Monday, January 31, 2005

GPS: by America, for America

I got an email from the US embassy here in Kathmandu a few weeks ago requesting all US citizens to provide GPS coordinates of their houses, if possible. The motivation given in the email is 'in case of an earthquake'. Right, and Bush is on a campaign for hearts and minds. When I think about embassies intervening in the lives of expatriots, I think of evacuation missions, but they're more helicopter on the roof in Saigon than they are about earthquake aftermaths. Before coming to Nepal, I did a lot of looking into the political situation here. The State Department has Nepal on its travel warning list. But then, this is a State Department run by neocons. The research included talking to a girl I knew who'd grown up in a number of travel-warning countries, as her parents are diplomats. She assured me that the Marines would not evacuate me if it really hits the fan. They would evacuate her - being the child of diplomats - but not any old American. The University of Texas says, historically, they do pick all of the Americans up, with the ambassador notably first. I wouldn't be on this line of thinking if the embassy hadn't asked for those coordinates.

So I'm outside with a headlight and Ewan's hand-held GPS, trying to get enough satellites. I've been thinking a lot about error in measurements recently, wondering whether the tarpul bearing fits should be N7/j6 or N7/k6. I couldn't get a reading better than nine meters. If I thought this nine-meter error would really be the difference, then I would worry. However, we live on the ground floor of a three-story building. I feel quite secure that, in the event of an enormous earthquake, we will be covered in two stories of low-grade concrete and poorly laid brickwork long before our GPS error is a problem. You should see the aggregate they use for the concrete here. I've been reading civil engineering handbooks recently for work - not a rosy read when the wall in front of you exhibit everything it says concrete shouldn't be.

Nevertheless, I abide. You know, GPS was made by the US military to guide weapons. To be as accurate as it is, the calculations take special relativity into account. Maybe it's general relativity - the one about the speed of light.

If anyone tells you that no one listens to Andrew W.K. in Nepal, then that person is a liar.

Saturday, January 29, 2005

jumanji!

Every now and then, it hits you that you're in the situation you're in. You're filled with that certain jeu de vie. It happened once to me at Stanford - it was right after a surprise birthday party freshman year. That was five years ago now. The day after, so hung over that it was easy to wake up in the morning at 8:30AM, I woke up not quite knowing how I got into the bed I was in. I biked to intro physics. On the way, I looked left with the beleaguered gaze of a college student, and saw The Stanford Post Card. USD10,000 picture. Then a girl named Loréna flipped over her handlebars in front of the lecture hall. You have to remember to hit the rear brakes first - flatspot if you have to. I sat next to her during the lecture. The lecture itself was memorable - it was the first of many lectures I'd have as a mechanical engineer on the bridge. It was dynamic vibrations time in the mechanics course, and we got to see the Tacoma Narrows bridge sway and break. The same bridge was referenced in E14, E15, ME80 (formerly ME111), ME33 (now ME70), and ME161. Each class blamed the failure on the phenomena described in the particular class. Sometimes it's resonant frequency, sometimes it's fluid eddy currents, sometimes it's materials. Lot of mileage on that one.

Anyway, that realization of circumstance happened again today. After a smart hair cut and straight-razor job, it hit me walking home. It happened again over drinks at the bar. I'm in Nepal. This is the place where the Tibetan look meets cinnamon dominican skin.

And I don't even know who won the superbowl. Hi KJCKJC.

And the Magnetic Fields' 69 Love Songs, mailed to me after the appeal of a previous post, is rocking my world. Stehpin Merritt.

In other news, I just checked my web site's stats for the first time. That's the kind of feature-rich publishing-oriented content omnis.com offers. Powerful operating environment. 42,000 hits? Top referrer is thefacebook.com? 4% Thailand? 1% Chilé?

Wednesday, January 19, 2005

on the United Nations and SUV's

About a week ago, on a day like many other days, I was walking to work, thinking about The Great Gatsby. Then, like a kick in the head, an enormous diesel sport utility vehicle really punches it coming up a driveway to the street, right in my path. The Kathmandu Mid-Town Rotary hat I wear all the time, which is way too small, falls off as I race to jump up on the next curb. I think about how that isn't how I want it to end, run down by the United Nations.


In Nepal, there are over 5,000 NGO's and INGO's. These organizations are here to help innumerable aspects of the Nepali society in adopting new practices to better the country and its peoples' lives. These organizations enjoy perks, including blue license plates and duty-free vehicles. The duty-free thing is a big deal, as Nepal likes to put 100%+ duties on cars. The more expensive the car, the higher the duty. That makes a USD55,000 Land Cruiser more than USD90,000 off the lot, in a country where the average annual income is under USD250. But the UN people get these things for the duty-free price of USD55,000. They might even buy five at a time and get a discount. And then they have these hired drivers that really like to throw it around. You can see how this situation can breed resentment amongst foreign twenty-four year-olds dodging these things on the road. Just imagine what the Nepalis think.

