Cocktail Party Physics

i think that i shall never see / a carbon offset as lovely as a tree

I overhead an exasperated parent the other day:  “The kid just won’t stop asking ‘why’ all the time.  Everything I say, she challenges.  She’s driving me absolutely nuts.”

We need more kids like that.

I know, easy for me to say since I’m childless by choice, but I really do believe that the biggest danger we face as a society is a populace that doesn’t want to think for themselves.  I am more than happy to have students challenge me about the material I teach.  In reality, though, they spend a lot more time challenging me on my attendance policy, my lack of understanding that they missed class due to a hangover, my grading policy, and my refusal to allow ‘do-overs’ for tests that didn’t produce the desired scores.  Most disppointingly, so many test answers are phrases regurgitated directly back from my notes with no evidence that the writer spent even a few seconds considering what those words meant and whether they were right.

While professors hate this trend, marketers but be thrilled.  Someone tried to argue the other day that the Tesla Model-S electric car was actually cheaper than a luxury gasoline sedan.  He told me that the New York Times said that the $57,400 list-price Tesla Model-S was actually only $35,000 "when you accounted for tax credits and gas savings". 

Sure enough, there was Elon Musk saying that the Tesla sedan would cost $57,400 list price, $49,900 after tax credits, and $35,000 “after factoring in gas savings”.   Anyone have a bell go off there?  A 'one of these things is not like the others' moment?

You can’t directly compare the first two items with the last.  There is a difference between one-time costs (purchase price and tax credits) and the more-nebulous issue of "gasoline saved" because the latter depends on how much you drive.  It will vary from person to person and it's money you get back, not money you don't have to put out in the first place. 

Probing further, I found an actual quote on a GM site about the Chevy Volt, which quotes Musk as saying.

“The ownership cost of Model S, if you were to lease and then account for the much lower cost of electricity vs. gasoline at a likely future cost of $4 per gallon, is similar to a gasoline car with a sticker price of about $35,000. That’s why we’re positive this car will be the preferred choice of savvy consumers.” 

Arg.  Now we’ve got leasing thrown in and I have no idea how they calculated the cost of the electricity  used to charge the car.  Inquiring minds want to know.  Or, at least, they should.

Goodyear does a pretty nice job in advertisements for low rolling resistance tires.  They tells us that we’d save 2600 miles worth of gas over the life of the tires.   An asterisked statement tells us that this estimate includes a lifetime of 65,000 miles and a 4% increase in fuel efficiency.  They even provide a calculator for you to input your car's mileage so you can see how much money you’d save.

During interviews for my Physics of NASCAR book, I interviewed a Todd Meredith, a manager at Joe Gibbs Racing.  I always ask whether a race shop has any employees with a physics background, since most are mechanical or aerodynamics engineers.  Todd thought for a moment and said,

“Yeah, I think we do… but I bet he doesn’t use anything you taught him.”

“I bet he does,” I shot back, “because we taught him how to think.”

That started a really productive and interesting conversation about the importance of science and math and how they are taught. In the end, racing is real-time advanced problem solving, and all the skills you learn as a scientist, engineer or mathematician are exactly the skills you need to be part of a race team.

Fundamentally, science and math are about learning how to evaluate data to ensure it’s valid, synthesizing multiple data sources, critically analyzing that data and coming to conclusions. We need these skills more now than at any other time in history.  Climate change, energy, manned vs. unmanned space programs, oil well leaks…  even if you don’t understand the details of the science, you HAVE to be able to understand if you’re getting the truth or being sold a load of goods.

It’s hard enough for scientists to find ‘The Truth”.  There are significant disagreements on directions for action in many areas (climate change, transportation, etc.) because we simply don’t have enough data to make unequivocal conclusions.  Although there have been some issues with advocacy getting in the way of science, that’s nothing compared to the number of people who are purposely twisting science to their own goals.  If Shakespeare were alive today, I suspect he would have chosen "public relations persons" rather than lawyers as his occupational target of choice.

The honorable people in marketing and public relations bring to light the most positive accomplishments of their company.  There are those who are less honorable.  How much "news" is actually a minimal re-write of a press release?  Some science "news" sites are simply places for universities and companies to post their news releases, and some science journalism is little more than a thin re-write of said news release.  Science is not the only place this happens.

I heard a NASCAR broadcaster make the following claim: "NASCAR offsets 100% of the carbon emissions from this race via their tree-planting program."  Anytime someone says "100%" or "always" or "without exception", my ears perk up.

OK, NASCAR has been (and is) doing a lot of good things to be environmentally responsible.  They were recycling used oil before it was cool, they are initiating recycling programs at tracks, even getting teams to minimize how much they run generators during race weekends.  All good things, but not very exciting.  Newspapers don't want articles about recycling oil.

But tree planting… beautiful PR idea.  Get your biggest stars out to dig the holes, put the trees at a local school or park.  Bingo.  So how many trees do we have to plant?

Some brilliant NASCAR PR person did major damage to the cause of logic and educating the public by deciding that they would plant ten trees for every “green” flag during a race.  Green flags wave at the start of the race, and after every caution, so the number of green flags depends on the number of accidents and amount of debris on the track. 

This is just wrong on so many, many levels, and it's not like this is difficult science.

Combusting one gallon of gasoline produces 19.4 pounds of carbon dioxide.  One gallon of gasoline weighs about 7 lbs – the additional mass making up the carbon dioxide comes from the oxygen that combines with the gasoline during combustion.  Two octane molecules combine with 25 oxygen molecules, which explains how the weight of carbon dioxide is greater than the weight of the fuel. 

But the important point here is that the amount of carbon dioxide emitted is directly proportional to the number of gallons of gasoline combusted.  Not only does this have absolutely NOTHING to do with how many green flags wave during a race, it’s a number we can calculate with pretty reasonable precision.

Forty-three cars run 500 miles, each getting about 4 miles per gallon.  I am overestimating the amount of fuel used by just a little:  the cars get about double the gas mileage during cautions and some cars don’t run the full race.  I’m calculating the upper bound. It wouldn't be hard to use the data on exactly how many laps were run by each car, but I'm not the one claiming I'm planting enough trees to offset the emissions, so I'm making an estimate.  When you do the calculation, it's about 5,375 gallons of gas in a 500-mile race.

I know – you’re horrified at this tremendous waste of gas.  Get over it: In 2009, the Department of Energy says the US consumed 137.93 billion gallons of gasoline. That means this country uses 4,373 gallons of gasoline every second. I guarantee you I could easily find enough U.S. NASCAR fans who would volunteer to use less gasoline in their everyday lives to compensate. Compare a weekend of NASCAR (including the media coverage and fans getting to the track) with a weekend of the NFL. You can make a better argument for saving fuel and emissions by eliminating a weekend of NFL football than you can a weekend of NASCAR.

Nonetheless, my hypothetical NASCAR race still uses 5,375 gallons of gasoline, which means that 104,275 pounds of carbon dioxide (about 52 tons) are released into the atmosphere.

One of the first things I remember learning about science is that people breathe in oxygen and breathe out carbon dioxide, while plants “breathe in” carbon dioxide and emit oxygen.  Photosynthesis combines water, carbon dioxide and energy from the sun to produce sugar and oxygen gas:

Six carbon dioxide molecules and six water molecules combine to produce one sugar molecule (the C₆H₁₂O₆) and six molecules of oxygen.  Plants covert the sugar into organic matter like stems, leaves and stalks.  

The problem with plants is that they lose their leaves (and, if they live in my house, they die).  The real masters at storing carbon are trees, because trees convert sugars into cellulose -- long chains of the repeating unit C₆H₁₀O₅.  As long as the tree is growing, it’s sucking up carbon dioxide.   Since each of us generates about 2.3 tons of CO₂ each year, we should all be doing out part to encourage trees to grow.

Now for the tricky question:  How much carbon dixoide does a tree absorb?  Turns out that's not as easy a question to answer as I thought.  You can find numbers ranging anywhere from 10-70 lbs of carbon dixoide per tree per year.

Let’s analyze this.  Since carbon dixoide is mostly stored as wood, the amount and type of wood are going to be important.  In other words, when it comes to trees and carbon sequestration, size matters.

Assume a cylindrical tree.  The volume of the tree goes like the diameter of the tree squared times the height.  Compare two trees of the same species the same height, but diameters that differ by a factor of two.  The one with the larger diameter stores four times as much carbon dioxide (pi r squared!).  The difference in storage is even larger, of course, because trees (unlike people) continue to grow upward, as well as getting larger around the trunk as they age.

Trees with denser wood store more carbon dioxide than trees with less dense wood.  Next time you’re at the home improvement store, compare trim made from pine with that made from oak or cherry.  I’ve summarized the mean densities of a couple of different species of trees on the graph below, which shows the height of the tree on the vertical and the type of tree on the horizontal axis.  Sorry about the labels being so small.  From left to right, they are: balsa, red pin, red oak, cherry, ebony and lignum vitae.  The densities are given in kg/cubic meter and range from 160 to almost 1400.  Red pine has a density of 370 – 660 kg/m³, whereas ebony (a hardwood) has a density of 960 – 1120 kg/m³.  The champ in terms of tree density is a tree called Lignum Vitae, which has a density of 1280 – 1370 kg/m³.

 

 

I noted that the larger the tree is, the more carbon it has stored.  So you might think big trees are the best to plant.  But what's really important is how fast the tree is growing - how fast it can convert carbon dioxide into wood.  Big means that the tree has stored a lot of carbon.  Fast growing means that the tree is storing a lot of carbon 

A tree grows slowly in the early years (while it's putting down roots), then has a period of more rapid growth, and finally tapers off as it approaches its maximum height, as I’ve diagrammed below.  The region of maximum growth is at the steepest parth of the curve, so you want to plant trees that are near the maximum in the derivative of their height vs. time curve.  Unfortunately, most nurseries do not put this data on the little tags that hang on the trees when you go to buy them.  Forestry types tell me that Southern Pine may reach its maximum growth period in 20-28 years, while Douglas Firs on the Pacific Coast require 60 years.  Things are a little more laid back on the Left Coast.

Speaking of laid back, consider also that tropical trees account for 95% of all tree-based carbon dioxide sequestration on Earth.  A tree without leaves isn’t doing much photosynthesis, which means it’s not removing carbon dixoide from the atmosphere.  Tropical trees work 12 months of the year, while boreal trees only work 3-6 months of the year.  Tropical trees are mostly hardwoods and grow more quickly than their cold-weather relations, so there are a lot of people who advocate that, if you're going to support tree planting, you should send money to oragnizations that are trying to re-plant tropical rain forests because those trees are more likely to have a larger impact than the pine trees you plant at a local park in New York.

