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.
Friday, December 01, 2017
Thursday, November 30, 2017
The largest prime number in a popular song is 8675309.https://t.co/A4aXni8NZU— Algebra Fact (@AlgebraFact) November 29, 2017
(Tip of the cap to MathFeed.)
Take a look at the data and suggestions, and see what you think.
Tuesday, November 28, 2017
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. "Well...is 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.)
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
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.)
Teaching the kids about science funding pic.twitter.com/rdwylryNly— Christophe🔬Leterrier (@christlet) November 25, 2017
(Tip of the cap to Kevin O'Keeffe.)
Sunday, November 26, 2017
(Tip of the cap to GrrlScientist.)
The Romans left over one hundred of these dodecahedrons across Europe, but we can only speculate their purpose pic.twitter.com/YvlWgbS4AB— History Lovers Club (@historylvrsclub) November 26, 2017
Saturday, November 25, 2017
(Tip of the cap to Sam Howison.)
Monday, November 20, 2017
Friday, November 17, 2017
Matrices, chaos, and birdtracks all make an appearance. The article also includes appearances by Gibbs, Silvester, Yorke, Cvitanović, and others.
Thursday, November 16, 2017
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.
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
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.
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
Monday, November 13, 2017
The title of Birgit's thesis is "Is Drosophila song amplitude structure a communication signal?".
Update: The links above show the rankings and vote totals for both awards.
Sunday, November 12, 2017
Saturday, November 11, 2017
Wednesday, November 08, 2017
(Tip of the cap to Henry Segerman.)
(This is one of the most brilliant headlines I have ever seen, especially with the accompanying picture.)
Tuesday, November 07, 2017
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
Every single New York Times front page since 1852. Look at the growth of pictures in news.— Carl Miller (@carljackmiller) November 3, 2017
(h/t Josh Begley). pic.twitter.com/zLxe01U2QX
(Tip of the cap to Sabine Hossenfelder.)
Saturday, November 04, 2017
"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
"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
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.
Friday, October 27, 2017
Sunday, October 22, 2017
A Non-Maleficence Aphorism for Mentorship: "First, don't be an asshole." pic.twitter.com/4ne87JmG4K— Mason Porter (@masonporter) October 22, 2017
Thursday, October 19, 2017
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.)
Monday, October 16, 2017
(That is my spontaneous gem from today's lecture. We're doing Frobenius series.)
Sunday, October 15, 2017
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.
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
Ancient roman dice tower used in the playing of dice games from IV AD pic.twitter.com/5TckuhqKqf— Museum Archive (@MuseumArchive) October 13, 2017
(Tip of the cap to Sydney Padua.)
Friday, October 13, 2017
(You're welcome. Tip of the cap to Ciro Cattuto.)
Sunday, October 08, 2017
(Tip of the cap to Lucas Lacasa.
Friday, October 06, 2017
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
Tuesday, October 03, 2017
Infinite-series techniques: "a good psychological restorative"— Mason Porter (@masonporter) October 4, 2017
Prescribed by Drs Bender & Orszag. Take 2 of these & call me in the morning. pic.twitter.com/RH6gk9jh5k
Update (10/04/17): PBS is now involved (as you can see below).
We agree... 🙃 https://t.co/3wUoBjaUHU— PBS Infinite Series (@PBSInfinite) October 4, 2017
Monday, October 02, 2017
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 CNN.com obituary, which includes some interesting tidbits that are not in the Billboard.com article above.
Friday, September 29, 2017
Thursday, September 28, 2017
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.
Sunday, September 24, 2017
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 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.
(Tip of the cap to Michael Stumpf.)
Sunday, September 17, 2017
"I see that you have made 3 spelling mistakes." Last words of Marquis de Favras after reading his death sentence before being hanged (1790). pic.twitter.com/b4aFy7yyJM— Klaas Meijer (@klaasm67) September 15, 2017
(Tip of the cap to George Takei.)
For science! I'm collecting D&D character backstories for training neural networks. Submit as many as you like. https://t.co/phclLHHfR3— Janelle Shane (@JanelleCShane) September 18, 2017
(Tip of the cap to Jennifer Ouellette.)
