My son’s elementary school held an ‘Invention Convention’ yesterday for 5th graders from across the city. He and a friend had been working for the past few weeks on a pencil with the lead and the eraser mounted on the same end. They were supposed to determine specific needs, investigate solutions, document the costs and hurdles involved with their design, and create a prototype to demonstrate – not unlike the process I have gone through for any number of website and print design projects.
All of these junior inventors came together to present their creations to a panel of judges from the school district, the university, and local industrial businesses. During the judging period, the students and their families were invited into the gym for a presentation given by a materials science professor. He performed a variety of demonstrations from heating a glass rod to create a fiber optic strand to using liquid nitrogen to super-cool a racquetball and some marshmallows, which he then let some of the kids eat (the marshmallows, not the racquetball).
There was little doubt that his presentation was practiced, polished, and had probably been performed dozens of times before. The experiments, as he called them, were entertaining even though I had seen many before. The thing that most struck me about his talk, was how matter-of-factly he mentioned some of the most memorable tragedies in recent history as he discussed instances where a material’s properties had been unable to hold up to its circumstances.
While heating several steel rods to the point that they were glowing a brilliant golden orange color, he noted that the torch he was holding was producing temperatures in the neighborhood of about 2,000 degrees. As set the torch down and began to gingerly bend the now flexible steel, he casually mentioned that the heat involved in the collapse of the World Trade Center buildings was about the same 2,000 degrees.
Later, during a discussion about insulative materials, he held up a heat shield tile from one of the Space Shuttles. Using the same torch as before, he melted a penny placed atop the tile while simultaneously touching the underside of that same tile with his bare hand to demonstrate how little heat was transferred. Afterwards, he noted that a damaged tile had allowed temperatures of nearly 17,000 degrees to penetrate the wing structure of the Space Shuttle Columbia, destroying it completely during re-entry in 2003.
The final demonstration involved the professor standing on a piece of tempered glass suspended between two chairs. The pane bowed slightly under his weight, but didn’t crack. Once he got down, he took a pair of pliers and clipped a tiny corner off of the same glass, shattering it instantly into a mist of a thousand pieces. During his explanation of combining tension and compression forces to create stronger materials, he said that car windows were the same way, except for the front windshield. That location is not suitable for tempered glass, he explained, because its strength might cause a passenger’s skull to be crushed on impact during a collision – an undesirable outcome, for sure. Instead, he said that safety glass is used, because it won’t shatter (and it apparently also allows unrestrained passengers to be ejected from the vehicle through the windshield without crushing their skulls).
I sat there, stunned. For one, that pane of glass had basically just disintegrated right in front of my eyes. Along with all of the fifth-graders, I thought that was pretty cool.
More to the point, I was acutely aware of the basic variables of suffering and destruction faced, at least in part, by this man and others in similar fields. Buildings, bridges, cars – all designed with calculated factors of safety, yet also with the realization that failures often exact a human toll. He was discussing these tragedies as if they were simply one of a dozen debriefing notes: yes, concrete has high compressive strength; sure, the steel may degrade under high temperatures; yes, structural failure will likely mean hundreds of casualties; of course we should limit skull crushing.
I wondered if my son, a newly disappointed 11-year-old inventor – his project was not one of the ten award winners – would continue on a path toward an engineering career. Will he one day be faced with decisions for which human safety is part of the project’s calculus?
I thought about my car out in the parking lot, not sure if I would look out of its tinted windows in quite the same way again.
But mostly, I was just happy knowing that a design mistake in my field might mean a broken browser plug-in or a confused call from the printing company about incompatible fonts.
Yes, I have always known that there were people whose job it is to calculate how easily my body might crash through the windshield of my car at 60 mph, but now I am even more certain that I have made a wise career choice to stick to questions of typography and color.
I’ve also vowed to take a little extra time to make sure that my seat belt is securely buckled from now on.