Tuesday, July 31, 2018
Title: Topological Data Analysis of Continuum Percolation with Disks
Authors: Leo Speidel, Heather A. Harrington, S. Jonathan Chapman, and Mason A. Porter
Abstract: We study continuum percolation with disks, a variant of continuum percolation in two-dimensional Euclidean space, by applying tools from topological data analysis. We interpret each realization of continuum percolation with disks as a topological subspace of [0,1]^2 and investigate its topological features across many realizations. Specifically, we apply persistent homology to investigate topological changes as we vary the number and radius of disks, and we observe evidence that the longest persisting invariant is born at or near the percolation transition.
And to give a story, or at least the hint of the interesting relationship that I sometimes have with typesetters and editors, here is a note that I received from them while we were working on the galley proofs.
Update (8/05/18): A nice way of phrasing things is that we're in a nonassociative situation, and hyphens are a great tool to indicate exactly (and tersely) where the parentheses should be to group terms in a way that renders their meaning unambiguous. (And, naturally, if somebody makes a change in my text that I don't like, my immediate desire is to change it back.)
Monday, July 30, 2018
great meme pic.twitter.com/d5AW6WliTy— Lex Flagel (@flagelbagel) July 29, 2018
(Tip of the cap to Michael Stumpf.)
Also, remember the mantra: FIPO (= "Fuck it. PLOS One.")
Sunday, July 29, 2018
(However, I do wish that the author had used the subjunctive in the 'what if' question.)
"Blueberry Earth" (new paper) by Anders Sandberg: https://t.co/hn1T10qErC— DynamicalSystemsSIAM (@DynamicsSIAM) July 30, 2018
Abstract: 'This paper explores the physics of the what-if question "what if the entire Earth was instantaneously replaced with an equal volume of closely packed, but uncompressed blueberries?" ... '
Update: Here is the first paragraph of the Summary: So, to sum up, to a person standing on the surface of the Earth when it turns into blueberries, the first effect would be a drastic reduction of gravity. Standing on the blueberries might be possible in theory, except that almost immediately they begin to compress rapidly and air starts erupting everywhere. The effect is basically the worst earthquake ever, and it keeps on going until everything has fallen 715 km. While this is going on everything heats up drastically until the entire environment is boiling jam and steam. The end result is a world that has a steam atmosphere covering an ocean of jam on top of warm blueberry granita.
Saturday, July 28, 2018
My biggest weakness pic.twitter.com/WvIeVPqoTl— Toby Hendy (@TobyHendy) July 28, 2018
(1) One of the main purposes of taking complex analysis is learning how to properly write Greek letters.
(2) I specifically practiced how to draw \xi when I took complex analysis.
(Tip of the cap to Dave Richeson.)
"Where did the authors smurf up this idea?"
"This figure is smurfed."
"The authors might want to consider smurfing the abstract a little bit more."
Update: I know; I know: this isn't very smurfy of me.
Update 2: "A total smurf job."
Tuesday, July 24, 2018
Here is a quote from the abstract: In the limit of low Mason number, the dynamical system admits a periodic solution in which the magnetic moment of the swimmer tends to align with the magnetic field. In the limit of large Mason number, the magnetic moment tends to align with the average magnetic field, which is parallel to the axis of rotation.
I operate in the limit of low Mason number, and I claim that this limit is singular.
Monday, July 23, 2018
Moreover: Hell yes!
This is a major issue for interdisciplinary students and postdocs (and more senior scholars), and this is a very helpful paper for them to read as they navigate these waters. I also really like the fact that Ray included two different versions of a 'Results' section in his opinion article.
Title: Quasiperiodic Granular Chains and Hofstadter Butterflies
Authors: Alejandro J. Martínez, Mason A. Porter, and Panayotis G. Kevrekidis
Abstract: We study quasiperiodicity-induced localization of waves in strongly precompressed granular chains. We propose three different set-ups, inspired by the Aubry–André (AA) model, of quasiperiodic chains; and we use these models to compare the effects of on-site and off-site quasiperiodicity in nonlinear lattices. When there is purely on-site quasiperiodicity, which we implement in two different ways, we show for a chain of spherical particles that there is a localization transition (as in the original AA model). However, we observe no localization transition in a chain of cylindrical particles in which we incorporate quasiperiodicity in the distribution of contact angles between adjacent cylinders by making the angle periodicity incommensurate with that of the chain. For each of our three models, we compute the Hofstadter spectrum and the associated Minkowski–Bouligand fractal dimension, and we demonstrate that the fractal dimension decreases as one approaches the localization transition (when it exists). We also show, using the chain of cylinders as an example, how to recover the Hofstadter spectrum from the system dynamics. Finally, in a suite of numerical computations, we demonstrate localization and also that there exist regimes of ballistic, superdiffusive, diffusive and subdiffusive transport. Our models provide a flexible set of systems to study quasiperiodicity-induced analogues of Anderson phenomena in granular chains that one can tune controllably from weakly to strongly nonlinear regimes.
