Hopf Bifurcations in the Dynamics of Love

As discussed in this paper, beware of Hopf bifurcations in the dynamics of love! Who knew that a Hopf bifurcation could be so emotionally deadly?

Update: Does anybody agree with me that this would make a fabulous movie title?

Community Structure, Web Cams, and Online Privacy

Here is an interesting new article about how network analysis can help invade privacy. And you know what the biggest cited culprit is? That's right: computation of community structure (which, as many of you know, is something I work on).

And, of course, I noticed when reading this that one of the linked pieces of evidence had a bad characterization of what modularity values indicate good community structure.

This is a good article, and when the author writes that ideas about network communities can be used to glean information people don't disclose, he is talking "community structure" in the technical sense. (And, yes, computing community structure can give one a very good idea about information that has not been revealed based on information in one's community that has been revealed. See, e.g. this paper of mine.)

Now I better read the final 6 pages of that Masters-dissertation draft. I keep avoiding finishing this...

(Tip of the cap to Peter Mucha.)

Best. Controller. Ever.

Seriously.

Cow Dung Flung

Some cows are more adventurous than others.

(Tip of the cap to Maria Satterwhite.)

Sigh...

I simply don't know whether to laugh or cry. Sigh...

Vin Scully will be back in 2012!

It's a year-to-year thing these days, so it's with great pleasure that I woke this morning to see a Facebook post from the Vin Scully page that he will continue to broadcast Dodger games in 2012. Sweet!

In other Dodger news, Matt Kemp became the second player in franchise history (Raul Mondesi was the first) to have a 30/30 season. (A "30/30 season" means a season in which a player hits at least 30 homeruns and steals at least 30 bases.)

Scientist of the Day

The scientist of the day, who I have chosen only because of the awesome match between his name and an article he wrote, is Ferric Fang, who studies iron. An e-mail from the Annals of Improbable Research pointed out this bit of awesomeness because of the following article:

The Role of Ferritins in the Physiology of Salmonella enterica sv. Typhimurium: A Unique Role for Ferritin B in Iron-Sulphur Cluster Repair and Virulence, Ferric C. Fang et al., Molecular Microbiology, Volume 63, Issue 5, March 2007 pages 1495?1507.

Mamma Mia!

Georgia Tech astronomers have found a new planet that seems to be made of diamond.

One has to go to the original paper to find this, but the same scientists also report what appear to be red plumber outfits on that planet. One of the scientists also claims to have heard muted words that sounded something like "Mamma mia!"

(Tip of the cap to the Georgia Tech Department of Physics.)

The Neuroscience of Comic Sans

The Onion has decided to delve into the deep, dark secrets of the neuroscience of Comic Sans. (I love the new center at Princeton!)

Cornell's New Rivalry with MIT

The last time I checked, the rivalry with MIT was supposed to be with my other alma mater (i.e., Caltech). And what is this Ivy+ bullshit? (A bit of MIT and Stanford wannabe-ism, it seems to me.)

The Art of Blocking the Plate

As any long-time Dodger fan can tell you, Mike Scioscia was an absolute rock behind the plate---he was simply awesome at plate-blocking.

Well, today's Dodger game had a pretty awesome plate-blocking incident in the top of the third inning. Juan Rivera of the Dodgers was trying to score from second on a single by Casey Blake, but Rivera missed the plate while coming down the line. The ball got past Cardinal catcher Gerald Laird, who decided (without possession of the ball) to block Rivera from the other direction as he went back to the plate from foul territory. This one is probably going to make some highlight reels.

The Impending War Against Algorithms

Apparently, there is going to be a war against algorithms. Guess which side I'm on? :P

(Actually, the article makes some important points, and I could certainly provide some comments from my own experiences.)

Finally, with this blog entry, I have reached a milestone. This is blog entry number 2500. Man, I produce a lot of text...

(Tip of the cap to whoever controls Matlab's Facebook account.)

Movies in Montreal

I saw three films at this year's Montreal World Film Festival.

The most important one to mention is the second one I saw. This film, called The Artist is a (mostly) silent film about a silent-film actor and how he deals with the coming of talkies. Not only is it meta, but it does meta exceptionally well: It is fantastic and is one of the most clever movies that I have ever seen. This one is slated to appear in US and UK theatres (presumably indie theatres) in the fall, and it is an absolute must-see. The film comes from France, and has both American and French actors in it. Awesome!

