Sunday, December 31, 2017
I'm pretty sure that Big Audio Dynamite was referring to PT Symmetry in one of their songs. :)
When scientists give keynote talks at conferences, we ought to play personal walk-up music (a la professional wrestling) to set the mood.— Mason Porter (@masonporter) December 31, 2017
(On days that I particularly want to empathize with the audience, I might choose "What Have I Done to Deserve This?" by the Pet Shop Boys.)
(This is also probably the one that Squeeze was singing about. ;) )
The Timewheel in Budapest is possibly the world's largest hourglass, and it needs to be reset every New Year's Eve. Each December 31, a team of four people uses steel cables to rotate it, preparing the monstrosity for another year pic.twitter.com/gpjg8pqK8g— Atlas Obscura (@atlasobscura) December 31, 2017
(Tip of the cap to Karen Daniels.)
Saturday, December 30, 2017
The Lucky Knot bridge in Changsha, China is a topologically fascinating structure. It's effectively three bridges woven into one and it has no beginning and no end https://t.co/uywNdJgMoF pic.twitter.com/PbNsMdtINA— Massimo (@Rainmaker1973) December 30, 2017
(Tip of the cap to Henry Segerman.)
Friday, December 29, 2017
Here is a choice quote: "The model of social licking among cows best predicts, as a target, cosponsorship among U.S. senators in the Ninety-Third Congress."
Note: The sentence is highly amusing, and I understand it in the context of the paper, but (1) the term "predicts" is misleading with respect to the analysis performed, and (2) one of course has to ask how the result changes if a different sample of networks is used. There has, of course, been a bunch of work (including by my collaborators and me) in the last decade and a half on examining similarities among networks.
(Tip of the cap to Brian Keegan.)
Monday, December 25, 2017
ICYMI here are photos of my #microbiology #Chess set (composed with lots of help from the twitter community). The pic of 4 pawns shows samples of finishes I am considering. Would love to hear comments! https://t.co/LcU2TPeyER pic.twitter.com/kYXd266Ifr— IAmSciArt: Chris Taylor (@IAmSciArt) December 25, 2017
(Tip of the cap to Paul Macklin.)
Saturday, December 23, 2017
My favorite part of this visualization is for a trip to Africa, as the rapid change in colors once you arrive on the content very nicely and tersely tells you something about the change in transportation mode (and topography, etc.).
I'm sure there are plenty of other similarly interesting things if one looks closely.
This map shows travel time from London in 1881 pic.twitter.com/CbMNxcDEpu— Conrad Hackett (@conradhackett) December 23, 2017
(Tip of the cap to Sydney Padua.)
Wednesday, December 20, 2017
With Christmas just around the corner, it's time to play the academia bingo. Who's going to win first this year? pic.twitter.com/UMVLgYJNBT— Sylvain ❄️👨🏻🎓 (@DevilleSy) December 20, 2017
(Tip of the cap to Sabine Hossenfelder.)
Tuesday, December 19, 2017
In the Wikipedia entry, I am amused by the deadpan nature of the information box in the upper-right corner.
(And, in case you're wondering, there are really good reasons to study genetically unusual orientations like this.)
Sunday, December 17, 2017
I figure that I should get practice at censoring my scholarly research, which naturally is neither evidence-based nor science-based (even when I publish it in a journal called "Archrival-of-Nature Advances").— Mason Porter (@masonporter) December 17, 2017
(Where is George Carlin when we need him?)#CDC7words pic.twitter.com/WvNuUSpKn5
Yes, under a suitable approximation, it appears that you can gave a soliton description of certain types of collective behavior in sheep.
Below are the title and abstract. (I was hoping for an intriguing picture from the experimental data, but alas the visuals in this article are run-of-the-mill.) In other contexts, when sheep (a type of 'active matter') behave like a fluid, there are obvious jokes to tell about "shearing instabilities".
Title: Sheep Soliton
Abstract: Monitoring small groups of sheep in spontaneous evolution in the field, we decipher behavioral rules that sheep follow at the individual scale in order to sustain collective motion. Individuals alternate grazing mode at null speed and moving mode at walking speed, so cohesive motion stems from synchronizing when they decide to switch between the two modes. We propose a model for the individual decision making process and parametrize it from data. Next, we translate this individual-based model into its density-flow equations counterpart, considering 1D-motion along the group trajectory. Numerical solving these equations display a solitary wave propagating at constant speed. Coupling individual and collective levels, groups motion can then be seen as a wave propagating at some fraction of the individual walking speed even though each individual is at any moment either stopped or walking. Considering the minimal model embedded in these equations, we show analytically that it has the Korteweg-De Vries (KdV) Soliton as a steady regime solution. This soliton emerges from the non linear coupling of start/stop individual decisions which compensate exactly for diffusion and promotes a steady ratio of walking / stopped individuals, which in turn determines the wave speed. The convergence to only one solitary wave from any initial condition, and which can recover from perturbation, gives a high robustness to this biological system.
