Cephalogenic

or, stuff that I dragged out of my head

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Location: Moncton, New Brunswick, Canada

Wednesday, April 09, 2008

Up And Down

I've been meaning to do this pair of words for weeks now. It's one of things that falls through the cracks.

The science-fiction blog Io9 posted a thing about an art display in a Tokyo department store containing these sentences:

In Tokyo, retail stores are turning into enormous metal caves. Here's one, installed by artist Kimihiko Okada on the ground floor of the Diesel store in Aoyama. Okada took a giant sheet of metal just millimeters thin and molded it into stalagmite shapes.

The first thing I thought was, "A giant sheet of metal just millimetres thin? You mean tin foil?" The second thing I thought was, "Stalagmite? You mean stalactite, obviously, because, they're hanging down." And the third thing I thought was, "Well, where do 'stalagmite' and 'stalactite' come from, anyway?"

My first thought was, as it turns out, wrong, because aluminum foil (yes, I know there's no tin it it, but it was still being called "tin foil" when I was kid) is much less then millimetres thick: it's no more than a fifth of a millimetre, and it takes some actual work to shape metal sheeting more than a couple of millimetres in thickness. It's not just like crumpling foil with your hands.

But my second thought was, of course, right, and the page has been changed (though not through anything I did).

As for my third thought, well, here goes. "Stalactite" comes from Greek "stalaktos", "dripping", because stalactites are formed when drips of mineral-laden water from a horizontal surface leave behind small quantities of their minerals, which build up over time to form icicles of stone. "Stalaktos" comes from the verb "stalassein", "to drip".

"Stalagmite", on the other hand, comes from Greek "stalagma", "a drop", because stalagmites are built up from the residual minerals of those same drops that form stalactites. "Stalagma" comes from the verb "stalassein", "to drip".

In other words, they're pretty much exactly the same word. But you mix them up at your peril!

You can always remember which is which, unlike the Io9 people, because "stalactite" has a "c" in it and "c" stands for the ceiling from which it dangles, but "stalagmite" contains a "g", which stands for the ground to which it is connected. Piece o' cake.

1 Comments:

Blogger Andrew said...

Fascinating.

I was going to try to address the same question today (last para here).

Merriam-Webster has both words originating in the late 17th-century...so my best guess is that someone was being all sciency and decided they needed words for different kinds. To the woe of schoolchildren everywhere.

Thursday, April 10, 2008 3:14:00 PM  

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