There are some ways of estimating how much carbon dioxide a tree will take in each year, like determining the mass of the tree based on its dimensions.  One is a really great exercise for middle or high school students.  They find that:

• A 10 year old Grevillea robusta (the southern silky oak, an evergreen Australian tree) that is 45 feet tall and 6 inches in diameter would sequester about 64 lbs of carbon dioxide per year.
• A newly planted Acacia angustissima (native to Central America and the US) at 2.5 yrs, 15 ft tall and 3” in diameter would take up about 21.5 lbs of carbon dioxide per year.
• Calliandra calothyrsus (powder puff tree, Mexico, Centra America) that is 10 years old, 15 feet tall and 8” in diameter would remove about 65 lbs of CO₂ per year.

In general, trees planted in the US have a difficult time reaching the numbers tropical trees can achieve.  Most people, noting that environment, rainfall and other conditions matter, will use an estimate that a tropical tree can absorb an average of 50 lbs of carbon dioxide per year.   "Tropical" usually means within 23 degrees North or South of the Equator, but let's count Florida as "tropical".

Let’s be generous and use the 50 lbs of carbon dioxide per tree per year number, which is probably 1.5 to 6 times larger than reality.  To offset the 104,275 lbs of carbon dixoide from the NASCAR race, you would need 2,085.5 year-trees.  "Year-trees" means that the product of the number of trees times the years the trees are sequestering carbon needs to equal two thousand and eighty five.  You could plant 2,085 trees and they will compensate for the race in one year.  Or you could plant a thousand trees and compensate in just over two years.

Last year’s Daytona 500 had nine cautions, so including the green flag that started the race, there would have been 10 green flags and NASCAR planted 100 trees.  The calculations above show that those 100 trees will offset the carbon emissions from the race in just under 21 years.  And I'm being really generous with giving each tree credit for 50 lbs of carbon dixoide per year.  If that number is 25 lbs per tree, we're talking more than 40 years before all the carbon from those five or six hours last February have really been accounted for.  (And yes, I do know that the race went 520 miles due to multiple green-white-checkers and I didn’t add in those extra 20 miles, which is another 215 pounds of carbon dioxide, and ignoring that probably accounts for the laps under caution and the cars that dropped out before the race was over.)

That estimate doesn't include the carbon emissions needed to take care of the trees for that long:  fertilizers, vehicles, replanting trees that die, etc.  

 In 2009, Petaluma Junior High School received 30 trees from NASCAR and Infineon Raceway to offset the carbon emissions from the race in Sonoma.  Sonoma is a road race, so it is shorter (224 miles) and we’re “only” talking about 2,408 lbs of carbon dixoide.  The kids from that junior high school are going to have their own kids in junior high school before the carbon from that race is offset.

Offsetting carbon emissions from planting trees is not the panacea it has been advertised to be.  One website calculates that, in order for the Earth to become carbon neutral, we would have to reforest a land area approximately equal to Spain every year and maintain that land in perpetuity.

The small impact NASCAR's trees will have on the environment is at least good; however, their decision to pursue - and publicize - a non-scientific approach to the problem is grievously wrong.  I'm offended  NASCAR thinks I'm stupid enough to fall for this. 

I'm also a wee bit irritated at some members of the "NASCAR media" who are willing to parrot the 'facts' they are handed without question.  I don't expect them to be experts, or even have time to call up a scientist to ask whether it's accurate. 

The fact of the matter is that you get credit for sequestering carbon as it is sequestered, just like you get credit for paying down your mortgage as you make the payments.  You don’t own the house by taking out a mortgage and you don’t offset your carbon emissions the minute the trees are in the ground.

As I tell my students over and over again:  If you don't understand something, the last thing you should do is repeat it.

Neat trivia I learned while researching, but couldn't slip into the blog:  Forestry professionals use the abbreviation "dbh" when describing trees.  dbh means "diameter at breast height".  Breast height is defined to be 1.4 meter.  There are apparently very strict physical requirements for being a forrestry professional.

 

what do we mean by "how much oil is left" in the gulf?

If Shakespeare were alive today, he might suggest that PR/branding/marketing people should go before lawyers.  The spin doctor's job is to make their company look good - even when it shouldn't.  The existence of spin doctors is reason number one why we must fix our badly broken education system.  If science teaches one thing, it is skepticism:  People shouldn't be so anxious to be told what to think.

This week marked the first peer-reviewed study of the Gulf Coast oil spill.  Big disclaimer here - it takes weeks (sometimes months or years) for research to make it from research to print, so the results are from measurements made in June; however, there are many more research reports to come.  The Truth is likely to be known only after multiple research groups have published on different aspects - probably on a timescale of years - and all of their data is analyzed in aggregate.  Science aims for precision, not speed. 

The last few weeks have brought heated debates on radio and television arguing over exactly "how much oil is left in the Gulf".  Estimates vary from "none" to "more than seventy-five percent".  How can people looking at the exact same system come up with numbers that are so different?

How much oil was released into the Gulf?  The National Incident Command (mostly the federal people in charge of managing the cleanup) uses a figure of about 5 million barrels and, on August 2nd, noted that about 17 percent of the oil released from the spill has been removed.

On August 19th, Ian MacDonald (a biological oceanographer from Florida State) testified in Congress and presented a very interesting fact:  the 5 million barrel total includes oil that was pumped directly from the well onto ships after the first capping attempts.  Initially, this larger figure doesn't make sense - why would the government use a bigger number? 

Because if you include the oil pumped directly from the well to a tanker, you've "removed" a higher percentage of the oil.  MacDonald (who argues that the total amount of oil that actually was released into the water was 4.1 million barrels) says that six percent was burned and four percent was skimmed.  If you use his numbers, a total of 10 percent of the oil was 'removed' from the environment.  The government number of 17 percent isn't wrong - but you can't compare the two numbers head to head.  The higher number sounds better, but it's important for the consumer (of information) to know what that number actually represents.

A report from NOAA (National Oceanic and Atmospheric Administration) in early August estimated - and that's an important word - that 74 percent of the oil from the leak had been: captured directly from the well; skimmed; burned; dispersed chemically; dispersed naturally; evaporated;  or dissolved into microscopic droplets. The rest of the oil washed ashore.  On August 4th, Carol Browner said on the Today Show that "more than three-quarters of the oil is gone."

Salad dressing made with oil and vinegar (or water) presents a challenge in mixing, as I've written about in the past.  Oil molecules don't like water molecules and water molecules don't like oil molecules.  You need to either whisk in the oil or shake it vigorously to form an emulsion.  An oil-in-water emulsion consists of very small droplets of oil suspended in water.  Most salad dressing recipes include dispersants of some type. Homemade dressings rely on things like mustard and egg yolk.  Commercial salad dressings use more exotic dispersants.  Few people call them dispersants, but these additives encourage the formation and persistence of the emulsion, which is pretty much what a dispersant does. 

I don't see any oil after shaking the bottle of vinaigrette in the fridge.  Is it 'gone''?  Evidently not, because the calorie count doesn't have separate columns for 'shaken' and 'not shaken'.  It's definitely 'not visible', but it sure the heck isn't 'gone'.

I happen to like my vinaigrette more on the vinegar side than the oil side, so I typically use a lower ratio than the recommended 3:1 oil:vinegar ratio for a classic vinaigrette.  My eating companions rarely agree with my acidic preferences, so I usually make the salad dressing with the 3:1 ratio and then add additional vinegar to a small container just for me.  That decreases the oil concentration, but not the absolute amount of oil - it's just spread out more than it was before.  That's not 'gone' either.

It would be really nice to have an equation that predicts how long oil takes to break down in seawater.  Such an equation does exist - in fact, a number of different models exist.  MacDonald's Congressional testimony makes the point that federal report (which makes no secret that its numbers/predictions are based primarily on theory) doesn't indicate which scientific formulae, models or predictors they used for their estimates. 

The Science paper researchers (along with researchers at other institutions that have peer-reviewed papers coming out soon) dropped sensors into the water and some even sent a submersible to look various 'plumes'.  The lead researchers on the Science paper (from Woods Hole Oceanographic Institute) reported on over 57,000 chemical analysis on a plume "only" 200 meters thick and about 2 kilometers wide over two weeks in June.  The plume measured was about 3,600 feet below the surface and extended more than 20 miles southwest of the well, traveling at about four miles a day.  The caveats, of course, are that this study occurred before the well was capped and two months ago. 

The use of the word 'plume' may be a little misleading because this is a collection of small oil droplets, presumably formed by the dispersant or natural actions.  It's not the billowing cloud you might picture. The Science paper reports significantly higher concentrations of a number of toxic compounds, including benzene at a rate of 50 micrograms per liter (which is 0.05 parts per million).  One part per million is about one drop in 40 gallons. The maximum allowable concentration of benzene in drinking water is 5 parts per billion, which is 0.005 parts per million or ten times less than the concentrations they measured. (Incidentally, commercial salad dressing is required to contain 30% oil.)

Dispersing is (in my opinion) not the same thing as removing.  How do we actually remove oil?

Crude oil is a collection of many different types of hydrocarbons, the exact composition of which varies from location to location.  The molecules, all of which are carbon and hydrogen atoms in various configurations, are separated into fractions according to their boiling points. The lighter fractions have fewer carbon atoms (and by association, fewer hydrogen atoms) and lower boiling points.  The pie chart below is representative of what might flow through a pipeline carrying Gulf Coast crude (See Appendix 6-A). Boiling points are shown in parentheses after the specific fraction name.

The light ends through medium naptha generally have a composition like gasoline, while the heavier components are more like oils.  A representative molecule from the gasoline range would be octane or isooctane (both C₈H₁₈), while a representative molecule from the oils side would be paraffin wax (C₂₅H₅₂).  The heaviest components of crude oil are like the binders for asphalt.

What everyone is counting on to actually 'remove' the oil are specific types of marine bacteria that eat oil.  The bacteria with the best PR appear to be Alcanivorax borkumensis, which loves hydrocarbons for breakfast, lunch and dinner.  They prefer alkanes, which are saturated hydrocarbons and very prevalent in crude oil.  David Valentine of UCSB has a nice video showing the dispersant and the bacteria's effects on oil in water on the PBS Newshour website.

If you've ever watched bacteria grow on bread (either due to a science project or reluctance to clean the fridge), you know that the growth of a bacterial colony depends on specific environmental conditions.  A. borkumensis likes water temperatures in the range of 20-30 C, and a 3-10 percent salt concentration, which makes it ideal in marine applications. 

A group at Bangor University studies the limiting factors this bacteria's growth. We already know that the bacteria population won't grow unless there is plenty of food (not a problem in this case).  The Bangor group has been studying whether you can 'fertilize' these bacteria to get them to grow faster.  They are examining how nitrogen and phosphorus may stimulate growth of the bacteria to allow them to deal with very large oil spills.

