May 19, 2002

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Science Olympiad

Dear Family,

For my birthday we went to the National Science Olympiad.  Its a very photogenic event, so lots of photos this week.  Some of the Science Olympiad photos were taken by Evan and are used here with permission.

This week also featured a spectacular double rainbow, featured in these pictures taken from the end of our driveway:

Evan is home from school so he helped with Olympiad preparations.  We needed to do a lot of testing and calibration of the Cowabungee.

We used the Durham Academy gym (left) and a local hotel balcony (right) as our drop test sites.  We also used the DA physics tower (not shown).  None of these sites offered the required 10 meter (33 foot) height, but all were useful places to gather good data.


Friday morning the team rode in a large bus to the University of Delaware at Newark.  Craig's Cowabungee was wrapped around a broom handle for transportation, and served as a walking stick.

The events themselves were not until Saturday.  Sher, Evan and I drove up Friday afternoon and evening, joining the team early Saturday morning.

Sher was a bit under the weather, so she dozed while Evan and I took turns driving and refining our computer models of the Cowabungee.

Hoards of middle school students build egg drop devices with straws for one of their events. Setting up the Robot Ramble Scrambler Cars waiting for competition.

Craig's first event was the Scrambler Car.  He and his teammate, Ned, operated a car built by other students who were not able to attend the competition.  The car must be powered by a falling 1 kilogram (2.2 lbs.) weight.  The car carries an egg in front of it.  It runs along the floor a preset distance and then stops.  At the end of the track is a board.  If the egg hits the board and breaks, this is bad.  If the egg hits the board and doesn't break, this is not great, but OK.  Scoring is determined by 2 runs of the car at the same distance.  Both speed and how close you get to the board factor into the score.

Craig and Ned set up the car for its first run. A judge paces alongside the car as it runs. A good but not great run, the car stopped about 6 inches short of the end of the track.


Unfortunately, the car hit the board on the second run.  The judges carefully check to see that no fluid is leaking from the egg.


Out of 60 teams, DA's Scrambler car placed 40'th.

Craig's best friend Adam also attended the Olympiad.  The picture on the left is Sher talking with Adam's parents, Rosie and John.  Right, John catches 40 winks between events.



Craig's second event was the Boomilever.  The goal here is to build a cantilever that can hold up to15 kg (33 lbs.).  After all of the Boomilevers are impounded they announce a target weight for this contest, which turned out to be 14.1 kg.  If your lever breaks, your score is determined by how much weight your lever held.  If your lever does not break, it is considered better than all levers that break, and the score is determined by the weight of the lever, with lighter levers scoring higher than heavier ones.


Setting up the Boomilever More setup Very gently adding sand for the lever to hold.

Unfortunately, DA's Boomilever did not quite hold the weight, breaking with a loud boom at 14.0 kg, good enough for 40'th place out of 60.

Cowabungee was Craig's main event.  This event was not used in state-level competition in North Carolina, so no one at DA had ever built a Cowabungee or seen a Cowabungee competition.  Craig had just 3 weeks to build and calibrate his rig.

Cowabungee is held in an older building with a wide open stairwell.  In this shot looking up, you can see the wooden launch platforms clamped to the railings. A Cowabungee team (not DA's) sets up for launch. Craig and Ned ascend the stairwell to set up their launch.  They have five minutes to get everything ready for launch.

I don't have a shot of Craig's second drop.

Unfortunately Craig's second drop, from 9.8 meters (32 feet) up fell too far and hit the bottom with a noticeable clunk.

This is farther than we'd ever been able to test, and any experimental scientist will tell you it is much less accurate to extrapolate from your data than to interpolate.

Craig's first drop was nearly perfect, with the bottle stopping just over 6 cm (3 inches) from the bottom of a 5 meter (16 foot) drop.

The bottle is partially hidden by the lamp in this shot.

Another team's second drop is captured near the bottom of its descent.

Overall, Craig placed 30'th out of 60 in the Cowabungee.  And, from watching the drops we learned a lot about how to do better next time.  The drop weight is a water bottle.  We partially filled our test water bottle to get different amounts of weight.  However, it is obvious that the weights used in the competition did not have a liquid sloshing around and complicating things.  Next year we'll use sand.  We'll also streamline the bottle to reduce air friction.

Note for those interested: the force required to stretch a rubber band is

F = K ( Lo / Ls ) ( Ls - Lo)

where Ls is the stretched length of the band, and Lo is the unstretched length.  This formula has the interesting property that as Ls grows to infinity, F approaches a constant value.  This in turn suggests that small errors in measuring K will produce large errors in predicting Ls when Ls is large compared to Lo.

I've included a couple of photos from events that Craig did not participate in.  These include one where you build a musical instrument.  Some of the instruments were truly astounding.  On the right is some flavor of Chinese zither.


Many of the Olympiad events are testing or lab events.  These are closed to parents and spectators.  However, there are enough building events to keep us entertained throughout the day.

One of my favorites is the "Wright Stuff" model airplane competition.  Students must build a rubber band powered airplane to a strict set of rules.  The airplane must take off from the ground and fly around the gym.  You win by flying for a longer length of time than anybody else.

The airplanes are designed to fly up in a helical pattern, circle near the ceiling, and then glide back down.  Winning times are over 3 minutes..

The center shot (above) shows a judge with a long pole retrieving a green airplane that got hung up in the basketball goal.

Craig's friend Adam is an expert in this event.  We were not able to take pictures of his competition because he flew his airplane at the same time as Craig's Cowabungee competition.

This picture (left) is a telephoto shot, digitally enhanced.

The Wright Stuff competition allows spectators, but spectators may only enter or leave between sessions.  During testing and competition the heating and cooling system is shut down and the doors are kept closed to prevent even slight breezes from upsetting the airplanes.

The final event of the day was dinner.  Dinner was done in two shifts, with the middle school kids eating first, then the upper school.  Dinner was a large affair, with 60 teams of 15 kids plus coaches and spectators.  We filled a large basketball arena with tables of 8 or so, each decorated with a centerpiece of helium balloons in U of Delaware colors.

It is a very large room, filled with a lot of curious and talented kids, and many, many helium balloons.  I suppose the result was inevitable.

Some of the middle school kids had cut the strings and let balloons float up to the ceiling.  Boring.

Durham Academy was one of the first teams to launch a soda can, carefully weighted to drift upward very, very slowly.

A competition was born.

DA's star freshman scientist watches as her can achieves perfect neutral buoyancy and floats off horizontally. After the centerpieces drift up, they get near the lights.  The warm rubber becomes slightly porous, the balloons loose some helium, and the project drifts back down.  They can then be relaunched after careful adjustment.

In addition to soda cans, many other items were used to weight the balloons.  Here Evan is carefully adjusting a sand-filled weight prior to launching.

Dinner rolls and wet paper napkins were also popular weights.

Craig helps a team from another school prepare a massive launch.

This project  became so large that eventually official looking people in bow ties forbade its launch.

The Olympiad was fun, long, and exhausting.  It poured rain all morning, there was no place to park, and the DA team struggled to find its bus, after discovering that two boxes full of crucial supplies had been left on the bus, which then disappeared.

In short, it was a great way to spend my birthday.

Love to you all,