Sunday, December 31, 2017

Tales from the ArXiv: Paper Updating Edition

Do you think the authors will update their paper again soon?

"Party-Time Symmetry"

Note: "PT Symmetry" stands for "Parity–Time Symmetry", not "Party-Time Symmetry", unless you're tired, in which case the latter may be the way that you read the abstracts of certain papers.

I'm pretty sure that Big Audio Dynamite was referring to PT Symmetry in one of their songs. :)

Walk-Up Music for Keynote Talks by Scientists

I've expressed this sentiment before, but let me reiterate it before the year is over.

An Annual Hourglass

This is really cool!

(This is also probably the one that Squeeze was singing about. ;) )

(Tip of the cap to Karen Daniels.)

Saturday, December 30, 2017

A Knotty Bridge

This bridge is so awesome!

(Tip of the cap to Henry Segerman.)

Friday, December 29, 2017

United States Senators and Social Licking Among Cows

I am amused by this 2002 paper by Faust and Skvoretz, called Comparing Networks Across Space and Time, Size and Species.

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

Microbiology Chess Set

This microbiology chess set is really cool!

(Tip of the cap to Paul Macklin.)

Saturday, December 23, 2017

Travel Time from London in 1881

This is really cool!

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.

(Tip of the cap to Sydney Padua.)

Wednesday, December 20, 2017

Academic X-Mas Bingo Board

I do very well on this Bingo board even without X-Mas!

(Tip of the cap to Sabine Hossenfelder.)

Tuesday, December 19, 2017

An Oxford Comma's Twitter Account

I should have known that an 'Oxford Comma' Twitter account exists. It's pretty funny.

(Tip of the cap to Kerstin Nordstrom.)

Jeremy, the Left-Coiled Snail

I'm not sure how I managed to miss this story before, but Jeremy the Left-Coiled Snail (who died in October, at the ripe old age of 2 or so), who was named after Jeremy Corbyn (on account of his being a 'lefty' snail), had a chance to shine in the spotlight earlier this year. And he even had scientists to help him with his sex life, though all of his 56 children ended up being righties.

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

Practicing for Scholarly Censorship in Modern Dystopian America

Tales from the ArXiv: "Sheep Soliton"

You had me at "sheep soliton".

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

A 1999 Death Knell for Examination "Blue Books"

This article from 1999 is "awesome" in historical context.

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

The Physics of a "Proclaimer" Walking 500 Miles, and then Attempting to Walk 500 More

I suppose this was inevitable, but there is now a paper on the physics of a "Proclaimer" walking 500 miles and then attempting to walk 500 more.

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

In Phase Space, No One Can Hear You Scream.

2018 Rock & Roll Hall of Fame Inductees

The 2018 inductees into the Rock & Roll Hall of Fame are Bon Jovi, The Cars (yay!), Dire Straits (yay!), The Moody Blues, and Nina Simone. Additionally, Sister Rosetta Tharpe received an award for early influence.

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

Roxanne, Accelerated

This appeals to me for various reasons. :)

I am amused.

(Tip of the cap to Card Colm Mulcahy.)

Upside-Down Dreidel Spinning

I prefer upside-down dreidel spinning. (It's in the wrist.)

As a kid, I didn't think spinning dreidels the normal way was sufficiently interesting, so I cultivated spinning them upside-down.

New Book: "Women in Mathematics"

The book Women in Mathematics (subtitled "Celebrating the Centennial of the Mathematical Association of America") is now available.

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

Natural Space Invaders

Check our this natural game of Space Invaders!

(Tip of the cap to Matthew Holden.)

Sunday, December 10, 2017

Alan Trammell and Jack Morris Elected to Baseball Hall of Fame by the Modern Era Committee!

Alan Trammell and Jack Morris were elected to Major League Baseball's Hall of Fame by the Modern Era Committee (one of the modern incarnations of the Veterans Committee).

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

Ordering Dice by Stirring Them (Not Shaking Them)

As stated in the Physics Focus blurb about this article, "A jumble of thousands of cubic dice, agitated by an oscillating rotation, can rapidly become completely ordered, a result that is hard to produce with more conventional shaking."

Also, take a look at the very short video.

Very cool!

(Tip of the cap to Andrea Welsh.)