These oil-gobbling bacteria need oxygen to survive.  You may also have heard reports that scientists are concerned that the bacteria colonies could grow so large that they significantly de-oxygenate the water.  So far, that doesn't look like a problem.

The federal report, which has been widely quoted, says that early signs suggest the oil is “biodegrading quickly."  A number of scientists quickly challenged this assertion.  Bacteria's metabolism decreases as the temperature decreases.  Water gets colder with depth, so bacteria metabolizing oil will be less efficient at lower depths. One of the problems with dispersants is that, at some oil droplet size, the force of gravity exactly counterbalances the buoyant force, so droplets are stuck at a particular depth.  It may take a very long time for these smaller droplets at lower depths to be eaten - remember that the Science paper looks at a plume 3600 feet below the surface.

There are also a lot of unknowns.  We have precious little data about how the dispersants used may change the bacteria's ability to digest oil.  I've been looking for hard information about exactly which components of crude oil the bacteria eat and - sort of importantly - the by-products of the eating process. Some groups have engineered bacteria so that they eat oil and produce plastic. I am suspicious that CO₂ might be a by-product of the metabolism, since it's released in human metabolism of sugars (hydrocarbons with oxygen) and combustion of gasoline. 

This is an interesting case study in communicating science.  The federal report that came up with the 75% 'gone' number was very specific about what they meant by 'gone', even though they included some things I wouldn't necessarily include.  By the time the information got reduced to a soundbite, though, the details were 'gone'.

Research scientists have been pretty unanimously vocal about their skepticism of the 75% figure. It is interesting because we usually go out of our way to emphasize the limits of validity of our conclusions, we make all kinds of caveats and generally put so many conditions on our results that our PR people want to pull out their hair (or ours).  I think the vocal outcry from the scientific community is because conclusions are being presented as 'known', when in fact, they are very tenuous.  There is nothing like drawing conclusions before the data are all in to get scientists riled up.

A very important role of science education - usually overlooked because it isn't easy to test - is teaching people how to think logically and rationally.  This becomes even more important when people are inundated with information from all sides, including professionals whose job it is to promote specific agendas.  It ought to be an attractive theme for today's students:  Don't take anyone's word - prove it for yourself.

stormy weather

Living in sunny Southern California, where it's 75, sunny and mild much of the time, kind of makes you forget that other regions experience this thing called "weather." The fact I moved here in the middle of a drought reinforced this notion of perfect year-round weather in my mind. But this year was a bit different: Los Angeles has been gray and drizzly for much of the winter/early spring. So, you know, we're suffering, too. It's just that "Drizzle-pocalypse" doesn't have quite the same ring to it as the "Snowpocalypse" that beset the Northeast earlier this year. Still, back in January, we were slammed by three major rainstorms back to back, severe enough to cause a small tornado in Long Beach, which hung around just long enough to pick up a sailboat in the harbor and drop it onto a nearby catamaran. Tornadoes are a bit like toddlers that way: "Watch me cause eerily targeted mayhem, just because I can.... Hey, wonder what would happen if I picked up this cow and dropped it into your kitchen, just for giggles???"

That was one of the memorable scenes in the blockbuster movie Twister (which I recently watched again while working out at the gym, since it makes regular appearances on cable TV). The storm chasers are hot on the trail of a twister, and a random cow wafts by their front windshield. ("We got cows!" became the hot movie quote of the season.) There's a lot of really cool science associated with tornadoes, and Twister did its part to ignite the public's interest in that science -- something that real-life storm chasers have mixed feelings about. For one thing, average folks decided storm chasing looked like a fun hobby, completely misunderstanding how dangerous actual tornadoes can be. For another, the science depicted onscreen was, shall we say, not quite in line with the standard textbook science of tornadoes.

In fine Internet tradition, nerd gassers were quick to point out all the scientific errors in the film almost as soon as it came out. These include the fact that air and debris in a real tornado will be pulled into the twister, not out, so you wouldn't get that awesome scene where the 18-wheeler is tossed back onto the two-lane road, skidding ominously towards our plucky storm chasers. Also, Helen Hunt and Bill Paxton's hair should have been flowing forward, not back from their faces -- except then how could we admire her classic bone structure and his ruggedly chiseled features?

Lightning and thunder don't flash/crash at the same time (light travels faster than sound, duh), and while it's true that tornadoes can change their path, but not as quickly and abruptly as depicted in the film. And while storm chasers do use the Fujuita-Pearson Tornado Intensity Scale to rank the power of such storms from F0 to F5, they can't look at their radar readings and immediately tell what a storm's ranking is likely to be -- consider that one artistic license to keep the plot moving along. (One person complained that the hail in the movie looked as though it had been taken out of a hotel ice machine. Given the challenges facing filmmakers on location, it probably was.)

For all the nitpicking we can do over the science of Twister, there's no denying it works as fantastic entertainment. And at least one aspect of the science is drawn from reality: the sensor system known as DOROTHY. It's based in part on the TOtable Tornado Observatory (TOTO, after Dorothy's dog in The Wizard of Oz) developed by NOAA scientists a few years before the film was made. TOTO was little more than a metal barrel (painted white, or orange in later incarnations) pimped out with pressure and humidity sensors, as well as other weather instruments like anemometers. Just as depicted in the film, TOTO could be strapped to the back of a pickup truck and transported into the field where tornadoes might be brewing -- ideally resting on a level, firm surface well away from wind and buildings or trees (or cows!), which filmgoers now all realize can turn into flying debris in a tornado's wake. Did we mention the increased risk of being struck by lighting, thanks to bringing a large metal container into open areas during a severe storm? 

Small wonder TOTO never really saw full deployment. The closest it came was on April 29, 1984, during a field test in Oklahoma, except TOTO was sideswiped by a relatively weak tornado and toppled over because its center of gravity was too high to withstand even the milder forms of extreme winds produced by a twister. It had more success as a portable weather station to monitor regular thunderstorms, but by 1987, TOTO went into early retirement; it was just too large and cumbersome to maneuver quickly (and safely!) into the path of an approaching tornado. No real-world scientist is keen to meet the fate of Cary Elwes' conniving rival scientist, after all. (And yes, real storm chasers in the predicament of Hunt's and Paxton's characters at the film's climax would have been dead within 15 minutes.) You can still see TOTO on display at the National Weather Center in Norman, Oklahoma, though.

One way real storm scientists study tornadoes is by deploying "turtles": small, well-grounded sensor packets placed in roads every few hundred yards, in hopes that a tornado will pass right over them and yield a few more of its secrets. And last spring, scientists launched the largest tornado-chasing project to date: the Verification of the Origins of Rotation in Tornadoes Experiment, or VORTEX 2, for short. It's the second such attempt; the first took place in 1994 and 1995, and the data greatly expanded scientific understanding tornadoes. VORTEX 2 had its first phase last spring, and phase 2 is happening, like, right now. Those results will hopefully shed some light on things like the role temperature, wind speed, structure and shape each play over the course of a tornado's lifecycle. What do you get for the nearly $12 million price tag? You get some nifty unmanned aircraft to monitor storm cells, along with a gaggle of sensor-filled tornado pods designed to be dropped right in a twister's path. And of course, you'll have the old standbys: scientists driving mobile radar machines and "Doppler on wheels" -- i.e., rugged trucks and vans lugging a bunch of expensive electronic weather monitoring equipment.

There's quite a lot of basic information readily available on the Interwebz outlining the fundamental science behind tornadoes, so I won't recap any of that here. But how about the unique damage caused by violent twisters, sometimes literally raising the roof off of a house, for example (and not metaphorically, a la P-Funk)? Well, one contributing factor is the Bernoulli effect, usually cited in simplified pop-sci explanations about how airplanes stay in the air  due to pressure differences in the air flowing above and under the wings. (In reality -- as some readers are no doubt aching to point out -- the aerodynamics of flight is far more complicated, but for the average non-scientist, the Bernoulli effect is sufficient to convey the gist of the principle at work.) Basically, the Bernoulli principle connects the elevation, pressure, and speed of any fluid (which technically includes both liquids and gases). The technical definition in physics for pressure is force divided by area (and force in turn is determined by pressure multiplied by the area of the object, whether it be an airplane wing or a roof).

In the case of a tornado blowing the roof off a house, the high winds whooshing over the roof at high speed  (say, around 260 MPH) creates a pressure difference between the inside and outside of the roof. Whether or not it's strong enough to raise the roof depends on whether that difference becomes great enough to cause "lift". Other factors that come into play include the overall weight of the roof and how securely it is fastened. This guy has actually crunched the numbers, and found that it's perfectly plausible for a tornado to raise the roof if it's not firmly anchored. And of course, once the roof lifts, the wind also blows in the space under the roof, equalizing the pressure, so it would come crashing down fairly quickly.

Incidentally, no, opening a window will not stave off such a disaster; that's a myth. Other myths that are best dispelled: (1) The safest spot during a tornado is the southwest corner of a basement. This is not necessarily true; it's usually the northeast corner, since the safest spot is whichever side or corner of an underground room is opposite the direction from which the tornado is approaching. (2) Taking shelter under a highway overpass is safe. Nope! It's actually a terrible idea, since the small area under the overpass creates a strong wind tunnel effect. In 1999, during a tornado outbreak in Oklahoma, the twisters hit three different overpasses and killed people each time. (3) Tornadoes can't cross major rivers or mountains. Alas, those wily storms can do both these things. Mocking an approaching twister from across a river is just asking for trouble.

Here's something you might not know about the science of twisters, though: they have a distinctive "voice." I'm not talking about the obvious rumblings of thunder, whooshing roars, the whistling of funnels, and screeching high winds. They also emit signals in the infrasound, just below the range of human hearing, and unlike the audible sounds -- which you can really only hear if you're fairly close the storm -- infrasound can travel great distances. Many acousticians specialize in designing sensors and other specialized equipment to isolate the infrasonic signals from tornadoes (as well as volcanoes, crashing waves, explosions and similar phenomena, all of which also produce infrasonic signatures). The aim is to develop better prediction and detection devices to give people more warning before a tornado hits. (Twister the film had that aspect right: people only have 13 minutes or less to respond and take cover when a tornado strikes.)

One of the scientists doing just that is University of Mississippi physicist Henry Bass, who told Discover magazine in 2007 that picking out infrasonic signals in tornadoes and hurricanes could provide "a way of supplementing the information available from satellites and airplanes," although he admits, "We don't know if it will work, but... [we'll] try almost anything." The Earth itself has a discernible "hum" as waves of energy flow through the crust, a phenomenon first detected in 1998 by seismic monitoring networks. In fact, infrasound might offer a plausible explanation for the belief that animals have some sort of "sixth sense" about approaching storms or natural disasters. Certain animals appear to be sensitive to infrasonic rumblings, such as elephants. Bioacoustics research Katy Payne (Cornell University) has studied elephants in the zoo, and way back as far as 20 years ago, she noted a kind of shuddering in the air around the animals, similar to the deep bass sounds emitted by a large pipe organ. She figured the elephants were making sounds just beyond the lower range of human hearing, in the infrasound.

