My name is Mason Porter. I am a Professor in the Department of Mathematics at UCLA. Previously I was Professor of Nonlinear and Complex Systems in the Mathematical Institute at University of Oxford. I was also a Tutorial Fellow of Somerville College.
Monday, December 31, 2018
Scales in the Universe
It reminds me of the 1977 video called Powers of Ten (of which there are also modern versions), except with new stuff that we now know!
(Tip of the cap to Sara Solla.)
Saturday, December 29, 2018
Pondering Social Contagions in the 19th Century
The winner of Answers magazine's big Question Competition of 1888 was Mr. E Bond of Bloomsbury, who submitted this entry: pic.twitter.com/0kU0Mwxlqj
— Dr Bob Nicholson (@DigiVictorian) December 28, 2018
And here is the beginning of the thread.
In 1888, Answers magazine ran a prize competition in which readers were challenged to send in 'The Most Interesting Question On Any Subject.' Reading through the results is like looking at Victorian Britain's Google search history...
— Dr Bob Nicholson (@DigiVictorian) December 28, 2018
Thread 👇👇👇: pic.twitter.com/Z4aQDTtM3E
Thursday, December 27, 2018
The Final Polishing Step Before Submitting a Manuscript or a Grant Proposal
In the new year, don't forget about this final, very important step when doing the final polishing of your manuscripts and grant proposals just before you submit them. :P
— Mason Porter (@masonporter) December 27, 2018
[Note: I clipped this comic years ago from LA Weekly. It fits academia like a clever but frustrating glove.] pic.twitter.com/K2ncYEatya
Friday, December 21, 2018
A Paper that Rejects Itself
Amazing. Train a network to classify papers (accept/reject). Then run the network on the paper describing the network, and it classifies the paper as a strong reject. This is why we can't have nice paper classifiers. (h/t @hardmaru) https://t.co/OC2baCI1Za pic.twitter.com/3N9wsKQ374
— Chethan Pandarinath (@chethan) December 21, 2018
(Tip of the cap to Karen Daniels.)
Thursday, December 20, 2018
Real-Life Binary Trees!
Here is picture proof that (reasonably) balanced binary trees exist in real life!
— Mason Porter (@masonporter) December 21, 2018
[I took this picture about a decade ago in front of @peetscoffee a few blocks from @Caltech.] pic.twitter.com/iwxfYtVSV4
Wednesday, December 19, 2018
Tales from the ArXiv: Motto: "Somebody has to Study this Shit!"
And I mean this literally: the title of the paper is "An Agent-Based Model for Bovine Viral Diarrhea".
Update: Normally, I hate it when papers are full of bullshit. However, I may need to make an exception in this case.
Tuesday, December 18, 2018
Self-Awareness and the Elephant in the Room
Elephants failed the mirror test for self-awareness — until researchers made the mirrors big enough for elephants to see themselves alongside other elephants.https://t.co/GnI2Z1hsi7 pic.twitter.com/SA5oRE65NU
— Quanta Magazine (@QuantaMagazine) December 18, 2018
(Tip of the cap to Steve Strogatz.)
Friday, December 14, 2018
But Are These Data Cookies Reproducible?
(Tasty, tasty reproducibility.)
Last day of class tomorrow! I baked cookies for my Intro to Data Analytics students, with frosted data plots. Lucky them. #DAatDU pic.twitter.com/j3TCNeDOBe
— Dr. Sarah Supp (@srsupp) December 14, 2018
(Tip of the cap to Javier Buldú.)
Update: Now that I think of it, "Sweet, sweet reproducibility." would have been better phrasing, given its larger set of allusions.
Wednesday, December 12, 2018
"Variability in Fermi–Pasta–Ulam–Tsingou Arrays Can Prevent Recurrences"
Title: "Variability in Fermi–Pasta–Ulam–Tsingou Arrays Can Prevent Recurrences"
Authors: Heather Nelson, Mason A. Porter, and Bhaskar Choubey
Abstract: In 1955, Fermi, Pasta, Ulam, and Tsingou reported recurrence over time of energy between modes in a one-dimensional array of nonlinear oscillators. Subsequently, there have been myriad numerical experiments using homogenous FPUT arrays in the form of chains of ideal, nonlinearly coupled oscillators. However, inherent variations (e.g., due to manufacturing tolerance) introduce heterogeneity into the parameters of any physical system. We demonstrate that such tolerances degrade the observance of recurrences, often leading to complete loss in moderately-sized arrays. We numerically simulate heterogeneous FPUT systems to investigate the effects of tolerances on dynamics. Our results illustrate that tolerances in real nonlinear oscillator arrays may limit the applicability of results from numerical experiments on them to physical systems, unless appropriate heterogeneities are taken into account.
Sunday, December 09, 2018
Lee Smith and Harold Baines Elected to Baseball's Hall of Fame by the Veterans Committee
These are not good picks, especially the one of Harold Baines. They belong more in the Hall of Very Good, rather than in the Hall of Fame. They had very good careers and compiled large numbers in various stats, but in my opinion they don't belong in the Hall of Fame. One of the things to think about when considering whether a player raises or lowers the standards of the Hall at their position. In my view, Lee Smith is a borderline case and I would put him just below the border, but he was the all-time saves leader for a while (and, in general, I can see the arguments in his favor), and he got many Hall of Fame votes for years. Thus, I only view this as a mildly bad pick. I understand it, but I wouldn't put him in the Hall. Part of the issue with Lee Smith has always been the overrating of saves, and I am not surprised that he got in through the Today's Game Era Committee, given the many votes he got from writers over the years in the regular voting. So I can mostly understand his case. But Harold Baines? He was a very good player, but he really lowers the bar at his position. He never got a sniff from the writers, nor did he deserve it.
I'm looking forward to the regular ballot, which will get us Mariano Rivera (who may break the record for highest voting percentage), Edgar Martínez (finally!), Roy Halladay, and maybe (and hopefully!) Mike Mussina will make it. Those four all richly deserve enshrinement in the Hall of Fame.
Maybe Lee Smith's election will help Billy Wagner's case?
