"Nonlinear Localized Modes in Two-Dimensional Hexagonally-Packed Magnetic Lattices"

One of my papers just came out in final form. Here are some details.

Title: Nonlinear Localized Modes in Two-Dimensional Hexagonally-Packed Magnetic Lattices

Authors: Christopher Chong, Yifan Wang, Donovan Maréchal, Efstathios G. Charalampidis, Miguel Molerón, Alejandro J. Martínez, Mason A. Porter, Panayotis G. Kevrekidis, and Chiara Daraio

Abstract: We conduct an extensive study of nonlinear localized modes (NLMs), which are temporally periodic and spatially localized structures, in a two-dimensional array of repelling magnets. In our experiments, we arrange a lattice in a hexagonal configuration with a light-mass defect, and we harmonically drive the center of the chain with a tunable excitation frequency, amplitude, and angle. We use a damped, driven variant of a vector Fermi–Pasta–Ulam–Tsingou lattice to model our experimental setup. Despite the idealized nature of this model, we obtain good qualitative agreement between theory and experiments for a variety of dynamical behaviors. We find that the spatial decay is direction-dependent and that drive amplitudes along fundamental displacement axes lead to nonlinear resonant peaks in frequency continuations that are similar to those that occur in one-dimensional damped, driven lattices. However, we observe numerically that driving along other directions results in asymmetric NLMs that bifurcate from the main solution branch, which consists of symmetric NLMs. We also demonstrate both experimentally and numerically that solutions that appear to be time-quasiperiodic bifurcate from the branch of symmetric time-periodic NLMs.

Some Academic Struggles and Survivorship Bias

Public Service Announcement: When you look at somebody's fancy CV (or fancy job or other hallmark of success), don't assume that they didn't have to go through major struggles — often many of them — before they got there.

PSA 2: Survivorship bias is a good thing to remember. pic.twitter.com/XaPk2Eoo0f

— Mason Porter (@masonporter) April 4, 2021

April Fooling: 2021 Edition

Well, the April 1st arXiv articles are out, and sure enough there are some of them that are in honor of April Fool's Day. For example, there is one about Taylor Swift and a paper that is "coauthored" by a cat in which the cat "analyzes" a laser pointer and a dot on a wall as a coupled dynamical system.

Update: Here are some other papers, although I don't think the one about procrastination qualifies. I saw that one in my own arXiv scouring, and in my opinion that one is more of the 'improbable research' style (something that first makes you laugh and then makes you think), rather than something that is simply a joke. (Tip of the cap to Celeste Labedz.)

Update (4/01/21): The article that I was thinking of — which concerns our poor estimation of how long things take — was indeed intended as a sort of a joke (based on the author's Twitter thread), but my own view of it is still as an example of 'improbable research'.

Update (4/01/21): Here is a joke about noodle knitting. (Tip of the cap to Katherine Seaton.)

Update (4/01/21): Some department websites also experienced a few changes. (Tip of the cap to Karen Daniels.)

Update (4/02/21): There is also now an article about various spoofs in physics and astronomy.

Update (4/02/21): The Santa Fe Institute finally created a web page for Dr. Ian Malcolm. Life finds a way, so to speak. (It has long been rumored that a certain SFI faculty member provided some inspiration for the fictional scientist. (As a subtle hint, think of The Power Law OF DOOM.)

Update (4/02/21): This fake rejection of Roxy Music fooled me.

"Twitter" in 1803: The Finger of Contempt

Twitter: 1803 style

Now where did I put my 👉Finger of Contempt? https://t.co/Y1yoNVLMtm

(h/t David Blau)

— Mason Porter (@masonporter) March 24, 2021

"Connecting the Dots: Discovering the “Shape” of Data"

Another of my expository papers just came out in final form. Here are some details.

Title: Connecting the Dots: Discovering the “Shape” of Data

Authors: Michelle Feng, Abighail Hickok, Yacoub H. Kureh, Mason A. Porter, and Chad M. Topaz

Abstract: Scientists use a mathematical subject called topology to study the shapes of objects. An important part of topology is counting the number of pieces and the number of holes in an object, and researchers use this information to group objects into different types. For example, a doughnut has the same number of holes and the same number of pieces as a teacup with one handle, but it is different from a ball. In studies that resemble activities like “connect-the-dots,” scientists use ideas from topology to study the “shape” of data. Ideas and methods from topology have been used to study the branching structures of veins in leaves, voting in elections, flight patterns in models of bird flocking, and more.

