Tuesday, July 2, 2019

Ellipse? Oval? Volume? Dummy!

ellipsoid
Shape of an ellipsoid
We long ago realized that way too many people are functionally illiterate when it comes to the different varieties of math. What's worse, however (at least IOHO), is that some of them try to pretend that they're not. Well, some are perfectly happy to pretend it if there's money involved. That's why people like Finn McCuhil write bullshit like "How to Calculate the Volume of an Oval" for websites like Sciencing.com.

McCuhil (very likely not his real name [clearly, for good reason]) went straight to a website that purported to have a formula for the volume of an ellipse. Had Finn not been innumerate, he would have known that 1) an ellipse is not the same thing as an oval; and 2) a two-dimensional shape like an oval (or an ellipse) does not have volume, which requires three dimensions. His examples of a casserole dish and a horse trough are not the three-dimensional shape, an ellipsoid, that is an ellipse rotated around one of its axes.
In other words, McCuhil was full of crap. Here's what he said to do to determine the volume of an oval horse trough:
  1. "Find the radius of each dimension."
  2. "Write down your answers..."
  3. "Enter the following into your calculator: 4 / 3 * 3.14 * r1 * r2 * r3 =. When you hit the = key, your answer will appear on the screen..."
We submit that his "solution" can be best described as utter bullshit, starting with the notion that each dimension of an oval horse trough has a "radius." In reality, McCuhil transcribed the formula for the volume of an ellipsoid (see image above); which is most certainly not the same thing as an oval horse trough. Idiot. In fact, double idiot: an oval is not the same thing as an ellipse.
An "oval" baking dish may be elliptical, but it still isn't an ellipsoid. An oval horse trough is likely to be a a rectangle with rounded ends, but is most certainly not an ellipsoid. That Leaf Group has allowed this garbage to stand for almost a decade is unconscionable, and that they paid our Dumbass of the Day to "write" it in the first place is, well, unfathomable.
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