Thursday, May 28, 2009

On Math, Muses, and Poets

When RM sent me this highly entertaining NYTimes column (by Strogatz) on using diff equ's to model love, I had to share it. Of course, in the process of said sharing, came another little gem from the Journal on Applied Math (from the Society for Industrial and Applied Mathematics).

An excerpt from the abstract:
Three ordinary differential equations are proposed to model the dynamics of love between Petrarch, a celebrated Italian poet of the 14th century, and Laura, a beautiful but married lady. The equations are nonlinear but can be studied through the singular perturbation approach if the inspiration of the poet is assumed to have very slow dynamics. In such a case, explicit conditions are found in the appeals of Laura and Petrarch and in their behavioral parameters that guarantee the existence of a globally stable slow-fast limit cycle. ... The result is that the calibrated model shows that the poet's emotions followed for about 20 years a quite regular cyclical pattern ranging from the extremems of ecstasy to despair. All of these findings agree with the recent results of Frederic Jones, who, through a detailed stylistic and linguistic analysis of the poems inspired by Laura, has discovered Petrarch's emotional cycle in a fully independent way.
In summarizing the work of Jones, the authors state that Jones made the assumption of the cyclical nature of Petrarch's emotions, and "on the basis of this conjecture, Jones... put all undated poems in chronological order." But in this case, the authors set up some basic behavioral parameters:

And found the solution to be a limit cycle.

Oh, and more pretty graphs:

The paper is highly entertaining, very readable, and not as verbose as you might otherwise expect. Really, papers in the humanities should read like this. Characterized by precision, humorous, and defended up to the limits of falsifiability. Well worth the effort to read it, for poets and scientists alike, not just the slender intersection of the two.


Rinaldi, Sergio. Laura and Petrarch: An Intriguing Case of Cyclical Love Dynamics. SIAM Journal on Applied Mathematics, Vol. 58, No. 4 (Aug., 1998), pp. 1205-1221

Current music: The Dandy Warhols - Bohemian Like You

Wednesday, May 27, 2009

So what type of combat training do you have? ... Fencing.

Verbatim review of Star Trek from D's parentals...

Father: "Fascinating from a cultural perspective. I don't empathize much wit our macho delinquent protagonist. Though obviously this appeals to a lot of people. At least his skill at hanging off cliffs by his fingertips saved his life many times."


Father: "I may have some Vulcan sympathies."


Father: "Although giving a success probability estimate of 4.3% for anything involving the decisions of a small number of people has too many significant digits. Really, it's a caricature of reasonableness in risk evaluation procedures."

Mother: "Yes... I didn't much like Spock's mother. She was a bit of a sop. Especially for that sort of environment."


D: "Didn't she only have about one minute of screen time?"

Mother: "Yes, but that minute was just filled with wide-eyed, soulful stares."

Current music: Paper Tiger - Jolien

Monday, May 25, 2009

teatime between bits of MATLAB coding...

Mother: I worry for those birds. That's not a stable branch and their workmanship on that nest is rather shoddy.

Me: I don't think there's much you can do to help. (Pause.) Oh, you meant you're going to super-glue the structure so it doesn't fall...

Mother: But they're likely to detach in the breeze if I don't! Or I could build them another nest...

Current music: Modern Music - Sixteen Going On Seventeen

Sunday, May 24, 2009

Wednesday, May 20, 2009

thoughts about H1N1

If the low death rate from H1N1 in the U.S. is due to superior medical facilities and early detection, then the Third World is in for some serious decimation. Can you imagine what might happen if H1N1 exploded in Sub-Saharan Africa? There would be few accurate numbers on the rate of spread, and there would be little or no access to the effective anti-virals.

Sure, you hear lots of people talk about how hundreds of people die from seasonal epidemics every year, and in this case, look how low the death rate is if patients are found early and given adequate treatment. That's because these people are assuming the entire planet looks exactly like the U.S., when they are much more likely to just die off in such large numbers, no monument can hold their names. The only way to stop from decimating the Third World is to slow the spread of H1N1 enough such that we get a vaccine in production before it's out there.

Current music: The Magnetic Fields - Washington, D.C.

