What Happens in Silwood Park Stays in Silwood Park

This evening, I'll be taking the train (and, apparently, replacement bus service) to Ascot to get myself over to Imperial College's Silwood Park campus for environmental fluctuations, recovery, and resilience of biological networks, which is part of their program on Grand Challenges in the Ecosystem and the Environment (GCEE).

Take a look at a a map of the local area, which covers Silwood, Windsor Park, and Maidenhead. Based on the names of some of the places on this map, it looks like I'm going to be pretty close to a Hellmouth. Also, this map is a great example of how awesome the Brits can be sometimes with their naming conventions. It would be pretty damn awesome, for example, if "Cheapside" has evolved to be a posh, expensive location filled with luxurious mansions. ("Unfortunately, I can't afford to live in Cheapside.")

Update: I have reached the center for population biology that Imperial College has at their Silkwood Park campus, and there are rabbits all over the place here. There is something right with the world.

"A Simple Generative Model of Collective Online Behavior"

Last Monday, PNAS published, in their early edition (so there are no volume or page numbers yet), a new article by my collaborators and me about how to model complex systems in a way that incorporates data directly into a simple model. We also illustrate with this example a nice situation in which several different situations (in particular, different parameter values, where one gets different qualitative mechanisms in different regions of parameter space) give the same qualitative long-time behavior (and very similar quantitative long-time behavior) so that one needs to consider the temporal dynamics explicitly to distinguish between the mechanisms. There are many papers that seem to assume mechanisms based on statistical fitting of long-time (or even equilibrium) behavior, and that is very dangerous. Here are the details about the article.


Title: A Simple Generative Model of Collective Online Behavior

Authors: James P. Gleesona, Davide Cellai, Jukka-Pekka Onnela, Mason A. Porter, and Felix Reed-Tsochas

Abstract: Human activities increasingly take place in online environments, providing novel opportunities for relating individual behaviors to population-level outcomes. In this paper, we introduce a simple generative model for the collective behavior of millions of social networking site users who are deciding between different software applications. Our model incorporates two distinct mechanisms: one is associated with recent decisions of users, and the other reflects the cumulative popularity of each application. Importantly, although various combinations of the two mechanisms yield long-time behavior that is consistent with data, the only models that reproduce the observed temporal dynamics are those that strongly emphasize the recent popularity of applications over their cumulative popularity. This demonstrates--even when using purely observational data without experimental design--that temporal data-driven modeling can effectively distinguish between competing microscopic mechanisms, allowing us to uncover previously unidentified aspects of collective online behavior.

Significance Paragraph (which is now a part of PNAS papers): One of the most common strategies in studying complex systems is to investigate and interpret whether any "hidden order" is present by fitting observed statistical regularities via data analysis and then reproducing such regularities with long-time or equilibrium dynamics fromsome generative model. Unfortunately, many different models can possess indistinguishable long-time dynamics, so the above recipe is often insufficient to discern the relative quality of competing models. In this paper, we use the example of collective online behavior to illustrate that, by contrast, time-dependent modeling can be very effective at disentangling competing generative models of a complex system.


This paper has gotten a little bit of press coverage. You can find links to press coverage for this article (and other articles of mine) on the press part of my web page.

"Peer Review Ring" Busted

A "peer review ring" (kind of like a prostitution ring, except with more scientists) at Journal of Vibration and Control has been busted. The situation is described in this article, and you can find more information about this peer-review scandal in this article.

The now-former Editor in Chief of JVC is Ali Nayfeh, who has written some very nice books on nonlinear vibrations. (I have one of his books. There is some really good stuff in there.) He has apparently "retired" as EiC, though my expectation is that it is a combination of genuine retirement and embarrassment that this scandal took place on his watch.

The choice quote comes from Retraction Watch, who started their report in the busting of the peer-review ring with "This one deserves a 'wow.'"

(Tip of the cap to Jennifer Nicoll Victor.)

3D Fractal Sculptures

These fractal sculptures look awesome!

Tending Towards Infinity

At the conference I am attending, I just saw a t-shirt with the text "Old mathematicians don't die, they just tend to infinity." I approve!

Well, the grammar could be better --- there should be a semicolon instead of a comma --- but I still love the shirt.

Monday Cricketblogging

Here are some pictures of me playing cricket last Friday. Also notice that I am consuming ice cream in the team photo (and that the number 137 was requested with complete forethought and malice).

What Happens in Madrid Stays in Madrid

I have arrived in Madrid for the 10th AIMS Conference on Differential Equations, Dynamical Systems, and Applications.

The internet at this hotel is painfully slow. :(

Let's Call The Whole Thing Off

You say "universality"
I say "bullshit"
Let's call the whole thing off.

This is inspired by this song, obviously.

Rogue Demon Hunters (For Real)

Yes, really.

For a Good Time, Call (Desmond) Jennings

Joe Maddon has decided to tip his cap to Tommy Tutone for the Ray's lineup tonight. I approve!

