Science


Ten years have passed since 9/11. The New York Times put the passage of time into days, and hours, and minutes, and seconds in today’s paper. [A Day That Stands Alone]

Three-thousand six-hundred fifty-two days have now passed. At 8:46 a.m. — the time when the first plane slammed into the north tower of the World Trade Center — 87,648 hours had gone by. Another [*]  5,258,880 minutes. Another [†] 315,532,800 seconds.

For the record, 315,532,802 seconds passed between 8:46 a.m. on September 11, 2001, and 8:46 a.m. today, September 11, 2011. The missing seconds were inserted into our collective timeline by the authority of the International Earth Rotation and Reference Systems Service. One of them passed (largely unnoticed, no doubt) at 6:59:60 p.m. on December 31, 2005 (in New York City), and the other occurred at the end of 2008.

As decades go, this one was as short as they come for us, even with its two leap seconds. Many decades include not two, but three occurrences of February 29th, and all decades beginning between 1972 and 1997 have contained more than two leap seconds in addition to the minimum‡ number of two leap year days per decade.

Nothing is simple.

WTC
Steve on the Hoboken waterfront, September 1, 2011.


* Do not be distracted in search of the anaphor. It’s missing, and the issue is not addressed here.

† Another Another is missing its anaphor. Press on, dear reader.

‡ The minimum during our lifetime. The last decade to contain only a single leap year (which was the leap year 1896) ended early in 1904, because 1900 was not a leap year, despite its divisibility by four. The next single-leap-year decade will not begin until the year 2096.

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The Soda Police are getting noisier lately, but their concern for public health is a subterfuge. When it comes down to brass tacks (and I doubt brass’s slight lead content is going to kill you when used judiciously in plumbing, by the way), the S.P. don’t care most about the public health or about overweight kids at risk for diabetes and heart disease. They’re hell-bent on demonizing soda, especially soda made by Big Food and sold by the Big Chain Store and Restaurant Corporation.

Demon or not, it probably won’t hurt Americans to drink less soda on average than we do now. It will definitely help the environment if we drink less of anything that comes in individual single-use containers — even water — if there’s an environmentally friendly alternative already in place.

Here’s a simple two-part proposal to bring back running water.

BBRW Part 1. Require public water fountains everywhere.

Schools, parks, subway stations, airports, shopping centers, offices, stores, and more. We already require a lot of things, sensible and otherwise, so the means is in place. Require enough of them so no one has to wait in line. These water fountains (bubblers in Wisconsin and parts of New England) should have good water pressure, and they should be designed so they can fill up a bottle, too — or there should be some faucets for that. Simply making it possible to fill a personal water bottle in an airport — and yes, you can carry one through security so long as it’s empty — will reduce heart disease.

No flow restrictors, either; use spring-loaded knobs to conserve. (I’m not going to say a word about those infrared hand-wavy travesties.) Restrictors belong in kitchens and showers, if anywhere. It doesn’t need to take ten minutes to deliver half a cup of water. ADA compliant, but otherwise basic and solid. Call me nostalgic, but I like porcelain-coated cast iron.

Room-temperature, pure water is already available from every municipal water system. Only a little effort makes it ubiquitous. (If you’re afraid it will give you cancer, carry your own personal PET-free container full of home-purified water.)

BBRW Part 2. Require water to be available everywhere soda is available, for less.

If a restaurant offers a meal that includes soda, require it to offer the same meal with the same size tap water for less money. Less by at least half the restaurant’s own à la carte price for the included soda. Except during water emergencies, require restaurants to offer tap water when patrons are seated.

 

Stop the endless debates over soda vs. fruit juice, sugar versus high-fructose corn syrup, artificially-sweetened beverages vs. sugary ones, and aspartame vs. stevia extract. Bring back running water.