These big sport utility vehicles are big status symbols. Forget about the S500 with blacked-out windows. If you're a private citizen and have a Pajero or a Samuri or a Land Cruiser, then you've really made it, probably through some aspect of government corruption. So the two major groups with sport utility vehicles are (1) international aid organizations and (2) corrupt businessmen.

It's difficult to get down on the United Nations, with all the good they do, but they are the principle offenders of the international organization sport-utilities-in-Nepal situation. It's just obscene. Maybe they really use these things outside Kathmandu - you know, 4WD Low for three days straight. But, like a mom with kids at soccer practice, a lot of these things spend their lifetimes driving around the streets of Kathmandu by Nepali drivers with white people along for the ride. A Toyota Land Cruiser is 1.94m [76 in.] wide and 4.87m [192 in.] long, with a fuel economy of 13 city, 16 highway. Let's forget about the highway number. The other vehicles on the road include the three-wheel tempos - these were pictured in an earlier post - and the most common car, by a wide margin, is the Maruti 800. The Maruti's about the size of a Geo Metro, it makes the Chevelle look like a spacious family car. You'd be amazed at the duece a Maruti can get through when it puts its mind to it. This a country with narrow roads, and the Maruti handles them well.


My father was in Nepal twice, quite a while ago. I remember he was gone for my fourth birthday. There was a puppy dog candle on the cake and Dad was in Nepal. He recounted to me a few years ago that while he was here, the group he was with had Chevy Suburbans. He said he felt absolutely silly showing up in small villages in three tons of American steel that barely fit on the road there.

Here's a tip for the UN and all the other international organizations around here: buy a smaller car for the city, if only to deal with the perception of all those people you're almost running over. Hearts and minds, hearts and minds. My bosses have a Hyundai Santro - really nice, with about a 1.2L engine. Here's a picture of one going fast:



Monday, January 17, 2005

moderation and prudence

Here's a surprise for anyone that knows me. I've stopped using an alarm clock. The 60 rupee model I was using broke about two weeks ago. At first, I let it slide. After a few days of realizing my alarm clock's still broken - this realization is only right before going to bed - I decided I needed to do something about it. So before falling asleep, I've been thinking real hard about getting up when I see the right amount of light on the window shades. Boom, it works. It happens between 7:45 and 8:30 in the morning. I'm getting better at the timing. It's amazing how you can improve at timing if you put your mind to it, like when Maya and I used to bet on when our math professor was going to take off his sweater. He always did at some point in the lecture, and after the first four dozen lectures or so of this, we got it down pretty good - three minute windows were going for a dollar each.

Today Ewan and I started walking to work as normal. When we got out to the major street, something seemed off. There were people walking up and down the middle of the street. Unbeknownst to us, today was a full-scale bandh day. That means no cars, no motorcycles, no businesses open whatsoever. One of the major communist political parties called this strike, the UML. That stands for United Marxist-Leninists, which is interesting because the communists are collectively referred to as the Maoists often.

What made the rest of the walk really interesting was that Ewan was carrying an old motorcycle tire. It has a future in one of the prototypes he's working on, and he picked it up over the weekend for free. Thing is though, when students have protests in Kathmandu, they almost always cover tires with kerosene and set them on fire. Nothing puts out a burning tire. The rioters get up really early in Nepal, and these protests usually happen around 8:30AM in our area. We've seen this quite a few times. So here we are, walking down the major street at 9:00AM, on a bandh day, carrying an old tire. We say to each other that this doesn't look very good, especially if there's been a tire-burning protest already this morning. When we round the next corner, sure enough, there are the remains of some burned up tires, lots of riot police, and a lot of people milling about. We were quite the focus of attention as we slid past the edge. Just great.

The internet doesn't close, though. Today I happened to visit imdb.com to look something up. It says Catwoman comes out on DVD tomorrow - ee gad. This has been addressed.

Sunday, January 09, 2005

the tarbato in 3D

Some people have asked me what it is exactly that I'm doing here in Nepal. I reply with the thing about wire bridges and a wire road. I understand this is not exactly clear to someone who hasn't seen them.


Last week, I made two short videos for my bosses to show some prospective clients, there's one of the entire tarbato (8.9 megs) and one of just the passenger chair (3.7 megs). A method of propulsion was omited from the videos, as there's an electric locomotion in the works. Existing photos of the human-powered tandem-pedaling car are in the gallery.


Did you know the Russians landed multiple probes on Venus in the 70's and 80's? They even returned color photos.

everything from the last two weeks

I've been off the blog for a while. We were spending a lot of time in the office, and not out in the field on the projects. I like field work, it gets me thinking.