Here is my tweet, in case you want to share it on social media.

Our introduction to topological data analysis (TDA) for teenagers and preteens is finally out in final form in Frontiers for Young Minds: https://t.co/6KQF2yyJUn@michellehfeng, Abby Hickok, Yacoub Kureh, MAP, & @chadtopaz

(plus special guest appearances by several Pokémon)

— Mason Porter (@masonporter) March 18, 2021

2021 Abel Prize: László Lovász and Avi Wigderson

The 2021 Abel Prize goes to to mathematician László Lovász and computer scientist Avi Wigderson "for their foundational contributions to theoretical computer science and discrete mathematics, and their leading role in shaping them into central fields of modern mathematics."

My Top-5 Emoji: The Power of Positive Thinking

😱🙄🤔🙀🤢

Yup. My top-5 emoji certainly do appear to be my aesthetic.

Because I believe in the power of positive thinking. https://t.co/XizplVRldD

— Mason Porter (@masonporter) March 16, 2021

An Ancient Roman d20

This is very cool!

1st to 3rd century Roman dice. pic.twitter.com/R8ZsgmCJ1S

— The French History Podcast (@FrenchHist) March 15, 2021

Previously, I blogged about an ancient Roman dice tower and an ancient Egyptian d20.

(Tip of the cap to Chris Klausmeier.)

Pro Tip: Life is Short. Be Cat 3.

life is short, be cat3 https://t.co/JmpPWMiQ81

— @jeffbigham (@jeffbigham) March 14, 2021

(Tip of the cap to Yisong Yue.)

An Epic Figure Caption

Wow. Just wow.

Clearly, it needs a figure to go with it.

(Tip of the cap to Jesús Cuevas Maraver, who retweeted this tweet.)

"The Waiting-Time Paradox"

Another of our papers for teens and pre-teens came out in final form today. Here are some details.

Title: The Waiting-Time Paradox

Authors: Naoki Masuda and Mason A. Porter

Abstract: Suppose that you are going to school and arrive at a bus stop. How long do you have to wait before the next bus arrives? Surprisingly, it is longer—possibly much longer—than what you might guess from looking at a bus schedule. This phenomenon, which is called the waiting-time paradox, has a purely mathematical origin. In this article, we explore the waiting-time paradox, explain why it occurs, and discuss some of its implications (beyond the possibility of being late for school).

RIP Dame Fiona Caldicott (1941–2021)

Today I once again have woken up to awful news: Dame Fiona Caldicott, who I know from her role as Principal of Somerville College, died today.

A tribute has been posted on the UK government page.

Here is her Wikipedia entry.

"Disease Detectives: Using Mathematics to Forecast the Spread of Infectious Diseases"

Our article for teens and preteens about modeling the spread of infectious diseases just came out in final form. Here are some details.

Title: Disease Detectives: Using Mathematics to Forecast the Spread of Infectious Diseases

Authors: Heather Z. Brooks, Unchitta Kanjanasaratool, Yacoub H. Kureh, and Mason A. Porter

Abstract: The COVID-19 pandemic has led to significant changes in how people are currently living their lives. To determine how to best reduce the effects of the pandemic and start reopening communities, governments have used mathematical models of the spread of infectious diseases. In this article, we introduce a popular type of mathematical model of disease spread. We discuss how the results of analyzing mathematical models can influence government policies and human behavior, such as encouraging mask wearing and physical distancing to help slow the spread of a disease.

Dodgers Sign Trevor Bauer!

The Dodgers have signed free-agent pitcher Trevor Bauer!

"Models of Continuous-Time Networks with Tie Decay, Diffusion, and Convection"

Another of my papers just came out in final form today. Here are some details.

