Parabolic vs. ellipsoidal – converting an e-mail into a suppository; either square, hex, or round…

RHS2009

I just ran a column about Reno High School and mentioned its famous dome, which the architect himself, (Monk Ferris), called parabolic in a 1951 newspaper article. A parabola. Then, this arrives in the e-mail this morning, from a friend I’ve known since 1950 at Central Jr. High. I’ve been writing a column for 28 years, but it’s bullshit like this that will bring the curtain down on the whole shebang someday:

Hi Karl,

The “dome” at RHS is not parabolic. It is roughly ellipsoidal – or rather roughly the upper half of an ellipsoid, which is the three-dimensional analog of an ellipse. Both an ellipse and an ellipsoid have two foci, and rays emanating from one focus are reflected to the other focus. This phenomenon is responsible for some “whispering galleries” and “whispering domes”. One of the attractions in the physics lab at CalTech was a small water tank in the shape of the bottom half of an ellipsoid. When it was filled with water, poking a finger into the water at one focus made a little column of water shoot up at the other focus.

 I haven’t set foot in RHS since 1959, but my recollection is that the dome is too shallow to be a true ellipsoid, and therefore incapable of transmitting whispers.

 Eric

click to read the offending column