OK, my dad was wrong. I was about ten. We had this exact conversation, and I said, "But, Dad, the word sounds like it means something like a parallelogram," and he said, "Yeah, I know, but the accepted definition is that it has rectangular faces." He was a professor of mathematics and I bowed to his authority. If anyone wants to argue with him about it, I can give you the address of Gan Zikaron Cemetery. On Wed, Jan 30, 2019 at 8:15 PM Tom Karzes <karzes@sonic.net> wrote:
Actually a parallelepiped is a 3d analogue of a parallelogram. The 3d analogue of a rectangle is a right rectangular prism, also known as a rectangular cuboid.
Tom
Allan Wechsler writes:
The word my father taught me for the three-dimensional analogue of a rectangle is "parallelopiped". Some author, I can't remember who, writes "2-box" and "3-box" and the like.
On Wed, Jan 30, 2019 at 6:07 PM Dan Asimov <dasimov@earthlink.net> wrote:
Good point!* I will now try to find if something comparable has been done for more general polyhedra.
—Dan
—————————————————————————————————————————————————————————————— * If you've never tried it, get a fat mass-market paperback (i.e., small format, c. 4"x7"), put a rubber band about it to hold it together, and note the disparate efforts needed in order to get it to spin 360º midair about the three axes perpendicular to the faces of this rectangular solid.**
** "Rectangular solid"??? Surely there is a shorter and punchier word for this common concept!
Andy Latto <andy.latto@pobox.com> écrit: ----- Assuming the die has 3 distinct moments, there are two stable ways to have the die spinning as it is tossed. I don't see any reason to expect the probabilities will be the same for these two different ways to throw the die. Or the unstable ways, but those are harder for the thrower to reproduce accurately. -----
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