RAY:It's 1936. You're in your second year of high school. Europe is on the brink of yet another war. In a secret location in Germany, German officers are gathered around a table with the designers and builders of its new personnel carrier. They're going over every little detail and leaving no stone unturned. They want everything to be flawless. One of the officers stands up and says, "I have a question about the longevity of the fan belt." You with me?
TOM: They spoke English there?
RAY: I'm reading the subtitles.
TOM: Anyway, he asks, "How long do you expect the fan belt to last?" The engineer says, "30 to 40 thousand kilometers. The officer says, "Not good enough. We need it to last at least 60K." The engineer says, "Huh. Not a problem. It's just a question of taking off the belt and flipping it over." The officer says, "That's unacceptable. Our soldiers will be engaged in battle. We can't ask them to change fan belts in the middle of the battlefield."
TOM: Well, it's a good point.
RAY:So, the engineers huddle together, and they come up with a clever design change. And I think I mentioned they do not change the material of the belt in any way, yet they satisfy the new longevity requirement quite easily. What did they do?TOM: Whew!
RAY: And what they did was they manufactured the belt with a twist in it. Imagine if you took your own belt and joined the two ends together, so you'd have an inside of the belt and an outside. But imagine before joining them, if you gave one end a twist and made it into what's called a Mobius strip.
TOM: Of course! Now it's going to go on both sides all the time.
RAY: Exactly. And in essence, you've doubled the length of the belt. You have allowed it to run on the inside and the outside at the same time.
TOM: Does Detroit know about this? We don't have any Mobius strip fan belts on American cars.
RAY: Well, it's a little-known fact that the fan belt lobby is very strong in this country.
TOM: They don't want them to last twice as long.
RAY: Of course not! Nor do we, who replace belts. Anyway, who's our winner, Tommy?
TOM: The winner is Liz Walsh from Lexington, Massachusetts.
[ Car Talk Puzzler ]