Jen-Luc Piquant, in her Internet wanderings, has discovered something even cooler than the real-world science of Twister: quantum tornadoes! Tiny twisters measuring the width of a single helium atom that are usually invisible to the naked eye! Oh yes, the subatomic realm has its own version of a twister, in the form of quantized vortices, which can only exist in superfluids -- or things that behave like superfluids, such as liquid helium, liquid crystals, Bose-Einstein condensates, and certain classes of superconductors. Researchers at the University of Maryland, College Park, chose to use liquid helium in their experiments with quantum vortices, which undergoes a phase transition to a "superfluid" state when it's cooled to below 2.17 Kelvin (i.e., colder than deepest space). These are prime conditions for quantum tornadoes to form, and if you spin the container that holds them, they assemble into a kind of lattice formation in response. 

There's a catch though: those quantum tornadoes are generally invisible, since they're so tiny that most wavelengths of light don't reveal them. So the UMD scientists injected a bit of hydrogen gas into the rotating liquid helium, which froze to form tiny solid particles roughly the size of a red blood.

You know how laser light tends to be invisible unless there are dust particles in the air to reflect that light? It's the same concept here. Those solid helium particles got pulled into the vortex, and when laser light was shone onto them, it bounced off and reflected back to the video camera, revealing the vortices, which apparently look for all the world like strings of spaghetti that twist and tangle together when stirred. Left on their own, however, in a uniformly rotating superfluid, and they behave the way Richard Feynman predicted they would in 1955: they arrange themselves in a triangular lattice pattern. 

Very little is actually known about the inner workings of these subatomic twisters, which is why the UMD scientists took real-time videos of solid hydrogen particles swirling around in superfluid helium, trapped in quantum vortices, and made what may be the first observations of so-called "Tkachenko waves" within the vortex. The name derives from Russian scientist V.K. Tkachenko, who first predicted in 1966 that when quantum vortices arranged themselves into that telltale lattice, the lattice would not be perfect. There would be tiny ripples (perturbations) that, when viewed from the side, would make the quantum tornadoes look as though they were swaying back and forth like seaweed -- or a twister's funnel snaking gracefully across the sky. And that's just what the UMD scientists observed. The hope is that further analysis will shed some much-needed light on why bizarre states of matter like superfluids, BECs, and superconductors behave in such mysterious ways.

climate change and scientific behavior

I don't know about other scientists, but I've been thinking twice before hitting 'send' on my emails lately.  The last thing I want is to nucleate "MagnetGate". Since it's been out of the public press for awhile, I'll remind you that 'ClimateGate' started when an unknown person (or persons) hacked into an e-mail server at the University of East Anglia.  E-mails were posted on the web and climate 'skeptics' (more on that later) have highlighted passages they claim a) suggest scientists have manipulated data to show false evidence for human-made climate change and b) engaged in a conspiracy to prevent scientists with opposing opinions from being heard.

Let's start with the common ground:  With the exception of the far fringes on the climate-change bell curve, everyone pretty much agrees that carbon dioxide (CO₂) levels have been rising since the dawn of the Industrial Age, and that the rate of increase has become greater in the last 50 years.  Greenhouse gases - like CO₂ - provide a blanket for the Earth that holds in warmth.  As the amount of greenhouse gases increase, the average temperature increases. The primary point of disagreement is whether the changes are 'anthropogenic' (human-caused).  The proponents of anthropogenic climate change advocate that changing our behavior will allow us to bring the rising temperatures back down to a 'normal' range.  Opponents claim that the fluctuations in temperature are within the normal range of climate variations and taking expensive measures to decrease greenhouse gas emissions is unnecessary and diverts that funding from other problems. With the exception of the extremes ("everyone become vegans and live in log cabins in Montana without electricity" and "Global warming is the biggest hoax ever") are a spectrum of opinions voiced by reputable scientists, as pointed out by Stephen K. Ritter in the cover story of this C&EN, a publication of the American Chemical Society.  C&EN alone makes the dues for being an ACS member worthwhile.   

Take the hockey stick plot (reproduced below) that shows temperature as a function of time.  In particular, the y-axis shows the difference between the average temperature of the northern hemisphere and the time-averaged temperature between 1961 and 1990 (in degrees C) and the horizontal axis shows time in years. Y-axis values below zero mean that the average temperature was colder than the time-averaged temperature and data above zero mean that the temp was warmer than the selected temperature.

There are four different colors on the plot.  The blue data use temperatures that have been inferred from tree rings, corals, ice cores and written records.  Thermometer readings are in red.  The black bumpy line is the average temperature for the northern hemisphere for that year.  The gray lines are the error bars.  Error bars denote how precisely (or with how much confidence) we know the temperature.  In the early years, this plot tells us that we know the temperature to within a little better than half a degree either way.

I still haven't finished the literature about how we know the mean global temperature back in 1000 to within a degree when the thermometer hadn't even been invented.  Galileo invented a water thermometer (which had some inherent measurement accuracy issues) in the 1590s.  Fahrenheit invented the mercury thermometer in 1714. I'm guessing that's why the size of the error bars suddenly goes down around 1600. 

But even with the best instrumentation, you have to worry about how and where measurements were made and how reproducible the measurements are.  Cities are urban heat islands, meaning that the temperature within a city can be 1-5 degrees Fahrenheit different than that of a nearby rural area.  If you put a thermometer too close to a building, it can measure reflected heat from buildings. You'll get a different measurement if you measure on asphalt or concrete because black surfaces absorb more heat than light surfaces.

Ritter's C&EN article mentions that Anthony Watts (who writes the 'Watts Up With That blog) checked 1070 of the 1220 stations in the U.S. Historical Climate Network, which is a subset of the 9000 weather stations throughout the US that are used to establish the mean US temperature.  He claims that 91% of the stations fail the National Weather Service's requirements for placing outdoor thermometry. 

Ritter does an outstanding job in his article of presenting the data and discussing the points on which different scientists disagree -- which was what I planned to do in this blog.

Luckily for me, he beat me to it, allowing me to comment on a couple of "things that make you go 'hmmm?" at the American Geophysical Union meeting. 

First, be careful what you wish for.  When Al Gore embraced climate change, I wondered what's not to like: more attention, more funding and a platform to communicate with the public.  Talk to a few people on the frontlines of this issue to see how lucky they feel. 

James Hansen,  who heads the NASA Goddard Institute for Space Studies recounts going to Houston to give a talk just a few days after the hacked emails. A group of bloggers started the rumor that (since he wasn't implicated in the emails), he obviously had hacked the emails, removed his name and leaked the remaining material to discredit his competitors.  His hosts felt they needed to provide him with a police escort.  There were even calls for capital punishment for Hansen.  OK, so maybe climate scientists aren't so lucky after all. 

Hansen recounts in a recently published essay that ClimateGate-type situations have happened before.  He cites some previous cases in which honest errors in data analysis (or provision) were used for sensational headlines that implied that the government or individual scientists had purposely misled people. 

Some of the most talked of the Climategate emails is correspondence between Phil Jones, director of the Climate Research Unit at UEA and Michael Mann of Penn State. For example, the following  from Jones:

"I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline."

The anti-anthropogenic climate people claim this is evidence that scientists are manipulating the data.  Mann says that the 'trick' was replacing proxy temperatures inferred from tree rings with actual air temperatures for dates after 1960.  The more accurate temperatures he substituted change the trends in the data.   'Trick' doesn't denote sneaky or underhanded:  It means a clever way of making something soluble.  The technique of substitution of variables in calculus was introduced as a trick.

After a bit of reluctance, Jones is releasing data so that others can re-check how his group manipulated it and verify that their conclusions are still valid.  As with Hansen's cases, questions were raised, and the science has to be re-visited.  This is how science is supposed to work:  Scientists debate the issue in the open, peer-reviewed literature and a consensus view emerges. 

Questioning the reproducibility or validity of results in not at all uncommon in science. I think what troubles people more are the emails in which it appears that Jones is out to prevent competitors from publishing in the peer-reviewed literature, getting some 'activist journals' excluded from being considered part of the peer-reviewed literature, or preventing some existing peer-reviewed literature from getting into the next IPCC (International Panel on Climate Change) study.  My initial response to this was "OK, so people are surprised that scientists are people?  We have feelings, we have jealousies, and we sometimes behave in ways that won't win us the 'Dr. Congeniality' prize."  But attending the AGU meeting gave me a new perspective.  As Ritter writes in his C&EN article (with the bolding mine):

"Skeptics counter that the "climategate" emails prove IPCC and leading climate scientists have evolved from being brokers of scientific information on climate science to being gatekeepers of information, preventing some valid but contradictory data from coming to light."

I am certainly don't know enough about the intricacies of climate data to say whether this is what is happening here, but it again wouldn't be the first time. Newton is famous for his rivalries with, well, just about everyone, usually over claiming credit for coming up with ideas.  This included Hooke, and Leibniz.  Edison did some pretty rotten things to his competitors, including Tesla. More recently, Gallo and Montagne quarreled over who had first discovered the AIDS virus, which included charges that Gallo had stolen the virus from Montagne's lab.  (Congressional and NIH inquiries cleared Gallo of these charges.)  There are many stories -- anecdotal and well-documented of scientists conspiring to prevent rivals from publishing first (or at all), of scientists stealing ideas from proposals they have reviewed, and a growing list of retracted papers with either outright fraud or sloppy work.

What constitutes gatekeeping data (selectively keeping or discarding data, and not sharing key data sets with others so that they cannot try to reproduce your results) is difficult question. If you've painstakingly gathered data, why should you have to turn over your work so that other people can data mine it and beat you to results?  On the other hand, science is founded upon the concept that scientific results are valid because other people can perform the same experiments and come to the same conclusions.  The scientific method relies on replication and debate, and it is difficult to have that debate if the original data are not accessible. 

I went to a series of climate change-related talks at the AGU meeting to see what "the community" thought. I could divide people into roughly two groups:  The first group are in-the-trenches scientists giving talks about very specific problems within their subfields of climate research.  Their results were presented very objectively, they pointed out uncertainties in their conclusions and showed evidence to counter questions raised by the audience.  The second group of speakers had a agenda that was more advocacy than science.

As a graduate student at an Association of Women in Science leadership conference, I remember clearly being irritated by a speaker who assumed that, because we were women in science, we were all liberal Democrats and antagonistic to the then-Republican-dominated administration.  The 'All intelligent people find this obvious' attitude bugs me because it is so antithetical to what science is all about: evidence and open debate.  I was, at the time, a card-carrying Democrat wholly antagonistic to the administration, but I'm also a scientist.  My view then and now is: Show me the evidence and let me make up my own mind.  Don't tell me what to think.