'Proof by Borges'

Pro Tip: 'Proof by Borges' also works for reviewing papers and grant proposals.

(These reviews are basically book reports anyway.)

Friday, December 08, 2017

Almost 11 Years in Review

11 years passed between this paper's initial submission and its final acceptance.

For the story, see this Quora answer

(Tip of the cap to Joel Miller.)

A Very Long Login ID

For reasons that I can't fathom, the staff member for the journal decided to give us a login ID with 71 characters.

Apparently, one can never have too many characters in a login ID, especially a prime one.

Be Careful with the 'Track Changes' Option

Here is a screen capture so that you can see this in full glory.

(Tip of the cap to Francis Su.)

Curvature Blindness Illusion

This is amazing!

Thursday, December 07, 2017

An Imposter Physics Professor with a "Compulsion to Teach"

The case of former physics professor Marvin Hewitt is a weird one.

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.[1] 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.)

'Thoughts and Prayers' and the Los Angeles Fires

Can 'thoughts and prayers' be exchanged for bitcoins? Asking for a friend.

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!

Wednesday, December 06, 2017

Knight Rider and the Non-Existence of Functions

I think that some mathematics presentations would benefit from an obvious allusion to Night Rider (where you need to imagine the proper word emphasis from the TV series).

"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

"Make Your Own G.O.P. Tax Bill"

In case you ever want to make your own G.O.P. tax bill, here is how.

"Random Walks and Diffusion on Networks"

Our review article on random walks on networks has its final coordinates. Here are the details.

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

The Museum of Failure

There is a temporary exhibit in Los Angeles called The Museum of Failure.

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

Claim: The Mathematics Subject Classification (MSC) Scheme Needs a Revamping

It's getting to be that time of year: it's the season to look at the dossiers of job applicants.

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.

Friday, December 01, 2017

Baseball's 2017 Comeback Players of the Year

Major League Baseball's Comeback Players of the Year were announced today. Mike Moustakas of the Kansas City Royals is the American League winner, and Greg Holland of the Colorado Rockies is the National League winner.

Thursday, November 30, 2017

The Largest Prime Number in a Song

(Tip of the cap to MathFeed.)

Tales from the ArXiv: Visibility of Women in Academic Seminars

This paper presents the results of research on visibility of women in academic seminar question and answer period. Some takeaways include the length of the Q & A period and who asks the first post-seminar question.

Take a look at the data and suggestions, and see what you think.

Tuesday, November 28, 2017

RIP Joel Franklin (1930–2017)

Joel Franklin, one of my favorite Caltech professors, died 11 days ago. Caltech posted an obituary yesterday.

During Junior year, a bunch of us took Joel Franklin's AMa 153 course on stochastic processes (especially during the first term, which could be used to satisfy Caltech's probability and statistics requirement). I also took Joel Franklin's linear programming course during my senior year.

Let's start with a story from Steve Van Hooser: "We'll start with the best story. Steven Michael, going through his material at the end of the term, found a homework set for Stochastic Processes that he forgot to turn in. He went to Franklin's office, and described his mistake. Franklin merely said: "Well..did you do it?" And Steven said yes. " it right?" And Steven said he thought so. So Franklin wrote a handwritten message to the registrar saying something to the effect of "Dear Judith [Goodstein], please change Steven's grade in AMa153 to an A. -J.N. Franklin". And that was that."

We invited Joel Franklin as a dinner guest in Lloyd House a couple of times, and Steve recounted a couple of those in his Facebook post.

Additionally, in Legends of Caltech III, we included a story filled with quotes from Joel Franklin. They give a good idea of the Joel Franklin experience, and this compilation from Jason Kastner (which I remember finding on his website at some point) inspired me to compile quotations from other professors who uttered many witticisms. Here is a version of the story from a .pdf of a pageproof version of the book. (I am pretty sure the typo in "the Navy way" definition was corrected before the final version.)

When I was in graduate school, I suggested Joel Franklin's book Methods of Mathematical Economics for the SIAM "Classics in Applied Mathematics" series, and thankfully that worked out. (Franklin originally published it with Springer, but there was some sort of falling out, and for a while the only way to get a "new" copy was as printed notes.)

In his honor, today we should all do something in "the Navy way".

