Archive for July, 2010

Somewhere, in every book on writing, there must be this rule: if you wish to engage your reader, do not mention “standard deviation” in the first sentence. Wait! Don’t go! Standard deviations are illuminating and powerful, really. Let me explain.

When I was pregnant with my first child I had a job at a small college teaching statistics, among other subjects. My baby was due on August 7th and I assumed she would be born close to that date, leaving me a week or two before the start of fall semester.

August 7th came and went, along with its pals the 8th, 9th, 10th, 11th, and 12th. On the 13th, stats geek that I was, I started to wonder about the standard deviation of due dates. (Bear with me.)

My doctor had told me that fewer than 5% of babies can finagle showing up on their assigned day. What she didn’t tell me was what happens to the other 95% of babies. What the vast majority of moms need to know is the variability of births around their due dates, in other words, the standard deviation. This magical number tells you the time-frame in which most women have their babies. It turns out that babies’ arrivals vary a lot more than I would have guessed: only 40% show up within a week on either side of their due dates.

My baby girl finally made her appearance sixteen days after August 7th. During those tedious days of waiting a friend told me that in India they gave mothers “due months” rather than due dates, an intriguing rumor that I’ve never been able to confirm.

Indeed, a “due month” seems to far better capture the reality of giving birth, as it melds together both the average and the variability. It reflects a wonderful acknowledgment of real world fuzziness over the single, crisp, over-simplified date that westerners seem to prefer.

It is often easier to reduce something to a single number, often an average (otherwise known as a mean), than to confront the complexities that are lost by that reduction. To say, for example, that average incomes have been steadily rising in the United States masks the reality that most of this gain occurred among the wealthiest Americans, and that income inequality, or the gap between rich and poor, has also been steadily rising.

The same reductionist peril occurs by summing up the threat of climate change as a simple rise in average global temperature. When the Intergovernmental Panel on Climate Change states that the temperature is predicted to rise between 3.2 and 7.2 degrees Fahrenheit in the 21st century, it fails to fill me with the intended dread.

On any given day, it’s not hard to imagine it being 5 degrees warmer. Right now, it’s 75 degrees outside. Climate change might push that up to 80 degrees instead. OK, I would hate it when it was 95 instead of 90, but at least here in Maine, it doesn’t seem utterly catastrophic. I can imagine a world in which spring came a little earlier, in which winters were not as cold, and in which I could grow figs in my garden.

Simple averages fail to convey that along with increases in temperature will come dramatic shifts in the variability of climate processes such as rainfall, strength of storms, and periods of drought. These changes in climate will be profoundly stressful for all plant and animal life on the planet.

Along with temps, global precipitation is expected to rise, but not by the same amount in all places. Rather, areas that are already dry, primarily the subtropical regions running in bands north and south of the equatorial tropics, are expected to become significantly drier. These regions include the southwestern United States as well as the Mediterranean, South Africa and southern Australia. Areas typically affected by drought will expand. Food production will be disrupted for much of the world, especially poorer lands.

The tropics and high latitude areas (including the northern and eastern United States and Canada) are expected to be much wetter, with a greater frequency of serious flooding and more snow in the winter.

Tropical storms are highly likely to increase in strength. On the Maine coast, sea levels, having already risen 7.2 inches in the last century, are predicted to rise nearly another 3 feet by the end of this century.

Nor does the thought of the thermometer going up a few degrees do justice to the profound ecosystem changes that are expected. Good, cold, winter weather, for example, provides many services, from enhancing maple syrup production, to keeping numerous pests at bay–including a variety of disease-laden mosquitoes. Many plants and animals will find it difficult, if not impossible, to make the relatively rapid changes needed to adapt.

Add in grave economic effects from more storms, floods and droughts (the Environmental Protection Agency reports that in the quarter century ending in 2006, there were 70 weather-related disasters in the United States costing over $1 billion apiece) and you have a scenario that is far different from going through an extra bottle of sunscreen each summer.

Reducing the threat of global climate change to the predicted average rise in global temperature gets in the way of our truly understanding the path down which we are heading. We can’t just think about averages; we have to think about standard deviations, probabilities, cumulative effects, regional variability, and long-term trends.

