A few weeks ago, the second annual Battle of the Bridges took place. We, Mr. Peer’s physics class of 2011, built bridges out of nothing but popsicle sticks and Elmer’s glue. There were various designs, but all conformed to the same set of rules (required length, weight limit, building restrictions, etc.). Each was the product of weeks spent in (more or less) grueling labor in research, gluing, sawing, and much more.
Each was taken and systematically destroyed.
A bridge with no breakage in its past
A bridge being prepared for the slaughter
A bridge bravely resisting its fate
A bridge that will live no more
The resulting carnage
Basically, you pile on weight until the bridge can’t take it anymore. The bridge with the highest ratio of the weight it held and its own weight is the strongest.
Popsicle sticks actually make better bridges than you’d think; first place held well over 200 lbs for at least 5 minutes before breaking (though that was definitely the exception, not the norm; most of them broke somewhere around 40 lbs).
This bridge got 2nd place for strength (I think it held almost 100 lbs)
Below you see my bridge before it was broken.
It certainly ended up being a very nice-looking bridge (it won 1st place for aesthetics), which surprised me, since I’d given its appearance little thought. My primary goal had been to make it strong.
But it didn’t last long. It broke under twenty lbs. The strongest parts of the bridge didn’t even break; they stayed intact while the parts that connected them collapsed. “I guess looks aren’t everything,” said my teacher when the bridge gave way. I had to laugh at that, but it bothered me that my bridge had been so weak (and yet still looked so nice). As my dad put it, I guess I’m “an artist, not an engineer.”
Of course, my bridge had not been entirely devoid of engineering concepts. The features that made it look the nicest (the parabolic curve shape, the triangles, etc.) were originally intended to add strength. The problem was that I didn’t know how to properly apply those principles.
Overall, the most common failing was that the bridges we’d built were like regular bridges, designed to hold weight uniformly. But the way we were breaking them, all the weight was concentrated at the center point (not surprisingly, most of them broke straight down the middle).
This bridge was a lot stronger than it looks, but didn't have enough support in the middle
All that work for nothing...
Have you ever focused so much on the big pieces that you neglected the smaller parts that hold everything together? Have you ever prepared for an all-around assault, when you really should’ve just focused on the one spot in the middle getting hit the hardest? Have you ever had lofty thoughts and ideas, but came undone when it came to applying them on a practical level?
I hear next year’s class will be using toothpicks…