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
I have only one question: Are we allowed to set the Lyapunov exponent? (Technically, I am thinking of the maximum one.)
why does my microwave have a CHAOS MODE pic.twitter.com/feV8M6uxQx— aoife (@AoifeeO) September 12, 2017
(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
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
Bee removes a nail to make a nest in a wall 🐝 pic.twitter.com/CXSjZAkVLA— Vala Afshar (@ValaAfshar) September 12, 2017
(I saw this Tweet because Sabine Hossenfelder liked it.)
Monday, September 11, 2017
Thursday, September 07, 2017
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
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
"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.
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
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.
Oh Neil, if you'd only lived to see Facebook and Twitter. pic.twitter.com/USZozDmZTE— Calling Bullshit (@callin_bull) September 2, 2017
Friday, September 01, 2017
When you want to go to The Masquerade, but the only masque you have is a Lorenz attractor.— Mason Porter (@masonporter) September 1, 2017
(Thanks to Juan Restrepo for the composition.) pic.twitter.com/QNB7O912vH
(This could, however, work very well at Dynamics Days.)
Thursday, August 31, 2017
For example, cavities are "just point discontinuities of oral hygiene!"
Wednesday, August 30, 2017
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.
I am spreading fake gnus. (This had to be done.) pic.twitter.com/eUcmp3qouZ— Mason Porter (@masonporter) February 11, 2017
Update (8/31/17): Thanks to Peter Mucha for the comments about kinematic versus dynamic viscosity. This helped me improve my comments above.
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
Saturday, August 26, 2017
Even if love doesn't tear their paper apart, the referees surely will.
I also wrote about this here and here.
Nothing beats the moment of revelation when you suddenly realize why they're called "joyplots". pic.twitter.com/8sbmDWGWg9— Stuart Ritchie (@StuartJRitchie) August 25, 2017
(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
We got the video from PRL's tweet.
Thursday, August 24, 2017
My favourite response from a Moscow student sex survey, 1903: 'In order to suppress sexual passion, I entered the faculty of mathematics'— Siobhán Hearne (@siobhanhearne) August 23, 2017
(Tip of the cap to Craig Montuori.)
Wednesday, August 23, 2017
The antics that the Phillie Phanatic would pull with Tommy Lasorda were even funnier.
Monday, August 21, 2017
Wednesday, August 16, 2017
(Tip of the cap to several people for this news. I got the tweet from Cathy O'Neil.)
Monday, August 14, 2017
Sunday, August 13, 2017
The first calculator to be able to perform all 4 operations automatically was invented by Anton Braun, a German optician, in 1727 pic.twitter.com/j8tj7LTUIA— Fermat's Library (@fermatslibrary) August 13, 2017
(Tip of the cap to Daniele Avitabile.)
Saturday, August 12, 2017
The journey is turning into a book tour in itself: signed Beyond Infinity at O'Hare and How to Bake Pi at LAX...in self-improvement!! pic.twitter.com/KqhdGnvoCR— Dr Eugenia Cheng (@DrEugeniaCheng) August 13, 2017
Thursday, August 10, 2017
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.)
Wednesday, August 09, 2017
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.
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
According to this, the most different job from "mathematician" is "mine shuttle car operator".
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
Saturday, August 05, 2017
Friday, August 04, 2017
(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!)
how probability distributions are related pic.twitter.com/1i8VHEHdy5— hardmaru (@hardmaru) August 2, 2017
(Tip of the cap to Michael Stumpf.)
Thursday, August 03, 2017
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. :)
Publish in journals. https://t.co/U2Oiin9Hu3— Michael Hendricks (@MHendr1cks) August 2, 2017
Tuesday, August 01, 2017
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
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
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!
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 538.com? — but I recently saw an estimate that put him in the top-5 third basemen of all time.
There is also a discussion at 538.com 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 538.com about Beltré's greatness as both an offensive player and defensive player.
Saturday, July 29, 2017
This is one of the most brilliant political cartoons of all time. pic.twitter.com/6FG4Wsg5pb— David Moser (@david__moser) July 28, 2017
(Tip of the cap to Melanie Mitchell.)
Friday, July 28, 2017
(Tip of the cap to multiple people.)