Well, technically, there are a few additional digits in the lineup and I don't remember '0' being used for the DH position before --- but points to Joe Maddon for doing this on purpose! That's the type of thing I would do. :)

Remember, the magic digits are 867-5309. And if you ever call that phone number --- no matter what timezone you're in --- make sure to ask for "Jenny".

(Tip of the cap to whoever posts for MLB on Facebook, though I didn't realize from their post that Joe Maddon did this on purpose. I am linking to a different article than the one from their post.)

Revenge of the Carnivorous Flying Squirrel

The carnivorous flying squirrel is real (and not just a private D & D joke between one of my friends and me). I think I rolled more critical hits in the infamous CFSA incident, which was from my first time as a dungeon master, then I have any time since.

I have seen the CFS, which appeared in Monster Manual II in the first edition of AD & D, in discussions of the lamest D & D creatures. Here is a Pathfinder version of this critter.

Tales from the ArXiv: Predicting Talk Attendance at Conferences

This paper discusses the predictability of talk attendance at conferences.

I think it depends: Is the conference in Snowbird or Maui? :)

The one time we had a SIAM dynamical systems conference in Maui, the attendance as a function of time was, in one word, "impressive". I did make an important connection that I am pretty sure led to my postdoc job at Georgia Tech. The lesson here is clear: attend conferences in Maui.

A Spectral Navigation Algorithm

Clearly, some users of London's transportation system are using a spectral algorithm for navigation.

(Tip of the cap to Sang Hoon Lee.)

Pictures from the Networks MRC

Here are some pictures from the inaugural workshop of the Mathematics Research Community on Network Science.

Recall: I was at Snowbird in an even year!

We're Tied for First Place!

With today's victory over the Cardinals and the Giants' loss to the Reds, the Dodgers are now tied for first place in the National League West. Yay! We were dragging our feet for so long this season and were already 9.5 games back only three weeks ago (with the Giants playing extremely well), and this season felt lost for a while even though it was early. Anyway, it was early. The Dodgers have overcome their deficit and are now tied for first place. Awesome!

Cubicles & Careers

Cubicles & Careers hits a bit too close to home at times (although my +5 Ivory Tower helps quite a lot). Let's go on a quest!

(Tip of the cap to Meredith Alden.)

"The Most Coveted Prize in Network Science"

Yes, yes it is. (Thanks to Aaron Clauset for graphical wizardry with the picture of the trophy.)

And, as a bonus, this is the first time that I ever embedded a picture on this blog. I should have done this for several previous entries for which I relied on links instead. Once CafePress starts obeying, I'll add this design to The Power Law Shop.

Update (6/28/14): A design is now posted in the Power Law Shop in case you want t-shirts or other swag.

My Blade and Shield

Definitely.

When Robbing Somebody, Don't Forget to Log Off of Facebook Before You Leave

Yes, really: criminals are getting stupider. If you're going to rob somebody, I think getting caught because you logged onto Facebook on their computer and forgot to log off is pretty "awesome".

(Tip of the cap to Andrea Bertozzi.)

2014 Mathematics "Breakthrough Prizes"

The five inaugural recipients of the Breakthrough Prize in Mathematics have now been anounced, and the list includes some very familiar names. :) It's really great to see new prizes like this that highlight fundamental research.

(Tip of the cap to Facebook posts from Physics Today, Mariano Beguerisse Díaz, and others.)

Tales from the ArXiv: It's Party Time!

You know you need sleep when... You read "parity-time" in the paper title "Gap solitons and symmetry breaking in parity-time symmetric microring CROWs" as "party-time".

Let's have a ball!

What Happens at a Mathematics Research Community Stays at a Mathematics Research Community

I am at the airport to head to the Snowbird Ski Resort in Utah (in --- gasp! --- an even year) to help run a Mathematics Research Community in Network Science.

Maybe there is even a future recipient of the coveted Karate Trophy among the network of network scientists that we'll be cultivating?

Runnin' Wild

I meant to post this video earlier. In it, you will see three runners score on a wild pitch in concert with a wild throw. I haven't seen a wild-pitch play clear the bases like this before.

Avoiding a Death Sentence with Coffee

Wow, this story is the first time that I have ever heard of the choice between drinking coffee regularly versus an immediate death sentence. (Eat your heart out, IRB?)

"A Quantitative Phrase of Deliberate Vagueness"

I love the phrasing "a quantitative phrase of deliberate vagueness" that this very interesting article on Yasiel Puig's defection uses to describe the phrase "a number of", which is something that I find irksome when it is used as a descriptor in scholarly articles.

The sentence in which this phrase appears is the following: A story has emerged from Despaigne's affidavit, the lawsuit, and its proceedings. It spawned a five-month investigation by The Magazine that included analysis of an array of legal documents and interviews with more than 80 people: Cuban baseball players in the U.S. both retired and active, talent scouts, sports agents, former MLB and players' union executives, federal law enforcement personnel, former Cuban government officials, former Cuban and American spies, Miami lawyers who have represented and are representing alleged smugglers who were and are the targets of criminal investigations, and --- to use a quantitative phrase of deliberate vagueness --- a number of smugglers themselves, who agreed to be interviewed under conditions of anonymity motivated by obvious fears.