One Response to “Bring Back Running Water”

  1. Jenne Says:

    Right on, Dr. Kass! as a mommy (read: permanent entourage) of a 2 year old, I’m astonished how many public-funded places either don’t have water fountains, or have faulty ones. And getting a cup of water from a retail establishment often involves complicated gyrations, as the standard is selling you a bottle of water.
    Bring back the water fountain, and have a tap on it for cups/bottles! Yes!

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While I was initially drawn to this 2008 New York Times article by the phrase “Male and female sand dollars,” I’m certain that “fish mucus split” will be what sticks.

Sand dollar, sex unknown. Click for source; licensed under the Creative Commons Attribution ShareAlike 3.0 License.

Even today, some things are worth repeating. Fish mucus split.

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Year after year, thousands of Americans are devastated to discover that their community has been stricken by a disease cluster. Some rare and frightening disease of unknown cause has visited their community like a plague. Residents are afflicted at rates many times the national average.

Despite years of study, billions of dollars, massive lawsuits and at least two Hollywood movies, little progress has been made towards understanding, let alone preventing, disease clusters.

The general public continues to suspect and blame environmental causes, especially chemicals with names that are hard to pronounce. The real reason for most disease clusters is likely something else.

Math.

Yes, math. Look at this map.

Click for full US map

This map shows the 2009 rate of aleatorum gravis, an emerging and debilitating disease that currently affects only one American in 5,000. In some communities, however, the disease is rampant. Counties with rates more than five times the national average are shaded in red, and those with more than twice the national rate are shown in the darkest shade of green. [Click on the image or here for the full U.S. map.]

Nebraska.

Clusters of a. gravis are concentrated in the nation’s heartland, especially Nebraska and neighboring states. Why? If you wanted, you could look for and find potential causes alarmingly close to each cluster. A gas pipeline, a chicken farm, a power plant, a landfill. Or you could have a lawyer look for you.

Look as hard as you want, but the fact is that the cause of these disease clusters is mathematics. There is no such thing as a. gravis. The map shows the result of randomly giving each U.S. resident the disease with a 1-in-5,000 chance. (Mathematica notebook and links to population and geographic data files available on request.)

Math, indomitable math, caused these clusters.

Randomness.

Cases of non-communicable disease come in clusters just by chance. So do bags of M&Ms that have more blues than average, but it’s hard to drum up fear about them. Randomness and uniformity are not the same thing.

By chance alone, some counties will end up with higher rates of any randomly-occurring disease than other counties. The Central Limit Theorem proves it. Which counties is anyone’s guess, but because of the Law of Large Numbers (not subject to repeal), small counties are more likely than large ones to end up with unusually high (or low) rates. Sanity check: When was the last time you read about a disease cluster the size of a large city, as opposed to a census tract, county, or neighborhood?

Science.

Do some diseases have non-random environmental causes? Sure. Cholera, to give a famous example. That’s why local and national governmental agencies like the CDC and the National Cancer Institute take reports of disease clusters seriously. But the good scientists there also understand the math, and I trust their advice about public health policy more than what I hear on the local newscast, on Oprah, or from yet another celebrity non-scientist.

Reminder: John Snow was a scientist. (He also drew a map to make his point, which was a darn good idea.)

By the way, you don’t even have to be in a red county to jump on the bandwagon of fear and woo. You can still decide your neighborhood is a disease cluster (when it’s not), get everyone riled up, and make a scary video. Or you can write for a shameful woo-purveying media giant. For free. Specifically, the one behind the recent stench of pseudoscience in the air about disease clusters, and who’s getting no link from here. If the miasma theory of disease were true, scientists would be dropping like flies from what they read.

Pseudoscience and pandering to unjustified fear waste society’s resources and sidetrack scientists from research that might make the world a better and less scary place.

3 Responses to “Math Causes Disease Clusters”

  1. Rene Najera Says:

    Thank you for this. It’s exactly what I wanted to say in the follow-up to the “scary video”. I just got sidetracked by anti-vaccine matters. Thanks again.