New Year's was great. I never wrote about it before, but we've had three guests on and off, and on again, here at our place in Patan. Before Christmas, a friend from Stanford, Rosie, and two friends of hers from back home in Wyoming came through Kathmandu. They'd been in India since October, and stayed with us a few days before their trek to Everest Base Camp for Christmas. Did you know there's a wrecked Russian helicopter up there? It just stays. No one can bring it down. There are surprisingly few pictures of us with Rosie, Christina, and Jesse. Here's the best one:


Which is not good photography, like this:


The girls said the trek was incredible, and they got some amazing photos up there. Rosie put a lot of these Everest Trek photos up at rosieinnepal.

For New Year's, we spent the night in Thamel, the tourist hub of Kathmandu. If you look hard, the party in Thamel goes until 4 in the morning.

The girls left a lot of weight that they didn't want to pack onward to Thailand. I've started to read the 10 kg of books. I just got done with 'The Snow Leopard' - it's an account written by a guy who accompanied 'an eminent field biologist' to Inner Dolpo in 1971. Dolpo is usually grouped with Mustang as the two areas of Nepal that are the last vestiges of traditional Tibetan life on earth, where Tibetan Buddhism and the older religion B'on are practiced as they were hundreds of years ago, lamas live in remote monasteries overlooking lakes that no boat has ever been in, and life is largely spent on surviving at high altitude. The author writes a great deal about his calm introspections up there, on life and consciousness. Bill Murray said in Groundhog's Day that he saw himself, in five years, 'living at high altitude, where he can really think clearly'. That was a line to impress Andy McDowell.

Thinking about what I'm doing here in Nepal, I'm not living out Bill Murray's line, as Kathmandu is only at 1000 meters - and I'm not given to the introspections on consciousness that Peter Mattiesson was, as I'm not removed from all aspects of 20th/21st century life, living in an ancient society of eastern thought. I'm also not an eminent modern writer who's devoted the last ten years of my life to Buddhism. The point is, while the topic is not deep introspection on consciousness, I am given to thought here - much more than I was at home. The thoughts are on my own life and the things that interest me. I've been reading a lot, and have drawn up plans for ideas that come to me. I have more ideas here than I do at home, probably because of the distance from the usual distractions of my life.

Two of the things I've been thinking about are limits of linear analysis, and the implication of geometry on optimizing mechanical design. There are a lot of things structural engineeers learn in school that ME's don't, even though ME's need to optimize geometries too. ME's designs see more non-ideal loading I think, but I think there are common principles. The Tar Pul carriage supports, in the nominal case, two point loads of passengers, so why not make the nominal carraige frame a two-segment furnicular arch, then go from there. I should put up some pictures to make more sense about the carriage thing.

The furnicular curve is the line of zero bending moment - that sounds good to design a structure around, doesn't it? ME's have the advantage over structural engineers that we don't have to be as afraid of tensile and complex shear forces - it's steel tubes, not concrete. Furnicular lines got me thinking more about the Tar Pul wire, a suspended cable under its own weight with a few additonal point loads:


Looks easy, but the more you think about it, it isn't. What's the departing angle of the wire just on either side of the loads. Leibniz, Huygens, and Bernoulli's solved the math problem of the shape of a hanging wire in 1669 - it's a catenary curve. But, if you use that equation, do you get the unloaded Tar Pul wire's shape, really? The Tar Pul, like most suspended-cable systems, have rigid horizontal end conditions for the wires. With those end conditions, the wires have a finite 'tangency section' at the ends. How long is the horizontal section? That depends upon the preload and the the modulus of elasticity, I think. The point is, it gets complicated quickly. Now let's add some point loads. Math says if you add a point load, there's a discontinuity in the cable. A discontinuity in applied force is the same thing as a discontinuity of the curve, since the curve's derived from a force balance. But a wire can't have a discontinuity, or it would break. But no loads are point loads. So, the loads must be distributed per Hertzian contact stresses, the wire must be continuous, and each wire segment between loads must form a furnicular curve of zero bending moment. I think we're beyond the limits of linear analysis.

But then, there's another way to look at things, the way Roark's Formulas for Stress and Strain looks at beam problems. That book has formulas for cases like this:


It may even have formulas for tangent end conditions and non-central loading, I need to look. Their fomulas make up for the point-load discontinuity problem by considering the beam as having a modulus of elasticity, and able to take bending moments - so then it's non-fernicular. Maybe we should constrain the Tar Pul wire kinematically and use this method. Fernicular or beam analysis - that's the question. Either way, it proves to be a tough problem. Maybe someone's written a book about this kind of thing. Someone built all those ski lifts, right?

In other news, some friends of mine have put together a blog site on liberal politics and the environment - I like it a lot, if only because I know these people aren't wacko leftists with wacko leftist agendas, acting to counter the outrageous statements of wacko conservatives with equally outrageous wacko liberalism. They're 'thinking'. It's myfleecevest.com.