Hard to resist…

I’ve been in a bit of a funk — my tv and computer broke last month, we don’t have cable/internet in our temporary apartment, and I’ve been swamped with work — but I simply cannot resist posting this video:

[Today's Big Thing]

One of the things I always liked about our work with force chains was how much they seemed like lightning. Even in slow motion that seems to be the case. Compare, for instance, with the distribution of force during a simulated meteor impact:

Burgers, not just for grillin’

In th early 20th century J.M. Burgers’ attempted to model fluid flow by adding a nonlinear term to the linear diffusion equation. The idea never panned out for modeling fluids, but the nonlinear diffusion equation, now known as Burgers’ Equation has been studied quite a bit nonetheless. More recently (1988, 1992, and 2002) a form of the Burgers’ Equation was derived for the twist dynamics of twisted scroll waves. Scroll waves are the 3D analog to spiral waves (think of a scrolled up piece of paper). Scrolls are found in many types of excitable media and a number of experts believe they play a role in cardiac arrhythmia.

Until this week there had not been good experimental evidence published for scroll wave twist behaving according to Burgers’ Equation. But now you can read all about in in Europhysics Letters, “Evidence for Burgers’ equation describing the untwisting of scroll rings” (volume 83, article number 30010).

Oh, and I’m still waiting to hear about Entropy Maximization from one of my esteemed colleagues in blogging. And is each of us publishing in a journal on the other ones current continent of residence something Alanis Morisette would call “ironic”?

What happened to John?

Hi everyone. I’m still alive and life has been interesting. Ann and I bought a house that we’ll move into in August, but in the mean time we’re packing up and heading to an apartment in Chapel Hill. The lease on our rental house is up at the end of the month and the crummy owners wanted to get it on the market so as not to miss out on those oh-so-common July renters rather than give us an extension of less than a year.

In addition to that fun, I’ve been to both Huntsville and Jacksonville briefly and watched one of my EPA mentors head off for industry.

Finally, on Sunday night, as we were driving into RTP to get some paperwork for the next morning’s mortgage signing, we got caught in a freak rain storm that caused puddles to form on Martin Luther King Parkway (a newly built, divided four lane road). The first puddle was fine (I was going less than 20 MPH so we didn’t even hydroplane) but the second one was two to three feet deep and as we plunged in my engine cut out and still hasn’t restarted. The water was most of the way up the passenger door and we were stuck for a good fifteen minutes or so before the water drained and we could push the car off the road (with the welcome help of some samaritans).

Fortunately, Andy’s googling and Mary’s dashing rescue allowed us to get out of the lightning and retrieve the needed papers in time for the morning.  Unfortunately, I may have totaled my relatively new, unpaid-off car. Oh, why couldn’t we have hydroplaned over that puddle? (Feel free to discuss the physics of that, or lack thereof, in the comments section.) In the meantime I am driving a rental pick-up truck — you should have seen the rental agent’s draw drop when I asked for one — in order to help with moving. For some reason everyone wants a compact right now. All I know is I’ve already ordered my “W - The President” bumper sticker.

In the meantime, I have a great story on how two ball boys saved Michigan’s undefeated season in 1997 as well as a nominee for the blog roll:

http://www.fivethirtyeight.com/

It’s like crack for anyone who likes graphs, statistics or politics (a triple-whammy for me). Also in the intersection of cool graphs and politics is Presidential Watch 08, which has great tools for plotting the political blogosphere as well as trends. Without these very impressive analyses, would we have ever been able to tell that Fox news leans Republican?

Finally, if you can show that playing Minesweeper is NP-complete, you can win a million dollars…

The Physics Arxiv Blog

In the physics community it is common practice to submit “finished,” but not yet peer-reviewed, research papers to a preprint server so that they become time-stamped (useful for establishing credit) and freely available to the public. Often, once a paper is revised in response to peer-review and published, a “preprint” copy of the final version is placed on the server so that copies can easily be obtained without tracking down whatever journal it was published in (something that has gotten vastly easier thanks to Google Scholar). The arXiv preprint server started in 1991 at Los Alamos (where it had the dubious-sounding address of xxx.lanl.gov since the Web was not yet especially World-Wide) and now hosts papers in physics, mathematics, computer science, and quantitative biology. Anyone who wants may subscribe to have a listing of all the new and updated papers on a given topic regularly sent via e-mail. For me, at least, scanning through the daily cond-mat listing is one of the main ways I try to stay current in my field.

