Zipf’s Law – modelling the megalopolis

Taipei urban skylineMore statistical sensawunda in the urban environment. Remember us mentioning that guy who suggested that cities can be considered  as super-organisms? Well, a mathematician chap called Stephen Strogatz dropped into the New York Times blogs to talk about Zipf’s Law and other statistical phenomena that surround our urban environments:

The mathematics of cities was launched in 1949 when George Zipf, a linguist working at Harvard, reported a striking regularity in the size distribution of cities. He noticed that if you tabulate the biggest cities in a given country and rank them according to their populations, the largest city is always about twice as big as the second largest, and three times as big as the third largest, and so on. In other words, the population of a city is, to a good approximation, inversely proportional to its rank. Why this should be true, no one knows.

[…]

For instance, if one city is 10 times as populous as another one, does it need 10 times as many gas stations? No. Bigger cities have more gas stations than smaller ones (of course), but not nearly in direct proportion to their size. The number of gas stations grows only in proportion to the 0.77 power of population. The crucial thing is that 0.77 is less than 1. This implies that the bigger a city is, the fewer gas stations it has per person. Put simply, bigger cities enjoy economies of scale. In this sense, bigger is greener.

The same pattern holds for other measures of infrastructure. Whether you measure miles of roadway or length of electrical cables, you find that all of these also decrease, per person, as city size increases. And all show an exponent between 0.7 and 0.9.

Now comes the spooky part. The same law is true for living things. That is, if you mentally replace cities by organisms and city size by body weight, the mathematical pattern remains the same.

It looks as if there’s a lot of things that mathematical analysis could tell us about the cities we live in. The question is, are these properties inherently emergent, or could we design our urban environments more effectively and adjust some of those efficiency values in the process? [image by tylerdurden1]

Good with faces? The Recognition Corps needs you!

little metal facesOK, so it’s not quite X-ray vision, but science has unearthed a slightly more prosaic super-power – super-recognisers are those rare folk with an excellent memory for faces. [image by Valeyoshino]

Super-recognizers report that they recognize other people far more often than they are recognized. For this reason, says Russell, they often compensate by pretending not to recognize someone they met in passing, so as to avoid appearing to attribute undue importance to a fleeting encounter.

“Super-recognizers have these extreme stories of recognizing people,” says Russell. “They recognize a person who was shopping in the same store with them two months ago, for example, even if they didn’t speak to the person. It doesn’t have to be a significant interaction; they really stand out in terms of their ability to remember the people who were actually less significant.”

One woman in the study said she had identified another woman on the street who served as her as a waitress five years earlier in a different city. Critically, she was able to confirm that the other woman had in fact been a waitress in the different city. Often, super-recognizers are able to recognize another person despite significant changes in appearance, such as aging or a different hair color.

I’m better with faces than I am with names, though not to that extent! Worse luck for me, as Randall Parker of FuturePundit suggests an employment fast-track for super-recognisers:

Imagine employing super-recognizers to watch for criminals in train stations, airports, and other places where large numbers of people pass. These are the people we should want to look at most wanted lists of criminals.

Yeah – let’s replace those horrible cameras with fallible meat-based undercover snooper agents! After all, we can always be sure the people on the most-wanted lists deserve to be there, right?

Right?

Viruses used to kill cancer cells

tamedviruswiA fascinating concept: researchers at the University of Oxford have developed a method that uses modified viruses to destroy cancerous cells, whilst leaving healthy cells intact:

The research team modified a common virus – called an adenovirus – so that it could deliver genetic therapy to destroy tumours without poisoning the liver.

The changes enabled the virus to keeps its natural ‘infectious’ characteristics to replicate in, and kill, cancer cells in mice.

But for the first time the virus is also recognised and destroyed by healthy mouse liver cells, so it is no longer toxic.

Poachers make the best gamekeepers, no?

[from Physorg][image from Physorg]

Friday Free Fiction for 22nd May

It’s Friday again… and unless I’m mistaken, this is one of those weekends where folk on both sides of the pond have a Monday off. Which is reason to be cheerful – so why not celebrate by reading some free science fiction stories online, eh? C’mon, your boss is probably coasting his way to close-of-business anyway, who’s gonna notice? Step this way…

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Here’s a bunch from ManyBooks:

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And a couple from FeedBooks:

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Jason Stoddard‘s Creative Commons release of Eternal Franchise continues; we’re up to chapter 8.1

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Yet another Shadow Unit Season 2 DVD Extra: “The Truth”

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News from Arkham Tales:

Issue #3 of Arkham Tales is now available for free download! This issue features a cover by George Cotronis, and contains fiction by Nicholas Ozment, J.C. Koch, Rob Brooks, Nandi Ekles, Eric W. Jepson, Maura McHugh, J.J. Beazley and Edward Morris.

Their server seems a little flaky at the moment (possibly just overloaded on release day) so give the refresh button a few jabs if you get a connection error.

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I’m not sure if it’s entirely meant to be read as fiction, but Ken MacLeod‘s “Invasion Dream” is a pretty weird read nonetheless.

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HUB Magazine #87 features “Nightlife” by Dean Grondo

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Here’s Memory part 37 by Jayme Lynn Blaschke

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The SF Signal gang have made my life a little easier with a couple of free fiction link posts. Meanwhile, here’s another few snippets that passed through there over the week:

  • The latest issue of Three Crow Press includes fiction by Catherine Knutsson, Glenn Lewis Gillette, T A  Moore, C M  SheVLin, Nu Yang, Brian Dolton, Shannon Page and Jay Lake, Gary McMahon, David Priebe, and Rick Silva
  • Conjunctions presents “Predecessor” by Jeff VanderMeer; looks like they have more free fiction over there, too, but a distinct lack of RSS feed.

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And to close us up, Sumit Dam sneaks in with “Lives of Quiet Desperation“.

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And that’s all, folks, as the cartoon pig used to say. Don’t forget to drop us a line if there’s something you think we should collect here next week, but more importantly, have the best weekend you can, OK? Peace…

Presenting the fact and fiction of tomorrow since 2001