  2. Deb Leddon Says:

    Hello,
    Your piece on ‘clustering’ due to math artifact/defect?, above is quite interesting. Could you please send the notebook with associated data files mentioned above to me?

    Would like to take a look. Thaks very much for your time and this offer,

    regards,
    Deb

  3. Math 131 Thursday, October 30 | Jeff Morford's Current Courses Says:

    […] interesting blog post by Kass can be found at http://www.stevekass.com/2011/04/13/math-causes-most-disease-clusters/. Why are rural counties more likely to have higher incidences of the […]

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Via Alan Boyle of Cosmic Log: this has to be embarrassing.

You create the first synthetic life form. You thoughtfully encode in its DNA wise words from three giants of literature and science: Joyce, Oppenheimer (quoting Felix Adler), and Feynman.

And you get one of the quotes wrong.

At least you can fix it. Imagine if there had been a typo on the Golden Record. Or if you’d flubbed the first words ever spoken from someone standing on the surface of the moon.

(I remember very well being befuddled when I heard Neil’s flub live – well, give or take a second or so, though this calculation is wrong – and I remained befuddled when I read it the next day, and I was unconvinced by the initial explanation a couple of weeks later.)

[To decode this post’s title, use the DNA decoding table here.]

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There is still no good answer to the question “Why can’t we walk straight?”, observed Robert Krulwich’s recorded voice at a recent live taping for Radiolab at The Greene Space. Robert’s observation ressounded¹ today on the “NPR sciencey blog” Krulwich Wonders.

For 80 years, scientists have been trying to explain this tendency to turn when you think you are going straight. … Try as they might, and they’re still trying these experiments, nobody has figured out why we can’t go straight.

When I was a kid, Someone thought they’d figured it out. One’s dominant leg took longer strides, They taught me. I also learned, or maybe inferred, that I should find a leftie to walk with me should I ever need to cross a desert in the fog, at night, or while blindfolded.

But hearing Robert talk about this twice in as many weeks, I realized that They’d been wrong, and that crossing a desert in the fog was not a challenge I’d be ready to meet. (Also, I only then realized that a leftie might not be handy when the challenge arose, anyway.)

Ignoring my sudden and deepening nonplus, I focused on the question. Analogy time.² Robert’s headlineworthy version of the question is an oversimplification of the quandary, but I’ll notwithstand that fact for now.

Why can’t we fly? (Some animals can.) Because we don’t have small bodies, hollow bones, and wings (like some flying-capable animals do); nor do we have really tiny invertebrate bodies and wings (like some other flying-capable animals do).

Why can’t we hear high-pitched sounds? (Some animals can.) Because human ears (unlike the ears of the animals that can) aren’t physically able to convert high-pitched sounds into nerve impulses.

Great_Barrier_Island_Pigeon-Gram_stamp_1899 So why can’t we maintain our direction over long distances without a visual point of reference? (Some animals, especially flying-capable ones, can.) Because (unlike those animals) humans never underwent any evolutionary pressure to develop a mechanism to do so?

Robert mentioned one of the trying scientists by name: Jan Sousman. Jan’s article, Walking Straight into Circles, recently appeared in the journal Current Biology (a cornucopia of articles at the titles of which biologists surely titter: Olfaction: When Nostrils Compete; Metastasis: Alone or Together?; Addiction: Flies Hit the Skids; Flagella and Cilia: The Long and the Short of It; and Melanocyte Production: Dark Side of the Schwann Cell).

Jan and his coauthors wrote a wonderful paper. Among many beautiful sentences and figures, they report that their subjects’ “walking trajectories show exactly the kind of behavior that would be expected if the subjective sense of straight ahead were to follow a correlated random walk.” They also mention J. R. R. Tolkien’s The Lord of the Rings: The Two Towers to point out that the belief “that people who get lost end up walking in circles is widespread.”

