“Parabolic” entered the skier’s lexicon shortly after the deep-sidecut revolution of the 1990’s, when the Elan Ski Company promoted its ground-breaking SCX^{TM} models as featuring “parabolic sidecut.” Although Elan had trademarked the term—and in fact, used it to describe the sidecut of even their more conventional “straight” skis—”parabolic” quickly fell into common use as the generic, but inaccurate, term for any deep-sidecut ski.

So, what is a “parabola”? A parabola is a specific “U”-shaped curve with unique properties, defined mathematically by quadratic functions like “y=x^{2}.” A “conic section,” it is the curve defined by the intersection of a cone with a plane that is tilted parallel to the edge of the cone.

**Parabolas--conic sections formed by the intersection of a cone and a plane parallel to the side of the cone.**

Parabolas appear often in our lives, from sports, to architecture, to dish antennas and old-fashioned headlight reflectors. An object like a baseball flying through the air—or a skier—follows a parabola-shaped trajectory. The main cables of a suspension bridge form a parabolic arc. (“Real” parabolas are only approximate, of course, due to small variables like air resistance, cable weight, and such.) The parabolic shape has unique properties in engineering, architecture, optics, and sound.

**Parabolas. (Top left) graph of a quadratic function, parabolic spotlight reflector, conic sections—the intersection of a cone and a plane parallel to the side of the cone, and a suspension bridge; (bottom left) supporting structure of the Tiehack arch bridge across Maroon Creek in Aspen; (bottom right) the trajectory of a cannonball, and the advertised shape of the sidecut curve of the pioneering Elan SCX ski—that gave rise to the generic but incorrect use of “parabolic” to describe modern deep-sidecut ski; and (top right), the trajectory of the center of mass of World Moguls Champion Patrick Deneen, flying off the kicker at Mt. Hood. (Note that real-life examples will only approximate a true parabola due to small variables like air resistance, cable weight, and such.)**

In skiing, “parabolic” has become a common, but generally inaccurate, descriptive term for the shape of modern, deep-sidecut skis. The Elan ski company—a pioneer of deep and experimental sidecut shapes—introduced the term to promote its revolutionary deep-sidecut skis in the later 1990’s (although it used the term to describe the shallower sidecuts of some of its more-traditional skis as well). Elan claimed that, compared with a round sidecut, its parabola-shaped edges would form a more perfectly circular arc on the snow (and therefore carve a cleaner turn) when tipped, pressured, and bent into reverse camber. Whatever the reason—whether the parabola, or merely the dramatically curvier shape—Elan’s new SCX^{TM} (“SideCut Experimental”) skis ignited a revolution in ski design that we still benefit from today. As other manufacturers followed the trend toward deeper sidecuts, “parabolic” became a common generic term to describe the new shapes, despite Elan’s objections that it was their trademark, first, and that for most (if not all) skis, it was technically inaccurate.

Now, nearly twenty years since the “shaped” ski's public debut, deep-sidecut skis are the norm, at least for general use. Now, so-called “shaped skis” are simply “skis,” and it is the traditional shallower shapes that call for an extra adjective (“straight” skis) to distinguish them from “regular” skis. Now that deep sidecut shapes are no longer unique and trendy, “parabolic” has become less common as an industry buzz-word. But it’s still the word that, right or wrong, started the ““shaped ski revolution.”