Additionally, the article title refers to an old baseball expression that has been used for decades to describe the often-legendary impatient while batting of many foreign-born Hispanic baseball players (especially those from the Dominican Republic). It apparently goes back at least as far as Rafael Ramirez in 1986, though baseball prospects in the Dominican Republic appear to have used it long before then. I really like the article title, as it takes an old baseball expression and then changes its meaning in an interesting way.

"I Stand By My Theory"

Today's Saturday Morning Breakfast Cereal is a big win---especially the last panel.

Fact of the Day: "Unibrow" is in the OED

Fact of the day: "unibrow" is indeed in the Oxford English Dictionary

Laplace's Equation: The Game

Thanks to my Somerville undergraduates for the very nice gift and card that they brought to today's leavers party. (The game is called Squint.)

No-Hitter for Clayton Kershaw!

Well, I slept through most of it (except for a few minutes), but Clayton Kershaw has pitched a no-hitter! The Dodgers' Josh Beckett also pitched a no-hitter less than a month ago. Yay! Also, we're playing well now and have crept back within 4 games of first place. Also, Kershaw had 15 strikeouts and no walks in the no-hitter --- this was one of the all-time great pitching performances!

It's My Zero-Gravity Espresso Machine, and I Can't Leave Home Without It!

If I ever go into space, I am going to insist on taking a zero-gravity espresso machine along with me.

(Tip of the cap to whoever posts for Physics Today on Facebook.)

RIP Tony Gwynn (1960–2014)

Today we have lost a baseball legend: batsman extraordinaire Tony Gwynn has died. Gwynn was way too young (and I have been writing way too many obituary blog entries lately, because too many people that I consider iconic or are connected to in some way have died). He was a fantastic hitter. He was also a class act.

Update: Jayson Stark put some of Gywnn's hitting achievements into perspective.

Update 2: At the bottom of this article by Jayson Stark, we can note additional amazing batting feats by Tony Gwynn. The comparisons between Gwynn and Adam Dunn are interesting when looking at strikeouts. Take a look at Gwynn's stats to see how little he struck out, and compare that to what the game is currently like. Just soak it in.

RIP Casey Kasem (1932–2014)

Casey Kasem, whose soothing voice presented weekly top 40 songs when I was a kid (and for many years before then), died yesterday. One thing I hadn't realized is that Kasem was also the voice of Shaggy in the cartoon Scooby-Doo!

Another recent death is that of Ann B. Davis (1926 –2014), who played the character Alice on The Brady Bunch (whose reruns aired when I was a kid).

The Science of Sir Mix-a-Lot

Well, I hope that the scientific article that describes this study has an allusion to Sir Mix-a-Lot. If I were a coauthor on the article, it certainly would have.

(Tip of the cap to Erik Bollt.)

Sea is for Cookie

That's good enough for me!

(Tip of the cap to John Baker.)

Pictures from Germany

This is a bit late, but here are my pictures from Germany from my trip there a few weeks ago.

Pictures from Sicily

Here are a bunch of very nice pictures from Sicily.

(Sadly, my camera lens has an issue, so I need to buy a new camera, but I still like the pictures a lot. The place is very pretty.)

Update (6/17/14): Here is a group photo from last Thursday's excursion at the summer school. The random dog photobombed us. (Tip of the cap to Sang Hoon Lee.)

Nice Throw!

Damn! Now that is a nice throw! So is this one from last year. In the first link above, Rob Neyer also discussed some other good throws and outfield arms more generally.

(Tip of the cap to numerous sources for this year's throw.)

What Happens in a Remote Village Stays in a Remote Village

Just about two hours ago, I finally made it to the remote village of Malfa on the remote Sicilian island of Salina. The first Mediterranean School of Complex Networks is being held here, and I'll be giving one of the "cocktail talks" that go with the school.

I didn't get any sleep last night, I took the coach from Oxford to Heathrow at 4am. Then I flew to Rome, and then to Catania. Then I took a 2-hour bus to a port city, though at some point the bus broke down in rural Sicily and we were stranded in a gas station for 45 minutes before a replacement bus came. And then I missed my 1.5-hour hydrofoil trip as a result of that, though it turns out that it was cancelled anyway. Then my backup hydrofoil to Salina (the last one of the night) was almost cancelled due to its malfunctions but was an hour late instead. And then the cab driver who was arranged to pick me up dropped me off first at the B&B and then at the restaurant where the summer-school banquet was in progress.

I'll take pictures of the place later. It's a pretty island, and the village is basically located on a volcano.

Update (6/12/14): An alternative---and arguably better---title for this blog post would be "What Happens on a Remote Mediterranean Island Stays on a Remote Mediterranean Island".