(Tip of the cap to Steve Van Hooser, who was part of our AMa 153 contingent.)

The Mathematics of Marbling

Aubrey Jaffer has done some really cool mathematical art in the mathematics of marbling. Also see the art in other parts of the website. Very cool!

(Tip of the cap to Alex Bateman.)

Tritares: Generalizing Guitars to Star-Graph Topologies

In case you want to generalize guitars using ideas from star graphs, you can consider tritares (and generalizations from its Y-shape to star graphs of Stieltjes strings).

I saw a picture of a tritare from the following talk: Star graphs of Stieltjes strings, by Christiane Tretter (Bern, SUI)

You can read about the tritare at this article as well as this one.

They tried playing the sound (from an online video) before the first talk this morning, and it hurt.

Monday, November 27, 2017

The Hungry Hungry Hippos Theory of Science Funding

The analogy definitely works...

This game looks like the classic Hungry Hungry Hippos but with different "graphics". (The version I had as a kid was not long after it first came out. I am pretty sure that I know where it is in my parents' house — which is a bit rare for my childhood stuff.)

(Tip of the cap to Kevin O'Keeffe.)

Sunday, November 26, 2017

Romans and the d12 Gaming System

It was clearly for the d12 system of role-playing games. :)

(Tip of the cap to GrrlScientist.)

Saturday, November 25, 2017

What Happens in Bielefeld Stays in Bielefeld

I am off to a conference in Bielefeld, in search of an existence proof!

Grammatical Paraphernalia and the Original Guardian

This — the debut of The Guardian — is interesting for many reasons, including its comma density and other grammatical paraphernalia.

(Tip of the cap to Sam Howison.)

Monday, November 20, 2017

Congratulations to Dr. Paul Brodersen

My D.Phil. student Dr. Paul Brodersen has officially finished his corrections for his thesis and has now officially graduated. His thesis, which was supervised jointly by Colin Akerman of Pharmacology and me, is called Relating Neuronal Coding to Network Architecture.


Friday, November 17, 2017

"Is it Possible to Take All Words Out of Mathematical Expressions?"

I just read a really cool new article in American Scientist about terminology, symbolic, and pictorial developments in mathematics.

Matrices, chaos, and birdtracks all make an appearance. The article also includes appearances by Gibbs, Silvester, Yorke, Cvitanović, and others.

Thursday, November 16, 2017

Giancarlo Stanton and José Altuve Win Most Valuable Player Awards

Major League Baseball has announced the winners of the 2017 Most Valuable Player (MVP) awards: José Altuve of the Houston Astros won handily in the American League over Aaron Judge of the Yankees, and Giancarlo Stanton of the Marlins edges out Joey Votto of the Reds by 2 points (in the 4th-closest MVP voting in Baseball history). Take a look at the vote totals for the American League and National League.

I am pleasantly surprised that Votto finished so close to Stanton. The consensus would be that it would not be this close (and Votto already was guaranteed to finish higher in the ranking than expected even when the top three were announced), though in my opinion Votto should have won.

The National League MVP was the one where it was hardest to predict who would win, and the close vote total at the top reflects that.

What Happens in Ithaca Stays in Ithaca (2017 Edition)

I am off to Cornell to give this year's Notable Alum lecture in the Center for Applied Mathematics (the program from which I got my PhD)!

It's my first visit to Cornell in more than 4.5 years and only my second visit since I graduated!

I am at the airport way too bloody early. All of the men's bathrooms in this terminal are locked.

Wednesday, November 15, 2017

Corey Kluber and Max Scherzer Win Cy Young Awards

As expected, Corey Kluber of the Cleveland Indians won the American League Cy Young Award. Also as expected, Max Scherzer of the Washington Nationals won the National League Cy Young Award.

In the National League, the Dodgers' Clayton Kershaw finished 2nd. Kershaw has ranked as follows in the last 7 National League Cy Young Award ballots: 1, 2, 1, 1, 3, 5, 2. Wow! That gives Kershaw 4.56 Cy Young shares, which is 4th all time. (You can see the Cy Young share rankings on this page, though at the time of this writing, the page does not yet incorporate today's results.) Kershaw is going to sail into the Hall of Fame, and Max Scherzer is making quite a case for himself as well.