Title: Models of Continuous-Time Networks with Tie Decay, Diffusion, and Convection

Authors: Xinzhe Zuo and Mason A. Porter

Abstract: The study of temporal networks in discrete time has yielded numerous insights into time-dependent networked systems in a wide variety of applications. However, for many complex systems, it is useful to develop continuous-time models of networks and to compare them to associated discrete models. In this paper, we study several continuous-time network models and examine discrete approximations of them both numerically and analytically. To consider continuous-time networks, we associate each edge in a graph with a time-dependent tie strength that can take continuous non-negative values and decays in time after the most recent interaction. We investigate how the moments of the tie strength evolve with time in several models, and we explore—both numerically and analytically—criteria for the emergence of a giant connected component in some of these models. We also briefly examine the effects of the interaction patterns of continuous-time networks on the contagion dynamics of a susceptible–infected–recovered model of an infectious disease.

"Persistent Homology of Geospatial Data: A Case Study with Voting"

A new paper of mine is out in final form today. Here are some details.

Title: Persistent Homology of Geospatial Data: A Case Study with Voting

Authors: Michelle Feng and Mason A. Porter

Abstract: A crucial step in the analysis of persistent homology is the transformation of data into an appropriate topological object (which, in our case, is a simplicial complex). Software packages for computing persistent homology typically construct Vietoris–Rips or other distance-based simplicial complexes on point clouds because they are relatively easy to compute. We investigate alternative methods of constructing simplicial complexes and the effects of making associated choices during simplicial-complex construction on the output of persistent-homology algorithms. We present two new methods for constructing simplicial complexes from two-dimensional geospatial data (such as maps). We apply these methods to a California precinct-level voting data set, and we thereby demonstrate that our new constructions can capture geometric characteristics that are missed by distancebased constructions. Our new constructions can thus yield more interpretable persistence modules and barcodes for geospatial data. In particular, they are able to distinguish short-persistence features that occur only for a narrow range of distance scales (e.g., voting patterns in densely populated cities) from short-persistence noise by incorporating information about other spatial relationships between regions.

The Baseball Hall of Fame Throws a Shutout

There will be no new 2021 Hall of Famers for Major League Baseball. (Curt Schilling would have made it—and his playing career is clearly of Hall of Fame caliber—but he's a collossal dipshit.) None of the "Veterans Committees" met because of the COVID-19 pandemic, so the 2021 induction ceremony will honor the 2020 inductees (along with the broadcasters and writers, who get particular awards).

Here is a tabulation of the 2021 ballot's winners and losers. As usual, I have been following things very closely on the Hall of Fame tracker, so I already had a very good idea of what was going to transpire (with very good estimates of final vote percentages). Now we also have the precise voting outcomes.

Scott Rolen, Todd Helton, Bill Wagner, Andruw Jones, and Gary Sheffield all mae very large strides.

Players who will debut on the ballot in 2022 include Alex Rodriguez and David Ortiz.

Update (1/27/21): Here is Jay Jaffe's roundup of how each candidate performed in the voting, as well as their prospects for future enshrinement in the Hall of Fame.

Update (1/27/21): Dan Haren has a fantastic sense of humor. Also check out his Twitter handle, which is an homage to the speed of his "fastball". I love it! (Tip of the cap to Jay Jaffe.)

Update (2/01/21): Here are Jay Jaffe's forecasts of the Hall of Fame voting for the next few years.

"Tunable Eigenvector-Based Centralities for Multiplex and Temporal Networks"

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

Title: Tunable Eigenvector-Based Centralities for Multiplex and Temporal Networks

Authors: Dane Taylor, Mason A. Porter, and Peter J. Mucha

RIP Hank Aaron (1934–2021)

Baseball has lost yet another giant: Hank Aaron died this morning, becoming the third baseball Hall of Famer to die this year already. (Baseball lost quite a few Hall of Famers last year, and we're off to a horrible start this year.) You can read about Hank Aaron's many accomplishments in his Wikipedia entry.

(Tip of the cap to Gregg Schneider.)

RIP Don Sutton (1945–2021)

We have lost yet another Hall-of-Fame Dodger: pitcher Don Sutton has died.

(Tip of the cap to Gregg Schneider.)