mostly chosen based on color and texture, as well as to accommodate dietary restrictions of colleagues. To make the inset galaxy, I created a vector drawing based on the M51 galaxy, extruded it into a solid, and 3D printed the resulting shape out of PLA to form an insert, which extended all the way down to the bottom crust.

Pie with a light crust, dark filling, and a white spiral galaxy inset in the filling Continue reading

  1. Although it ended up being a more general baking contest, the original email about the contest described it as a pie-baking contest, hence the pie.  

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Building a Cosmic Coffee Table

Now that I finally have a couch (and am living in an apartment big enough to comfortably fit one, unlike when I was in grad school), I decided I also needed a coffee table. Instead of just buying one, I decided to build one instead, with an astrophysics-related theme. To make construction without access to a woodworking shop easier, I sketched out a design based on square birch dowels, after which I selected a Hubble Space Telescope image of the Tarantula Nebula to use for the tabletop, and got to work building the table.

Black wooden coffee table with image of Tarantula Nebula on top and slats on the bottom Continue reading

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JWST Gingerbread Cookies

To get into the holiday spirit and in anticipation of the long-awaited launch of the James Webb Space Telescope (JWST),1 I decided to bake some gingerbread cookies in the shape of JWST’s primary mirror, which is comprised of 18 gold-plated hexagonal segments. The cookies are 10 cm across, with hexagonal segments are 20 mm flat to flat, making them 1:66 scale replicas of the mirror.

Three gingerbread cookies in the shape of the JWST primary mirror with gold hexagonal segments stenciled on Continue reading

  1. The launch is scheduled for Christmas Day, as of writing.  

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Square Equal-area Map Projection

Several weeks ago, my paper on a novel square equal-area map projection was published in ACM Transactions on Spatial Algorithms and Systems, titled A Square Equal-Area Map Projection with Low Angular Distortion, Minimal Cusps, and Closed-Form Solutions. For mathematical details, the reader is directed to the paper, but I’ll discuss what motivated its development and outline the projection’s benefits here. The projection uses a quincuncial arrangement, which places the north pole at the center and splits the south pole between the four corners of the square, forming a quincunx pattern that resembles the “five” marking on a standard six-sided die. This arrangement has been previously used by the Peirce quincuncial projection, the Collignon quincuncial projection, and the Gringorten projection.1

Map of the world displayed using the new projection Continue reading

  1. Gringorten, Irving I. “A square equal-area map of the world.” Journal of Applied Meteorology and Climatology 11, no. 5 (1972): 763–767.  

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