Tuesday, April 29, 2014

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.

Saturday, April 26, 2014

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!

Friday, April 25, 2014

"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.

Thursday, April 24, 2014


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.

Tuesday, April 22, 2014

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.

Sunday, April 20, 2014

The Eyes Have It

Here are some very cool pictures of animal eyes.

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

Saturday, April 19, 2014

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.

Friday, April 18, 2014

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.

Thursday, April 17, 2014

"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.

Wednesday, April 16, 2014

"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.

Tuesday, April 15, 2014

"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!

Monday, April 14, 2014

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.)

Sunday, April 13, 2014

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.)

Friday, April 11, 2014

"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.

Wednesday, April 09, 2014

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.

Tuesday, April 08, 2014

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.)

Sunday, April 06, 2014

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.

Wednesday, April 02, 2014


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!

Tuesday, April 01, 2014

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.


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.)