Friday, December 07, 2018
"'C' is for Cookie": Academic Evaluation Edition
Comment 2: Apparently, some of my what we did in mathematics in Somerville was an even better idea than I thought. ;)
'The provision of chocolate cookies had a significant effect on course evaluation. These findings question the validity of (student evaluations of teaching) and their use in making widespread decisions within a faculty.' HT @KStackWhitney (photo: Dschwen) https://t.co/lO1v18tmf5 pic.twitter.com/N6epK3GinU
— Erika Marín-Spiotta (@emsaurios) December 7, 2018
(Tip of the cap to Jacquelyn Gill.)
Tuesday, December 04, 2018
Jewelry and Differential Equations
Wolfram Alpha thinks that I may want to find jewelry, even though I asked it about a differential equation. pic.twitter.com/PpfoFUbEUb
— Mason Porter (@masonporter) December 4, 2018
Tales from the ArXiv: Laundering Anti-Money
Wow! I wonder what happens when laundered anti-money collides with laundered money?
Tuesday, November 27, 2018
Tales from the ArXiv: Grandma Got Run Over By a Reindeer
Extra Special Mathematics Terminology
One of my favorite terminology fails in mathematics is the notion of an "extra special group" (which has the added bonus that my undergraduate abstract-algebra professor was unable to say it without also giggling): https://t.co/BsW1dgDYaC
— Mason Porter (@masonporter) November 27, 2018
So inspired!#terminologyfail
Monday, November 26, 2018
"Motor Primitives in Space and Time via Targeted Gain Modulation in Cortical Networks"
Title: Motor Primitives in Space and Time via Targeted Gain Modulation in Cortical Networks
Authors: Jake P. Stroud, Mason A. Porter, Guillaume Hennequin, and Tim P. Vogels
Abstract: Motor cortex (M1) exhibits a rich repertoire of neuronal activities to support the generation of complex movements. Although recent neuronal-network models capture many qualitative aspects of M1 dynamics, they can generate only a few distinct movements. Additionally, it is unclear how M1 efficiently controls movements over a wide range of shapes and speeds. We demonstrate that modulation of neuronal input–output gains in recurrent neuronal-network models with a fixed architecture can dramatically reorganize neuronal activity and thus downstream muscle outputs. Consistent with the observation of diffuse neuromodulatory projections to M1, a relatively small number of modulatory control units provide sufficient flexibility to adjust high-dimensional network activity using a simple reward-based learning rule. Furthermore, it is possible to assemble novel movements from previously learned primitives, and one can separately change movement speed while preserving movement shape. Our results provide a new perspective on the role of modulatory systems in controlling recurrent cortical activity.
Wednesday, November 21, 2018
Introduction to "Confusion Equations"
Tales from the ArXiv: Shit's About to Get Octonionic!
One thing that I find really exciting in the last few years is seeing octonions show up more and more in (in-the-process-of-becoming) practical things!
"Shit's about to get octonionic!", as some of us might say. ;)
Tuesday, November 20, 2018
Adrián Beltré Announces Retirement
I was hoping that Beltré would continue playing, as he's still very effective. Also, if he spent time playing as the oldest player in the Major Leagues, he would have become the first player ever to spend time as both the youngest player in the Majors and as the oldest one.
Sunday, November 18, 2018
A Useful Exercise for Junior Scholars on the Academic Job Market
There are various ways to do such an exercise, and I suspect most people will be doing it without looking at submitted applications in the above way. Gather a set of postdocs in a sufficiently broad field (e.g., "applied mathematics" or even just "mathematics"), as it's a good part of the exercise to see how you evaluate people who are studying topics that are somewhat outside of your expertise. Make sure there is a strict time limit, as you want to see what you notice — both good and bad — about applications in that setting, as it's a realistic setting for how applications are evaluated when it counts. I think you'll pick up some good insights this way, and you can also give each other helpful advice to improve your application materials.
There are various things that we (= senior academics) talk about and give as advice all of the time, but it's good to really try it for yourself. Then you'll see what you notice — both good and bad — in the bundle of applications that you read really quickly.
And, importantly, good luck on your job hunts!
Incidentally, you can find my research statement, teaching statement, and LaTeX file (with drafts of various 'personalization' paragraphs) from my time on the job market, to get my first faculty position, over a decade ago on this Web page
Rubik's Poincaré Disk
#Twisty #puzzle guest tweet. #Hyperbolic #Rubik's cube analogue shown solving in the Poincaré disk model. 24-color puzzle based on the regular {7,3} #tiling. https://t.co/fH15fczvKw pic.twitter.com/3mHMGiygQ2
— Tiling Bot (@TilingBot) November 18, 2018
Friday, November 16, 2018
Which 2-Digit Parent Mathematics Subject Classification Should I Pick as my Primary Classification?
The Mathematics Subject Classification does an "awesome" job of classifying me: https://t.co/chQW9cCotC
— Mason Porter (@masonporter) November 16, 2018
This classification ontology is horrible for applied mathematicians in general, and that can really hurt them on the job market. pic.twitter.com/DnYYBI2Muh
Applied mathematicians face this all the time (though my own research portfolio is a particularly extreme case of MSC failure) on the job market in their job applications for postdoc and faculty positions in mathematics departments in the United States. They forced to submit the standard American Mathematical Society (AMS) cover sheet, and they are then categorized according to an ontology that fails them utterly. It is systematically unfair to applied mathematicians.
The MSC needs to be revamped.
"Layer Communities in Multiplex Networks"
Here are some other details:
Title: Layer Communities in Multiplex Networks
Authors: Ta-Chu Kao and Mason A. Porter
Abstract: Multiplex networks are a type of multilayer network in which entities are connected to each other via multiple types of connections. We propose a method, based on computing pairwise similarities between layers and then doing community detection, for grouping structurally similar layers in multiplex networks. We illustrate our approach using both synthetic and empirical networks, and we are able to find meaningful groups of layers in both cases. For example, we find that airlines that are based in similar geographic locations tend to be grouped together in a multiplex airline network and that related research areas in physics tend to be grouped together in a multiplex collaboration network.
Thursday, November 15, 2018
2018 Most Valuable Player Awards
Some of the rankings are available on this page. Complete point totals are available for the American League on this page and for the National League on this page.
"WHAT IS... a Multilayer Network"
Armin Straub has taken it upon himself to post a comprehensive list of all "WHAT IS..." articles. Mine is the 149th such article.
Wednesday, November 14, 2018
2018 Cy Young Awards
Tuesday, November 13, 2018
2018 Major League Baseball Managers of the Year
What Happens in Columbus Stays in Columbus
Monday, November 12, 2018
Ohtani and Acuña Jr. are the 2018 Rookies of the Year!
