rubix rhymes

That’s the state of my rubix 4-cube, which I recently re-noticed, hiding behind a vase. The core was not too bad, but the edges were a pain; I never really figured out the rules. I just kept trying different things and hoping my pattern recognition circuits were being subliminally helpful. In the end, it’s been reduced to a 3-cube, which is all that really matters: the rest is (in theory) a bunch of vertex swaps, vertex shuffles and edge swap/shuffles. (Oh and don’t get too comfy with the edges lined up… they’re gonna be re-positioned… though hopefully* not scrambled, during the final steps).

But it’s not the edge shuffles I’m not worried about… basic twists’ll do, and occasionally the Deanster, my pet eponym for the algorithm a friend taught me a long time ago for edge shuffles. It’s beautifully poetic… almost sing-song… have a listen:

“up, around, up, around, up around – around,
down, around, down, around, down around – around”.

You can’t forget an algorithm like that. It’s… what is it – iambic heptameter?! No matter: I internalised it’s poetic nature long before I could feebly grasp, 3-dimensionally, what the hell it was even doing (and what it is doing is pretty effin’ elegant). So why can’t the vertex swap/shuffles be this memorable? Without a ditty of some sort as a mental crutch I am doomed to have to look up the algorithms each time I get to this stage. And that sucks! It means I can no longer say I have solved the whole thing by myself from beginning to end!

I mean look at the vertex swap, for example. The algorithm is
y, -x, -y, z, x, -z, y, x, -y, x, x.

The best I can do with that is

down, in (and) lift (to) wind,
out, rewind (you’re) down (and) out:
lift, out (and) out!

Christ.

The vertex shuffle isn’t much better… but interestingly, it starts and ends with the same meter / cadence as the swap algorithm, when also converted into iffy poetry:

down, in (and) lift (back) in,
down, out (and) out,
lift, out (and) out!

Whilst the Deanster reflected a certain symmetry and simplicity of motion, the vertex moves are far from elegant: they have a certain horrid, irreducible complexity that even poetry cannot hide. Hmm… poetic analysis of algorithms could be an interesting research/exercise. Why has no-one jumped on this perfectly zany idea?

Oh well. I still love the cube. And it still kicks my ass. All is as it should be, I guess.

*just read about the possibility of gnarly “parity errors” on the 4-cube :o(
Hell I don’t even understand what one *is*. I’ma roll with the whole ‘ignorance is bliss’ thing and hope I deek murphy’s law.

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