Quite some time ago a friend of mine was granted an interview with a major software company. The interview went very well and they offered him the job. To celebrate, a number of us went to the Seattle waterfront, ordered some fish and chips, and sat down to hear about the interview. My friend talked about the questions he faced in the interview. One question in particular caught my attention. The interviewer asked him, “Why are manhole covers round?” My friend replied succinctly, “Because it is the only shape that will not fall through its own hole.” The interviewer was very impressed. My friend launched a very successful career with the software company.
Later, I stewed over the question. Something about it bothered me. I couldn’t quite put a finger on it. Then it hit me (not the manhole cover)! There is a ledge that the cover rests on, and its opening is a bit smaller than the cover. However, the reason manhole covers do not fall through their own hole is not because they are round! What keeps them from falling through the hole is that the cover’s smallest diameter (or diagonal) is larger than the hole’s largest diameter/diagonal. It is not the only shape that will not fall through its own hole! It may be the most efficient shape, but not the only one. A better answer to the software company’s question may be, “Because we prefer more efficient round manhole covers.” There are numerous shapes that would suffice. They are not very efficient, having quite large rims for the covers to rest on, ensuring they do not fall through their own holes. But, they work.
The software company and my friend were right in that a round manhole cover will not fall through its own hole, but also wrong in that it is not the only shape that fits that criteria. The real reasons have to do with economy and ease of removing and replacing the cover. Surely one would not want to manufacture one of the covers in the above illustration. However, what I learned is that we too easily claim to know exactly why something is what it is without pursuing underlying principles that reveal deeper, more complete reasons.
Some theories are built on shreds of evidences to formulate “truth,” only to later be outdone by newer evidences. One such example pertains to theories developed on Neanderthal remains found in the mid 1800’s. In an anthropology class that I took during my college years the professor waxed eloquently on the physical, mental, and cultural characteristics of the Neanderthal. They were certainly bi-pedal, a separate, yet related species to humans, not very intelligent, probably communicated with grunts, having little to no speech, used very primitive techniques to survive, and walked hunched over. This was all presented as fact.
Well, much of this description has changed, thanks to the Neanderthal Genome Project, conducted by the Max Planck Institute for Evolutionary Anthropology and broadcast by NOVA in Neanderthals on Trial. The analyses of DNA samples of Neanderthal bones indicate that most of the previous claims were misled. They discovered that not only were the Neanderthals closely related to humans (cross breeding successfully with humans from Africa and other areas, leaving many of us with traces of Neanderthal DNA), but that they had substantial language centers in their brains.
I hope to be a person willing to uncover and consider things we know today that are built on fragments of information that, over decades of use, have become solid and unquestionable “truth.” And when new evidences surface, I am determined to not turn my head, close my eyes, or argue that it just cannot be so. I want to keep an open mind: evaluate the data, contemplate its ramifications, and exhibit a willingness to adapt my stance to account for the new information.
– Sam Augsburger