The first film I saw was Surnuaiavahi Tutar (The Graveyard Keeper's Daughter), which comes from Estonia. It was decent, and the strong-willed young girl protagonist was an interesting character.

The third film I saw, Aballay, El Hombre Sin Miedo hails from Argentina. I saw it because of the home-team connection. It was ok. I'm glad I speak Spanish, as occasionally some important meaning was lost in the subtitles. (The accents were rather thick, though, so at times I did need to rely on the subtitles.)

I doubt that either the first or third of these films will be released in theatres in the US, but you definitely want to go and see The Artist.

Juxtaposition

Today walked several miles along Rue St Catherine, where there are literally sex shops directly across the streets from churches. (Montreal is a strange juxtaposition of French and English, sex and Catholicism, and Celine Dion and smoked meat.) I went both farther west and farther east along St Catherine than I had ever previously done. I need to check to see whether I went all the way to the west end. I remember "vowing" in 2004 to one day walk the entire length of Rue St. Catherine.

By the way, one of the movies I saw today was fantastic. More on that in another blog post (after I watch the third of my three movies).

Jim Thome Hits 600th Career Homer

Jim Thome hit 2 home runs tonight and has become the eighth Major League player with at least 600 home runs. Very nice!

Adventures in the Montreal Airport

Here are some things that happened after my arrival in the Montreal airport.

1. I got a bit confused when I tried to dry my hands in the bathroom. A condom dispenser was where a hand dryer should be, so I held my hands and waited expectantly for about 20 or 30 seconds before realizing that the dryer was the object next to the dispenser. (It's kind of like the Mr. Coffee and Mr. Radar scene in Spaceballs.) Sometimes I wonder how I got this far in life.


2. I was in line at customs when I overheard the following conversation:

Teenage or college-age guy: Physics is everything, and everything is physics.

Young girl (maybe 13 years old): I thought everything is math.

(Comment: I approve!)


3. The Canadians gave me a bit of a hard time after I got through customs and I was trying to leave. First, a security guy bugged me while I was trying to get my luggage and asked to see my passport and my entry card, and he asked me to explain myself. (This lasted a few minutes and was a much more significant grilling than what I got from the customs officer.) Then I got asked stuff a third time when I tried to turn in my entry card and leave. What the Hell, people? I'm here to do math!

What Happens in Montreal Stays in Montreal (Take IV)

Tomorrow I am flying to Montreal for my 4th visit to that city, and Montreal just so happens to be one of my all-time favorite places to visit.

I will be there for a mathematics study group with industry, though while I am there, I will be partaking of indie films (and perhaps other things) at the Montreal World Film Festival and sipping the best hot chocolate I have ever had (yum!).

Update (08/19/11): Here are some pictures from Montreal.

Invention of the High Five

I just read a very interesting article that discusses the invention of the high five. Tommy Lasorda plays a role in it (and not a positive one at all) and might even hold a key missing piece of the puzzle.

Read it and Weep

The Onion really hits the nail on the head sometimes.

Anyway, this article has an absolutely wonderful title: Scientists Say Newly Discovered Earthlike Planet Could Support Robust Economy.

The article itself is meh, but the title is awesome!

Visualization: How Scientists at Various Stages See Each Other

There is absolutely no truth whatsoever in this visualization of how scientists at various stages see each other. None whatsoever...

(Tip of the cap to Tom Maccarone.)

Another Caltech Movie

Yes, that's right. It looks like there will be a fictionalized version of the documentary Quantum Hoops (which I still need to see).

Oh, and of course there is also this movie.

(Tip of the cap to Craig Montuori.)

Pi = 3.2?

Well, apparently the lovely state of Indiana once attempted to legislate the value of Pi to be 3.2. That was a rather irrational thing for the Indiana state legislature to attempt.

On a similar note, you should read the article Alabama Pi in this book.

(Tip of the cap to Jed Yang.)

Temporal Evolution of Financial-Market Correlations

Here's another new paper of mine that just came out.

Title: Temporal Evolution of Financial-Market Correlations

Authors: Daniel J. Fenn, Mason A. Porter, Stacy Williams, Mark McDonald, Neil F. Johnson, Nick S. Jones

Abstract: We investigate financial market correlations using random matrix theory and principal component analysis. We use random matrix theory to demonstrate that correlation matrices of asset price changes contain structure that is incompatible with uncorrelated random price changes.We then identify the principal components of these correlation matrices and demonstrate that a small number of components accounts for a large proportion of the variability of the markets that we consider.We characterize the time-evolving relationships between the different assets by investigating the correlations between the asset price time series and principal components. Using this approach, we uncover notable changes that occurred in financial markets and identify the assets that were significantly affected by these changes. We show in particular that there was an increase in the strength of the relationships between several different markets following the 2007–2008 credit and liquidity crisis.