The two main articles to which I linked include the entire rankings and vote totals for this year's Cy Young Awards.

Things for Mathematicians to be Grateful For

Today's entry in the blog Math with Bad Drawings has some brilliant pictures!

It's really hard to pick a favorite. Maybe the one with the analyst or the one with the belated referee report?

Tuesday, November 14, 2017

Torey Lovullo and Paul Molitor Win Manager of the Year Awards

Torey Lovullo of the Arizona Diamondbacks and Paul Molitor of the Minnesota Twins have been named the 2017 Managers of the Year in the National League and American League, respectively. The Diamondbacks and Twins saw the two largest win increases from 2016; this is often a good recipe for who will be named Manager of the Year. In the National League, Dave Roberts of the Dodgers finished second.

Monday, November 13, 2017

Congratulations to Dr. Birgit Brüggemeier!

Congratulations to my D.Phil. student, Dr. Birgit Brüggemeier (who I cosupervised with Stephen Goodwin of the Department of Physiology, Anatomy, and Genetics) for officially completing her D.Phil at University of Oxford. Her thesis, in corrected form, has officially been approved.

The title of Birgit's thesis is "Is Drosophila song amplitude structure a communication signal?".

Aaron Judge and Cody Bellinger are the Rookies of the Year!

Unsurprisingly, Aaron Judge of the Yankees has been named (unanimously) as this year's Rookie of the Year (ROY) in the American League. Also unsurprisingly, Cody Bellinger of the Dodgers has been named (also unanimously) as the National League ROY. The selections were not surprising, and the fact that they were unanimous is also not surprising. Judge and Bellinger were the clearly dominant rookies in their respective leagues.

Update: The links above show the rankings and vote totals for both awards.

Awesome Trippy Architecture

Wow! These are really cool!

(Tip of the cap to Sydney Padua.)

Sunday, November 12, 2017

German Caricature Map from 1914

This German caricature map from the onset of World War I is fancy.

(Tip of the cap to I Fucking Love Maps.)

2017 Silver Slugger Awards

The 2017 Silver Slugger Awards, which purport to indicate the best hitter at each position in each league, have been announced.

Saturday, November 11, 2017

Wednesday, November 08, 2017

Tales from the ArXiv: How to Make Any Shape "Zippable"

Awesome pillows await!

(Tip of the cap to Henry Segerman.)

Headline of the Day: "Sheep Learn to Recognise Celebrity Faces from Different Angles"

This applies to all kinds of sheep. :P

(This is one of the most brilliant headlines I have ever seen, especially with the accompanying picture.)

2017 Gold Glove Awards

Baseball's 2017 Gold Glove Awards have been announced.

Tuesday, November 07, 2017

RIP Roy Halladay (1977–2017)

Ugh. Former Major League ace pitcher Roy Halladay has died in a plane crash.

Halladay will make the Hall of Fame — though it may take a bit of time because of his relatively low win total, as many voters seem to have trouble adjusting win totals for era — though sadly he won't be around to enjoy it.

Sunday, November 05, 2017

A Phase Transitions in the New York Times Front-Page Picture Density?

Visually, it seems like it resembles a phase transition (watch how suddenly the density changes), so I expect that one could see that arise in a simple model.

(Tip of the cap to Sabine Hossenfelder.)

Saturday, November 04, 2017

What Happens in Barcelona Stays in Barcelona

I am off to Barcelona for the Macfang workshop.

"Macfang" stands for "Mapping Complexity Foundations and Applications of Network Geometry". It is a conference on network geometry, spatial networks (both explicit and latent), and related topics.

At some point, I'll even prepare the slides for my talk.

Friday, November 03, 2017

Quote of the Day: Conservation of Pain

Me, to my (graduate-level) ODE students in office hours this afternoon:

"The amount of pain is conserved.

[nontrivial pause, while I think about the accuracy of my statement]

(Well, technically, the amount of pain is non-decreasing.)"

Update: This quote was quite a doozy. It's the type of quote that, when my professors accidentally backed into them, I liked to write them down for posterity.

Wednesday, November 01, 2017

Houston Astros Win 2017 World Series

Congratulations to the Houston Astros, an excellent team, a worthy opponent, and World Series champions for the first time in their 56-year franchise history.