Update (12/18/17): I forgot to make a snarky remark along the following lines: One first needs to do a continuum approximation to get a relevant nonlinear wave equation.
For the actual sheep, one would think that there is some energy shedding as the wave propagates. :)
Saturday, December 16, 2017
First, it's interesting to read about the origin of blue books. Here is part of it:
Michele V. Cloonan has a theory. As chairwoman of UCLA's Department of Library and Information Science, she believes they evolved from the cheaply produced, paper-covered school books, almanacs and novels known as the bibliotheque bleue, or blue library, in 18th century France.
Before the invention of chlorine bleach in 1774 revolutionized paper production, white books had to be made from white rags. Blue books came from blue rags, often from the old clothes of sailors. Blue paper was the cheap stuff, used for the covers of throwaway books.
And, earlier in the article, we have this excerpt: "Well, those exam booklets, after torturing college students with writer's cramp for almost 150 years, may finally be on the way out.
They're being replaced, of course, by the floppy disk." (LOL!)
And another beauty: "Equipped with the same level of encryption security used by the Federal Reserve Bank, the software makes cheating impossible." (LOL!)
And, of course, the blue book also ought to have a snake on it...
(Tip of the cap to @mathematicsprof.)
Friday, December 15, 2017
Quoting from the abstract: In this paper we examine the feasibility for a Proclaimer, modelled on the average Scottish male human, to walk such distances without food. It was found that a Proclaimer, would lose 1.3% of its body mass after 500 miles and 2.8% after 500 more.
That seems like a rather significant underestimate of how much body mass the Proclaimer would lose.
(Tip of the cap to Sabine Hossenfelder.)
Wednesday, December 13, 2017
My students have their ODE (ordinary differential equation) final tomorrow morning, and I’ve got the perfect shirt to wear for the occasion: "In phase space, no one can hear you scream." pic.twitter.com/79hoysL80A— Mason Porter (@masonporter) December 14, 2017
For the second year in a row, Depeche Mode was nominated but didn't get in. Maybe they'll make it next year?
Tuesday, December 12, 2017
I am amused.
Sort of a fun lesson in compound interest, I guess. Roxanne by the Police, but every time they say "Roxanne" the song gets 5% faster :) https://t.co/oAUlEt2HDv— Mike Lawler (@mikeandallie) December 12, 2017
(Tip of the cap to Card Colm Mulcahy.)
As a kid, I didn't think spinning dreidels the normal way was sufficiently interesting, so I cultivated spinning them upside-down.
I was able to download it for free at UCLA, so this should also be the case at other universities with similar deals with the publisher (Springer).
Monday, December 11, 2017
(Tip of the cap to Matthew Holden.)
Sunday, December 10, 2017
Alan Trammell is richly deserving of this honor and should have made it a long time ago, but I'm annoyed (though not surprised) that Jack Morris made it. Jack Morris doesn't belong in the Hall of Fame. Once again, Marvin Miller was not elected to the Hall of Fame, and he too should have been elected a long time ago.
The committee had 16 members, and people needed to be named on at least 12 ballots to make the Hall of Fame. Morris was named on 14 ballots, and Trammell was named on 13 of them. Miller has missed by 1 vote before, so I wonder how many ballots he was on this time. (Members of the committee could vote for a maximum of 4 players.)
The choice of players to be considered by the Modern Era Committee was a bit strange, and there were various people who were not considered this year who I hope will get consideration by this committee in the future.
Update: Some of the vote totals are listed in this article. Ted Simmons missed by just 1 vote, and Marvin Miller missed election by 5 votes. As it turns out, Trammell and Morris are the first living former players elected by one of baseball's Veterans Committees (under various names and guises) in 16 years. It is true that the 1980s are woefully underrepresented in Cooperstown, though Morris remains a weak selection.
Saturday, December 09, 2017
Also, take a look at the very short video.
(Tip of the cap to Andrea Welsh.)
Friday, December 08, 2017
For the story, see this Quora answer
(Tip of the cap to Joel Miller.)
Apparently, one can never have too many characters in a login ID, especially a prime one.
Here is a screen capture so that you can see this in full glory.
Protip: When doing a big treason, don't track changes in Microsoft Word. https://t.co/DMgE6cdAWM— Ben Collins (@oneunderscore__) December 8, 2017
(Tip of the cap to Francis Su.)
Thursday, December 07, 2017
Quoting the Wikipedia entry: Marvin Hewitt (born 1922) was an American impostor who became, among other things, a university physics professor.
Hewitt was a high school drop-out with no qualifications who wanted to become an academic. He always used names and identities of real-life people in his impostures. He later claimed that he had a "compulsion to teach".
This reminds me of the fictitious movie critic David Manning. (And, of course, there is the story of Sidd Finch.)
(Tips of the cap to MathFeed and Boing Boing.)