The 2018 class of Major League Baseball rookies was very strong indeed!
Sunday, November 11, 2018
"Roll for Initiative"
I think I've decided on what message to put on my tombstone. ;) 👻 pic.twitter.com/i7CbQp9xJO
— Mason Porter (@masonporter) November 11, 2018
(Well, "Roll for surprise." probably conveys the implication better, but it doesn't seem as good.)
Congratulations to Dr. Alejandro Martínez!
His thesis work includes several awesome papers, including this one, this one, this one, this one, and this one. (Alejandro also has additional papers from his thesis era that are in collaboration with other people.)
Alejandro is now a postdoctoral scholar in computational biology in Chile.
Monday, November 05, 2018
Plants that Look like Stones
Lithops, South African plants that have evolved to look like stones. pic.twitter.com/6NQqniKZbJ
— Back To Nature (@backt0nature) November 5, 2018
Sometimes the Refereeing Process Actually Works :)
Me: "Yes, we need to upload the revised version to the arXiv reasonably soon. We changed it substantially (we had a very thorough and helpful referee), so I didn't want to only point you to the old version."
Response: "I hesitated to tell you this in the first message, but I was the referee--thanks for the compliment, all the more meaningful since you didn't know!!"
As frustrating as this can all be (and it is very often indeed), sometimes the process really does work, and sometimes you end up accidentally complimenting somebody a lot instead of accidentally having egg on your face. ;)
Sunday, November 04, 2018
Tales from the ArXiv: The Power Law OF DEATH
And on the heels of The Power Law OF DOOM, we now have claims of The Power Law OF DEATH in a new arXiv paper called "Statistical study of time intervals between murders for serial killers".
In both cases (and as is common), the claims of a power law are unlikely to be justified statistically.
See also The Small-World Network OF LUST, this old blog entry, and this old blog entry.
Wednesday, October 31, 2018
Why are Pencils Yellow?
"Hardtmuth settled on yellow to communicate the graphite’s geographical origins, while also linking its product to the long-held Chinese associations of royalty, and therefore superiority." https://t.co/Mn1LjGRbYQ
— Samuel Arbesman (@arbesman) October 31, 2018
Monday, October 29, 2018
E. L. Ince and the State of Differential Equations in England in 1926
E. L. Ince, being snarky about the state of the study of differential equations in England, in the preface of his classic 1926 book on the subject. pic.twitter.com/nLPXLv5mNt
— Mason Porter (@masonporter) October 29, 2018
Saturday, October 27, 2018
Dodgers Win Game 3 of the World Series 3–2 in 18 Innings!
It's a great day for a ball game. Let's play two!
Many records were set, including longest postseason game (by time) and longest World Series game (by both inning and time). It tied the record for most innings in a postseason game.
(We're still down 2 games to 1, so we have an uphill climb. But today was really exciting. Let's see what tomorrow brings!)
Friday, October 26, 2018
812 Double Pendulums with Different Initial Conditions
This is what 812 double pendulums with different initial conditions look like https://t.co/jklEvfb5EI | https://t.co/ctsPCmFfEJ pic.twitter.com/jMar6rlRma
— Massimo (@Rainmaker1973) October 26, 2018
Monday, October 22, 2018
Spatial and Information Efficiency in Price Lists
theres gotta be a better way to convey this information pic.twitter.com/pHEswDU0TC
— sean (@seanposting) October 21, 2018
(Tip of the cap to Heather Zinn Brooks.)
"Network Science In Education: Transformational Approaches in Teaching and Learning"
Title: Network Science In Education: Transformational Approaches in Teaching and Learning
Editors: Catherine B. Cramer, Mason A. Porter, Hiroki Sayama, Lori Sheetz, and Stephen Miles Uzzo
The book also includes my chapter about developing my undergraduate mathematics course about networks.
Sunday, October 14, 2018
Which Headline Do You Prefer?
Seen in the wild: @sfchronicle using two different headlines for the same article. pic.twitter.com/xPhbvbAMzV
— Mason Porter (@masonporter) October 14, 2018
Using a 'Sort' Function to Order the Chicken and the Egg
Wel that settles that. 😂 pic.twitter.com/0xHvS8Dply
— allie, 🎃 the spookiest 👻 transbian 💀 (@aBagorn) October 14, 2018
(I saw this through a 'like' by Chris Danforth on Twitter.)
Friday, October 12, 2018
A Map of Every Building in America
"A MAP OF EVERY
— Marc Abrahams (@MarcAbrahams) October 12, 2018
BUILDING IN AMERICA" RT @JenLucPiquant @jswatz: Here is the online version of the big, weird, fun thing I was telling you about yesterday... I loved working on this. https://t.co/loRUJhGJJo
A Really Fancy Visual Illusion
Amazing motion illusion.
— Alice Proverbio (@AliceProverbio) October 12, 2018
V5 is firing due to V4 saturation! pic.twitter.com/oNgxRXXN3f
Thursday, October 04, 2018
Amazing Visual Illusion: A Dynamic Müller–Lyer Illusion
This is probably the best illusion I've ever seen. The blue and red lines are all the same length; none is moving or changing size, and they’re all at the same level. Only the arrowheads are moving. https://t.co/bDyeOKXgbC pic.twitter.com/V6KrmLkiPr
— Steve Stewart-Williams (@SteveStuWill) October 4, 2018
(Tip of the cap to Marcel Salathe.)
Wednesday, October 03, 2018
Look at Me, I'm 𝞧 sub d...
Sooo, Max Born, who gave us the statistical interpretation of the quantum mechanical wavefunction, is the grandfather of Olivia Newton-John @olivianj of Grease fame. How did I not know this.
— Michelle Kuchera (@MKizzyy) October 3, 2018
Tuesday, October 02, 2018
How Many First-Authored Papers in "Leading" Journals Does One Need to be Hired as an Assistant Professor?
How many first-authored papers in “leading” journals does an ecologist need to be hired as a tenure-track asst. prof at an R1 university? Not nearly as many as most ecologists think. https://t.co/qpfozljVD0 pic.twitter.com/VrcfEbTjdh
— Dynamic Ecology (@DynamicEcology) October 2, 2018
FYI: I have seen several things on this blog over the years that are relevant far beyond their core ecology audience, so it's worth a look beyond this post.
