Negatives?!!

A teacher I know was explaining something to his class. Looking for a modern-day analogy his students could relate to, he compared it to the music of the Beatles. But that didn't help either! The blank stares on his students' faces told him they had no idea who the Beatles were.

It doesn't take long to be forgotten!

I thought of my teacher friend recently... and of the many times I tried to explain historic footnotes when teaching Shakespeare over the years. (Concepts and word meanings have changed a lot in the 500 years since he wrote his plays.)

I am currently reading a Pulitzer Prize winning book,  Pilgrim at Tinker Creek by Annie Dillard. Originally published in 1974, it is now considered a "modern classic."

Modern? To me, yes!

But reading the following description...

The sun in the west illuminates the ground, the mountains, and especially the bare branches of trees, so that everywhere silver trees cut into the black sky like a photographer's negative of a landscape.

The teacher in me pauses, picturing the image. 

Wait a minute! How many students in this day of digital photography even know what a negative is?! How many years before the classroom edition of this modern classic will need a footnote to explain this to a new generation of students?! (Or does it already have one?!)