I went to a town hall at AGU entitled "Talking Climate".  A town hall is not a scientific research session per se, but more informal. The blurb for the town hall was:

The public has significant gaps in its understanding of climate change. Naturally, scientists are best equipped to fill these gaps. However, many scientists are unaware or untrained in how to best convey their ample knowledge to non scientists. Because they're already experts in their field, they can make inaccurate assumptions about other people's understanding of weather, climate, and human-caused warming. Our goal is to cultivate an educated public that can make informed decisions. In this town hall meeting, communications professionals will provide the basics of delivering accurate yet easy-to-understand science to the public and the media.

I was hoping to get from the session (which was very respectably attended for 7:15 in the evening) some information that would help me address people who ask questions about the hockey stick plot.  The web tells you that it's right and that it's wrong, and it is really hard to tell which of the sites I should believe. 

The conveners were Kim Curtis, a former AP reporter and now with the communications firm resource|media, and science & technology writer/editor Susan Hassler.  (I hope I have Susan's name right, as I couldn't find it in the program.) There was some valuable information from the session:  For example, Hassler had a list of words scientists use differently from their conventional meaning. For example, 'aerosol' to most people conjures up a can of hairspray, not particles suspended in the air.  Words like 'bias', 'error', 'exploit', 'scheme', 'proposal', and 'risk' have very specific meanings and when we use them in discussions with journalists or the public, we are asking for things to be taken out of context.  They covered some important points about not assuming too much knowledge on the part of your audience, not using jargon, not allowing details to obscure the main point, and making numbers meaningful by comparing them to things people have direct experience with.

However, I started getting a little uncomfortable when Ms. Curtis compared a statement from an IPCC report

"most of the observed increase in global average temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations"

with a quote from an NRC report.

"The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability. Human-induced warming and associated sea level rises are expected to continue through the 21st century... The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue."

Ms. Curtis criticized the NRC report for not making the point as clearly as the IPCC report.  I understand that a communications company is paid to support a particular point of view; however, the NRC report was from 2001, while the IPCC report is from 2007.  That statement was likely the strongest the panel felt comfortable making at that time.  Having been on a NRC panel, I know  there is a lot of wordsmithing done to ensure that the conclusions are defensible based on the evidence.  Ms. Curtis also showed only a portion of the IPCC quote.  The full quote is:

"Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.  It is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent (except Antarctica)."

You have to read carefully to figure out the difference between the two sentences.  The second sentence addresses warming over each continent as opposed to over the globe as a whole.  I was very disappointed that the session was really more on how to advocate without providing the evidence I as a scientist would need to feel comfortable talking about the issue.  I read the IPCC executive summary myself to determine what I thought they were actually comfortable saying.

A later session was PA24A "Providing Climate Policy Makers with a Strong Scientific Base".  Again, the 'intelligent people don't need to be convinced of...' attitude was pretty evident. What bothered me most was typified by a statement by Ann Staudt of the National Wildlife Federation in which she said that anyone who didn't believe in anthropogenic climate change wasn't really a scientist. Similar comments had been made in the town hall.  Ritter points out in his C&EN article that some typify dissenters as 'climate-change antagonists', or 'deniers'. Have even scientists lost the idea that science should be the objective voice of reason?

There is an outstanding editorial in the LA Times by Daniel Sarewitz and Samuel Thernstrom, two scholars with very very divergent political bents, but some common conclusions. Scientists claim some type of ultimate authority by being above the fray and answering only to Nature (the entity, not the journal).  Sarewitz and Thernstrom point out that it has never been the case that scientists are unbiased providers of the Truth, and that "Science, in other words, is replete with the same human failings that mark all other social activities." They conclude:

The real scandal illustrated by the e-mails is not that scientists tried to undermine peer review, fudge and conceal data, and torpedo competitors, but that scientists and advocates on both sides of the climate debate continue to claim political authority derived from a false ideal of pure science. This charade is a disservice to both science and democracy. To science, because the reality cannot live up to the myth; to democracy, because the difficult political choices created by the genuine but also uncertain threat of climate change are concealed by the scientific debate.

I entered science with the naive ideal of a field in which everyone was engaged in a search for Truth (the concept, not the elementary particle).  The fact that there really isn't a 'pure science' because evidence early in my career when I found some graduate students had solutions manuals and others formed exclusive study groups. Then there's grant getting, tenure... I've fallen out of the ivory tower. It's not a secret in the scientific community we sometimes eat our own young, that people fall so much in love with their own theories that they become unable to even consider other points of view, or that some scientists forge data for publications and attention.  But so far (mostly) the scientific method has worked. I will never win an argument to change the charge on the electron because everyone else can measure it and see that I'm wrong.

The problem is that the science of climate change is so complex and uncertain that -- if this is as imminent a danger as some project -- we don't have time to figure it out before we decide to do something.  Perhaps ClimateGate is a good thing in the end because it shows the public that not all science is as certain as the measurement of the acceleration due to gravity they made in high school.  Perhaps scientists, like medical doctors taking money from the pharma companies or journalists writing about people they know personally, should be required to disclose their sympathies.

I'll start. I agree with AGU's position statement on climate change. I believe in anthropogenic climate change, but I think there is a lot of uncertainty about how bad it could be.  Recognizing the inherent uncertainties in a fluctuating, aperiodic, non-linear system, and the fact that there may be some significant questions about some of data and its interpretation, it still seems to me that if we don't act now and the worst case is right, we may not have another chance. It's almost Pascal's wager.  You might as well believe in climate change because if we are in a natural cycle and the temperatures come back down, we're out money.  If it's not a natural cycle and we do nothing, we're pretty much screwed.

That's a practical and decidedly unscientific opinion.  But perhaps there is still some white shining though the soot on the ivory tower.  Even though, science may not be 'pure' as Sarewitz and Thernstrom put it, that doesn't mean we shouldn't strive for it to be so.

help make michael a hottie

I'm on the road, first in Waterloo, Canada for the Perimeter Institute's Quantum 2 Cosmos Festival -- you can read about a couple of the highlights over on Twisted Physics -- and now in New York City for the Imagine Science Film Festival. Several blog posts are in the works, but in the meantime, I had to dash off a quickie. You see, over at The Crunchy Chicken, they're running a poll asking us to vote on the Hottest Man in Climatology. Apparently there were slim pickins':

I wanted to write a post about the Hot Men of Climatology, but when I went a huntin' for hotties, pretty much what I found were older men sporting a lot of hair or none at all. And, the only hot thing going on was more related to warming temperatures than chiseled abs. But, I've found the up and coming (well, under 50ish) "hot" men of climatology for your review. Let me know if I missed any :)

One of the candidates is Michael Mann, a climatologist at Penn State whom many of you might know from the RealClimate blog, which he writes with Gavin Schmidt. Michael is behind in the polls. In fact, he might even lose to Gavin, which really sticks in his craw. So I made him an offer: I would write a post asking people to vote for him on the condition that, should he win, he agrees to pose in a thong, preferably of the Borat variety -- although an S&M posing pouch would do just as nicely. :) He agreed (although I suspect now he hopes he loses)!

So head on over to The Crunchy Chicken and vote for Michael, who in addition to being a Hot Climatologist, is also pretty much a mensch. Tell your friends! And if you're in NYC, I'll be at the city's premiere of Randy Olson's SIZZLE! Friday night. Come down and say hi!

China report

  I've been back from China for about a month and I'm still processing the experience, but I thought I'd tell you all a little about some of my observations in and out of the classroom. I was hired to teach English language and culture but really, in three weeks, there's not much language teaching you can do, so it mostly winds up being an English culture summer camp and conversation program. Which is great. There's a lot more learning of language that goes on in informal sessions than formal ones, and it was really a pleasure to get to know both the students and faculty of the Harbin Institute of Technology (HIT).

Harbin is an industrial city in the north of China, with a population around the same size as New York's. As Chinese cities goes, it's pretty new, springing up in the late 1800's when the Russians built a railroad from Vladivostok to a sleepy fishing village on the Songhua River for trade purposes. Russian Jews migrated there and helped build the city, giving Harbin its first hospitals, schools and libraries as well as two synagogues and a sizable cemetery that's still lovingly cared for by the Chinese. At one time the city housed an international, multiethnic population and was called the Paris of China, and passed through both Russian and Japanese hands before becoming wholly Chinese. Now, its population is almost exclusively Chinese, with a few Japanese and Korean residents. (If you're interested in pictures, you can see what I took at my Flickr account, or our fearless leader, Marcy Bauman's. You can also take a look at my blog posts about the trip.)

The city has a number of universities and top-notch schools. HIT is the third-best university in China, on par with our MIT and like MIT, focused on science and technology fields. The students are chosen from the top 2.5 percent of those taking the national admissions exam, so they are smart, smart kids, and HIT tends to promote from within its graduate population. One thing the language barrier often does is disguise just how darn smart folks are, and I know I was underestimating the intelligence of most of the people I was talking to. The few technical conversations we had were as much hampered by my lack of technical vocabulary as their lack of English vocabulary. I met aerospace, civil, environmental and all other kinds of engineers, materials scientists, chemists, computer scientists and new media specialists, economists and architects, and people specializing in technological innovation, with research areas as diverse as composite materials, solid oxide fuel cells, optical thin films, and microporous and mesoporous materials. Many of my students were studying alternative energy technologies and environmental sciences.

These last two subjects are big issues for China, and you can see the need for them all over Harbin itself. The weather was beautiful during the first week of my stay: warm and dry and windy. I was really puzzled when people kept asking me if I found Harbin's air dirty. And then the next week we had a temperature inversion and I understood the question. You can see the difference in the two photos I took from my 15th floor window on campus:

There's blue sky underneath that smog, believe it or not. And that's the way it was for most of my visit. It's not eye-stinging or smelly like the air in Pittsburgh was when I lived there in the late 70's, but it makes New York on a bad day seem edenic. Ozone shmozone. Most of what's in the air is not car exhaust but coal smoke. There were several coal-fired electricity plants on campus, and that's where most of China's power comes from. At least in Harbin, cars are a relatively small part of the problem because there just aren't that many per capita yet (not so for Beijing and Shanghai). That doesn't stop the traffic from being completely insane, but that has more to do with the total disregard for signs (if there are any) and rules of the road than numbers. And the donkey carts don't help, either, I'm sure. Especially the ones on the expressway. Or the massively laden trikes.

