Tuesday, April 06, 2021
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.
Sunday, April 04, 2021
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.— Mason Porter (@masonporter) April 4, 2021
PSA 2: Survivorship bias is a good thing to remember. pic.twitter.com/XaPk2Eoo0f
Wednesday, March 31, 2021
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.
Wednesday, March 24, 2021
Wednesday, March 17, 2021
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— Mason Porter (@masonporter) March 18, 2021
(plus special guest appearances by several Pokémon)
Tuesday, March 16, 2021
😱🙄🤔🙀🤢— Mason Porter (@masonporter) March 16, 2021
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
Monday, March 15, 2021
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.)