Message #3737

From: Marc Ringuette <ringuette@solarmirror.com>
Subject: Re: [MC4D] 3-cycle demo on phys 2^4
Date: Sun, 25 Jun 2017 10:24:31 -0700

(welcome, Okko!)

Hey, Ed, regarding Melinda’s physical 2^4 puzzle,

(1) Nope, I haven’t written down a big table of move equivalents,
although my videos will give you enough to figure it out. The
one-sentence version is: any mc4d move that leaves the stickers on the
R+L faces still on the R+L faces, has a simple twist in the phys 2^4
puzzle. With the addition of a single rotation to this common subset
– any rotation that moves the R+L faces onto a different pair of faces,
FOro and FUro being the two phys 2^4 sequences discovered so far to do
this – the entire mc4d state space can be reached on the phys 2^4 and
vice versa.

(2) Nope, nobody else has written down the move table either. That’s
not too surprising, since nobody else but Melinda and me have made
physical versions of the puzzle yet. C’mon, gang, get building! It’s
fun, and it’ll only take you a couple of days. :) I suspect people
are waiting for Melinda or me to provide some nice step-by-step
instructions that can be completed in 3-12 hours, or even better, just
wheedle one of us into building them one.

(3) The "virtual physical" 2^4. It feels slightly goofy to take
Melinda’s puzzle, whose key feature is the ability for a physical
realization, and then make a simulation of it. Heh. However, it
would actually be really useful, given that a lot of people won’t manage
to surmount the energy barrier associated with building the physical
puzzles.

(4) Thinking about it, it would be really useful to create a virtual
physical 2^4 puzzle, in Javascript, shown side-by-side with the MC4D
style simulation, with each move being executed simultaneously on
both. And as a side-effect of creating the MC4d style rendering in
Javascript, we would easily be able to also produce a
web-browser-compatible version of all of MC4D’s n^4 hypercube puzzles
that would make them that much more accessible to people who reluctant
to use the Java app. Such a version could be far less general and
tricky than MC4D itself, because it would be so much more limited (just
4d, in a particular simplified/hacked projection). Sort of a "gateway
drug" to full MC4D. It would be FANTASTIC if somebody programmed this.

(5) A teaser: I’ve been trying to work out an extension of
Melinda’s physical 2^4 puzzle into a physical 3^4, and making some good
progress. However, with 81 pieces and 972 magnets, it’s fairly
impractical to create physically in a way that can actually be operated
by hand. Pretty much the only way it is likely to come to exist is in
a "virtual physical" version in Javascript.

Cheers
Marc

On 6/24/2017 1:21 AM, ‘Eduard Baumann’ ed.baumann@bluewin.ch [4D_Cubing]
wrote:
>
> [Is there a] table which gives the "phys 2^4" moves for each "one
> click on mc4d" ?
>

> How about a "virtual physical 2^4" ?
>