Wednesday, August 29, 2012

Blast From The Past


Each Fall, after my kids leave for school, I take the opportunity to lighten the load around the house.  It’s not so much an effort to exorcise the demons of their childhood as much as to clean out the clutter.  To them, each piece of debris is a forgotten memory; to me, it is rubbish compromising my chi.  Not everything gets the ‘heave ho.’  I have carefully boxed up and stored report cards, artwork, and term papers as well as beanie babies, baseball caps, and an impressive collection of tiny Zamboni machines.  On the other hand, the American Girl dolls, Betty Spaghetti sets, Magic The Gathering Cards, and Funny Bones are long gone.

Today’s task uncovered a long forgotten box of rocket supplies.  Back when my son was just starting school—in those years when kids still think their parents have magic powers—my husband came across a hobby rocket section while I was picking up supplies in a craft store.  Realizing that he was now an adult and did not need parental permission or supervision, we left the store with a fuselage or two, a launch pad, and a package of engines.  Together, he and my son began assembling and decorating rockets.  I will never forget the amazement in my son’s eyes at the first launch, when the darn thing lifted off in a burst of smoke.  Soon, the two became an amusing pair of macho and macho-in-training—barely containing their excitement as they headed to the soccer field to blow things up.

I always thought it remarkable that we could trespass on school property with incendiary devices, sending the ever larger and larger rockets into the air, without causing the local police detail to put an end to it all.  Even when the occasional wind gust sent a projectile into a neighbor’s yard, they would chuckle amiably when asked for permission to retrieve the spent the tube.  For my son’s ninth birthday, we held a rocket party, walking 20 excited young boys down the street to shoot rockets into the air.  We used the extra manpower for search and rescue detail.  When all the rockets were recovered we rewarded them with cake.

Then there was the elementary school Science Fair.  We live in a town where every other house contains a Harvard or MIT professor.   There are seven Nobel Prize winners living here.  The guy who invented the Internet lives here.  My children’s friends are the offspring of notable physicists, biologists, chemists, and engineers.  It was hilarious to see 3rd, 4th, and 5th graders displaying “their” projects.  Most required an understanding of more science than I had learned in my own lifetime.  It was an interesting display of the intellectual bench strength of the community—more Science Exhibition than Science Fair.

My son came home with the Science Fair permission slip and asked if he could do something with rockets.  “Absolutely,” I agreed, glad that he was trying to lever his own interests.  “What do you have in mind?”  “I was wondering if we could try to figure out how high they go,” he answered.  “OK,” I agreed, “but whatever we end up with, you will have to learn the science and how to explain it.”  He was in 3rd grade at the time and not expected to complete this on his own.  Participation was voluntary and I was happy he had an interest, but I was determined that his project would reflect something around which a 9-year old could wrap his head.

That night we had a family meeting, laying out the equipment that we had on hand.  We discussed various approaches.  My son’s original thought was to launch different size rockets with the same engines to see how the size and shape affected distance.  It was a good idea, but the problem was in being able to measure or prove how high the rockets went.   I had my son draw a sketch of his experiment, showing how he thought he could assess height or distance.  He drew a line of rockets on their launching pads, then himself kneeling several feet away watching while the rockets soared upward.  He thought he could tell visually when each rocket reached its peak and began falling again.  It was a good approach, but very unscientific.  The human eye was not reliable enough; too much observation bias for my statistically-oriented husband.  

That’s when I saw it—there on my son’s diagram—a perfect right triangle.  When the observer stands back from the rocket observing its trajectory, it placed the rocket at the apex of a right angle.  If one could ascertain the true angle from the ground for observing the peak of the trajectory, it was mathematically possible to determine the height of the rocket using sines, cosines, and tangents.  Although the math was far beyond the comprehension of a third-grader, it was possible to build an Excel spreadsheet that allowed him to input his observations and retrieve a result.

My son, however, was infinitely more fixated on the mechanics for determining the angle accurately.  He envisioned a viewing scope (small tube) mounted on something hinged, allowing him to follow the rocket into the air.  When it hit its peak, he could freeze the viewer and measure its angle.  He drew a sketch of what he imagined in his head.  “I think we can build that!” I announced.

In the end, it required less than $10 in materials from Home Depot:  a small piece of PVC pipe, a fitting to attach the pipe, a small hinge, a few small screws, and a piece of 1x3.  At no charge, they cut the long piece of wood to our specifications.  Back home, my son got a kick out of using an electric drill and making his design come to life.  He called it the “Angled Rocket Viewer.”

The math was advanced in concept but simple to implement.  Once the Excel spreadsheet was set up, (an example of “miracle occurs here” if ever there was one,) it was an easy project for a third grader to execute.  On a Saturday morning, we took a range of rockets of different sizes to the field and set them off from a fixed spot.  My son got down in the grass and operated his viewer, carefully measuring his angles and recording them on his paper spreadsheet next to the name for each rocket.  My daughter, only 6 at the time, played the important role of watching where the rockets fell and running to retrieve them.

On Science Fair night, we were amazed at the bells and whistles going off in the school cafeteria.  There were lasers and engines (and maybe even a linear accelerator or two).  My son stood proudly in front of his poster that diagrammed his problem of how to measure the height of his rockets.  On his table he displayed an assortment of rockets.  On center stage was his “Angled Rocket Viewer.” 

The school principal approached and asked him to explain his project.  My husband and I stood back a few steps, listening to him explain how he loves to launch rockets and how he wanted to use them for his project.  He showed her how his observation of the launch created a right triangle, and how he learned that there were “special properties” of right triangles that made it easy to calculate its sides if you know the angles.  Proudly, he demonstrated his “Angled Rocket Viewer.”  She asked him if he made it and he answered, “I designed it, too.”

There were no prizes or ribbons at this Science Fair.  Who would dare to compare one parent to the next?  But at the end of the night, my son stood a little taller.  This is what I remember today as I gaze into the large plastic storage box filled with cardboard tubes and small explosives.   Smiling, I reseal the cover and stick it back in the overstuffed closet.

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