Update: It's also not required to have lots of citations to get a top faculty job. It would be good to see a distribution of what people have had in practice. (The number of citations listed by Google Scholar for me for 2006 is 53.)
Monday, October 01, 2018
Dodgers Win 6th Straight National League West Division Title!
We face the Atlanta Braves in one of the two National League Division Series starting on Thursday. Go Dodgers!
Monday, September 24, 2018
Will the Authors of this Paper Look Back in Anger?
"Can high-density human collective motion be forecasted by spatiotemporal fluctuations?"
— Chris Danforth (@ChrisDanforth) September 24, 2018
Eigenmodes of crowd dynamics at an Oasis concert. #moshmathhttps://t.co/srSG8Biyui pic.twitter.com/XxnlBQuDFJ
Wednesday, September 19, 2018
Tuesday, September 18, 2018
Trying to Divide by 0 on a Mechanical Calculator
Division by zero is a mathematical challenging concept: see what happens when you try in on a mechanical calculator https://t.co/cfo52jdEGr pic.twitter.com/5jho6XqX7Q
— Massimo (@Rainmaker1973) September 18, 2018
Monday, September 17, 2018
"Inferring Parameters of Prey Switching in a 1 Predator–2 Prey Plankton System with a Linear Preference Tradeoff"
Title: Inferring Parameters of Prey Switching in a 1 Predator–2 Prey Plankton System with a Linear Preference Tradeoff
Authors: Sofia H. Piltz, Lauri Harhanen, Mason A. Porter, and Philip K. Maini
Abstract: We construct two ordinary-differential-equation models of a predator feeding adaptively on two prey types, and we evaluate the models’ ability to fit data on freshwater plankton. We model the predator’s switch from one prey to the other in two different ways: (i) smooth switching using a hyperbolic tangent function; and (ii) by incorporating a parameter that changes abruptly across the switching boundary as a system variable that is coupled to the population dynamics. We conduct linear stability analyses, use approximate Bayesian computation (ABC) combined with a population Monte Carlo (PMC) method to fit model parameters, and compare model results quantitatively to data for ciliate predators and their two algal prey groups collected from Lake Constance on the German–Swiss–Austrian border. We show that the two models fit the data well when the smooth transition is steep, supporting the simplifying assumption of a discontinuous prey-switching behavior for this scenario. We thus conclude that prey switching is a possible mechanistic explanation for the observed ciliate–algae dynamics in Lake Constance in spring, but that these data cannot distinguish between the details of prey switching that are encoded in these different models.
Note: This paper is actually the third in a series of papers that arose from Sofia's doctoral thesis. In all three, we studied prey switching in plankton as a dynamical system. However, although we were concerned in all three papers with the same ecological situation, we modeled it in three different mathematical ways: using piecewise-smooth dynamical systems (in paper 1), using fast–slow dynamical systems (in paper 2), and using smooth dynamical systems (in this paper). It is really important to model the same phenomenon in different ways and to compare the qualitative features of the different models against each other as well as to empirical data. I am really pleased with this effort, which Sofia did a superb job of leading.
"Frequency-Based Brain Networks: From a Multiplex Framework to a Full Multilayer Description"
Title: Frequency-Based Brain Networks: From a Multiplex Framework to a Full Multilayer Description
Authors: Javier M. Buldú and Mason A. Porter
Abstract: We explore how to study dynamical interactions between brain regions by using functional multilayer networks whose layers represent different frequency bands at which a brain operates. Specifically, we investigate the consequences of considering the brain as (i) a multilayer network, in which all brain regions can interact with each other at different frequency bands; and as (ii) a multiplex network, in which interactions between different frequency bands are allowed only within each brain region and not between them. We study the second-smallest eigenvalue λ2 of the combinatorial supra-Laplacian matrix of both the multiplex and multilayer networks, as λ2 has been used previously as an indicator of network synchronizability and as a biomarker for several brain diseases. We show that the heterogeneity of interlayer edge weights and, especially, the fraction of missing edges crucially modify the value of λ2, and we illustrate our results with both synthetic network models and real data obtained from resting-state magnetoencephalography. Our work highlights the differences between using a multiplex approach and a full multilayer approach when studying frequency-based multilayer brain networks.
Bonus: This paper has an easter egg. Can you find it? (Hint: This is Spinal Tap.)
Tuesday, September 11, 2018
A Very Exciting (and Dangerous?) Mathematics Conference
Some mathematics conferences are more dangerous than others.
— Mason Porter (@masonporter) September 11, 2018
(Bernadette Stolz-Pretzer is apparently attending a particularly exciting conference. Thanks for posting this picture and letting me share it.) pic.twitter.com/wKiax2gWOA
P.S. I wonder what they actually have in mind with that session? I'm at a loss. I suppose it's clearer to the people who are actually attending the conference?
Tuesday, September 04, 2018
Referee Reports for the Watts–Strogatz 'Small World' Paper
Steve Strogatz posted his referee reports (with annotations for their revision plans) about his genre-defining 1998 ‘small world’ paper with Duncan Watts.
It just goes to show that misguided, skeptical reports (see Referee 2 in the upper right) happen to the best of us.
Referee 2 was confused about the implications of the work to systems other than those studied (and possibly even to those applications)…
(The source is Steve's tweet. I posted the picture separately to orient it correctly.)
Monday, September 03, 2018
Googly Eyes, and Freshness of Fish
The headline pretty much sums it up: Store shut down after owners caught sticking googly eyes on fish to look fresher
P.S. There are also other uses for googly eyes.
(Tip of the cap to Renée O'Rear Handley.)
Hindsight's 2020 Presidential Campaign
Saturday, September 01, 2018
What Happens in Sydney Stays in Sydney
The only previous time I was in Australia was in 2005 for my interview at University of Sydney. (I am visiting a collaborator at Macquarie University, and I'll be giving one teach each there and at University of Sydney.)
