Schlieren imaging

January 25th, 2009

I’ve been building demos and lab activities for the meteorology and oceanography class I’m teaching.  Most recently, I threw together a Schlieren imaging system, which displays slight changes in air temperature or composition, allowing you to see air currents in motion.

It was a good enough demo that I decided to capture some video from it and put it up on Youtube.  Enjoy!


What can Warcraft teach us about education?

November 4th, 2008

Read an interesting op-ed piece from Inside Higher Ed about using lessons learned from World of Warcraft in college education. I wish I could say I ran into this from the “college professor” side of my life, but it ain’t so. Anyway, the article is titled “Fear and Humiliation as Legitimate Teaching Methods“.

My response:
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I’m a college physics professor. I spend my days teaching people to do complicated things. And then I go home at night and teach another group of people to do other sorts of complicated things, because I’m also a raid leader in World of Warcraft. It’s kind of a busman’s holiday I guess…

Anyone who questions the author’s basic premise — that online worlds have something to teach us about social interactions in the real world — has never played one of these games. The social interactions are a core element of the game, and success or failure is determined more by your ability to form, participate in, teach, and lead large groups of people.

In fact, a raid leader “teacher” in an online game faces challenges a college professor wouldn’t dream of. In my physics class today I taught conservation of momentum to a group of mostly-white, mostly-American young people between 18 and 20 years old. This weekend, I’ll be teaching the “Battle for Mount Hyjal”, which is ten times as complicated, to a group ranging in age from 14 to 70, in background from stay-at-home moms to oil-rig workers, in education from high school dropouts to PhDs. Professors talk a lot about the difficulty of teaching in a diverse classroom — you have *no* idea.

That said, though, I don’t agree with the author’s conclusion, that teaching by fear and humiliation is a useful tactic. There’s no question that it can be *effective* — I’ve played in guilds led by the sort of folks the author describes, and these guilds are often very successful. And similarly, I think many of us have experienced the stereotypical “fascist professor” in our own education, who rules his or her class with an iron fist, and forces students to come to class prepared, for fear of his/her wrath and humiliation. I think most of us who’ve experienced that have found that it did, indeed, encourage us to focus on the material.

However, that stereotype is fading from American college campuses, and for good reason. What is gained in discipline and focus is lost in creative thinking and independence. Students are terrified to explore new ideas, for fear they’ll be shot down and mocked. The same is true for leader/teachers in online games.

When it comes right down to it, most of us in higher education are academics for the same reason 11 million people play Warcraft: because we think it’s fun. If we stifle that sense of fun in our students, we do ourselves a disservice, no matter where we’re teaching.

So you want to save the developing world…

September 11th, 2008

Here’s my advice to starry-eyed optimists looking to Make a Difference. The underdeveloped world is not underdeveloped because the people there are short on clever technology, short on cash, or short on basic health care. They’re short on all of these things, but that’s not the basic problem. The basic problem is you can’t get here from there. What the developing world lacks most is transportation.

In your average poor central African town, with dirt-track roads, no rail, and no ports, you can’t install electricity because you can’t ship the generator in. Even if you could, you can’t ship the fuel in. You can’t set up good medical facilities because you can’t get supplies in, and even if you could you can’t get people in the countryside to the town for medical treatment. The people are willing to work for next to nothing: in the developed world that would be cheap labor and a business opportunity, but you can’t set up a factory because you can’t get the machinery in, you can’t get the raw materials in, and you can’t get the finished goods out. And the list goes on.

The “China Miracle”, in which China transitioned from a rural farming economy to an industrial powerhouse, was, in my opinion, not due to political changes. Fantastically cheap labor has always been available in 20th-century China, but that’s true of every developing country. Where China differs is in transportation infrastructure. Unlike, say, central Africa, China was able to develop a massive infrastructure of railways, major ports, and now highways, providing every part of the country with access to world markets, to buy and to sell.

Of course, I’m drastically oversimplifying: poverty in the underdeveloped world is a complicated problem. But if you want to save the world, I say, start with roads. Rails. Bridges. Ports. Build them to last, keep them in good repair, and the world will beat a path to the developing world’s doorsteps, drawn to the siren song of cheap labor.

Trivia challenge: Song title poker

August 17th, 2008

Make the best poker hand you can out of five “cards”: each card is a
song title.  For instance, “99 Red Balloons” by Nena plus “Love Potion
No. 9″ by the Searchers gives you a pair of nines.  Five song titles
containing the word “spade” will give you a flush, and so on.  Each
song title can be used only once as a single card, even if it’s got
multiple numbers or suits in it.
Songs should be well-known rock, hip-hop, or country songs: no classical allowed — too many of those are numbered.
My solution after the break…

Read the rest of this entry »

Precipice Trail, Acadia National Park

August 11th, 2008

Last week I took a vacation in Acadia National Park in Maine with my wife’s family.  They’ve gone to this park almost every year since my wife was a kid, so there’s not much that they haven’t seen.  Take that, together with a very heavily-travelled and pretty tame national park, and I didn’t expect to find much excitement during the trip.
One day we stopped by the trailhead for the “Precipice Trail”.  My father-in-law wanted to look for peregrine falcons on the cliff wall, but what caught my eye was the trail itself.  The Precipice Trail begins at the base of a sheer cliff, and goes up a 1000-foot-high hill in just 1/2 mile.  “A nontechnical climbing route, not a hiking trail”, the sign said.  “Not for those afraid of heights”, it said. I started drooling.