Tuesday, May 12, 2009

H1N1: pandemics in perspective

My dear critical readers, I know you're a smart bunch. I recognize the need to not freak people out, but seriously: what is wrong with presentation of the following data set?
WASHINGTON (CNN) -- The swine flu virus that has sparked fear and precautions worldwide appears to be no more dangerous than the regular flu virus that makes its rounds each year, U.S. officials said Monday. [That's last week, Monday a week ago, mind you.]

"What the epidemiologists are seeing now with this particular strain of U.N. is that the severity of the disease, the severity of the flu -- how sick you get -- is not stronger than regular seasonal flu," Homeland Security Secretary Janet Napolitano said Monday as the worldwide number of confirmed cases of swine flu -- technically known as 2009 H1N1 virus -- topped 1,080.

The flu has been blamed for 26 deaths: 25 in Mexico and one in the United States, according to the World Health Organization.
First, reporting the raw numbers of deaths in the upswing of an epidemic tells you nothing about the dynamics of the situation. Moreover, "how sick you get" or the severity of the illness is NOT the same thing as how "dangerous" an illness is. I don't know if I'm the only one who thinks this, but I would evaluate the "dangerousness" of an illness as its fatality rate, that is, if you get sick, this is the probability that you will actually die. For instance, the probability you will die in a given skydiving jump is 1 in 100,000 (0.001% fatality). [1] Similarly, "you would have to jump 17 times per year for your risk of dying in a skydiving accident to equal your risk of dying in a car accident if you drive 10,000 miles per year." [1]

The fatality rate for the 1918 H1N1 flu was > 2.5%, as compared to < 0.1% [2]. In comparison, fatality rate is about 0.1% for the Asian and Hong Kong flus,[3]. Let's take a quick, back-of-the-envelope look at the numbers for the 2009 H1N1 virus. It has been in Mexico the longest, so we have the best sample size in terms of latency. 58 deaths divided by 2,282 cases gives us 2.54% (5/12/2009), which looks pretty similar to the 1918 H1N1 virus.

There are a couple ways of looking at this. The fatality rate of swine flu is approximately 1 - fatality of anthrax (in 2-3 days). And given the population of the planet, even anthrax has no chance of ending civilization. And the Black Death, depending on your geographical region, killed 20-80% of the population. (The fatality rate of the bubonic plague is supposed to be in the neighborhood of ~50% in 3-7 days without treatment.) In comparison, the fatality rate of SARS was ~9.6% (globally, with medical attention), even though it varied widely by region. [4]

So... no, it's not the end of the world. 2.54% risk of death is not large in the grand scheme of things (looking at the planet as a whole), but it's pretty high for normal life. And remember, this is risk without potential reward, thrill, or even entertainment. On a personal level, my fatality risk acceptance is ~1% for, say, the magical granting a superpower of some kind (the alternative being 'life continues as normal'). Higher if I get to choose the superpower in question. Maybe about ~0.1-0.01% if I only level up. (Those who know me know that I am generally not at all risk-averse. For instance, when playing video games, when you don't die in real life.)

Seriously, wouldn't you rather go skydiving instead? Yes, go skydiving about 50 times a year for the rest of your natural life (assuming you're 25 now...)? Or go skating on thin ice? If there's a medical team within reach, your risk of death from hypothermia is relatively low.

Don't. Panic. But go wash your hands.

Current music: t.A.T.u. - Белый Плащик

hanging by threads of palest silver

From spring 2009

From spring 2009

Current music: Garbage - Stroke of Luck

Monday, May 11, 2009

Chirp-stream Digest

Swine Flu Tweets:
Berkshire Tweets:
  • It dawns on me that this is investment as a tool for intelligently planned production on the planet. #brk
  • Try drinking every time charlie says "I've got nothing to add." #brk
  • "that was slick, striking up a conversation with the guys we were cutting in front of..." -ar #brk
  • Best seats possible. Sprinting ability is useful. Yeehaw!
  • somalian cab driver named den. what's he doing in omaha?
  • - meta-image
  • - Omaha old marketplace
  • - seen in omaha -- friends don't let friends...
  • - is this how you imagine Omaha?

Amusement, Cbae and TTL:
Current music: Vienna Teng - Stray Italian Greyhound