So “because we can’t” isn’t really such a good answer. Our proprioception (that sixth sense that allows us to touch our noses in the dark when we haven’t had too much to drink) does provide a subjective sense of straight ahead. However, it isn’t very reliable for very far or for very long.`


¹ I initially wrote reappeared, which on rereading, sounded (or more sensibly, looked) wrong, because Robert’s voice never appeared (as in became visible to the eye) in the first place. Unable to solve the Miller Analogy SEE : REAPPEAR :: HEAR: with an existing word, I had to invent the perfect answer: res̈ound (which should appear as the word resound with an umlaut/trema/diaeresis over the s). This answer is in fact all the more perfect (not to mention very unique) for having been invented by a “greater New Yorker.” Unfortunately, as much as I like the idea of using ¨ to estop a preceding prefix from losing its strict meaning, it fails in practical terms. Very few consonants appear in Unicode preëquipped with the dots, and Unicode’s zero-width combining diaeresis, the solution in theory, is unworkably fussy.

² Yay!

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Science overload — always a welcome thing — happened at The Greene Space last night. On the menu? Radiolab Live: Symmetry, with guest artist John Cameron Mitchell singing Origin of Love from Hedwig and the Angry Inch.

Hosts Jad and Robert dwove¹ expertly, pointing out many wonderful (mostly asymmetric) sights left and right. Looking-Glass milk, carvone, tartaric acid, and Jimmy Carter, to name a few.

I pulled out my notebook twice during the show: first, to jot down a hairy pun, and second, to sketch a schematic of the cloud chamber I owned as a kid. I’ve retired the pun and won’t divulge it here; it served its intended purpose. (Andy responded, “Ow. Even I’m offended.”) But I have a bit more to say about the cloud chamber.

In my hasty schematic, I labeled the head of the pin AMERICIUM, but subsequent research suggests that it was radium, not americium, on the head of the pin. Fortunately, I never suffered from pica. The kit also contained a chunk of uranium ore.

I didn’t play with the cloud chamber quite as much as I did with some of my other dangerous toys like the Creepy Crawlers Thingmaker (my favorite childhood toy of all, no contest), the Wham-O Air Blaster (which became increasingly dangerous each time my brother thought of something new, like pencils, to fire from it), the Vac-U-Form, the chemistry set — mercury (I especially enjoyed freezing bits of it with dry ice), carbon tetrachloride, ammonium dichromate, and potassium permanganate were among my favorite chemicals — the Slip-’n-Slide, the lawn darts, or the Clackers.

Nor was the Atomic Energy Lab the radium-containing possession I carried with me most often as a child. That distinction goes to the radium-dial watch Dad gave me in junior high school. The watch was stolen from my gym locker one morning in 1970, unfortunately — but perhaps unfortunately for the thief more than for me.

The only radium I know I own any more is in the painted dial of the Jefferson Electric Golden Hour clock in my bedroom. The radium is no doubt decaying apace and will continue to do so for centuries to come. But alas, the zinc sulfide phospor has broken down, and the dial no longer glows.


¹ The verb dweave (past tense dwove) and the noun dwive will be coined in a future installment of “Word of the Day.”

One Response to “Yet Here I Am”

  1. your brother Says:

    The air blaster merits mention, along with the vacu-form.
    [Added. -SK]

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Internet news aggregator robots never leave me alone. Internet news aggregator robots, never leave me alone.

Every day or more, one of the news aggregator robots gets both my attention and my goat. Here’s one of today’s missiles: “CDC: Most Teens Choose to Abstain,” at cbn.com. The first paragraph:

A recent study shows that most teenagers are virgins, contradicting claims from family planning groups that most young people do not abstain from sex and more sex ed should be taught in schools.