Comparing Community Structure to Characteristics in Online Collegiate Social Networks

My first paper on Facebook networks, which was originally submitted to SIAM Review in September 2008, has finally been published in final form in that journal. The project itself was first formulated in December 2004 (and January 2005) and the initial work started with Eric Kelsic's Caltech SURF project at the end of June 2005. So it's been a long road. The sequel to this paper is already on the arXiv, but in the meantime let's savor the publication of the present paper.

Title: Comparing Community Structure to Characteristics in Online Collegiate Social Networks

Authors: Amanda L. Traud, Eric D. Kelsic, Peter J. Mucha, Mason A. Porter

Abstract: We study the structure of social networks of students by examining the graphs of Facebook "friendships" at five U.S. universities at a single point in time. We investigate the community structure of each single-institution network and employ visual and quantitative tools, including standardized pair-counting methods, to measure the correlations between the network communities and a set of self-identified user characteristics (residence, class year, major, and high school). We review the basic properties and statistics of the employed pair-counting indices and recall, in simplified notation, a useful formula for the z-score of the Rand coefficient. Our study illustrates how to examine different instances of social networks constructed in similar environments, emphasizes the array of social forces that combine to form "communities," and leads to comparative observations about online social structures, which reflect offline social structures. We calculate the relative contributions of different characteristics to the community structure of individual universities and compare these relative contributions at different universities. For example, we examine the importance of common high school affiliation at large state universities and the varying degrees of influence that common major can have on the social structure at different universities. The heterogeneity of the communities that we observe indicates that university networks typically have multiple organizing factors rather than a single dominant one.


Update (9/16/11): This article turns out to be the cover story of that issue of SIAM Review. Sweet!

Update 2 (9/18/11): Here is a better picture of my cover article. Now I just need my physical copy to arrive so that I can show it to certain people who insist that I am a physicist rather than a mathematician. :)

They shall know me by my trail of coffee.

See what I mean?

(This type of rant works much better with a whiteboard.)

Quote of the Day: Reasonable Edition

I just saw an awesome quote from George Bernard Shaw that I don't remember ever seeing before: The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

Comment: Amen!

Side Quest

I started a side quest while at the workshop at KITP.

I'm a Distraction.

Apparently, my t-shirts have the ability to distract airport security officers---good to know.

"Is that the one in Palo Alto?"

A snippet from an actual conversation:

"Are you a Caltech alum?"

"Yes."

"Is that the one in Palo Alto?"

(I am wearing a Caltech shirt today. The barista at the coffee place was the other person talking.)

Incidentally, my response was "That is Stanford. I wasn't cool enough to get into Stanford." (I love the fact that that comment has 2 nice meanings.)

Irony of the Day: Barabási's Publication Record Fit to Lousy Power Law

Somehow, I think that this paper was inevitable. In Fig. 2 on page 4, Albert-László Barabási's publication record is fit to a crappy power law. Unfortunately, it appears that the authors were attempting to be earnest in their efforts. (I think that this would have been a hilarious thing to do as a prank. I wish that I had thought of it!)

Seriously: Wow!

Update (8/04/11): Here is what Cosma Shalizi has to say.

Where is he from now?

This spy chief used to be an Afghan. I wonder where he's from now?

Tales from the ArXiv: Sleeping Well with Quantum Mechanics

When writing a paper in the field of psychoceramics, it becomes conceivable to end one's conclusions with the sentence "What is sure is that the author, with his new HAT, sleeps much better now!"

(Actually, I ought to find a way to have that kind of conclusion in one of my papers---or at least to find a way to sleep better!)

Internet Explorer Users are Dumber Than Average

Well, at least some recent data analysis suggests this.

Actually, the proposed mechanism of IE being the standard browser and people who might be dimmer overwhelmingly being ones who don't bother installing a different browser beyond the default does make sense. But it amuses me to think that maybe the connection runs deeper. :)

(Tip of the cap to Iain Macmillan.)

Update (8/03/11): Then again, maybe not. (Tip of the hat to Nick Jones.)