Overwhelming? Perhaps, but dumbing down the threat to the risk of needing to prune the lilacs two weeks early will sap the energy we need to fix the mess we’ve made.

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If you can fly to the moon, who cares what you eat. That must be why the only food you can purchase at the National Air and Space Museum in Washington DC is from McDonald’s. You can go either to the McDonald’s restaurant on the main floor, or for a refreshing change of pace, the McDonald’s cafe on the upper floor.

Of course many of us would be content there, munching a burger and fries, but enjoying a meal for a brief moment in time is not the same as caring about it. Caring is reserved for foods that have deeper meaning to us: traditional meals, recipes perfected by someone we love, or food that is specific to a certain region (think Thanksgiving dinner, grandpa’s pineapple jam, and Maine lobster).

Should you, however, find yourself wandering hungrily around the National Air and Space Museum at lunchtime, as I was last month, you may be shocked to discover that you are just a few hundred yards away from a dazzling celebration of traditional, regional, and meaningful food.

You need only step next door where you will find the Mitsitam Cafe of the Museum of the American Indian. Here, you can start your meal sipping cold cucumber soup topped with bittersweet chocolate cream. Or, you might, as my eight year old did before anyone could stop her, order an enormous slab of fry bread and top it with pickled chilies and pinto beans.

You can wander around sampling side dishes like salsify salad and black eyed peas with horseradish root and spinach. If you’re really famished you can settle in to a venison loaf with Saskatoon berries, a bison steak with wild cherry sauce, or chicken tortillas with huckleberry and pine nut mole.

With your feast you can try cool hibiscus, chipotle and lime juice or hot atole, a thick Mexican beverage made with corn flour, water, cinnamon, vanilla, and chocolate. Dessert choices are equally intriguing: mesquite pinon cookies, golden yucca cake, and guava tapioca pudding.

The cafeteria is divided into five areas, each representing the cuisine of a different region: the Northern Woodlands, the Great Plains, the Northwest Coast, Meso America, and South America. Each region offers a full menu of choices from soups to desserts.

I was fascinated by the way in which the cafe echoed and reinforced the spirit of the museum. As I wandered through the galleries, reading about the different Indian tribes, I was most struck by the powerful connection of each of these groups to the specific places in which they lived. The masks, the symbols, the stories, and the way of life of each tribe, was inextricably interwoven into a very specific region of the Americas.

In the cafeteria it surely would have been simpler to create a single menu with each dish labeled according to place of origin, rather than to create five different areas each with their own complete menu. But, a major message of the museum is to highlight the importance of sense of place, of understanding and respecting where you are, and of connecting to a specific ecosystem and with the particular plants and animals that live there.

We cannot simply pull out a lovely aspect of one or another region–a scallop dish from the northwest coast or chilis from Mexico–rather, it is in the whole, taken together, that the essence of each people is realized.

As fitting as the Mitsitam Cafe is to the American Indian Museum, so is the McDonald’s to the Air and Space Museum. The history of flight, culminating in space travel, is a history of the wildest achievements of industrial society and of our breathtaking capacity for innovation and ingenuity. Yet, these brilliant achievements go hand in hand with the terrible consequences of burning fossil fuel to transport ourselves everywhere willy nilly–even to the moon. We now have to contend with the likes of climate change and off shore oil spills. We have not figured out how to harvest the benefits of our inventions without the negatives.

McDonald’s is similarly a reflection of brilliant success in using the tools of our industrial society: massive farms, cheap transportation, and global markets, to create foods that everyone, everywhere seems primally driven to enjoy. Yet again, the many nasty unintended consequences of this food, such as wreaking havoc with our health, displacing authentic local cuisines, and devastating the environment, are swept out of sight to be dealt with elsewhere.

Traditional societies did not have the luxury of sweeping too much under the rug. If they destroyed their food or water supplies, they had to live with the consequences. In the Mitsitam Cafe you eat as if the harvesting, the processing, and the eating all have consequences. You eat as if you understand how your actions are connected to everything else. You eat as if you cared.

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