This article is part of the theme issue ‘Nonlinear energy transfer in dynamical and acoustical systems’.
Sunday, July 22, 2018
(Also, I am highly amused!)
Money quote from the programming language's GitHub page:
"Rockstar is a dynamically typed Turing-complete programming language.
Rockstar is designed for creating computer programs that are also song lyrics, and is heavily influenced by the lyrical conventions of 1980s hard rock and power ballads."
Update (7/23/18): I wrote a blurb about Rockstar for the Improbable Research blog.
Saturday, July 21, 2018
I love this.— Jim Bliss (@JimBliss23) July 21, 2018
When the Far Side came out in 1982, paleontologists realised they'd never actually named that part of a stegosaurus and began using the term informally. And now, 36 years later, if you type "Thagomizer" into a search engine... pic.twitter.com/pMDYoOrT8d
(Tip of the cap to C E Watkins.)
Friday, July 20, 2018
“Mason’s knowledge was as faded as the book from the British sun.”— Mason Porter (@masonporter) July 20, 2018
Proof of existence of sunlight in England. :) pic.twitter.com/d7z7YbgLAy
Thursday, July 19, 2018
Wednesday, July 18, 2018
Quoting from the abstract: "The model is highly versatile, as the motion of the walkers can be fed on topological properties of the nodes..."
Comment: But don't feed them after midnight.
With Corey Seager out for the year, having Machado to play shortstop the rest of the year is most excellent indeed!
Tuesday, July 17, 2018
Monday, July 16, 2018
Friday, July 13, 2018
Wednesday, July 11, 2018
On some website pop-up menus, there are so many possible titles that it's really hard to choose the most appropriate one to use.— Mason Porter (@masonporter) July 11, 2018
(Click to see the full list. Some selections are cut off.) pic.twitter.com/mRgnGMMxkd
Now we just need real-life Sinai and stadium billiards (and, of course, a mushroom billiard, to make Lyonia happy).
Unveiling the elliptical pool table designed by @AlexBellos captured local imagination: https://t.co/BlSu2PQ95m , https://t.co/bPVtkHF6Bh , https://t.co/MPAdoNv8pU . 1st in North America, 3rd in the world. Planning formal event at @WaterlooMath in the fall.— Stephen M. Watt (@Stephen_Watt) July 11, 2018
(Tip of the cap to Alex Bellos.)
Update: The table pictured in the article appears to be a circle, rather than a more general ellipse.
I have never laughed out loud reading a journal article, until I saw this little gem from Lakens, Scheel, and Isager (2018). Talk about total transparency!https://t.co/4eAsdvFbMI pic.twitter.com/OsVUTYf71e— Stacy T. Shaw 🇭🇷 (@StacyTShaw) July 11, 2018
Tuesday, July 10, 2018
Ukrainian photographer Vyacheslav Mishchenko catches these unbelievably stunning up-close photographs of snails pic.twitter.com/Lhgj2zcx6S— Life on Earth 🌴 (@planetepics) July 10, 2018
(Tip of the cap to Invisible Scientist.)
Thursday, July 05, 2018
Interested in #MASON for agent-based modeling? Check out our new paper: The MASON Simulation Toolkit: Past, Present, and Future. More details @ https://t.co/II9TFkQ7SU The link also points you to a lot of new demo models for GIS & ABM pic.twitter.com/8OnbC5ckud— Andrew Crooks (@AndyCrooks) July 4, 2018
(Tip of the cap to Sang Hoon Lee.)
Tuesday, July 03, 2018
And now, on this occasion, even the band itself accidentally tagged me in their Facebook post instead of themselves!
Rock on! ("Folk on?")
One of these years, I seriously need to crash one of their shows with a short mathematics lecture.