"Inventive • Reserved • Efficient • Analytical • Sensitive"

An analysis of the words in my Facebook posts comes up with the descriptors "inventive", "reserved", "efficient", "analytical", and "sensitive". I can't argue with the results.

(Tip of the cap to David Williams.)

RIP Bob Welch (1956–2014)

Former Dodger Bob Welch died on June 9th (i.e., yesterday, given that I haven't gone to bed yet), supposedly of a heart attack. You can read more about Bob Welch, who also had a great deal of success with the Oakland Athletics, on his Wikipedia and Baseball-Reference.com pages. Welch won an epic battle against Reggie Jackson early in his career --- in the 1978 World Series --- and he was the last pitcher (1990; 27-6) to win 25 or more games in a season. Seeing this news makes me think of Don Drysdale's death in 1993. Their ages were very similar (and way too young).

Happy Tetris Day!

Today is the 30th anniversary of the initial release of Tetris.

(Obviously, it's the 70th anniversary of D-Day as well.)

Buzzword Bingo: NetSci 2014

For your enjoyment, I present to you the first buzzword bingo board for NetSci 2014.

"Effect Diminished Under Empirical Scrutiny."

Today's Saturday Morning Breakfast Cereal has the following choice line:

What's the scientific way to say "We fucked up?"

"Effect diminished under empirical scrutiny."



Yup!

The Phillie Phanatic's Bar Mitzvah

The Phillie Phanatic took its turn up in the proverbial chair for its Bar Mitzvah. That's pretty damn funny.

Estimating Expected Age from a Name

Fivethirtyeight.com has some very cool infographics that summarizes some basic features of distributions of names for people based on age. Very cool stuff!

One of the plotted examples is "Joseph", which has a median age of 37. The median "Mason" is age 6. I am around that age mentally, so I guess it fits. (Or maybe I'm just ahead of my time?) One thing I noticed is that the female names with old medians include many that I definitely associate with older people (but I don't feel the same association for the male names with old medians), though that might well be a function of things like The Golden Girls --- which was brought up in the article --- and panels from The Far Side.

(Tip of the cap to Anna Iwaniec Hickerson.)

What Happens at NetSci Stays at NetSci (2014 Edition)

Tomorrow I'll be flying off to the US to head over to Berkeley for NetSci 2014, where I will be giving way too many talks. It promises to be the best NetSci ever!

Booze Under the Microscope

Here are some awesome pictures of booze under the microscope. I approve!

YouTube Goes Nonlinear!

YouTube goes nonlinear!

Yup, that's right: Steve Strogatz has posted videos of his lectures from his course on an introduction to nonlinear science on YouTube.

If you want to get an introduction to nonlinear science from one of the master expositors, now is your chance.

Even if you don't have much of a math background, you'll get a lot out of watch this. So nerd groupies are encouraged to watch. :)

(Tip of the cap to Steve for passing along the link --- and, especially, for posting the videos!)

Timelapse Video: Ants Devouring a Gecko

This video of ants devouring a dead gecko is kind of gruesome, but it's also fascinating. They picked it clean!

Josh Beckett Pitches a No-Hitter!

Josh Beckett of the Dodgers has pitched a no-hitter! This was the first no-hitter of 2014 and, more importantly, it was the first no-hitter by a Dodger pitcher (i.e., it was "our" first no-hitter) since Hideo Nomo threw one in Coors Field in 1996. And because today's game was a day game, I got to watch it even with the 5-hour time difference between the UK and Eastern time. Yay!

Josh Beckett was running on fumes for the last couple of batters in the 9th inning. Beckett used to be a much more dominating hurler than he is now. He must have had a couple of low-hit games before (though this is his first no-hitter).

Coach Manny Ramirez

In bizarre news the Cubs have signed Manny Ramirez to be a player-coach at AAA. The idea of Manny Ramirez coaching anybody makes me LOL.

RIP Richard L. Liboff (1931–2014)

Steve Strogatz just e-mailed me to let me know that Richard Liboff, my PhD supervisor, has died. The obituary only came out yesterday, but Richard died on 9 March. The comment, which is recalled in the Cornell obituary, that Richard made about his book in the Spiderman movie was quintessentially him. (I remember that incident when Cornell first had a press release about it.)

Richard seemed pretty crazy at times (though, to be honest, I bet that my students would say the same thing about me!), and we ultimately had a falling out (and I couldn't get him to respond to e-mails after fall 2003 or early 2004), but I do have a soft spot for him --- and I have some of my own stories to tell, of course. Richard was quite a character, and Cornell's obituary conveys it very well. In some ways, this is like the closing of a final bit of my graduate-school chapter, although I still have strong contacts with many of the Cornell faculty.

Here is a link to Richard's wikipedia page. He is best known for his quantum mechanics book, of course. (Given how well-known his book is, I'm rather surprised that his obituary hasn't circulated much more widely. It certainly deserves to be. Through his textbooks, Richard made extremely important expository contributions to generations of young physicists and other scientists.)