YoungCoupleEmbracing-20070508Image by Kelley Boone, some rights reserved (CC-BY-SA 2.0)

This kind of blabbery drives me nuts. They might has well have said, “A recent study shows that the earth is flat, contradicting claims from Unitarians that the planets revolve around the sun and astronomy should be taught in schools instead of the Bible,” when in fact a recent study showed no such thing, and even if it had, it wouldn’t contradict what the Unitarians supposedly said. Maybe if I’d been on the debate team I’d know how to respond more effectively.

If I were a fundamentalist Christian who wanted to justify abstinence education, I wouldn’t quote or misquote studies, nor would I attempt to use logic. I’d be honest: “According to my church, the world is flat, most young people abstain from sex, and abstinence should be taught in schools right after study hall and before creationism. That’s what I believe, because faith in the church is my guiding light.”

Studies be damned, science be damned, the church is the ultimate authority. I might have more respect if they put it that way more often. (I would still object if it got to the point of the Constitution be damned and laws be damned.) Why should fundamentalists care a whit about the fact that science is consistent, well-founded, and predictive? Why should they care about evidence from studies and measurements, if faith, not intelligence, is their life’s compass? I can disagree, disapprove, and be dismayed, but I have no appeal. We live on different planets; we grew up in different universes.

Anyway, for readers who might appreciate facts and figures, let me explain the CBN’s vulpigeration.

What is “sex,” anyway? For its study, the CDC defined “sex” to be heterosexual vaginal sexual intercourse¹ only (though the boy need not stay on top). Many English speakers would call a bunch of other things people do naked with others sex, but the CDC’s restrictive definition should suit the Christian Broadcasting Network in two ways. First, this definition doesn’t infringe on the way CBN might define another word, “sodomy.” They might prefer it for that bunch of other things people do naked with each other. Second, it yields higher virgin percentages. As far as the CDC and CBN.com are concerned, you’re a virgin if you haven’t been part of any penis-in-vagina hanky-panky, even if you’ve gotten plenty naked and nasty with one or more hims or hers.

Fact: Most young people do not abstain from sex. (Or “sex.”) Not during their entire youth, which is what CBN.com suggested. According to the CDC study, most (65% of) boys aged 18-19 and most (60% of) girls in the same age group have had heterosexual vaginal sexual intercourse. The CDC numbers suggest that most young people do abstain from sex “sex” until about age 17 or 18, but abstaining until you stop abstaining is not the same thing as abstaining. Using the CBN.com logic, you could say that all people abstain from sex, ’cuz they all do — until they stop, and most stop, as we know from all the babies being born and abortions being performed. Few babies (or aborted fetuses) are incarnate nowadays.


¹ Additional information available on the internet.

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While my part of the world was embroiled in a heat wave last week, brutal midwinter cold was gripping Vostok Station high atop the mountains and ice of central Antarctica. At times, it was more than two hundred degrees colder in Vostok than it was here in the U.S. Northeast.

Vostok A few days earlier, by coincidence, I’d installed the last of my three SodaStream carbonators and ordered two refills. On the 7th, in the middle of the heat wave, the local distributor exchanged my empties, leaving me with four pounds of freshly compressed carbon dioxide and two questions.

  1. Is four pounds of CO2 a lot compared to the amount already inside my condo, not counting the basement?
  2. When the temperature drops below -109.3 °F, the sublimation point of carbon dioxide, does it snow dry ice?

I’m happy to share with you the answers.

1. Yes, quite a lot. The volume of my condo, not counting the basement, is about 7,000 cubic feet, or about 200,000 liters, and while I have far too much junk, my place is still mostly full of air. And like air most places, the air in my condo is mostly nitrogen, oxygen, and argon, and about 400 parts per million of it (by volume) is carbon dioxide. My condo contains a fifth of a million liters of air, I figured, so I’ve got a fifth of 400 liters of CO2, or about 80 liters.

