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Rebirth Island and the Sensitivity of Location

The Aral Sea has been shrinking rapidly since the Nineteen Sixties, as I mentioned a while back on the Mesofacts blog. But there’s something I didn’t previously touch upon: the issue of Rebirth Island in its center.

Over the weekend, my wife and I were looking at an old Rand McNally atlas I had first received back when I was in middle school. In it, the Aral Sea is large and liquid and doing just fine. And in its center is the island of Vozrozhdeniya, or Rebirth Island. It stood out to us because there was a national border running directly through its center, dividing it between Kazakhstan and Uzbekistan.

But in recent years, due to the vanishing Aral Sea, the island is no longer an island. It first became a peninsula in 2001, and is now an undifferentiated part of the mainland. The name “Rebirth Island” now rings in one’s ears as a sad taunt about its nonexistence.

But here’s the wrinkle: during the Cold War, the Soviet Union used Rebirth Island as a laboratory for biological warfare. While the lab is now abandoned, it was located there due to its isolated position. And it was indeed perfectly placed, until irrigation decisions “relocated” a carefully isolated highly dangerous base into the middle of a vast open plain.

A lesson from applied complexity: when constructing a top-secret base while also engaging in irrigation projects at the same time, recognize that they can occasionally work at cross-purposes.

On the Nature of Commuting

The New Yorker has an article by Nick Paumgarten entitled There and Back Again all about commuting and why some people are willing to endure unreasonably long travel times. It focuses mainly on New York City and Atlanta, evidently a commuting Hell. As a bonus, the article also includes a brief etymology of the term ‘commute’:

The term “commute” derives from its original meaning of “to change to another less severe.” In the eighteen-forties, the men who rode the railways each day from newly established suburbs to work in the cities did so at a reduced rate. The railroad, in other words, commuted their fares, in exchange for reliable ridership (as it still does, if you consider the monthly pass). In time, the commuted became commuters.

Network Theory in Cities

Jason Kottke recently pondered what the minimum number of New York City residents one would need to choose, such that these people know every single person in the city:

Any guesses as to the smallest group size? Better yet, is there any research out there that specifically addresses this question? Or is it impossible…are there people living in the city (shut-ins, hermits) who don’t know anyone else?

People have been commenting about it on the blog, where the consensus seems to be about 10,000 people (this sounds pretty reasonable). My two-cents (which can be seen as the first comment on kottke) are reproduced here:

 This is actually a well-established problem in graph theory called the vertex-cover problem. It is NP-hard, which means that there are no really good algorithms for it (although some approximate algorithms are good within a factor of two). In terms of answering this for NYC itself, my guess would be something on the order of 1000 or so. But I don’t have a good reason for that number, just a feeling. You could probably do better by assuming a power-law distribution for the number of acquaintances and derive a better estimate, but I haven’t thought about that in detail.

Urban Ants and Heat Tolerance

About a month ago, I discussed the Heat Island Effect (where cities are warmer than their surrounding areas). Well, it turns out that this phenomenon has affected the evolution of the organisms that live in cities, or at the very least, ants. In their paper Urban Physiology: City Ants Possess High Heat Tolerance Angelleta et al. demonstrate that urban ants have a higher heat tolerance than rural ants. Further studies will have to be done on city mice and country mice.

CDC To Cut Funding for Disease Tracking

The CDC is planning to scale back its main disease surveillance system, BioSense, and will now only focus on tracking diseases that occur in the largest cities in the United States. While this might be due to budget cuts, this strikes me as a foolhardy decision. To focus only on the larger cities is to miss the sources of possible outbreaks. While in decades past this might have still provided enough time to stem the outbreak, nowadays, when travel is routine and widespread, epidemics can spread to the entire United States extremely rapidly (here are some flu simulations, for example). By limiting detection to only large cities, this might remove the element of early-warning and possibly make it too late for proper counter-measures (by the time the outbreak is detected, it has already gone national or international). If the CDC has done simulations and studies that show that the lead-time gained is negligible, that would be good to know and would assuage my concerns, but I have not heard anything about that. If you are aware of anything like this, please let me know.

Braess’s Paradox

Braess’s Paradox, named after Dietrich Braess, is when you add roads or capacity for cars, and thereby worsen traffic (or alternatively, you lower traffic costs by removing roads). Formally, this simply means that the current traffic equilibrium state is not the optimal one. Dietrich Braess, on his website, notes that this concept has applications to computer networks in addition to traffic networks.