I published my first science paper jointly with Richard. It is nowhere near my best paper, but it will always be my first one.

Update (5/25/14): I noticed that this blog entry was getting several hits, so I tried to figure out the mechanism via Google (no luck yet). In the process, though, I found something really interesting that I never knew: Richard self-published a novel! (Given the details of the Amazon page, I am assuming that it was self-published.)

The Science of Failure

One popular thing to study in complex systems these days is the so-called science of success.

One of these days, I hope to have a suitable project within studies of citation networks or other things related to 'success' so that I can use the title "The Science of Failure" for some of my presentations.

Update (6/06/14): As Mikko Kivelä pointed out to me when I first wrote this post, "The Science of Mediocrity" would also be an excellent title of a talk to give in this area.

Singular 'They' and Personal Pronouns of Indeterminate Gender

Damn you, English, for not having a non-awkward singular personal pronoun of indeterminate gender.

Apparently, the singular 'they' --- which I like to use informally, but which I have ingrained in me from my education as being technically incorrect --- used to be considered correct until a 19th century backlash. (Also see a discussion on Wikipedia of various alternatives to a generic 'he'.

Bah, I think we've gone backwards.

Update: I didn't state this explicitly, but I have third-person in mind.

Update 2: Travis Hime reminds me of an issue of Dinosaur Comics about this issue (though 'they' was used historically in the singular to achieve gender neutrality until the backlash).

RIP Martin Gutzwiller (1925–2014)

It went under my radar, but Martin Gutzwiller (a pioneer in quantum chaos and other fields of physics) died on 3 March 2014. I was looking him up because I am sitting in a small library (and, seemingly, game room) in MPIPKS and I noticed a collection that was donated by a former Martin Gutzwiller Fellow, which I didn't realize they had here. Here is Gutzwiller's MPIPKS page.

New Journal for Data Sharing from Nature Publish Group

I strongly approve of Nature Publishing Group's new journal that focuses on data sharing. This will do a lot of good! Sometimes, one has a nice data but suboptimal ways of sharing it, and a short paper that introduces the data set is a nice alternative to a mega-analysis with that data when one really wants to focus on the data itself for its own sake just to see what other people do with it. The barrier to have to see what one finds with the data shouldn't automatically have to be a barrier for publishing the data itself in a manner that is convenient for sharing and getting credit for hard work in assembling it.

(Tip of the cap to Sang Hoon Lee.)

What Happens in Dresden Stays in Dresden

I am taking the train from Berlin to Dresden, where I will be visiting the Max Planck Institute for the Physics of Complex Systems. I'll give a seminar while I am there, of course.

Here is some thematic music for the occasion.

Two-Dimensional Rubens' "Tube"

Here is a two-dimensional version of a Rubens' Tube, which is a flame-based apparatus for demonstrating standing waves. Very cool!

Discontinuity (for my Love)

Some words of wisdom that I gave to some of my freshers today: "Discontinuity" is a better word for this than "jump"... though admittedly it wouldn't have sounded as good if the Pointer Sisters had sang "discontinuity for my love".

What Happens in Berlin Stays in Berlin

This evening, I'll be flying to Berlin to visit one of my high school friends for a couple of days. I'll be there until Sunday afternoon, when I will hop on a train to Dresden.

Here is some thematic music for the first leg of my trip.

This is my first trip to Germany, which marks my second new country for 2014.

Nomenclature of Academic Events

Jorge forgot "journal club" in this handy flowchart for naming academic events.

(Tip of the cap to Amir Zarrinpar.)

Physicians Versus Physicists

At lunch today, there was some confusion on whether one of my colleagues was a physician or a physicist (he's the latter). My contribution went along the following lines:

'Both medicine and physics include operations, but many more of them are reversible in physics.'

[The gist and important specific words are accurate; this is not the exact sentence construction.]

Expense Claims and Fortune-Cookie Fortunes

Hmmm.... I should start including fortunate-cookie fortunes (as easter eggs) with the mounds of receipts that go with my expense-claim forms.

Maybe something like "Confucius says switching to per diem will bring good luck."

The Exploding Whale

Is this video the one that brought down UGCS when I was a frosh at Caltech?

This website has a rather comprehensive account of the exploding whale, anniversaries of the event, and information about some of the key players in the event (or at least in its broadcast).

A Terse Summary of My Feelings on Research-Project Supervision

Here is a terse summary of my philosophy on the projects that I supervise:

Question on assessment form: "Did the student complete the agreed upon work by the end of Hilary Term?"

My answer: "I don’t understand this question. Sorry. Projects end when you run out of time."


When it comes to publishing papers, this is qualified with things like "or you get bored or we decide it's time to work on something else", etc. But projects don't end. You run out of time, run out of money, get bored, decide to move on, need to get a job, etc. But there is always something else that one could do.

Roll for Charisma!

No, really: Roll for charisma!

Our Work on Modeling of Bipolar Individuals in The Guardian

The title of the entry basically already says everything, but Marc Abrahams (of Ig Nobel Prizes fame) has written an article about our work on modeling bipolar individuals in The Guardian. An excerpt of the blurb also appears in the Improbable Research blog.