"Isomorphisms in Multilayer Networks"
Title: Isomorphisms in Multilayer Networks
Authors: Mikko Kivelä and Mason A. Porter
Abstract: We extend the concept of graph isomorphisms to multilayer networks with any number of “aspects” (i.e., types of layering). In developing this generalization, we identify multiple types of isomorphisms. For example, in multilayer networks with a single aspect, permuting vertex labels, layer labels, and both vertex labels and layer labels each yield different isomorphism relations between multilayer networks. Multilayer network isomorphisms lead naturally to defining isomorphisms in any of the numerous types of networks that can be represented as a multilayer network, and we thereby obtain isomorphisms for multiplex networks, temporal networks, networks with both of these features, and more. We reduce each of the multilayer network isomorphism problems to a graph isomorphism problem, where the size of the graph isomorphism problem grows linearly with the size of the multilayer network isomorphism problem. One can thus use software that has been developed to solve graph isomorphism problems as a practical means for solving multilayer network isomorphism problems. Our theory lays a foundation for extending many network analysis methods—including motifs, graphlets, structural roles, and network alignment—to any multilayer network.
Friday, August 31, 2018
The Winning Game and a Potentially Interesting Dodger Factoid
This year, our win leader is Ross Stripling (with 8 wins), who is currently on the disabled list.
We have a good chance to make the playoffs, and there is an even better chance that none of our pitchers will get double digits in wins. "Accomplishing" both of these things in the same season is not easy.
(I found this out from Charley Steiner on tonight's broadcast.)
Thursday, August 30, 2018
"Do Complex-Systems Scientists Dream of Emergent Sheep?"
Do complex-systems scientists dream of emergent sheep? :)
— DynamicalSystemsSIAM (@DynamicsSIAM) August 30, 2018
Update: And, to complete the picture, note that there is also an old game called Netrunner.
Carpeting Dragon*Con
Many Dragon*Con costumes and related things still invoke the old carpet.
Here is an article (to which I can't get full access) that appears to be about carpet-related costumes more generally (though the front picture is one from Dragon*Con).
Wednesday, August 29, 2018
Scientific Journals are for Kids!
It is "an open-access scientific journal written by scientists and reviewed by a board of kids and teens."
Here is some text from their online blurb:
That is why distinguished scientists are invited to write about their cutting-edge discoveries in a language that is accessible for young readers, and it is then up to the kids themselves – with the help of a science mentor – to provide feedback and explain to the authors how to best improve the articles before publication.
As a result, Frontiers for Young Minds provides a collection of freely available scientific articles by distinguished scientists that are shaped for younger audiences by the input of their own young peers.
I approve!
(Tip of the cap to Petter Holme.)
Tuesday, August 28, 2018
Advice to Students: "Think for Yourself."
"We are scholars and teachers at Princeton, Harvard, Yale, and other institutions who have some thoughts to share and advice to offer students across the country. Our advice can be distilled to three words:
Think for yourself."
The full statement, which I signed, is worth reading.
Monday, August 27, 2018
The Karate Club Will Long Live in Network-Science Infamy
(However, Mark misspelled "awesome" as "dubious", for some reason.)
Snarky Karate Club lore (t-shirt + ZKCC) has made the 2nd edition of Mark Newman's textbook on networks (the closest thing we have to a standard introductory text).
— Mason Porter (@masonporter) August 27, 2018
Should I be happier about having papers & research cited in the 2nd edition, or about the t-shirt being cited? 🤔 pic.twitter.com/yCjq4MCzer
P.S. You can see the history of the ZKCC at this website and buy ZKC memorabilia at The Power Law Shop.
Friday, August 17, 2018
Infinite Loop
well played pic.twitter.com/KVZV799qmB
— Leon Fayer (@papa_fire) August 16, 2018
(Tip of the cap to Manlio De Domenico.)
Tuesday, August 14, 2018
What Happens at WorldCon 76 Stays at WorldCon 76
I am looking forward to geeking out!
(I am also looking forward to getting out of this crowded, shitty airport. LAX is awful.)
Monday, August 13, 2018
A Wassermanian–Faustian Bargain
Earlier today, I was looking for 'balance' in "Social Network Analysis" by Wasserman & Faust, but instead I found the 'beast'.
— Mason Porter (@masonporter) August 13, 2018
(I suppose that social network analysis is sometimes a Wassermanian–Faustian bargain.) pic.twitter.com/cm4jZiupeW
Friday, August 10, 2018
"Network Analysis of Particles and Grains"
Title: Network Analysis of Particles and Grains
Authors: Lia Papadopoulos, Mason A. Porter, Karen E. Daniels, and Danielle S. Bassett
Abstract: The arrangements of particles and forces in granular materials have a complex organization on multiple spatial scales that range from local structures to mesoscale and system-wide ones. This multiscale organization can affect how a material responds or reconfigures when exposed to external perturbations or loading. The theoretical study of particle-level, force-chain, domain and bulk properties requires the development and application of appropriate physical, mathematical, statistical and computational frameworks. Traditionally, granular materials have been investigated using particulate or continuum models, each of which tends to be implicitly agnostic to multiscale organization. Recently, tools from network science have emerged as powerful approaches for probing and characterizing heterogeneous architectures across different scales in complex systems, and a diverse set of methods have yielded fascinating insights into granular materials. In this article, we review work on network-based approaches to studying granular matter and explore the potential of such frameworks to provide a useful description of these systems and to enhance understanding of their underlying physics. We also outline a few open questions and highlight particularly promising future directions in the analysis and design of granular matter and other kinds of material networks.
Thursday, August 09, 2018
A Touching Song about a Matrix Entry that is not Well-Defined
Monday, August 06, 2018
Workshop on Evidence-Based Diversity Initiatives
Tired of expensive diversity initiatives that haven’t really changed much? So are we 😴. We want to give you 💰 to work on projects based on evidence. Meet new people, change the game. Join us on Sept 21 + 22 @turinginst: https://t.co/gOH4KvRQM7 #womeninSTEM x @STEMGamechange pic.twitter.com/PPgDvIqqy9
— Dr Jess Wade 👩🏻🔬 (@jesswade) July 25, 2018
(P.S. Jess Wade has been doing amazing things in her prolific writing of Wikipedia entries.)
Saturday, August 04, 2018
What Happens in San José (Costa Rica) Stays in San José (Costa Rica)
Thursday, August 02, 2018
Our Physics Today Obituary of Norman Zabusky
Previously, we wrote an obituary of Zabusky for DSWeb.
Wednesday, August 01, 2018
2018 Fields Medals
You can also read short prize citations for the four Fields Medalists and the Nevanlinna Prize (in theoretical computer science).
