There's a great article at New Scientist this week talking about the Vikings.
(Disclaimer: Yes, the 2011 edition of Labville will have a high Viking quotient. Vikings are cool. Apologies to my 11th century Anglo-Saxon readers.)
It had always been accepted that Vikings used the sun for navigation. But what did they do on cloudy or foggy days? The sagas tell of a "sunstone" which was used. Some scholars have suggested that this was a slate of calcite, which is both translucent and polarizes light. That means that it would actually filter out sunlight, unless it's pointed directly at the sun. Other scholars said that wouldn't work.
Finally, a study was published last year where people tried out the theory. It didn't work perfectly, but I would guess that being able to navigate some of the time in cloudy weather was just fine for the Vikings, compared to the alternative. And so, huzzahs all around - for the researchers, for the vikings, for geology... and sunglasses manufacturers, who now get to say their newest product incorporates "the wisdom of the Vikings". Everyone wins!
That's all well and good, but there's one other point to this story: The calcite sunstone was suggested in 1967, and it didn't get tested until now. Why not? Calcite is cheap, and fog is free, right?
I suspect that's because it was always taught as "a possible theory" in class, and then the matter was dismissed. The next subject came up, and students kept taking notes. It reminds me of the classical definition of a scholar: one who learned entirely through books. This wasn't a compliment! In the early days of universities, students would be draw flowers from their botany textbooks, rather than from the garden. Anatomy charts would be based on Galen's diagrams from the 2nd century, rather than what doctors saw when they cut people open.
The highest goal of education is to teach students to think critically, and for themselves. It's a consummation devoutly to be wished, but we should always remember that critical thinking doesn't come naturally. It's very easy indeed to fall into habits of lazy thought.
On that note, I've adopted a new laboratory at work, and one of the first things I did was take inventory, and tidy up. There was one shelf in particular piled up with box after box of spare GC columns. Conscientiously, I stacked them all up, nice and neat, and it wasn't until I was finished that it occurred to me to look inside them... which was when I found out that half of them were empty, and had been since the early 90s.
Critical thinking, indeed.