Precipice Trail route

Now, I’m no mountain climber, and to be honest I’m not in great shape.  But this looked like a challenge I could manage.  Everyone in my wife’s family is either terrified of heights or physically unable to do serious hiking, so the following afternoon I had them drop me off at the trailhead, and tackled it alone.  (Which I don’t recommend.  Bring a buddy.)

The trail starts off through the forest, but it isn’t long before it gives you its first challenge: it climbs over a 10-foot-high boulder, using a couple of metal rungs bolted into the stone.  The trail could just as easily go around: this is just a test to make sure you’re prepared for some climbing.  At this point I met a father with his son: the son was hanging half-off the top rung, supported by his dad.  The kid was yelling “Can we just go home?!  I’m not really comfortable with this!”  I passed ‘em by and kept on.

The next section of the trail climbs steeply up a bouldery talus slope.  Lots of rock-hopping as the trail goes over and sometimes *under* the boulders.  After a few hundred vertical feet of climbing this stuff, I was gasping for breath.  Yeah, I’m *that* out of shape.  At the top of the rock pile, a side trail splits off the main one.  Or at least, it used to.  I had intended to return to the parking lot on this path, but it was blocked off, with a warning that an earthquake and landslides had closed this trail.  Very reassuring.

After another switchback, the trail got serious: it started to run along narrow ledges, with a sheer cliff drop several hundred feet to the ground. At first, a steel-pipe railing was there to provide some reassurance, but soon, it vanished.

Precipice Trail, lower down: bridges and railings

Most of the vertical climbs went up metal rungs and ladders bolted into the side of the rock.  It’s really a well-built trail, and physically, it’s a piece of cake to climb.  Mentally, though … the picture below doesn’t show the 500 feet of open air beneath you as you scramble up these rungs.

Precipice trail, rungs and ladders

I soon caught up with another family, and ended up following them the rest of the way up.  They had just driven into the park, stopped at the first trailhead, and started hiking.  They had no water, no map, and no idea that they’d picked the most challenging hike in the park. (I gave ‘em a bottle of my own water.)

Precipice Trail, family and ladders

Almost all of the trail gives you something to hang on to: well-placed crevices, carefully-installed metal pipes, or actual steel ladders.  In some places there are beautiful stone staircases.  But in a few places, it’s just a free walk along a ledge with no handholds.  The ledge is never too narrow to walk along, but when the rocks are slippery and wet with rain, things get a little exciting.  The few places where the iron rungs were missing, destroyed by landslides, were also exciting.

Precipice Trail, exciting ledge

Here’s a view of the trailhead, from about 2/3 of the way to the top.  A 1000-foot drop really isn’t very far if you’ve spent much time in Yosemite, but it’s definitely enough to ruin your day.

Precipice Trail, lower down: view of trailhead

One more shot, from a section near the top of the trail:

Precipice Trail, ledge near top

The view from the top wasn’t nearly as exciting as the views going up: this is one trail where getting there is all of the fun.  I took an easy route back down to the bottom.

Oh, and that kid I mentioned, struggling at the first boulder? He made it to the top.

All in all, this is one of the most fun hikes I’ve ever attempted.  Physically, it wasn’t that difficult: I’ve done hikes with much bigger elevation gains.  And really, it wasn’t all that dangerous: it was well-maintained, with metal pipes to hang onto almost everywhere you needed them.  Just scary enough to be fun, without being terrifying: just difficult enough to satisfy, without making me regret trying it.  If you’re ever in Acadia and can tolerate heights, I highly recommend this trail.

Utilities and “rate decoupling”

July 17th, 2008

Massachusetts’ Department of Public Utilities yesterday ordered electricity and gas companies to change the way they bill customers: rather than billing them based on how much electricity they use, they’ll charge for electrical distribution based on the cost to keep their distribution systems running.

The government makes the point that while we require utility companies to encourage consumers to save energy, they have a profit motive to do exactly the opposite: they make more money the more power their consumers use.  This change will remove that profit motive, encouraging utility companies to promote conservation.

But while it gives utility companies a reason to get their customers to conserve, it removes conservation incentives for the customer — and it’s the customer whose behavior has to change.  If your energy distribution bill is the same regardless of how much energy you use, why use less?