If Harbin is any indication, one of China's biggest priority has got to be infrastructure. I'm used to not being able to drink the water when I go somewhere out of the country, but in Harbin no one drinks the water. You can wash in it, and wash your clothes and dishes, but you can't drink it because there are no purification plants and largely unregulated wastewater dumping. Cooking and drinking water is all bottled, which adds its own problems in recycling (that's what the guy on the trike is hauling, incidentally). In one of the first conversations I had with the faculty when school started, I spoke with a prof whose specialty is construction materials and engineering and we talked about the lack of regulation in China, not only in building materials and codes but in industry as well. Where we have legislation like the Clean Air and Clean Water Acts (however badly they're enforced), China has nothing but local committee oversight, which is subject to bribery and corruption. (Interestingly, while I was writing this, the New York Times published the first of a series called "Toxic Waters: America's Growing Pollution Problems." So it's not like we're doing such a great job either. But the major difference is that we have the legislative framework to deal with it.) There seems to be a major push in Harbin, to correct some of these issues, at least on the wastewater front; streets all over the city were torn up both for new sewage and water lines and for a new subway the city is putting in. And many of my students were keenly interested in environmental issues and abatement technology. I got a lot of questions from both faculty and students about how pollution is managed in the States (and was grateful for 10 years of editing environmental impact statements to give me the background to answer them).

But the two issues that really struck me as an educator and a science geek were the attitude toward education in general and how different it is talking about science without religion getting in the way. I was teaching mostly incoming freshmen and sophomores, and not only were they some of the brightest students I'll ever have the privilege of teaching, I've never had students who were so eager or so respectful. This program was basically a three-week summer camp and still there was nothing my students balked at doing. Homework? Sure, no problem! Write in class? No problem. Ask me awkward questions about Tibet? Sure, happy to. Eat lunch with you? Absolutely. Students were on time, every day, or almost humiliatingly apologetic if they were late. They stood up to answer me in class. And thanked me after each one. After day one, I was reeling with culture shock. This is not to say my students here are not hungry or grateful, but in a completely different way. My students here know they've missed out on something and want to make up for that so they can get good jobs and support their families. The intellectual hunger in Chinese students is just that: intellectual hunger for new ideas, new ways of thinking, new information.They have a visceral love of learning you see in some of the best schools here and with individual students even at third tier U.S. schools. In part, that's because getting into college is so competitive, even more so than here. The major difference, and something I missed, was that Chinese students won't often argue with you. They're so respectful, and often used to learning by rote, that disagreeing with a professor seems rude to them. Teachers are really important people in China, and paid accordingly. We could really learn something from that.

And yet, one of the faculty and I had a conversation about this and he insisted that U.S. schools were still superior because we taught students to think independently. Gosh I wish that were still true. As I recently said in another conversation over here, our schools are leaning more and more toward shaping students for particular careers and offering them skill sets, rather than the ability to learn quickly and think for themselves, which can be applied in any career. (I'm not saying you don't need skill sets, especially in the sciences, but along with that, you need critical thinking skills and imagination, rather than just the skill sets. It's what sets a technician apart from a scientist.)

The unit that I taught was about science in the U.S. and covered a little history of science (the development of the scientific method, major discoveries, major players); the two-way exchange between science and culture; women in science; science in entertainment (thanks, Jen!); communicating science; current controversies; and how the public views science. We watched a couple of CSI episodes, Minority Report and The Matrix, and a couple of clips from Babylon 5. Some of the entertainment was familiar, and some not, but the references that went right over everyone's head were the religious and mythological allusions in The Matrix—not surprising, since that same stuff goes right over my head in Chinese opera. More confusing for them, though, was the whole idea that people would actually disbelieve scientific fact in favor of religious teachings or myth. When I described the controversies about teaching evolution in public schools and what ID and creationism were, they were clearly boggled. When I asked how many of them had some sort of spiritual belief, whether Buddhism, Confucianism, Islamic, or Christian, not one hand went up. (Just to clarify, each of those religions is legal in China; there is an active Buddhist temple in the city, some of the faculty are Buddhist, and though the Jewish population is long-gone, their synagogues were not razed during the Cultural Revolution as were most of the Christian churches. So this wasn't fear of reprisal that kept them from professing religious belief. It was simple lack of interest.) For the Chinese, if anything plays this role in forming or deforming scientific thought, it's politics, and I think that's less true now than it was during, say, the Cultural Revolution.

And these two facts, if anything, are what's going to allow the Chinese to roll over us economically in ten or twenty years. Not their sheer numbers, but their respect for education and their lack of muddying religious issues. They're intensely proud of their country and their accomplishments, which are indeed impressive, and that pride and ambition and ability will carry them a long way. Unless the US gets its priorities straight (more money for education, better pay for teachers, more access to quality education for everyone), we're soon going to be buying more than cheap tchotchkes, outsourced electronics, and pirated movies from China. We'll be importing technology we should have invented and produced ourselves.

miles (per gallon) to go before understanding fuel economy

The rocket scientist just bought a new car.  He claims he was thinking about trading in his old Pontiac Aztek well before I bought my new car, but even if we were thinking about the need for new cars at the same time, I guarantee we had distinctly different thought processes in deciding what kind of cars to buy.  I have a much more aerodynamic dog than he does (hound dog vs. golden retriever), so a convertible made a lot better sense for me than for him. (Sorry, Katie...) 

One obvious consideration in buying a car is fuel economy.  Fuel economy is the figure of merit for everything from advertising to the "Cash for Clunkers" program.  C for C only allowed you to trade in cars with an EPA fuel efficiency rating of 18 mpg or less.  If you had a Toyota Camry and you wanted to get a new Prius, you were on your own.

So which is better:  going from a car that gets 34 miles per gallon (mpg) to one that gets 50 mpg, or changing from a car that gets 18 mpg to one that gets 28 mpg? For the precise among you, let's define 'better' to mean saving you the most money in fuel costs.  So the first one is better, right?  You've got a 16 mpg improvement vs. a 10 mpg improvement.

Not so fast.  Let's say you drive 18,000 miles each year.  The amount of gas you need to drive 18,000 miles if you get 18 miles per gallon of gas is 18,000 miles/18 miles per gallon = 1,000 gallon.

Miles per gallon	Gallons of gas needed for 18,000 miles
18	1,000
28	643
34	529
50	360

If I change from a car that gets 18 mpg to one that gets 28 mpg, I save 1000-643 = 369 gallons of gas.  If I change from 34 mpg to 50 mpg, I save 529-360 = 169 gallons of gas.  Sort of counter intuitive, huh?  That's what Richard P. Larrick and Jack B. Soll of Duke University found in a study in which they asked people to rank order five pair of proposed mpg changes in order of "their benefit to the environment (i.e. which new car would reduce gas consumption the most compared to the original car?)"  Sixty percent of the respondents rank ordered the changes according to the difference in mpg.

If you plot (as the authors did in their paper) the amount of gas used for a fixed driving distance vs. the miles per gallon your car gets, the plot is definitely not linear. I've made a similar plot for three different driving distances - 10,000 miles, 15,000 miles and 20,000 miles and indicated on the graph where the two mileage differences I compared above are located.

This is an example of linear reasoning being applied to a case in which it doesn't apply.  In some countries, the figure of merit is a quantity like how many gallons you need to drive 1000 miles.  (Actually, the quantity is liters per 1000 kilometers since just about everyone in the civilized world except us uses the metric system.)  I calculated the gpm (gallons per mile) in the table below and you can compare the fuel efficiency much more easily.  

Miles per gallon	Gallons per 1000 miles
18	55.5
28	35.7
34	29.4
50	20.0

Larrick and Sole argue that gallons per mile and not miles per gallon should be used to help people understand energy efficiency, but I would argue we need to take it one step further.  I used to like to ask my graduate students the following question:  "What one skill do you want your students to have when then enter the intro course in your discipline in college?" 

For me, the answer is the ability to really read graphs.  That's a little bit of a cheat for an answer because there's a lot of math tied up in understanding graphs.  But a graph gives you so much more information than a number does.  In this case, we're really not interested in just a number:  we're interested in the slopes between the sets of points -- or (dare I say) the derivatives of the curves. On the graph below, I've identified the slopes between 15 mpg and 20 mpg and between 35 mpg and 40 mpg with dark lines.  The lines are a lot steeper for the low-mpg interval than for the high-mpg interval, even though we're looking at a 5-mpg difference in both cases.

Another important thing to notice is that how much you drive in a year makes a pretty significant difference.  This graph tells me that the more miles you drive, the more important it is for you to improve the fuel economy of your car.  The little old lady with the Mercedes who only takes it out on a Sunday for church is not making too much of a dent in the petroleum stores.  The person who drives from Allen to downtown Dallas five days a week, 50 weeks a year really needs to worry about fuel economy.

The final thing I would hope people notice from the graph is the total amount of fuel.  Changing from a 10 mpg to a 12 mpg vehicle definitely saves fuel; however, you're still using a lot more fuel than if you went to a 15 mpg or 30 mpg vehicle.

Of course, there's a caveat - there always is.  Although the study focused on environmental impact in terms of fuel used, don't forget that there can be significant differences in terms of emissions.  In fact, the two best things you can do with your current car to help the environment are to make sure your car is tuned up so that if combusts the fuel efficiently, and maintain the right tire pressure.

My hopes for getting students to learn how to use and digest information from graphs is probably doomed for disappointment.  People want the easy solution:  just give me one number I can base my decision on.  Just as No Child Left Behind has reduced school performance to standardized test scores, and all universities care about anymore is how many students are enrolled and whether the students think the professors are entertaining - never mind what they learn, the average person wants things to be laid out.  I'm with Einstein:  Everything should be made as simple as possible.  But no simpler. 

Maybe we need a test before you're allowed to buy a new car.  On second thought, that would probably kill the Big Three faster than they've been able to do it themselves.

NEW VOICES: the iceman cometh

NOTE: I would love to be blogging about zombies or the quantum Hamlet effect or The Time Traveler's Wife, or any number of cool science-y things, but instead I am STILL writing The Damn Book. Here's Alex Morgan again, saving the day with yet another nifty guest post.

I was at the Traverse City Film Festival a few weeks ago and saw No Impact Man, which opens in September. It documents a year in which Colin Beavan and his wife, who live in a small Manhattan apartment, give up everything they are doing that might harm the environment. They decide not to buy any new clothes or household items. They stop getting take-out and restaurant food (including Starbucks coffee!) and buy food only if it is produced within 250 miles of their home. They use bicycles for transport and take a train only for a few trips outside the city, still within the 250 mile limit. As the year progresses, they give up more and more. For example, they stop using toilet paper. After about six months they flip the circuit breakers and go without electricity, meaning candles for lighting and nothing for heat.