For those of you wondering, I am safe. I have a utilitarian suitcase packed in case I need to leave home in a hurry, but things look clear for my place right now and UCLA is somewhat more normal today (though classes are cancelled again today).
The Hellscape video is really impressive!
Not the typical morning commute... pic.twitter.com/kJIOQeqsIK— A. Mutzabaugh CMT (@WLV_investor) December 6, 2017
Wednesday, December 06, 2017
"In this paper, I will present a shadowy flight into the dangerous world of a function that does not exist."
Coming in 2018 to a university near you.
Here is the original quote (which you can find on this page): Narrator: Knight Rider, a shadowy flight into the dangerous world of a man who does not exist. Michael Knight, a young loner on a crusade to champion the cause of the innocent, the helpless, the powerless, in a world of criminals who operate above the law.
Tuesday, December 05, 2017
Title: Random Walks and Diffusion on Networks
Authors: Naoki Masuda, Mason A. Porter, and Renaud Lambiotte
Abstract: Random walks are ubiquitous in the sciences, and they are interesting from both theoretical and practical perspectives. They are one of the most fundamental types of stochastic processes; can be used to model numerous phenomena, including diffusion, interactions, and opinions among humans and animals; and can be used to extract information about important entities or dense groups of entities in a network. Random walks have been studied for many decades on both regular lattices and (especially in the last couple of decades) on networks with a variety of structures. In the present article, we survey the theory and applications of random walks on networks, restricting ourselves to simple cases of single and non-adaptive random walkers. We distinguish three main types of random walks: discrete-time random walks, node-centric continuous-time random walks, and edge-centric continuous-time random walks. We first briefly survey random walks on a line, and then we consider random walks on various types of networks. We extensively discuss applications of random walks, including ranking of nodes (e.g., PageRank), community detection, respondent-driven sampling, and opinion models such as voter models.
Special Guest Star: A very weary random walker
Sunday, December 03, 2017
Notice the Nintendo Power Glove in the picture...
(I never bought the Power Glove, but I did buy a U-Force. I liked the idea, but the technology wasn't yet ready for practical use. Just image me playing Galaga by waving my hands back and forth. That was just about the only game with simple enough controls that the controller was even usable, and even then it was much harder than using something conventional.)
Is anybody able to tell what the portable game system under the yellow cans is?
The first thing that came to mind when I saw the post was New Coke, of course.
I should go to this exhibit!
Saturday, December 02, 2017
Every year, when I go through these dossiers, I am reminded at how poorly I fit into the two-digit MSC (Mathematics Subject Classification) scheme, as I my work is split across many of them without any obvious single home. Nonlinear and complex systems (and networks) shows up in the depths of many of the two-digit numbers, without a single obvious parental home. It is very easy for people who work on these (and other) kinds of interdisciplinary topics to fall into the cracks, and the extant MSC scheme and the extreme reliance upon it exacerbates this problem. It needs a revamping.
Simply put, the MSC is very poorly suited for classifying applied mathematicians. And because people have to use an American Mathematical Society (AMS) cover sheet when applying to US math departments and they also have to list MSC numbers on that cover sheet, people who work in such areas are hurt very severely on the academic job market for postdocs and junior faculty positions.
In my early applications, I put the two-digit number 37 ("Dynamical systems and ergodic theory") as my main subject area, but my application then often ended up in the hands of people proving theorems in those areas, and as a dirty applied mathematician I was often sunk at that point. I think that listing 37 in this way was a very serious mistake on my part. Things of course have worked out well in the end — yay, survivorship bias! — and working in between fields is far more fun and rewarding than not doing it, but it can also create an extra hurdle when on the job market, especially because of the major role that the MSC ontology plays in how applicant dossiers are doled out to different people to evaluate (and thus in who is reading the dossier). Thankfully, if it does work out, there is also the potential of benefits from the proverbial first-mover scientific advantage (or, to generalize, an early-mover scientific advantage), but first one has to get to that point and there are extra hurdles in the way.
While now it's more of a cosmetic thing for my personal situation (though other interdisciplinary people have to deal with this serious issue when on the market), this was very frustrating when I was applying for postdocs and my initial faculty jobs, as my application could so easily get siphoned off into the wrong spots and not find the right ones, purely as a result of the MSC ontology, which I was required to use in applications to US math departments as part of the AMS cover sheet.
Update: To illustrate my subject areas, take a look at my MathSciNet listing, although it only indexes a small subset of my papers and it captures a vanishingly small (well, not literally, but take a look on Google Scholar, and you will see that it is a factor of more than 50) fraction of my citations. I don't have a home within the MSC ontology, and most of the two-digit identifiers in which my work is best represented are still in 2017 often not construed to be areas of applied mathematics. Many people are open-minded, but many others are not, and the issues with the current MSC contribute seriously to this problem.
Update: By the way, as of right now, Google Scholar registers 10146 citations to my work. Meanwhile, MathSciNet registers 184 citations. These numbers differ by a factor of approximately 55.14.