Tuesday, July 31, 2018
"Topological Data Analysis of Continuum Percolation with Disks"
Title: Topological Data Analysis of Continuum Percolation with Disks
Authors: Leo Speidel, Heather A. Harrington, S. Jonathan Chapman, and Mason A. Porter
Abstract: We study continuum percolation with disks, a variant of continuum percolation in two-dimensional Euclidean space, by applying tools from topological data analysis. We interpret each realization of continuum percolation with disks as a topological subspace of [0,1]^2 and investigate its topological features across many realizations. Specifically, we apply persistent homology to investigate topological changes as we vary the number and radius of disks, and we observe evidence that the longest persisting invariant is born at or near the percolation transition.
And to give a story, or at least the hint of the interesting relationship that I sometimes have with typesetters and editors, here is a note that I received from them while we were working on the galley proofs.
Update (8/05/18): A nice way of phrasing things is that we're in a nonassociative situation, and hyphens are a great tool to indicate exactly (and tersely) where the parentheses should be to group terms in a way that renders their meaning unambiguous. (And, naturally, if somebody makes a change in my text that I don't like, my immediate desire is to change it back.)
Monday, July 30, 2018
A Cartoon Depiction of Deep Learning Versus Traditional Machine Learning
great meme pic.twitter.com/d5AW6WliTy
— Lex Flagel (@flagelbagel) July 29, 2018
(Tip of the cap to Michael Stumpf.)
The Paradox of PLOS One and Scientific Reports
Also, remember the mantra: FIPO (= "Fuck it. PLOS One.")
Sunday, July 29, 2018
Tales from the ArXiv: "Blueberry Earth"
(However, I do wish that the author had used the subjunctive in the 'what if' question.)
"Blueberry Earth" (new paper) by Anders Sandberg: https://t.co/hn1T10qErC
— DynamicalSystemsSIAM (@DynamicsSIAM) July 30, 2018
Abstract: 'This paper explores the physics of the what-if question "what if the entire Earth was instantaneously replaced with an equal volume of closely packed, but uncompressed blueberries?" ... '
Update: Here is the first paragraph of the Summary: So, to sum up, to a person standing on the surface of the Earth when it turns into blueberries, the first effect would be a drastic reduction of gravity. Standing on the blueberries might be possible in theory, except that almost immediately they begin to compress rapidly and air starts erupting everywhere. The effect is basically the worst earthquake ever, and it keeps on going until everything has fallen 715 km. While this is going on everything heats up drastically until the entire environment is boiling jam and steam. The end result is a world that has a steam atmosphere covering an ocean of jam on top of warm blueberry granita.
Saturday, July 28, 2018
Complex Variables and the Meaning of 𝛏
My biggest weakness pic.twitter.com/WvIeVPqoTl
— Toby Hendy (@TobyHendy) July 28, 2018
Two remarks:
(1) One of the main purposes of taking complex analysis is learning how to properly write Greek letters.
(2) I specifically practiced how to draw \xi when I took complex analysis.
(Tip of the cap to Dave Richeson.)
Smurfy Peer Review
To wit:
"Where did the authors smurf up this idea?"
"This figure is smurfed."
"The authors might want to consider smurfing the abstract a little bit more."
Update: I know; I know: this isn't very smurfy of me.
Update 2: "A total smurf job."
Tuesday, July 24, 2018
Tales from the ArXiv: Low and High Mason Numbers
Here is a quote from the abstract: In the limit of low Mason number, the dynamical system admits a periodic solution in which the magnetic moment of the swimmer tends to align with the magnetic field. In the limit of large Mason number, the magnetic moment tends to align with the average magnetic field, which is parallel to the axis of rotation.
I operate in the limit of low Mason number, and I claim that this limit is singular.
Monday, July 23, 2018
Opinion: "Are Theoretical Results 'Results'?"
Moreover: Hell yes!
This is a major issue for interdisciplinary students and postdocs (and more senior scholars), and this is a very helpful paper for them to read as they navigate these waters. I also really like the fact that Ray included two different versions of a 'Results' section in his opinion article.
This guy knows how to write an abstract https://t.co/D8tWZi7VCn pic.twitter.com/980OFvCv3U
— Adam J Calhoun (@neuroecology) July 23, 2018
"Quasiperiodic Granular Chains and Hofstadter Butterflies"
Title: Quasiperiodic Granular Chains and Hofstadter Butterflies
Authors: Alejandro J. Martínez, Mason A. Porter, and Panayotis G. Kevrekidis
Abstract: We study quasiperiodicity-induced localization of waves in strongly precompressed granular chains. We propose three different set-ups, inspired by the Aubry–André (AA) model, of quasiperiodic chains; and we use these models to compare the effects of on-site and off-site quasiperiodicity in nonlinear lattices. When there is purely on-site quasiperiodicity, which we implement in two different ways, we show for a chain of spherical particles that there is a localization transition (as in the original AA model). However, we observe no localization transition in a chain of cylindrical particles in which we incorporate quasiperiodicity in the distribution of contact angles between adjacent cylinders by making the angle periodicity incommensurate with that of the chain. For each of our three models, we compute the Hofstadter spectrum and the associated Minkowski–Bouligand fractal dimension, and we demonstrate that the fractal dimension decreases as one approaches the localization transition (when it exists). We also show, using the chain of cylinders as an example, how to recover the Hofstadter spectrum from the system dynamics. Finally, in a suite of numerical computations, we demonstrate localization and also that there exist regimes of ballistic, superdiffusive, diffusive and subdiffusive transport. Our models provide a flexible set of systems to study quasiperiodicity-induced analogues of Anderson phenomena in granular chains that one can tune controllably from weakly to strongly nonlinear regimes.
This article is part of the theme issue ‘Nonlinear energy transfer in dynamical and acoustical systems’.
Sunday, July 22, 2018
I Would Code Anything for Love (but I Won't Code That)
(Also, I am highly amused!)
Money quote from the programming language's GitHub page:
"Rockstar is a dynamically typed Turing-complete programming language.
Rockstar is designed for creating computer programs that are also song lyrics, and is heavily influenced by the lyrical conventions of 1980s hard rock and power ballads."
The Rockstar programming language, where power ballads = code https://t.co/l4sdSlV0BV pic.twitter.com/a7Fhm9zlf5
— Samuel Arbesman (@arbesman) July 23, 2018
Update (7/23/18): I wrote a blurb about Rockstar for the Improbable Research blog.
