Here’s an old riddle I heard at a party recently:<\/p>\n
“A family of four needs to cross a bridge. Only one or two can cross at a time. They must share one flashlight which must be brought back after each trip. Father takes 10 minutes. Mother takes 5 minutes. Sister takes 2 minutes. Brother takes 1 minute. They must get across in 17 minutes total. What order should they go in?”<\/p>\n
It sounds impossible – the intuitive “best solution” takes 19 minutes (Brother escorts each of them across and then returns for the others, 10+1+5+1+2 = 19).<\/p>\n
I spent 30 minutes trying to discover “out of the box” solutions. Dad carries Sister? They find a boat? Toss the flashlight back across the bridge? I was assured no such tricks were necessary. Finally I set out to prove the problem impossible, as follows: Five trips are necessary. A trip with Dad takes 10 and a trip with Mom takes 5, for a total of 15, leaving only 2 minutes remaining to make three trips. Impossible, right? Yes, if Dad and Mom go separately. So if there is a possible solution, it must involve\u2026<\/p>\n
That line of thinking led me to the simple “in the box” solution (which you are welcome to email me for if you can’t figure it out). And I realized there is a lesson here. It has become fashionable to think “outside the box,” as if that is a virtue and and the best answers are always “out there.” Maybe sometimes they are. But other times the best answer is right here inside of the box, over in a corner you neglected to check out.<\/p>\n
This is a lesson for engineering design, where the search for clever solutions can cause us to overlook some mundane but highly effective solutions. Life is that way too, sometimes. We want a clever diet rather than a simple admonition to “eat less and exercise more.” We want a prescription for Christian growth more exotic than “read your Bible, pray every day.” Maybe, just maybe, the solution is inside the box after all.<\/p>\n","protected":false},"excerpt":{"rendered":"
Here’s an old riddle I heard at a party recently: “A family of four needs to cross a bridge. Only one or two can cross at a time. They must share one flashlight which must be brought back after each … Continue reading