The peanut gallery is skewering us. (Well, there is a mixture of coherent opinions that happen to be different from mine --- which I respect, as one could then have an intelligent discussion with such people about the merits or lack thereof of our research --- and then people who are just either trolling or being vitriolic.) I still need to learn not to read the comments section when one of my articles makes the press. Inevitably, those comments are not going to improve my mood.

In case you were wondering, if you look in the papers that have cited our paper (even though there are not many such papers), you will see that some of our ideas have helped subsequent work, that there is now more scientific evidence that the toy model that we cooked up does seem to capture some things (a similar model has now been derived mechanistically drawing from biochemical considerations), etc. The idea is that one can start with a toy model as a perspective to try to get at the simplest possible mechanisms and use such things --- in combination with clinical data to estimate parameters in such simplistic models --- to really try to get somewhere. This is a complementary way to "Big Data" approaches, and I think that trying to use simple (and even extremely simplistic) models can guide experiments, clinical studies, and so on. Our work on its own cannot do this, as we didn't use real data (which we didn't have), but modelling can inform clinical studies (and experimental studies more generally), and data from such studies can be incorporated into simple models to really try to get somewhere. Our paper is one extremely small stone in this endeavor, but I do believe that it is genuinely a stone.

Somewhere, In a New Mexico Desert...

Oh, wow. The legend is actually true!

You want to see me include a lot of exclamation points and mean it? Well, now you get to! Now this is AWESOME!!!!

P.S. I actually beat that game. It was painful. Because of control glitches and other glitches, you keep getting stuck in a damn well. And it takes more than 30 minutes of real time each time to get the damn alien out of the well. And the game just sucked in general as well. There is a good reason that these cartridges were buried.

Update: A desert, not a "dessert". Please excuse the typo in the original title.

MRI Scans of Produce

Here are some MRI scans of produce. Just because.

Baseball's Borders

This visualization of Major League Baseball's borders (in terms of which team is "the team" for different geographic areas) has been circulating online. I like its depiction of baseball rivalries.

The first thing I noticed is how much more area the Giants occupy than the Dodgers. However, I really want to see how the visualizations looks when one uses a cartogram to normalize based on population size.

(Tip of the cap to Tom Maccarone [who sent it to me most recently], Jennifer Victor, and others.)

Semester Program: Dynamics of Biologically Inspired Networks" (Spring 2016)

Our Mathematical Biosciences Institute (MBI) semester program on the mathematics of biologically inspired networks is now officially online.

Mark your calendars!

"Top Theoretical Physicists, R&B Singers Meet To Debate Meaning Of Forever"

Well, The Onion has just produced another big win. My choice "quote" comes from Ed Witten:

"This assertion then raises a problem of even greater complexity: how to adequately measure the depths of one’s love, a task we now know is impossible thanks to groundbreaking work by a research collective from Caltech and Motown Records."

"However, as for the commonly held assertion that forever is tonight, even a cursory knowledge of quantum mechanics suffices to prove this notion false," Witten added.

Nevermore!

Apparently, ravens keep track of the rank order of other ravens in dominance hierarchies.

We need to add a citation to this paper in our revision of our own work related to dominance hierarchies, if for no other reason than to be able to make Edgar Allan Poe jokes in our presentations.

Albert Pujols Hits 500th Career Homerun

Albert Pujols just hit his 500th career homerun. Very nice!

Here are Major League Baseball's all-time homerun leaders. ESPN's story on Pujols's milestone is on this page.

Awesome Pictures of Snails

Yup, you read that correctly: here are some awesome pictures of snails.

The Eyes Have It

Here are some very cool pictures of animal eyes.

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

Showing Students Where To Look

This is what I try to do when I teach, but I feel like the way we have things organized at Oxford and the frequent, persistent questions trying to get ultra-precise statements of what is "examinable" run counter to what I think is the best philosophy for how to teach. And the rules of the game that this university has established simply encourages (and, arguably, demands it in practice) such nonsense. So. Damn. Frustrating.

A Shotgun Approach to Calculating π

Here is a literal(!) shotgun approach for calculating an approximate value for π. I approve! (I think...)

Now let me quote from the arXiv paper (which is called "A Ballistic Monte Carlo Approximation of π"): "We compute a Monte Carlo approximation of {\pi} using importance sampling with shots coming out of a Mossberg 500 pump-action shotgun as the proposal distribution."

Chickens and Baseball

In the 1950s, some psychologists taught a chicken to only eat when it hit safely in a toy version of baseball.

San Diego Chicken, ear your heart out!

(Tip of the cap to whoever does Facebook posts for MLB.)

Update (4/22/14): Here is what the Improbable Research Blog has to say about chickens and baseball.

Advertising Win

I love this advertisement that IFLS posted.

"We've Always Done It This Way"

I wholeheartedly agree with the sentiment in this IFLS post.

