Monday, August 21, 2017

"Subtitles: What the Book is Actually About"

Just for the irony, I'd like to write a book called "Subtitles: What the Book is Actually About". :)

Wednesday, August 16, 2017

Eclipses Go Meta

Good. Something is right in the world. (Also, I strongly approve of this!)


(Tip of the cap to several people for this news. I got the tweet from Cathy O'Neil.)

Monday, August 14, 2017

What Happens in Edmonton Stays in Edmonton

Today I'm off to Edmonton — home of the Eulers!

I will be giving an invited talk at a (mostly) pure-math conference on differential equations.

Sunday, August 13, 2017

A Sweet Early Calculator!

Very cool!



(Tip of the cap to Daniele Avitabile.)

Saturday, August 12, 2017

Differential Equations and "General Fiction"

Eugenia Cheng's tweet below reminds me that when I was in grad school, a local store (a coffee place that also sold books) once had a certain differential-equations textbook in their section on "General Fiction".

Thursday, August 10, 2017

A Tetris-Themed Glass Window (and Other Nerd Furniture)

Take a look at this sweet nerd furniture!

Update (8/11/17): Initially I described the Tetris window as a "stained-glass window". As Aaron Clements pointed out on my Facebook post, a correct description is actually "colored glass blocks with mortar".

(Tip of the cap to Rachel Simmons Carter.)

Another Optical Illusion: How Many Circles Can You Find?

Here's another optical illusion. It's not as visually striking as the other one I posted recently, but it's interesting (and, unlike the other one, the basic qualitative feature of the illusion is not one that I have not encountered before).

Wednesday, August 09, 2017

"Core-Periphery Structure in Networks (Revisited)"

One of my papers just came out in published form. In fact, it's a SIAM Review reboot (with some new sections and other updates) of our paper from a few years ago. Here are the details.

Title: Core-Periphery Structure in Networks (Revisited)

Authors: Puck Rombach, Mason A. Porter, James H. Fowler, and Peter J. Mucha

Abstract: Intermediate-scale (or “meso-scale”) structures in networks have received considerable attention, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. Numerous types of meso-scale structures can occur in networks, but investigations of such features have focused predominantly on the identification and study of community structure. In this paper, we develop a new method to investigate the meso-scale feature known as
core-periphery structure, which entails identifying densely connected core nodes and sparsely connected peripheral nodes. In contrast to communities, the nodes in a core are also reasonably well-connected to those in a network’s periphery. Our new method of computing core-periphery structure can identify multiple cores in a network and takes into account different possible core structures. We illustrate the differences between our method and several existing methods for identifying which nodes belong to a core, and we use our technique to examine core-periphery structure in examples of friendship, collaboration, transportation, and voting networks. For this new SIGEST version of our paper, we also discuss our work’s relevance in the context of recent developments in the study of core-periphery structure.


"A Roadmap for the Computation of Persistent Homology"

One of my papers just came out in published form. Here are the details.

Title: A Roadmap for the Computation of Persistent Homology

Authors: Nina Otter, Mason A. Porter, Ulrike Tillmann, Peter Grindrod, and Heather A. Harrington

Abstract: Persistent homology (PH) is a method used in topological data analysis (TDA) to study qualitative features of data that persist across multiple scales. It is robust to perturbations of input data, independent of dimensions and coordinates, and provides a compact representation of the qualitative features of the input. The computation of PH is an open area with numerous important and fascinating challenges. The field of PH computation is evolving rapidly, and new algorithms and software implementations are being updated and released at a rapid pace. The purposes of our article are to (1) introduce theory and computational methods for PH to a broad range of computational scientists and (2) provide benchmarks of state-of-the-art implementations for the computation of PH. We give a friendly introduction to PH, navigate the pipeline for the computation of PH with an eye towards applications, and use a range of synthetic and real-world data sets to evaluate currently available open-source implementations for the computation of PH. Based on our benchmarking, we indicate which algorithms and implementations are best suited to different types of data sets. In an accompanying tutorial, we provide guidelines for the computation of PH. We make publicly available all scripts that we wrote for the tutorial, and we make available the processed version of the data sets used in the benchmarking.

Tuesday, August 08, 2017

"Opposite" Jobs

According to this website, the "opposite" job of a kindergarten teacher is a physicist, whose opposite job is a model (so it's a directed similarity measure, as it should be, so really one should write "most different" rather than "opposite" to encapsulate the directionality).

According to this, the most different job from "mathematician" is "mine shuttle car operator".

Huzzah!

Surpise!

I am highly amused by this classification. :)

Cassandra

My collaborator Sam Howison brought up Cassandra in our skype meeting today. Apropos to current reality, "Cassandra is a prophetess in Greek mythology who was blessed with foresight but cursed never to be believed."

Naturally, the first thing that came to my mind that Sam mentioned Cassandra was not the prophet, but rather the ABBA song (which turns out to be a B-side). And checking the lyrics, the song does indeed refer to the prophet.

Monday, August 07, 2017

Awesome Optical Illusion: Bathroom Tile Edition

Versions of this optical illusion (much less elaborate variants of it) appear to be ubiquitous in restaurant bathroom tiles. :)

Saturday, August 05, 2017

Dodgers Have Best 50-Game Run Since 1912!

With their come-from-behind win today, the Dodgers are now 43–7 in their last 50 games, the best 50-game run since the 1912 Giants! Wow!

Friday, August 04, 2017

A Multiplex Network of Relations Between Probability Distributions

OK, quickly: Which distribution is the most central? :)

(There are quite a few comments on the tweet. I haven't looked at them, but I wonder if people are picking apart inaccuracies? I haven't spent the time to vet this diagram, but I really like the idea!)

A Classic Article: "More is Different"

Now that it's officially August 4th, today marks the 45th anniversary of Philip Anderson's famous article, More is Different, a landmark article for the study of complex systems. Here is a link to the full article, in case you don't have access to Science articles.

(Tip of the cap to Michael Stumpf.)

Thursday, August 03, 2017

What is the Weirdest Historical/Superstitious Practice in Academia?

This is definitely it.

I saw this yesterday, but I didn't post it because the embedded tweet wasn't showing the original question. I should have taken a screenshot and posted it. :)

Tuesday, August 01, 2017

Mathematicians and Physicists on Twitter

Here is a list of mathematicians on Twitter with 1000+ followers. However, they missed me. I would rank number 70, assuming they didn't miss anybody with more followers than me.

Here is a list of physicists on Twitter with 1000+ followers. I am not on this list either, though it can be argued that I am also a physicist (in addition to being a mathematician).

Update (8/03/17): My account is now on the list of mathematicians.