Close Window A tribute to Apollonius (247-205 B.C.) of Perga "The Great Geometer" The birthday of Apollonius is not known.  The NCB has chosen to honor him on September 22 or 23, the day of the autumnal equinox, one of two annual dates when day and night are the same length.  Apollonius named the Conic Sections - the parabola, ellipse, and hyperbola.  Moreover, he chose the ancient Greek names of "ellipse" and "hyperbola" for their meaning in relationship to the  "parabola." For a parabola, any point on the curve is equidistant to both the focus and its directrix.  He chose "ellipse" for its meaning of "falling short."  Certainly we recognize one axis of an ellipse is always shorter than the other.  Continuing his pattern, "hyperbola" was chosen for its meaning of "throwing beyond"  where the distance from any point on the curve to one focus is always greater than the distance to its second focus. Though formulated in the 3rd century B.C., these curves along with the circle, are probably the most studied around the world.  Only the sine and cosine, along with exponential and logarithmic functions are any competition. Interestingly, the corresponding literary terms are parable, ellipsis, and hyperbole.