As for us, this was our first World Series in 29 years. It was fun to get back (and get all the way to Game 7) after so many years. Hopefully we'll be back next year and try again.

This World Series had a lot of record-breaking. (Cody Bellinger's strike-out record was a particularly annoying one.)

This year was one of those rare years in which the two teams that I believe to be the two best faced off against each other in the World Series.

As a factoid, Brandon Morrow pitched in all 7 games in this World Series, the first pitcher to do that since Darold Knowles in 1973 and the second ever pitcher to do that. Today's Game 7 was the first World Series game 7 that was ever played in Dodger Stadium.

I assume that George Springer will be named the Most Valuable Player of the series.

Update: Yup, George Springer is the series MVP.

Update: And to top it off, Carlos Correa just did a live marriage proposal (it was accepted) while he was being interviewed.

Mathematician Wins 2017 Dance Your Ph.D. Contest!

That's right: The top overall video in the 2017 Dance Your Ph.D. contest was for an explanation of braid groups! Awesome!

Sunday, October 22, 2017

A Non-Maleficence Aphorism for Mentorship: "First, Don't be an Asshole"

Thursday, October 19, 2017

We're Going to the World Series!!!!

The Dodgers are going to the World Series for the first time since 1988!!!!!!!!

Update: The co-most valuable players (co-MVPs) of the National League Championship Series, in which we just beat the Chicago Cubs, are Chris Taylor and Justin Turner. (I thought that Justin Turner would be the lone MVP, but this choice also seems sensible.)

My Own. Personal. Polynomial.

My own. Personal. Polynomial.

Something to interpolate.
Before it’s too late.

Anyway, here is my personal polynomial.

(Tip of the cap to Dave Richeson.)

Monday, October 16, 2017

Quote of the Day: Differential Equations and Star Wars Robots

"You know you're in trouble if the different cases for your differential-equation solutions start sounding like the names of Star Wars robots."

(That is my spontaneous gem from today's lecture. We're doing Frobenius series.)

Sunday, October 15, 2017

Alternative Cuss Words

I am highly amused by this pamphlet of alternative cuss words.

Well kiss my grits!

Some of the alternatives (e.g., "cotton pickin" and some others) that are considered ok in this crib sheet are actually really bad if one thinks about them. And some of the ones to "handle with care" seem just fine to me. Also, I'm not sure what game-show hosts like Alex Trebek, Pat Sajak, and Bob Saget have to do with any of this.

(Tip of the cap to Ajay Johnson.)

Update: Steve Van Hooser pointed out "son of a motherless goat" as a particularly good one. Indeed it is, and I fondly remember its use in the show Perfect Strangers.

"The Interested Reader"

I love how many mathematics papers refer "the interested reader" to various sources for more information.

It is a little-known—but not terribly surprising—fact that most mathematics papers have only a single reader, who may or may not actually be interested in further discussion.

Saturday, October 14, 2017

An Ancient Roman Dice Tower

It would be awesome to whip out one of these — ideally, along with an ancient d20 — during a Dungeons & Dragons game.

(Tip of the cap to Sydney Padua.)

Friday, October 13, 2017

An MRI Scan of Broccoli Looks Like Fireworks


(You're welcome. Tip of the cap to Ciro Cattuto.)

Sunday, October 08, 2017

Visualizations of Music

These visualizations are really cool!

(Tip of the cap to Lucas Lacasa.

Friday, October 06, 2017

Dame Frances Kirwan Named "Savilian Professor" at University of Oxford!

Here is some really big news: "Dame Frances Kirwan has been elected to the Savilian Professorship at the University of Oxford. Frances will be the 20th holder of the Savilian Chair (founded in 1619), and is the first woman to be elected to any of the historic chairs in mathematics."

This is a very big deal. (See the Wikipedia entry for a discussion of this professorship.)

I know Frances. (We were colleagues in the Mathematical Institute at University of Oxford, of course) She is awesome (both as a mathematician and as a person).

Frances is somebody who is well-known within mathematics but pretty much unheard of outside mathematics.

Wednesday, October 04, 2017

Headline: "Massive Wave of Butterflies Lights Up Denver Weather Radar"

How very chaotic. :)

At least the radar wasn't jammed.

