Message #3990

From: Luna Harran <scarecrowfish@gmail.com>
Subject: Re: [MC4D] Re: Physical 2x2x2x2 canonical moves video
Date: Sat, 17 Feb 2018 01:08:20 +0000

That’s a very interesting rotation you’ve got there. I wouldn’t be sure how
to notate it myself either. Moves that involve restacking aren’t what I’m
familiar with.

I do think that sixth move needs to be done, but I would settle for
canceling it if the next move is the same type of move.

Your scrambler sounds perfectly fine for solving, although I would be
careful using it for timed solves, especially as you get closer to the
faster times. I myself plan a lot in inspection, and so the extra
visibility is a big help. Perhaps generating that position and then
executing a few more random moves would be a good middle ground. That way
you’d have a different starting state, but still a fully scrambled one.
There is definite need for a scrambler as times come down.

~Luna

On 17 Feb 2018 00:57, "damienturtle@hotmail.co.uk [4D_Cubing]" <
4D_Cubing@yahoogroups.com> wrote:

Hi all,

Finally starting to catch up with discussions, and I’m happy that the set
of legal moves seems to have been established. I assume that I can take the
set of moves in Melinda’s video here as the moves I can use for solving?
That suits me fine. I did however seem to find a different approach for
that awkward type of full puzzle rotation that seems to be getting called a
gyro move. I made a rough video demonstrating it, hopefully it’s clear
enough. I’ve not learned the notation yet so I don’t know how to write it
down.

https://youtu.be/TP8v-rXbJmc

I have a question about this. As executed, it’s 6 ‘moves’. However, after 5
moves it’s in a legal state and the last move is a legal move. Does that
mean I can stop after 5 moves? Does the answer depend on whether the next
move I do after the gyro is to separate the two 2x2x2 cubes, reorient them,
and put them back together, since it’s the same type of move and therefore
they can be simplified into a single move?

I’ve not been able to film with my usual setup recently but that should be
back to normal soon (don’t worry, just lots of tidying and organising my
flat and things are a bit of a mess). I’ll get some more videos up soon
hopefully, including a solve once I’ve practised some.

I also made a scrambler, unfortunately the closest thing to a programming
language I can use is R, which might not be common enough to be useful.
Rather than random moves, it generates a random (legal) position and
outputs an image. I then assemble the puzzle into that state. Personally I
think this works fine as I’m too busy looking for pieces to take in much
information and benefit from a lot of inspection time, but I’m interested
in what others think. I understand if people are sceptical of seeing the
scrambled state too much, but I think it’s worth the trade-off for being
fully scrambled. I’ll happily try to make the code available if anyone
wants, but if there’s enough demand it might be better if someone makes a
more portable version, it wasn’t too difficult to code.

Matt