The sticking point in their experiment comes after giving up electricity. They have no working refrigerator. How are they going to cool food, for example, milk for their young daughter? A ceramic pot-within-a-pot device that is supposed to use evaporation for cooling doesn't work in their apartment. Finally, they end up "cheating" by borrowing ice from a neighbor's refrigerator. Their journey of no-impact living is documented further on Beavan's website. What interests me is the ice.

I was a kid in the 1950's, and at that time in Savannah the iceman would still make regular deliveries to people's houses. My mother's mother – we called her Nanny – had an icebox as well as a refrigerator. Nanny was born about 1880 and grew up without electricity in a small town in Tennessee. Her family used kerosene lamps for lighting and iceboxes for food. When electricity became available, she didn't trust it and never gave up her lamps or her icebox. She used both alongside of their electric descendants. The kerosene lamp on her night stand was never allowed to go out.

To my child's eye, the iceman was a scary giant. He would come to the house with a monster cube of ice on a leather pad on his shoulder. He used a hook to hold the ice in place and then swung it down into the icebox in one practiced sweep. Nanny's icebox was the smaller variety that came up to my eye level but to an adult's waist. It was white metal, like the refrigerator, not the wooden kind.

Nanny kept mason jars of water and various other items in the icebox. I remember the butter sitting in a dish on top of the ice itself. The ice melted, but slowly, so that it lasted until the next day. The melt water flowed into a pan that had to be emptied regularly. The icebox was messy and smelly, but that didn't bother Nanny. She was used to it.

Where did the ice come from? In the 1950's, it was made at "the ice company," situated, I remember, in downtown Savannah near the post office. But where did it come from in 1880? I asked, and the answer surprised me. It came from lakes in New England.

Beginning in the early 1800's, "ice cultivation" became an economically significant industry in the United States, comparable to agriculture. Lakes in New England, and other parts of the country with hard winters and reasonable access to transportation, were designated for ice making. In the winter, after they were frozen to between one and two feet thick, they were cleared of snow. Then the ice was scraped clean, scored into squares, and sawed out as blocks, which were stored in warehouses. These "ice houses" needed effective insulation – commonly made from sawdust – and a system to drain the water, so that the ice would stay as dry as possible.

Ice farmers favored sawdust for insulation also when shipping their crop. Savannah, Charleston, and New Orleans were early ports of call in the ice trade, which eventually included Britain – American ice was considered higher quality than Norway ice – and even India. This cultivation and harvesting of ice diminished as artificial means of production became more efficient, but it lasted well into the Twentieth Century. The principles of ice manufacture had been known before the Nineteenth Century. William Cullen at the University of Glasgow in 1748 demonstrated that the evaporation of liquid ether generated cooling.

The International Exhibition of 1862 in London featured two ice-making machines – one based on the vaporization of ether, the other on ammonia – which thrilled the crowds in the summer heat. However, the journey from science to engineering to production can take many decades, where efficiency is often the issue after feasibility has been established. It takes energy to run the motor that operates the pump that compresses the refrigerant in a typical ice maker. Efficiency and reliability of refrigeration machinery improved to the point that seventy-five years after the London exhibition, harvesting "natural ice" was no longer economical. But now our society is reconsidering all its energy costs.

The no-impact man had to borrow refrigerator ice from his neighbor. But within 250 miles of Manhattan there are lakes that freeze in the winter, so the old technology of ice cultivation, harvesting, and transport could be resurrected to get no-impact ice. That is, most of the cost would be in labor and transportation, the same as for small-scale food farming. Such cultivated ice would be "more expensive" than machine-made ice, but perhaps only if the cost doesn't include global warming and other ecological disasters looming for our children and grandchildren.

My grandmother had no problem making do with less impact. Colin Beavan and his family were willing to be inconvenienced and to pay more for their food. Ice farming is perfectly feasible, perfectly aligned with the spirit of no-impact.

the ones that got away: science through cross-disciplinary eyes

There's a song by Bruce Cockburn called "The Trouble With Normal" that has stuck with me for years since I first heard it in graduate school. The line in its entirety goes "The trouble with normal is it only gets worse," an observation that applies to so many facets of life: political leaders, repressive regimes, pollution, war, gas prices, age—you name it. It seems to take humans a surprisingly short time to adjust to new conditions, no matter how bad they are. Worse, it seems to take us an equally short time to forget what things used to be like. We dismiss the reminiscing of old folks as just that: dreams of a golden age edited by memory.

This is one reason why studying history is so important. You know: those who forget history are doomed to repeat it, and all that. But history, the kind practiced by historians rather than paleontologists, can also give us a glimpse of what's wrong with our environment, or at least how drastically it's changed in some cases. This is the basis of at least part of the newish discipline of climate study, and some branches of archaeology. Turns out it's also providing a picture of what human predation has done to the size and quantity of ocean fauna.

The History of Marine Animal Populations (HMAP) and its ongoing Census of Marine Life (CoML) project is using records as diverse as old ship logs, literary texts (literary texts! Yay!), tax accounts, newly translated legal documents and even mounted trophies, to track historical sizes, abundance and distribution. Some of the images that are coming to light are, in a word, boggling, but it delights me to no end to see this kind of cross-disciplinary approach. Specialization is a necessity in science, but for big pictures, it always helps to stand back and switch your filters. Dusty stuff like old whaling ships' logs and other documents, for instance, are usually the domain of historians, but they've offered a resource to calculate the pre-whaling whale population with 95% statistical certainty. The decline in population in the very short time that whaling was practiced world-wide is appalling. For example, researchers calculate that southern right whales alone numbered between 22,000 and 32,000 in the early 1800s, declining rapidly once whaling began. By 1925, perhaps as few as 25 reproductive females survived. That's not just predation. It's slaughter on the scale of the buffalo.

We're not used to thinking about whale populations in terms of tens of thousands. As Jennifer pointed out when I first posted the link to this particular study on Facebook, that phenomenon is something that biologist-turned filmmaker Randy Olson calls "shifting baselines," and those shifting baselines can be deeply deceiving. Andy Rosenberg, of the University of New Hampshire, points out that appraising modern marine life through the narrow window of observations during recent decades "skews perceptions" of "natural" marine life sizes, abundance, habitats and vulnerability. Put another way, we're pleased when whale populations climb back to a few thousand or so, but the real baseline to measure their progress against is much larger. When you know that, you realize the poor whales still have a long way to go and their population gains seem far more fragile and worthy of further protections. Having the correct baseline, this one provided by historical documents not current scientific census data, can help form the correct international policy to protect them.

Then there's that size issue.

Fishermen, God love 'em, always talk about the one that got away, and it's inevitably a huge beauty that no one believes actually existed. Fish just don't get that big, unless you're fishing for the big guys like marlin or grouper, right? The photo at right (courtesy of HMAP/CoML) illustrates the decline in size, species diversity and abundance of gamefish in the Florida Keys between 1956 and 2007. There are some real beauties any fisherman would brag about in the top, earliest photo that make the recent catches in the bottom photo look puny-ass by comparison. The study found that from 1956 to 1960, large groupers and other large predatory fish dominated the catches, including sharks that averaged nearly two meters long. By contrast, small snappers with an average length of 34.4 cm dominated catches in 2007. Just today, in one of my cooking magazines touting the wonders of summer trout, was a photo of a guy holding a wee little fishie that barely spanned both palms, something I would have been told to throw back as a kid. Overfishing makes the catch amounts and individual sizes smaller simply because fish aren't allowed to fully mature before they're caught and eaten. You don't grow a 500 lb. grouper overnight. It takes, in fact, about 30 years. An 800 lb. grouper may be as much as 50 years old. I'm glad my middle age spread isn't that drastic. Freshwater fish grow more rapidly, but they still take time to mature into the three-foot-long pike my uncle pulled from the lake 40 years ago.

This drop in average fish weight isn't a modern phenomenon. Once humans started fishing with nets or weirs, the fish were in trouble. The Romans apparently were fishing with nets quite early on, but it wasn't until the middle ages that evidence of reduced sizes in the fish themselves begin to be recorded. That's when improvements in boat design and equipment allowed fishermen to start dragging those nets farther from shore, rather than just casting them and hauling them up, as in the picture above, from an 11th century Byzantine manuscript (International Journal of Nautical Archaeology/CoML). But in the course of this study, researchers determined that the human impact on the oceans began much earlier than previously thought, as early as the Middle Stone Age: 300,000 to 30,000 years ago, which is 10 times earlier than previously believed.

This is where I get really tickled about this kind of study. Where does the evidence come from? Not just archaeology. That can only find physical evidence of the fishing methods and tools, and if you're lucky, fish bones in the midden heaps. Nope, the evidence about how small the fish have gotten comes from literary texts. Latin and Greek verse written in the 2nd century CE was used to determine that the Romans were even then learning to trawl in a limited way and finding that, over time, it reduced the size of the fish they caught. Old logbooks and collections of sea lore were also studied for comparison purposes. Even old restaurant menus were scrutinized. Researchers also cited a text written in Sicily in 1153 that describes the seas of the North Atlantic as having "animals of such great size that the inhabitants of the islands use their bones and vertebrae in place of wood to build houses. They make hammers, arrows, spears, knives, seats, steps, and in general every sort of thing elsewhere made of wood."

Our biggest problem with this kind of literary evidence is that we find it hard to believe, in view of our own experiences. It's like the hillbilly who, when a giraffe was shown to him, declared, "There ain't no sich animal!" Krakens? Yeah, right. But we know that deep sea (and polar ocean) critters often exhibit an inordinate gigantism we didn't expect and can't fully explain, like the giant isopods found on the deep sea floor (imagine a foot-long pill bug). And there really are giant squids, though one big enough to pull down a ship hasn't yet been found. And to be fair, there's a great deal of exaggeration and sheer make-believe in the early histories. Look at Isidore of Seville's Etymologies, which describes the Blemmyes, who were an actual African tribe, as having their faces on their chests because they had no heads. To be fair, he stole it from Pliny the Elder, whose Naturalis Historia was the first encyclopedia and model for those that followed, at least in format if not veracity.

So how do you tell the fact from fiction in old sources? Statistical analysis and confirmation from other sources. In addition to the literary sources, researchers used photographs of previous catches, legal documents, tax accounts, whalebone buttons, paintings, old pavements, isotopes, and ice cores to develop backcasts. This cross-disciplinary approach gives a much broader picture than just observations of what's currently in existence. It's studies like this that help us inot just magine but undertstand, for instance, what Manhattan might have looked like when Henry Hudson sailed into the harbor or what the world might look like without us.