It says that the most dangerous phrase in the English language is "We've Always Done It This Way". Every damn person in Oxford should take note of this. This place is guilty of such nonsense beyond belief.

My best answer to a particularly egregious one in a Mathematical Institute committee meeting went something along the lines of an immediate ripost of "Then we'll finally be correcting a longstanding inadequacy."

(And I have found several situations where, unsurprisingly, the "always" turned out only to be a couple of years --- including the example above.)

"Prey Switching with a Linear Preference Trade-Off"

For the third day in a row, one of my papers has appeared in final published form. Here are the details.

Title: Prey Switching with a Linear Preference Trade-Off

Authors: Sofia H. Piltz, Mason A. Porter, and Philip K. Maini


Abstract: In ecology, prey switching refers to a predator’s adaptive change of habitat or diet in response to prey abundance. In this paper, we study piecewise-smooth models of predator-prey interactions with a linear trade-off in a predator’s prey preference. We consider optimally foraging predators and derive a model for a 1 predator-2 prey interaction with a tilted switching manifold between the two sides of discontinuous vector fields. We show that the 1 predator-2 prey system undergoes a novel adding-sliding-like (center to two-part periodic orbit; "C2PO") bifurcation in which the prey ratio transitions from constant to time-dependent. Farther away from the bifurcation point, the period of the oscillating prey ratio doubles, which suggests a possible cascade to chaos. We compare our model predictions with data on freshwater plankton, and we successfully capture the periodicity in the ratio between the predator’s preferred and alternative prey types. Our study suggests that it is useful to investigate prey ratio as a possible indicator of how population dynamics can be influenced by ecosystem diversity.


P.S. Check out the name we introduced for the new bifurcation that we discovered.

"Dynamics on Modular Networks with Heterogeneous Correlations"

Another one of my papers came out in final form today. (That's two days in a row, and there is a third that will be out imminently.) Here are the details.

Title: Dynamics on Modular Networks with Heterogeneous Correlations

Authors: Sergey Melnik, Mason A. Porter, Peter J. Mucha, and James P. Gleeson


Abstract: We develop a new ensemble of modular random graphs in which degree-degree correlations can be different in each module, and the inter-module connections are defined by the joint degree-degree distribution of nodes for each pair of modules. We present an analytical approach that allows one to analyze several types of binary dynamics operating on such networks, and we illustrate our approach using bond percolation, site percolation, and the Watts threshold model. The new network ensemble generalizes existing models (e.g., the well-known configuration model and Lancichinetti-Fortunato-Radicchi networks) by allowing a heterogeneous distribution of degree- degree correlations across modules, which is important for the consideration of nonidentical interactingnetworks.


The basic idea is that we have developed a new random-graph ensemble that allows one to consider heterogeneous levels of homophily (which, in this paper, we use as degree homophily) in different parts of a network. You can also relate this to metapopulations in biology. We examine some simple dynamical processes on such ensembles.

The Hotter Institute of Technology

Caltech is apparently now the hotter institute of technology, according to a new prank by Caltech students during MIT's prefrosh weekend this year. I approve!

(Tip of the cap to Heather Dean.)

Update (4/17/14): the California Tech has an article about how things went down.

"Convergence Time towards Periodic Orbits in Discrete Dynamical Systems"

One of my papers was published in final form today. Here are the details.

Title: Convergence Time towards Periodic Orbits in Discrete Dynamical Systems

Authors: Jesús San Martín and Mason A. Porter


Abstract: We investigate the convergence towards periodic orbits in discrete dynamical systems. We examine the probability that a randomly chosen point converges to a particular neighborhood of a periodic orbit in a fixed number of iterations, and we use linearized equations to examine the evolution near that neighborhood. The underlying idea is that points of stable periodic orbit are associated with intervals. We state and prove a theorem that details what regions of phase space are mapped into these intervals (once they are known) and how many iterations are required to get there. We also construct algorithms that allow our theoretical results to be implemented successfully in practice.

"Bird Flocks Shatter on Impact"

Research shows (technically, "suggests") that bird flocks shatter on impact. That is all.

(By the way, the reason it is "suggests" is because these are numerical simulations.)

(Tip of the cap to whoever posts for Physics Today on Facebook.)

What Happens in the Bay Area Stays in the Bay Area (Spring 2014 Edition)

I am up obscenely early for my travel to the Bay Area. I'll be hanging out with my peeps and also giving a talk in the Stanford Networks Forum. Bring it on!

Monopoly Streets in Real Life

Here are what the streets in Monopoly (in the Atlantic City version, which is the original distributed version) look like in real life.

(Tip of the cap to Shahram Shokrian.)

Tales From the ArXiv: A Violent Sci-Fi Novel or Mathematical Physics?

The title of this paper amuses me greatly. It is called "Killing tensors, Warped Products and The Orthogonal Separation of The Hamilton-Jacobi Equation". Stay tuned for our exciting conclusion!