(Tip of the cap to Ioana Marilena.)

Tuesday, October 03, 2017

Infinite-Series Techniques: "A Good Psychological Restorative"

Yes, really—at least as prescribed by Drs. Bender and Orszag. Take two of these and call me in the morning.

Update (10/04/17): PBS is now involved (as you can see below).

Monday, October 02, 2017

RIP Tom Petty (1950–2017)

After experiencing cardiac arrest earlier this morning, and amidst conflicting reports earlier in the day, it's now been confirmed—unfortunately but unsurprisingly—that Tom Petty has died at the age of 66. (This is consistent with the recent shelf life of rockers. :( )

I got the chance to see Tom Petty and the Heartbreakers in concert for the first time just 11 days ago, and they were awesome!

You can read more about Petty from Wikipedia page. He has a lot of awesome songs, and here's a link to Learning to Fly as just one of them. Because of the music video for Don't Come Around Here No More, Petty will also always be my vision of The (Mad) Hatter. There are many other awesome songs to which I could also link.

Here is the obituary, which includes some interesting tidbits that are not in the article above.

Nobel Prize in Physiology or Medicine Awarded for Work on the Circadian Rhythm

The 2017 Nobel Prize in Physiology or Medicine was awarded for discovering molecular mechanisms that control the circadian rhythm!

Friday, September 29, 2017

The Importance of Specifying Units

It is extremely important to specify units. :)

Also: very well-played!

(Tip of the cap to Melvin Leok.)

Thursday, September 28, 2017

New Technology: Playable Records Made from Oreo Cookies

I know this sounds nuts, but I'm serious! And I from a physics perspective, this seems eminently doable.

I know of a great song that would be perfect to turn this into a Caltech-themed prank...

Given these developments, we clearly need a DJ Cookie Monster to take proper advantage of this new technology.

Pictures from Puebla

Here is my photo album from Puebla.

Some of the pictures from the archaeological site are especially cool!

Sunday, September 24, 2017

What Happens in Puebla Stays in Puebla

Today I am flying to Puebla, Mexico to attend LANET 2017, the 1st Latin American Conference on Complex Networks.

As you probably know, there was an earthquake there a few days ago, but the conference is still happening (and only a few people have cancelled). The show must go on!

Friday, September 22, 2017

The Dodgers Win the National League West

The Dodgers just beat the Giants 4–2 and are now National League West champions for the 5th year in a row. Today's win was our 98th of the year.

The inevitable celebration got delayed quite a while by our horrible slump, but we did it—and on Tommy Lasorda's 90th birthday to boot!

Next stop: the National League Division Series on Friday 6 October at Dodger Stadium.

What Programmers Say When Their Software Doesn't Work: Top 20 Responses

I have witnessed several of these and used some others.

(Tip of the cap to Michael Stumpf.)

Sunday, September 17, 2017

Words Well Hung

I can see myself uttering last words along these lines (though I can do without the hanging).

(Tip of the cap to George Takei.)

Contribute to Science with your Dungeons & Dragons Backstories

Yes, really.

(Tip of the cap to Jennifer Ouellette.)

The Origin of Zork

Here is a short article about the origin of the landmark text-adventure computer game Zork.

We should calculate some network statistics of the Great Underground Empire map. (See the salient hand-drawn figure in the article.)

Saturday, September 16, 2017

But Can We Set the Lyapunov Exponent?

Apparently, there is a microwave with a 'CHAOS' mode (in all caps).

I have only one question: Are we allowed to set the Lyapunov exponent? (Technically, I am thinking of the maximum one.)

(Tip of the cap to George Takei.)

Update: It looks like chaotic dynamics actually are explicitly involved. (Tip of the cap to Melvin Leok for the link.)

Update 2: Following up on Melvin's comment, I did some googling and found this article. I still haven't figured out which system they used. I suppose I should treat this like the chaotic water wheels. The people who designed this option could have chosen any one of the standard models.

Update 3: Bah. The relevant reference is in a conference proceeding whose parent domain is dead (probably long dead). I might actually have to use a physical library to determine decisively which system was used. (Jaroslav Stark, one of the authors of the above perspective piece, died several years ago. I could potentially see if his coauthor, who I have never heard of, is reachable. The names of the authors of that conference proceeding are going to defy Google.)