Apparently, a lot bigger, with a lot more in it. At any rate, it's good to remember that our "normal" isn't necessarily the norm.

body heat

I am in Portland for the day, having dragged myself out of bed at an ungodly hour (4 AM) to catch my flight. (On the plus side, there is almost no traffic on LA freeways at that hour.) The reason: to visit the city's Green Microgym founded by personal trainer Adam Boesel last year. Perhaps you read some of the press coverage the opening generated: Boesel has retrofitted much of his exercise equipment (stationary bikes, treadmills, elliptical machines) so that gym members can produce a little bit of usable energy during their workouts -- not a lot, mind you, but enough to run the fans, for example, or the stereo system. Combine that with other strategies for improving energy efficiency, and Boege keeps his electricity costs to a bare minimum. In time, he thinks he can break even, and maybe even turn a small profit.

He's not the first to ponder the potential of all those city dwellers -- ahem! like me! -- spending hours upon hours running or cycling in place to stay fit and trim, like hamsters on one of those little wheels, with little else to show for it other than improved health (which, admittedly, is a valuable thing). Lots of amateur engineers over the years have tried building their own energy-generating bikes to, say, run their coffeemaker in the morning. Several companies have cropped up in recent years specializing in retrofitted exercise equipment: ReRev.com in St. Petersburg, Florida, for example, which installed a set of retrofitted elliptical machines in a 28,000 member gym in Gainesville, or entrepreneur Jim Whelan's Green Revolution. There's an entire research program devoted to human-powered energy at the Delft University of Technology in The Netherlands.

For the Green Microgym, Boesel started with four linked Team Dynamo stationary bikes connected to a bank of batteries, capable of generating up to 200 watts for every hour of exercise -- enough to run an LCD TV and stereo system for the entire workout period. It's a team effort, too, with all four riders helping to charge the batteries.

Sounds good in theory; Boesel found in practice that the battery option isn't nearly as efficient in generating useful energy as a machine with a "grid-tie" inverter that sends the generated energy directly into the power grid. (That's a device that lets people with solar panels, for instance, "spin the meter backward" and sell power back to their local power company. Boesel literally plugs those machines right back into the wall socket.) There is a greater conversion loss when you feed that generated energy back into the battery, for some reason.

See, that's why you need to do the experiment. Nonetheless, Boesel has reduced his energy costs significantly: he consumes on the order of 9 kilowatt hours per month, which is ridiculously low for a commercial enterprise. In addition to retrofitted machines, he employs a lot of common-sense conservation measures, like turning off machines and TVs when they aren't in use, and judicious use of the A/C and lighting. Apparently the average treadmill takes 1500-2000 watts to operate; you'd need nine Lance Armstrongs chugging at full power to keep just one of those suckers operating. Incremental improvements can add up over time, particularly for a small business like the Green Microgym. He estimates he saves between $75 and $150 a month, which isn't going to set Wall Street on fire -- but it can help defray the creeping costs of running your own gym.

I don't know exactly how much energy my gym in LA uses, but it's a hell of a lot more than the Green Microgym's consumption. Granted, it's a lot bigger, with more machines (each with its own little TV monitor), a cutting-edge sound system, large mounted TVs all over the gym, a heated pool, large locker rooms with sauna and steam room and showers, etc. But there's a lot of little ways to eliminate waste here and there -- like turning off the mounted TV screen on your elliptical machine after you're done working out, or feeding the energy produced by the exerciser back into running the little TV screen. And given the amount of sunshine LA gets in a typical year, I'm constantly surprised by how few places make use of solar panels. Yeah, yeah, they're expensive, and existing buildings can be difficult to adapt to that kind of renewable energy source. But it's a terrific future investment in sunny SoCal.

In general, we routinely overestimate how many calories we burn when we exercise (and underestimate how many food calories we consume). Seeing just how little energy I produce on Boesel's retrofitted elliptical is an eye-opener in itself, particularly since the resistance increases the harder I work. I'm breaking a sweat, starting to breathe hard, and the little light bulb he's hooked up to the front of the machine as part of the test phase barely stays lit. (The retrofitted elliptical was built with help from students at the local university.) I always suspected my gym's machines were overly optimistic about my physical exertions. Boesel has actually worked really hard to make sure his retrofitted machines feel just like the old ones, giving the user control over the resistance level. But once you're talking about watts instead of calories burned, you're dealing with smaller numbers. Some of that is related to body mass: Boesel figures he can produce 75-80 watts consisently -- that is, at a pace he can sustain for a full hour's workout -- compared to my measly 40 watts (and frankly, half the time during my mini-workout the gauge dips into the 30s -- the shame!).

The body is a heat engine, as physicists well know, and thermodynamics is a tricky thing, with many different factors coming into play. It's easy to come up with a wrong or misleading answer -- hence the recurrence of folks convinvecd they've just invented a perpetual motion machine. (Once again, for the record: there is no such thing as "free" energy.)  Matt over at Built on Facts had a terrific post about this last December, just in time for Christmas, about the effect climbing a steep hill has on how many calories someone would burn during the climb. "If you're going a long way uphill your height changes quite a bit, and correspondingly, so does your potential energy," he explains.

Being a thorough sort of guy, Matt actually crunched some numbers for how many calories a 160-pound man would burn climbing the stairs of the Empire State Building, based on that increase in potential energy. He assumes you reach the top 1050 feet above ground, and assumes a gravitational acceleration of 9.8 meters per second squared. The answer: he found a total change in potential energy of 230,000 joules. Woo-hoo! At least until you convert that into calories. It's about 54 food calories. Now you're less ecstatic, aren't you? Let Matt explain what's going on here:

Surely something that difficult would burn a lot more calories, you'd think. And it does. The immense effort you expend in climbing is mostly budgeted to different bodily processes. You have to move extra air in and out of your lungs. You have to circulate blood at a much higher rate. You have to process the complicated chemistry required to keep your muscles moving. All of these things take energy and by the time the shoe meets the stair most of the energy has already been lost, eventually ending up mostly in the form of heat. Your body can't afford to overheat and so you begin sweating to carry the excess heat away. All that energy had to come from somewhere and it came from the food you ate. By the time you're on the observation deck looking over Manhattan, you'll have used up a lot more than 54 calories.

In other words, it takes energy to run your body's machine. That's great news, potentially, for your waistline (depending on one's total caloric consumption), but the human body is an energy hog. In that respect, it's a highly efficient little heat engine, because by the time it gets done extracting energy for all those functions, there's precious little available to be harnessed as usable work. We see the same effect in Boesel's Green microgym. The BBC ran an article about this back in 2006, quoting energy consultant Graeme Bathurst, who said bluntly, "The key issue in this case is that human don't use very much energy."

If someone eats 2000 calories a day, that translates into just enough energy to run a 100-watt bulb for 22 hours -- assuming 100% efficient conversion, which doesn't exist. Something is always lost in the conversion -- in the case of exercisers, we lose energy by sweating off excess body heat, for example -- which is why many physicists refer to those pesky laws of thermodynamics as the laws of "thermogoddammics."  Or as Bathurst puts it (far less colorfully), "The energy burnt is not converted directly into mechanical movement, and so it is not possible to harness the full energy usage."

How about that rowing machine mostly sitting idle in my gym? Let's say I rowed furiously on that thing for 10 minutes, thereby burning 100 calories. (We are being optimistic; it would be much less, particularly given my pathetic lack of upper body strength these days.) That's enough to run a 100-watt bulb for one hour on paper, but we'd be lucky to harness 50% of that. For a gym with 40 machines of all sorts -- rowing, cycling, running, walking, ellipticals -- that means users could generate some 25kWh of electrical energy during the two-hour peak period of the gym. Again, we're being idealistic, assuming all the machines would be in use and "that all individuals were genuinely attempting to work out," according to Bathurst. (We're looking at you, Princess, the girl in full makeup and swanky color-coordinated gym togs talking on her cellphone while strolling on the treadmill, not breaking a sweat. Get moving! You're ruining our overall energy output!)

That's not going to save the gym much money in terms of overall operating costs, but it's equivalent to running a few households for a day. It's probably sufficient to run your little TV monitor, or recharge your iPhone before heading home. According to an article last year in the Christian Science Monitor, a gym in Boston has a special stationary bike retrofitted to have a laptop built into the top. The laptop has no battery. It is powered entirely by the person pedaling, so someone can get in a decent spinning workout and still surf the Web and answer a few emails.

I am not sure this approach would work for me: I like to push myself and really work up a sweat at the gym, which means I get winded. When I get winded, I can't really focus on things like responding coherently to an email. Plus, the article doesn't say anything about whether sweat dripping onto the keyboard would damage it; anyone who's spilled tea or soda on their keyboard can attest that these are fragile things. But I could definitely be motivated to run a DVD player or small TV monitor or my iPod from my own exertions. Boesel actually sells retrofitting kits for home exercise equipment, and assured me I could probably find a refurbished spinning cycle for half price on E-Bay. (He's right; I checked.) It wouldn't take up much space in the downstairs guest room. I must take this matter up with the Spousal Unit, because even if I don't end up generating much overall energy, it would be kinda fun to do the experiment.

My gym is a long ways off from being able to break even on its energy costs, even if they retrofitted all their equipment tomorrow. Even Boesel's Green Microgym hasn't achieve 100% efficiency yet; the poor economy hasn't helped. But he's getting close! Add in the investment costs for retrofitting equipment, adding solar panels and other energy efficient approaches, and it's easy to see why venture capitalists might not be keen on the idea of green microgyms as a business prospect. It might not be a model that can scale up beyond a community gym, but I'm rooting for Boesel as he tries to take things to the next level.

Personally? I think they're missing the larger perspective. Sure, the current gym "culture" is one of energy waste, and such habits can be hard to break en masse. Nonetheless, it can be done. Regular readers know I drive a Prius since moving to Los Angeles (before that, I was a public transport kind of girl, which is easy to do in NYC and Washington, DC). My favorite feature is the graphical display that shows you exactly how many miles per gallon you're getting at any given moment. And that constant influx of real-time information makes me appreciate all the more just how much energy we consume when we drive our 3000+-pound cars. It has literally altered my driving behavior. I accelerate more slowly, take advantage of downhill sections of the road to coast a bit, brake less suddenly, etc., all for the thrill of the occasional tiny inch upwards in my overall average MPG. (I'm currently at 49.5 MPG over 2-1/2 years of combined city/highway driving, and counting.) This combination of practices is common among Prius drivers, and even has its own term: "hypermiling."

Are we saving the planet? Not really -- not when you consider the energy costs that go into building and transporting our cars in the first place, and other peripheral costs. Ours is a complex, highly interconnected energy environment; that's what makes even basic thermodynamics such a bear to contend with. But I am personally saving money on gas. And the Prius has made a difference, in thousands of tiny, hard-to-quantify ways. Just like driving a Prius has made my hyper-aware of how much gas I burn, so, too, can retrofitting exercise machines help raise people's awareness of just how much hard work it takes simply to light a 60-watt bulb. And that can only be a good thing. Adam Boesel can bring a Green Microgym to Echo Park whenever he wants. I'll be his very first gym member...