The newest addition to our blogroll is a very cool idea — The Physics Arxiv blog. The author combs through the daily update emails and writes about the interesting papers they see and you’ll never guess how I stumbled across it. Sometimes papers on arXiv are kinda crazy and take a long time to get published (if ever). Sometimes research is happening so quickly that entire research groups dictate what they do in response to the latest preprint (right Joe?). No matter what it’s a neat blog and a good way to stay current in physics.

A Post by John About Baseball

I meant to do this yesterday, when it would have been more believable, but here I am on a regular old day writing about baseball. In case you missed it, non-linear dynamics guru Steven Strogatz and graduate student Samuel Arbesman had a paper in the New York Times on using a game simulator to simulate every at bat for all of baseball 10,000 times. They then used this artificial data set to look for trends, including a really cool distribution of hitting streak records (the real record of 56 games is held by Joe DiMaggio). Apparently DiMaggio’s record — according to Wikipedia, “the top American sports feat of all time” — was actually to be expected. In the 10,000 samples the median record was 53 games.

Thinking of Brad…

Wired has a brief write-up on an oscillatory reaction that has also made Slashdot.  Of course, it’s the Briggs-Rauscher reaction and not Brad’s beloved Belousov-Zhabotinsky, but it’s still a nice video.  I wonder if the two reactions are natural enemies, as with robots and dinosaurs (remember, one is from the future, the other from the past).

Small and Wang

Unfortunately the wisdom of Biggus Dickus is lost to the ages, so we must make do with Numerical Methods for Nonlinear Estimating Equations by Small and Wang.

I have no further comment.

like sands through the hour glass…

…so are the Days of our Llives.

It is my hope that by being shameless enough to go first, that everyone else will start blogging their publications as they come along. I want to know all about reaction-diffusion systems, nuclear field theory, granular matter, and whatever else comes up. At least, I want to know as much about them as fits into an interesting blog post. And who knows, maybe one of the world’s Nelly Furtado fans (she is the Matron Saint of Lunchtime! visitors) will be inspired to read a research paper…

To start things off, I finally got my first research paper from Duke published in a peer-reviewed journal — a mere 17 months after defending. Behold “Response to perturbations for granular flow in a hopper!” (Please note, the exclamation point is within the quotation marks only to conform to a grammatical rule I don’t agree with, and not to indicate that the actual title is exclaimed, although that would have been cool.)

World’s Smallest Trophy

If ever there were a task that this blog was suited to, I think that winning the world’s smallest trophy is it.  The APS and Physics Central are sponsoring a Nano Bowl to promote interest in physics via a football-related video.  The winners get $1000 and a “nanoscale trophy” made of “silcon and metal.” 

They seem to be suggesting some sort of mechanical demonstration, but I think that a statistical/non-linear analysis might be much more interesting.  I remember reading about the physics of the “Mexican wave”

the vague and corrupting hope that, in a crisis, the government would bail them out

“In the financial markets, you have to care what other people think, even if what they think is screwed up. Crowd dynamics build on each other. But these things — hurricanes, earthquakes — don’t exhibit crowd behavior. There’s a real underlying risk you have to understand. You have to be a value investor.” John Seo

The New York Times has a great article on the catastrophe insurance, emphasizing that freaky behavior occurs in the long tail of probability distributions. It’s a Sunday Magazine feature article (meaning that it’s a hefty ten web-pages long but it has some really cool stuff on statistics, finance, and the life of a mathematician named Seo who has made it big in finance. After taking a temp job because the insurance at his new post-doc didn’t cover his wife’s pregnancy, he ended up with a $250000 salary and $40000 signing bonus after six weeks of work.

Apparently he’s a genius at pricing unusual events. Rather than being counter-intuitive, the article suggests that he has a knack for coming up with prices that actually seem fair.