Message #3650

From: Melinda Green <melinda@superliminal.com>
Subject: Re: [MC4D] Re: Physical 4D puzzle achieved
Date: Sun, 12 Feb 2017 19:35:01 -0800

Yes, the reorientations were all 120 degree twists about the long diagonals through their black stickers. I knew the black stickers had to remain where they were because it was a twist of the black face.

The magnets do not want to allow the twist or the piece reorientations, though the central 2x2x2 cube was happy once it was fully reorientated. The frames where you see my hand are the configurations that the magnets do not allow. Matt’s pattern should allow everything.

-Melinda

On 2/12/2017 7:23 PM, Christopher Locke project.eutopia@gmail.com [4D_Cubing] wrote:
>
>
> Melinda,
>
> Yes, that looks like a correct twist of the +y hyperface about the +z axis! If the colors are labelled: (-x brown, +x purple, -y gray, +y black, -z light blue, +z green, -w blue, +w red), then that 90 degree twist should move those middle 8 physical cubies around in a 90 degree twist just like you did, and the x/w stickers should move blue -> purple -> red -> brown. From step 3 to 4, I take it you did a 120 degree twist about a diagonal axis that goes through the center of each cubie and the total center of the physical puzzle (where black stickers are)?
>
> By the way, was the magnetic orientation okay after doing those twists? In the video move I pointed out (https://youtu.be/Asx653BGDWA?t=1410), you had problems doing some twists after the double inversion due to magnet positioning.
>
> Best regards,
> Chris
>
> On 2017年02月12日 17:55, Melinda Green melinda@superliminal.com [4D_Cubing] wrote:
>>
>> Matt,
>>
>> Christopher’s messages were a bit to opaque to me but I’m starting to get the gist. It’s good to know that this 90 degree twist is a valid move though it’s unfortunate that it’s far from pure. These almost look like gear-cube twists now. I even think I can guess how the orientations are supposed to end up after the appropriate reorientations of the black pieces. (Alternating CW and CCW twists of each piece about their black stickers.) I’ve attached a sequence of snaps showing the process. (Also here <http://superliminal.com/misc/twist90cp.jpg> in case the attachment doesn’t work.) The second snap shows the twist in progress. The third shows it completed, with me holding it in place against the magnets. You can see what I mean about the puzzle looking completely scrambled by this one twist. The fourth snap shows it with all 8 of the twisted pieces reoriented. The interesting thing is how it results in a much less scrambled looking puzzle.
>>
>> Christopher,
>>
>> I hope the photos helped. One interesting to note is that the end result of the sequence (plus a simple rotation) resembles the result of the double swap you highlighted in the video (https://youtu.be/Asx653BGDWA?t=1410) so maybe there’s hope for a more practical way to reach the full 2^4 state space.
>>
>> Thanks!
>> -Melinda
>>
>> On 2/12/2017 3:46 PM, damienturtle@hotmail.co.uk [4D_Cubing] wrote:
>>
>>
>
>
>
>