Saturday, July 21, 2018
Scientific Nomenclature: The "Thagomizer"
I love this.
— Jim Bliss (@JimBliss23) July 21, 2018
When the Far Side came out in 1982, paleontologists realised they'd never actually named that part of a stegosaurus and began using the term informally. And now, 36 years later, if you type "Thagomizer" into a search engine... pic.twitter.com/pMDYoOrT8d
(Tip of the cap to C E Watkins.)
Friday, July 20, 2018
Proof of Existence of Sunlight in England
“Mason’s knowledge was as faded as the book from the British sun.”
— Mason Porter (@masonporter) July 20, 2018
Proof of existence of sunlight in England. :) pic.twitter.com/d7z7YbgLAy
Thursday, July 19, 2018
A Buzzcock Conjecture
You can also take a look on Twitter.
Wednesday, July 18, 2018
Tales from the ArXiv: Don't Feed Random Walkers After Midnight
Quoting from the abstract: "The model is highly versatile, as the motion of the walkers can be fed on topological properties of the nodes..."
Comment: But don't feed them after midnight.
Dodgers Trade for Manny Machado!
With Corey Seager out for the year, having Machado to play shortstop the rest of the year is most excellent indeed!
Tuesday, July 17, 2018
Medieval Fantasy City Generator
I also wonder if it uses any generative-model ideas from urban analytics and/or complex systems?
(Tip of the cap to Dungeons and Dragons Memes.)
Monday, July 16, 2018
Heart and Caffeine Plushies
Here are my two latest @GIANTmicrobes plushies: Heart and Caffeine
— Mason Porter (@masonporter) July 17, 2018
The heart is particularly adorable. pic.twitter.com/LV1IuVCWf5
"Message-Passing Methods for Complex Contagions"
Friday, July 13, 2018
Creating Wikipedia Entries for Underrepresented Scientists and Engineers
Meet @jesswade, a scientist working to increase the number of underrepresented scientists and engineers on @Wikipedia: https://t.co/4JAJirmWDp #WomenInSTEM @WikiWomenInRed pic.twitter.com/f6jiX47WLL
— Wikimedia (@Wikimedia) July 13, 2018
Wednesday, July 11, 2018
Titles
On some website pop-up menus, there are so many possible titles that it's really hard to choose the most appropriate one to use.
— Mason Porter (@masonporter) July 11, 2018
(Click to see the full list. Some selections are cut off.) pic.twitter.com/mRgnGMMxkd
Real-Life Elliptical Billiard Table
Now we just need real-life Sinai and stadium billiards (and, of course, a mushroom billiard, to make Lyonia happy).
Unveiling the elliptical pool table designed by @AlexBellos captured local imagination: https://t.co/BlSu2PQ95m , https://t.co/bPVtkHF6Bh , https://t.co/MPAdoNv8pU . 1st in North America, 3rd in the world. Planning formal event at @WaterlooMath in the fall.
— Stephen M. Watt (@Stephen_Watt) July 11, 2018
(Tip of the cap to Alex Bellos.)
Update: The table pictured in the article appears to be a circle, rather than a more general ellipse.
Algorithmic Author Ordership
I have never laughed out loud reading a journal article, until I saw this little gem from Lakens, Scheel, and Isager (2018). Talk about total transparency!https://t.co/4eAsdvFbMI pic.twitter.com/OsVUTYf71e
— Stacy T. Shaw 🇭🇷 (@StacyTShaw) July 11, 2018
Tuesday, July 10, 2018
Awesome Close-Up Photos of Snails
Ukrainian photographer Vyacheslav Mishchenko catches these unbelievably stunning up-close photographs of snails pic.twitter.com/Lhgj2zcx6S
— Life on Earth 🌴 (@planetepics) July 10, 2018
(Tip of the cap to Invisible Scientist.)
Thursday, July 05, 2018
My Eponymous Agent-Based-Model (ABM) Simulator
Interested in #MASON for agent-based modeling? Check out our new paper: The MASON Simulation Toolkit: Past, Present, and Future. More details @ https://t.co/II9TFkQ7SU The link also points you to a lot of new demo models for GIS & ABM pic.twitter.com/8OnbC5ckud
— Andrew Crooks (@AndyCrooks) July 4, 2018
(Tip of the cap to Sang Hoon Lee.)
Tuesday, July 03, 2018
"My" Eponymous Band
And now, on this occasion, even the band itself accidentally tagged me in their Facebook post instead of themselves!
Rock on! ("Folk on?")
One of these years, I seriously need to crash one of their shows with a short mathematics lecture.
Monday, July 02, 2018
"International Conference on Newfangled Methods"
They're not even trying anymore. How sad. pic.twitter.com/rHrk905Kex
— Grace Lindsay (@neurograce) July 1, 2018
Sunday, July 01, 2018
What Happens in Newcastle Stays in Newcastle (2018 Edition)
Thursday, June 28, 2018
RIP Harlan Ellison (1934–2018)
Here is a picture with him at Dragon*Con in 2003. He complimented me on the shirt I was wearing, and rolled his eyes to signal to me (while I was waiting patiently at the front of the line) that the person in front of me in line for his autograph (who gave him tons and tons of things to sign) was an idiot. For me, he signed a well-read copy of the 35-year retrospective of his work, and he agreed to be in the picture below. Unlike recent Dragon*Cons, Ellison's autograph was free. He seemed to appreciate the fact that I had obviously read the book that I asked him to sign.
Update: Here is an obituary from The Nerdist.
Tuesday, June 26, 2018
Another Living Network
Parasitic crustacean, Dendrogaster sp. found on the seastar, Mediaster brachiatus. Collected at depth of 300m, Kumanonada-sea, Japan. pic.twitter.com/uy2J3FD2dk
— M (@manpokenautilus) June 25, 2018
Other examples of living networks are fungal networks.
(Tip of the cap to Jessica Rosenkrantz.)
Monday, June 25, 2018
"Detecting Sarcasm with Deep Convolutional Neural Networks"
Detecting Sarcasm with Deep Convolutional Neural Networks https://t.co/C05UdMjCoe pic.twitter.com/q50x9QqXhD
— KDnuggets (@kdnuggets) June 24, 2018
(Tip of the cap to Peter Rothman.)
