Some Impossible Objects

Here are some "impossible" objects:

		1. The Freemish crate: See the next one.
		1a. Asymmetric Freemish crate: I don't know which is the original. This is drawn about as often as the one above.
		2. The Penrose staircase: Often drawn by M. C. Escher. Clockwise is downstairs forever.
		3. The tribar: Another impossible object by R. Penrose. It's hard to know how to color it, as the interior becomes the exterior.
		4. The tribox: This is just the left end of the tribar, twice.
		5. The Penrose triangle: Another famous impossible object by R. Penrose. This is sometimes called a tribar (see #3, above).
		6. The ambihelical hexnut: That is what one site on the WWW calls this impossible object. I don't know who invented it.
		7. An ambiguous ring: I don't know who invented this. By the way, this is not a Mobius (Möbius) strip.