Wednesday, September 13, 2017

New to the Blogroll: Math with Bad Drawings

On occasion, I have really enjoyed entries from the blog Math with Bad Drawings, and I am now adding it to the blogroll (much later than I should have).

Great Opening Lines from Literature as Written by Mathematicians

I approve of this blog entry!.

(Tip of the cap to MathFeed.)

21-Game Winning Streak!

This year's Cleveland Indians now are alone at the top with an American League record 21-game winning streak that matches the 1935 Chicago Cubs for the second-longest streak since 1900. The Major League record is 26 non-losing games (it included a tie) by the 1916 New York Giants.


Update (9/15/17): The Indians lost today to the Royals. They won yesterday, so their win streak reached 22 games. Wow!

Tuesday, September 12, 2017

The Bee Nailed It

(I saw this Tweet because Sabine Hossenfelder liked it.)

Monday, September 11, 2017

"Lock the Taskbar"

Does he think it's not kosher?

(Tip of the cap to Dave Richeson.)

Thursday, September 07, 2017

Last Will and Temperament

I haven't seen this picture in several years.

I humbly request that, when I am gone, many of these (but with my name, instead of this guy's) be made and installed at appropriate spots all over the world. I may have to put this as a condition in my will.

Also, I want my sign to be grammatically correct.

P.S. The title is an allusion to this skit.

(Tip of the cap to Gabor Vattay.

Wednesday, September 06, 2017

"Nonlinear Coherent Structures in Granular Crystals"

My review article on granular crystals (and especially work on it during the last decade) just came out in final form. Here are the details.

Title: Nonlinear Coherent Structures in Granular Crystals

Authors: Chris Chong, Mason A. Porter, Panayotis G. Kevrekidis, and Chiara Daraio

Abstract: The study of granular crystals, which are nonlinear metamaterials that consist of closely packed arrays of particles that interact elastically, is a vibrant area of research that combines ideas from disciplines such as materials science, nonlinear dynamics, and condensed-matter physics. Granular crystals exploit geometrical nonlinearities in their constitutive microstructure to produce properties (such as tunability and energy localization) that are not conventional to engineering materials and linear devices. In this topical review, we focus on recent experimental, computational, and theoretical results on nonlinear coherent structures in granular crystals. Such structures—which include traveling solitary waves, dispersive shock waves, and discrete breathers—have fascinating dynamics, including a diversity of both transient features and robust, long-lived patterns that emerge from broad classes of initial data. In our review, we primarily discuss phenomena in one-dimensional crystals, as most research to date has focused on such scenarios, but we also present some extensions to two-dimensional settings. Throughout the review, we highlight open problems and discuss a variety of potential
engineering applications that arise from the rich dynamic response of granular crystals.

Tuesday, September 05, 2017

Sunday, September 03, 2017

Complex Analysis, Simple Analysis, and Congressional Support for Perverse Sheaves

This quote encapsulates one of the great stories in the history of U.S. government funding (and legislative and others' skepticism of such funding):

"On April 9, 1975, Congressman Robert Michel brandished a list of new NSF grants on the floor of the House of Representatives and selected a few that he thought might represent a waste of the taxpayers’ money. One of them (on which I happened to be one of the investigators) was called “Studies in Complex Analysis.” Michel’s comment was, “ ‘Simple Analysis’ would, hopefully, be cheaper.” I shudder to think of what might happen if certain members of the current Congress discover that the NSF is supporting research on perverse sheaves."

You can see some more details in an old blog post from John Baez.

Happiness is Not Communicating :)

Note that, on average, the happier people spend much less time communicating with other people electronically. (For example, notice the result for "Phone".)

I take that a step further and try not to spend too much time communicating with others (electronically or otherwise), and I am extremely happy!

(Tip of the cap to Hiroki Sayama.)

Saturday, September 02, 2017

"Bullshit and the Art of Crap Detection" (1969 Speech)

Take a look at this speech by Neil Postman from 1969. It is called "Bullshit and the Art of Crap Detection".

I had heard of this before, and I found it today through the Twitter post below, where again note that it was uttered in 1969.