Also, look where the utility company stands.  It now wants its customers to use less energy, but those customers have no incentive to reduce usage.  How can it earn more money?  By cutting back service and delivering as little energy as legally possible.  Every uninspected transformer, unmaintained power line, and summer brownout means less cost to the company for the same revenue, and thus higher profits.

The state puts itself in the position of a family with an obesity problem, caused by the family’s habit of eating dinner every night at a fast-food restaurant.  The problem, as they see it, is that the restaurant manager has no incentive to encourage them to eat less.  Their solution?  Demand that the restaurant set up an all-you-can-eat burger buffet.

The family begins eating two burgers per meal because hey, why not?  The fast-food joint tries to get the Smiths to eat less, but the family has no reason to listen.  So the manager starts cutting costs. One day, they’re out of root beer.  The next, no cheese.  The day after that, sorry, no meat patties today, but we’ve got plenty of plain buns…  And so on.

Energy usage is controlled by the customer, not the energy company, and the utility company’s best interests are rarely the public’s, no matter what pricing scheme is used.  There are two ways to make the consumer use less of something: ration it, or make it cost more.  The first option is off the table: a large state energy tax is an option that, while unpleasant, might actually work.

Economic predictions

April 11th, 2008

I was reading the Freakonomics blog on the New York Times, which asked for a predictions: “How bad will the 2008 recession be?”. The measure uses a scale of 1-10, with the 2001 recession as a 4 and the Great Depression as an 8. Here’s my reply:

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I’m more of a betting man than an informed authority, so I’ll go “all in” and say 8-10. But that’s just a sort of Richter scale magnitude of economic changes: I don’t think what we’re about to see will look anything like the Great Depression.

The key is international economics. Foreign investment in the U.S., and in U.S. dollars, is increasingly looking like a house of cards. A bunch of things are happening all at once:

  • China’s domestic consumer market is growing fast enough that soon they won’t need to rely on US consumers, at which point keeping their currency cheap compared to the dollar will be unnecessary and counterproductive.
  • The Euro is becoming a viable alternative to the dollar as a global currency.
  • Unprecedented US deficit spending, and rock-bottom Fed interest rates, are tending to devalue the dollar. The only thing holding it up is massive investment in dollars by foreign investors.
  • The war in Iraq has caused foreign trust and confidence in the U.S. to reach an all-time low.

So here’s my prediction. The “housing bust recession” is small — call it 3-4 on your scale — but it causes foreign investors to decide divest their dollars and dollar-valued assets. A classic “bank run” panic begins, everyone sells their dollars, and the dollar drops into the toilet.

The rest of the world begins to rely on the Euro as a stable currency. Foreign manufacturers can no longer sell their goods in the U.S., but they switch over to selling to the burgeoning Asian consumer market, and life outside the U.S. goes on.

The U.S. experiences massive inflation, as foreign goods become priced out of reach. But exports become extremely profitable. The value of goods relative to services increases, and the U.S. makes a gradual transition back to an industrial / agricultural economy. Farms, mines, and manufacturing plants reopen after decades of stagnation, while shopping malls shrivel and die.

Is this a bad thing? In the short term, definitely. But the fundamental problem with the U.S. economy is its massive amounts of government and consumer debt, and an economy focused on selling things rather than making them. A period of heavy inflation and currency revaluation will render those debts negligible, and revamp our balance of trade.

Why colophons are worth reading

August 15th, 2007

Suppose you’re in charge of printing and shipping for the new book Harry Potter and the Deathly Hallows.  How do you go about printing up 100 bazillion copies of the book and shipping them throughout the world, as quickly and cheaply as possible?   In today’s global economy, I would have guessed that the answer was, “print ‘em all in a gigantic factory in China, load them into a thousand cargo containers, and ship ‘em out.”

Turns out, this isn’t the right answer.  I was reading the colophon of my copy of the book — that’s the very last page, which talks about the physical book, where it was printed, what font was used, and so on.  My copy was printed in Taunton, MA, not ten miles away from where I bought it.  I thought, “no way this is a coincidence.”  I asked two other friends: theirs were printed in Fairfield, PA and Harrisonburg, VA.

Apparently, instead of one big factory, the books were printed in dozens, maybe hundreds of bookbinding companies all around the world, as near to the consumers as possible.  Now, my two friends live in the Bay Area, not in PA and VA: probably the wholesale distributors who supply their local bookstores are in these states.
Now I’m curious just how many different printers were used. So far, 3 different books, 3 different printers, no two alike.

August 1st, 2007

Chicagoans Protest as Indiana Lets a Refinery Add to Lake Pollution

Wow, it sure is a tough political problem when one state objects to another’s pollution. Seems like managing interstate disputes like this might be a good job for the federal government. Wouldn’t it be cool if we had some sort of federal agency in charge of this, an Agency for Environmental Protection or something?

August 1st, 2007