"Looking for Tom Lehrer"

I'm still in the middle of this new article about Tom Lehrer, but clearly I need to pass this along.

The article has some neat stuff in it --- take a look, for example, at who he hung out with in college.

(Tip of the cap to Steve Strogatz.)

"The Competitive Foursome"

The so-called Competitive Foursome work some magic with the strings and piano, and they provide some laughs as well. Very, very cool!

(Tip of the cap to Alan Champneys.)

An Eigencheese Sandwich

This spectral graph theory workshop is clearly getting to me: a few minutes ago, "egg and cheese sandwich" sounded like "eigencheese sandwich" to me.

Awards for Top Relievers Named After Mariano Rivera and Trevor Hoffman

Major League Baseball has instituted a new award for top relievers. The one for the American League is named after Mariano Rivera, and the one in the National League is named after Trevor Hoffman. I approve!

Update: Rob Neyer has written an interesting piece describing the history of awards for Major League relievers.

Darth Pooh

In case you were curious about what Winnie the Pooh might sound like as a Sith lord, wonder no further. I present to you... Darth Pooh.

(Tip of the cap to Michael Woods.)

Honeybee Sting Pain as a Function of Body Location

In case you are wondering, here is a new paper that concerns the pain of honeybee stings as a function of body location.

I love the section on author contributions: Michael L. Smith conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper, and was the experimental subject.

Ouch! (For SCIENCE!!)

Also, if you have have access to the website, you might also want to read about Stuperspace. (The authors have Caltech affiliations...)

(Tip of the cap to Ioannis Kourakis.)

2014 Dodgers "Proudly Sponsored" by a Cemetery

I am listening to the Dodger game because the EPSN brodcast has resulted in a national blackout (grrr....), so I can't watch the game on my computer.

And I just heard a promo that the 2014 Dodgers are "proudly sponsored by Forest Lawn Memorial Park" (a local cemetery).

That was the straight line; you provide the joke.

Chiiiipwiiiiiiiiiiich!

The clarion call in the title of this entry refers to the delicious dessert known as a Chipwich, which sadly no longer exists in its original form.

I almost bought a Chipwich variant at CVS, but it's just not the same when (1) it is not as good as the original and (2) it isn't thrown in the general direction of your head at a high speed. (Many of the substitutes are really good, and I am sure that this one is just fine --- even though I don't think it had any chocolate chips stuck to the side --- but the mood of the moment was for the original version.) According to the Wikipedia page, the particular variant that I saw today appears to be the reason that the original Chipwich doesn't exist anymore.

For those of you who are unfamiliar with particular bits of Caltech --- or at least Lloyd House --- history from the mid to late 1990s, Chipwiches are also the reason that I sometimes brought a baseball glove with me to Lloyd House dinners on Friday nights (and why I sat with my back to the wall on those nights, if I could possibly help it). Frozen chipwiches chucked at high speed hurt a lot if they manage to hit you. But with a baseball glove and one side protected, I was well prepared.

By the way, the clarion call was sometimes pronounced more like "Chiiiiiiiiiiipwiiich".

Funky Animal Defense Mechanisms

IFLS has an interesting article about funky animal defense mechanisms. Take a look!

Videos of Two of My Talks

In February 2013, I gave a talk on Cascades and Social Influence on Networks at Cornell University. I was giving the Center for Applied Mathematics colloquium (i.e., the colloquium in the program from which I got my PhD). This was my first visit to Cornell since I graduated in 2002. During the past few days, I gave updated versions of this talk at Simon Fraser University and University of British Columbia.

In December 2011, I gave a plenary talk on Social Structure of Facebook Networks at a conference in Henley.


Enjoy!

Fooling Around in April

This entry from CafePress is a big win. (Tip of the hat to Heather Dean.)

In a Facebook post, Tears For Fears announced a new collaboration with Kid Rock.

As usual, there are also some appropriate papers on the arXiv. I noticed one on my own that just isn't funny, so I'm ignoring it. But Kevin Hickerson and Physics Today found A Necro-Biological Explanation for the Fermi Paradox, which has been submitted for publication in The Necronomicon.

My former colleague Lew Lefton from Georgia Tech was on the receiving end of a joke this year. (Tip of the cap to the School of Physics at Georgia Tech.)

For those with some time on their hands, there is the Google Maps Pokemon Challenge.

The Guardian also included a report about a curious and symmetry-breaking outcome of Scottish independence. (Tip of the cap to Cecilia Mascolo.)

Here is a summary of fake products from a few tech companies. (Tip of the hat to Sham Kakade.)

The White House got into the action with a President's Council on Beards. (Tip of the cap to whoever posts for MLB on Facebook.)

Depeche Mode has an April Fool's Day prank with new t-shirt designs with lyrics on them, but this joke was really lame.

Update (4/04/14): I'm posting this belatedly, but here is a summary of some of the April Fools Day pranks from various tech companies and some others. I like the one from CERN. :)

Update (4/04/14): NPR's prank was brilliant. (Tip of the cap to Lada Adamic.)