Friday, September 01, 2017

The Masque of the Chaotic Attractor

(This could, however, work very well at Dynamics Days.)

Thursday, August 31, 2017

"Everything Sounds Better with Mathematics"

As the blog Math with Bad Drawings points out, everything sounds better with mathematics.

Damn right!

For example, cavities are "just point discontinuities of oral hygiene!"

Wednesday, August 30, 2017

Fake µs

I am very amused by the title ("Fake μs: A cautionary tail of shear-thinning locomotion") of this paper.

It's too bad, though, that "µ" is the standard notation for kinematic viscosity, as the title would be even more amusing with the notation "𝜈" for dynamic viscosity. It would then be "Fake 𝜈s". In any event, I approve! (And things are open for a sequel paper about dynamic viscosity.)

Also, I like viscous puns.

I previously used a variant of this pun, as you can see below.

Update (8/31/17): Thanks to Peter Mucha for the comments about kinematic versus dynamic viscosity. This helped me improve my comments above.

"Skype a Scientist" Program

I just received a classroom 'match' through the Skype a Scientist. My match is a 9th-grade classroom, but the range is kindergarten through 12th gradel.

Fellow scientists: You should sign up for this! It's a really good cause!

"Skype a Scientist matches scientists with classrooms around the world! Scientists will skype into the classroom for 30-60 minute Q and A sessions that can cover the scientist’s expertise or what it’s like to be a scientist. We want to give students the opportunity to get to know a “real scientist”, and this program allows us to reach students from all over the world without having to leave the lab!"

Update (9/06/17): I now have been matched with a second classroom. I believe I indicated that I was happy being matched with up to two classrooms.

Sunday, August 27, 2017

Another Cool Visual Illusion

(Tip of the cap to Justin Lanier.)

Saturday, August 26, 2017

Will Love Tear this Research Apart?

Yes, the actual reason that this type of visualization is now called a "joyplot" is because of the classical Joy Division cover. Sometimes things are right in the world.

Even if love doesn't tear their paper apart, the referees surely will.

I also wrote about this here and here.

(Tip of the cap to MathFeed.)

Update (8/27/17): You can also see some discussion of this visualization in my Facebook post.

Friday, August 25, 2017

Popsicle-Stick "Cobra Wave"

This is cool! Here is an explanation.

We got the video from PRL's tweet.

Thursday, August 24, 2017

Quote of the Day: Moscow Student Sex Survey from 1903

This quote speaks for itself.

(Tip of the cap to Craig Montuori.)

Wednesday, August 23, 2017

28th Anniversary of Ejection from a Game of Expos' Mascot

28 years ago today, The Expos' mascot (Youppi!) got ejected from a game against the Dodgers, partly at the urging of Dodger manager Tommy Lasorda.

The antics that the Phillie Phanatic would pull with Tommy Lasorda were even funnier.

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".



I am highly amused by this classification. :)


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.

Monday, July 31, 2017

Dodgers Get Yu Darvish (and Two Left-Handed Relievers)!

The Dodgers made a huge trade today: we acquired starting pitcher Yu Darvish from the Texas Rangers for three prospects.

In separate deals, we also traded for left-handed relief pitchers Tony Watson of the Pirates and Tony Cingrani of the Reds.

Sunday, July 30, 2017

Dodgers Win (Again)!

Dodgers win!

This team is so amazing.

We now have an astounding 74–31 record (after our 8th win in a row, and recently we had 10-game and 11-game winning streaks).

We also now have a 14-game lead!

Adrián Beltré Gets 3000th Career Hit!

Adrián Beltré just got his 3000th career Major League hit.

Next stop, Cooperstown! And it will be on the first ballot.

Beltré has been appreciated more in recent years as his counting numbers approach 'magic' milestones, but I still don't think most people truly appreciate just how excellent his career has been. I can't remember who wrote this — was it — but I recently saw an estimate that put him in the top-5 third basemen of all time.

There is also a discussion at about future members of the 3000-hit club. The next member will be Albert Pujols, who will become the second person from the Dominican Republic (Beltré is the first) in the 3000-hit club. I believe that the next person after that will be Miguel Cabrera and then Robinson Canó. (Here are the active leaders in career hits.)

Update: Here's a new article in about Beltré's greatness as both an offensive player and defensive player.