At room temperature, CO2 is effectively an ideal gas, so I don’t need Google to convert 80 liters to moles, which is going to help with the calculation. A mole of an ideal gas at standard temperature and pressure¹ occupies 22.4 liters, so I’m living with about 4 moles of CO2. (And maybe a few voles, too, but that’s not relevant here.) A mole of any chemical compound means 600 sextillion molecules of the stuff. Fortunately, we don’t have to do any sextillionary arithmetic. What makes a mole a mole is that it’s the number of Daltons (neutron or proton+electron masses, more or less) in a gram, so the mass of a mole of a chemical compound is simply its molecular weight in grams. The molecular weight of CO2 is² 12+2×16, or 44, so a mole of CO2 has a mass of about 44 grams or an ounce and a half.

Four moles of CO2 in my condo — that’s about six ounces, or less than a tenth of what’s squeezed into my two new Sodastream carbonators.

2. No. The temperature -109.3 °F is the sublimation point of CO2 at one atmosphere. That’s the temperature at which dry ice in your house or cooler chest (which is pure CO2 solid under an atmosphere of air pressure) sublimates; it’s not the temperature at which CO2 in plain air would precipitate into “snow.” Carbon dioxide won’t precipitate out of the air unless it’s cooled to the sublimation point for its partial pressure in air. That’s (see above) about 400 millionths of an atmosphere at sea level, and roughly two-thirds of that at Vostok Station, elevation 11,000 feet. Smart guy David R. Cook at Argonne National Laboratory has generously used some tax dollars to spread the word. He proposes that the temperature would have to be much colder than –110 — in fact about 220 degrees below zero on the Fahrenheit scale (and no, that’s not “twice as cold” as -110) for CO2 to precipitate at Vostok Station.

Typical partial pressures of CO2 on earth are unfortunately off the scale of the phase diagrams I could find, so I can’t provide more details or confirm what David says. You can, however, see the trend in the phase diagram below. The boundary between the periwinkle and salmon regions is where CO2 sublimates or “snows.” The lower the pressure, the lower the temperature.

800px-Phase_changes_of_CO2 Public domain image from Wikimedia Commons.

The phase diagram also answers a question I didn’t think to ask.

  • Are full SodaStream carbonators filled with liquid or gas? Liquid.

They’re about a liter big, which (using the calculations above) translates to an internal pressure of several hundred atmospheres, which is well within the green region. How cool is that? Liquid CO2 right here in my house.

Call it chemistry or call it physics, this is all great fun.

Related links: How Much CO2 is in a Bottle of Soda?, The Influence of CO2 on the Chemistry of Soda, Soda’s Contribution to Global Warming


¹ Standard temperature and pressure is 20 °C and one (sea level) atmosphere of pressure. That’s close enough to the conditions in my condo. Around room temperature, gas expands at a rate of about 1% per 4 °C rise in temperature. It also expands as you climb above sea level, by about 1% for each 300 feet. The second derivatives are small, and the contributions from the partial derivative of volume with respect to temperature and altitude add, so yadda yadda yadda, we’re within a few percent. It was worth a quick thinking through, though.

² There are a some simplifications here, but again, they don’t affect the overall calculation by more than a percent or two. The value 44 assumes that every molecule of CO2 is made up of the predominant isotopes of carbon and oxygen, carbon 12 and oxygen 16, and that single atoms of these isotopes weigh exactly 12 and 16 Daltons, respectively. The “official” atomic weights as periodically reviewed by IUPAC would be more accurate, and they give a molecular weight of 44.01. The discrepancy reflects the distribution of isotopes on earth as well as other details that probably involve higher physics and chemistry well beyond my understanding. In addition, it would seem to me that this measurement ought to be called the molecular mass, but when measuring any property of such tiny things, you’re going to run up against quantum mechanics and other complications, so I suppose whoever understands all of this can call it what they want.

One Response to “The Joy of Chemistry”

  1. Jacob D. Duncan Says:

    Thanks for sharing an interesting post about carbonated soft drinks and carbonation in general. I learned so many new facts about my soda maker.

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