Sunday, June 24, 2018
Yet Another Amazing Tiling from Tiling Bot
I strongly recommend looking through Tiling Bot's feed.
#Hyperbolic #tiling shown vertex-centered in the orthographic model. Truncated {3,12}. pic.twitter.com/tpsPWqOBOi
— Tiling Bot (@TilingBot) June 24, 2018
Saturday, June 23, 2018
What Happens in Oxford Stays in Oxford
I'll also be participating and speaking at Howison-fest, a workshop in honor of Sam Howison's 60th birthday.
Thursday, June 21, 2018
"FU" Stands for "Fundamental Unit"
Remember: "FUs are biologically well defined".
This screenshot is from this new paper.
(Tip of the cap to Alex Vespignani.)
Ground Control to Major Tom: Perfect Photographic Timing
Perfect timing. pic.twitter.com/4bVoqBHoH2
— You Had One Job (@_youhadonejob1) June 20, 2018
Wednesday, June 20, 2018
Poincaré Disk: Fantasy Edition
A surface obtained by gluing six heptagons. Universal cover in the Poincaré model (the same character shown = the same point of the surface). Weapons to show that this is not orientable (it has Euler characteristic -1). Constructed by DivisionByZero [ https://t.co/zgD3J7pG4f ] pic.twitter.com/J1MzJKCkYl
— Zeno Rogue (@ZenoRogue) June 20, 2018
A Bulging Visual Illusion
The image appears to bulge out, though it consists of squares aligned vertically and horizontally. pic.twitter.com/uwb0HJPyiw
— Akiyoshi Kitaoka (@AkiyoshiKitaoka) June 20, 2018
(Tip of the cap to Ben Orlin.)
Scholarship: Part of the Scientific Reward System
Also: scholarship ;)
— DynamicalSystemsSIAM (@DynamicsSIAM) June 20, 2018
Tuesday, June 19, 2018
Apple Seismology
Quoting the article's lead: Just as an earthquake’s seismic waves reveal properties of Earth’s interior, elastic surface waves on an apple can tell us about what’s going on inside the fruit.
This research may be a contender for an Ig Nobel prize.
Update: Apple seismology was discussed originally in a 1973 mathematical modeling paper by J.R. Cooke and Richard Rand. (This paper is cited in the Physics Today article above.)
An Alternative to a Faculty Retreat
#justsaying
Hitting a Major League Home Run Before One's First Major League Home Run
Quoting from the article to which I linked:
On Monday, the Washington Nationals rookie crushed a tiebreaking, pinch-hit, two-run homer against the New York Yankees in the continuation of a game that started May 15 — five days before his big league debut.
According to the Elias Sports Bureau, Soto's blast will not be considered his first major league homer, but it will be counted as a home run hit on May 15.
Saturday, June 16, 2018
"Female Drosophila melanogaster Respond to Song-Amplitude Modulations"
Title: Female Drosophila melanogaster Respond to Song-Amplitude Modulations
Authors: Birgit Brüggemeier, Mason A. Porter, Jim O. Vigoreaux,and Stephen F. Goodwin
Abstract: Males in numerous animal species use mating songs to attract females and intimidate competitors. We demonstrate that modulations in song amplitude are behaviourally relevant in the fruit fly Drosophila. We show that Drosophila melanogaster females prefer amplitude modulations that are typical of melanogaster song over other modulations, which suggests that amplitude modulations are processed auditorily by D. melanogaster. Our work demonstrates that receivers can decode messages in amplitude modulations, complementing the recent finding that male flies actively control song amplitude. To describe amplitude modulations, we propose the concept of song amplitude structure (SAS) and discuss similarities and differences to amplitude modulation with distance (AMD).
Thursday, June 14, 2018
Adrián Beltré Now has More Hits than All Other Non-US-Born Players
He passed Ichiro in the game that ended a few hours ago.
Saturday, June 09, 2018
Sunday, June 03, 2018
Excellent Notation for Predator–Prey Dynamics
LaTeX is so much better when you have emoji. pic.twitter.com/SYxgUXpWYN
— Mike Bostock (@mbostock) June 2, 2018
(Tip of the cap to Karen Daniels.)
Triumphant Return of The Power Law Shop
I'm happy to announce the triumphant return of The Power Law Shop!https://t.co/1sgZacqhhv
— Mason Porter (@masonporter) June 3, 2018
Just in time for #netsci2018 (@netsci2018).
We're trying to fill a universal and critical need for scale-free swag.
Saturday, June 02, 2018
Jack and Jill had Issues
Well, I just didn’t realise that Jack and Jill had so many mishaps as well as falling down the hill. Here are some, as recounted in this little 1806 chap book, just 212 years ago https://t.co/SnLDtBTCia pic.twitter.com/mBkro0bvmn
— Journal of Art in Society (@artinsociety) June 3, 2018
Mathematics is an Experimental Science
'Mathematics is an experimental science, and definitions do not come first, but later on.' -- Oliver Heaviside
— Analysis Fact (@AnalysisFact) June 1, 2018
(Tip of the cap to Steve Strogatz.)
Friday, June 01, 2018
A Brief Celebration of #NationalDonutDay
In honor of #NationalDonutDay, which is apparently today.
— Mason Porter (@masonporter) June 1, 2018
Also with some #topologicalentropy
P.S. There is a day for everything. pic.twitter.com/3zze0exZJr
Thursday, May 31, 2018
Tales from the ArXiv: "Calculating Spherical Harmonics Without Derivatives"
A part that some of you may find interesting is the pedagogical discussion at the beginning of Section 5, which starts: "Historically, there are five ways that spherical harmonics can be derived."
The one that is easiest (by far) for me to understand is the oldest method, which is by solving the differential equation. But I am mathematically inclined, and people with more physical intuition may prefer other methods.
(People who are more comfortable than I am with Lie manipulations may also prefer other approaches.)
Anyway, I appreciate the discussion in this paper.
Sunday, May 27, 2018
"Can Multilayer Networks Advance Animal Behavior Research?"
Title: Can Multilayer Networks Advance Animal Behavior Research?
Authors: Matthew J. Silk, Kelly R. Finn, Mason A. Porter, and Noa Pinter-Wollman
Abstract: Interactions among individual animals — and between these individuals and their environment — yield complex, multifaceted systems. The development of multilayer network analysis offers a promising new approach for studying animal social behavior and its relation to eco-evolutionary dynamics.