Message #1713

From: David Smith <>
Subject: Re: [MC4D] Re: 24-cell FT solved!
Date: Sun, 15 May 2011 11:32:00 -0700

Hi Nan,
Congratulations on solving the 16 and 24-cell!  I’ve been enjoying these
conversations, despite my silence.  I look forward to seeing who will win
Roice’s contest! (It won’t be me!)
All the best,

— On Sun, 5/15/11, Nan Ma <> wrote:

From: Nan Ma <>
Subject: Re: [MC4D] Re: 24-cell FT solved!
Date: Sunday, May 15, 2011, 3:28 AM


Hi Matt,

My move count was 54199. I know there’s a big room to improve. My way of separating permutations from orientations does incur large move counts. So, good luck on a shortest move solve!


On Sun, May 15, 2011 at 12:18 AM, Matthew Galla <> wrote:


Congrats Nan,
I knew I wasn’t gonna be fast enough to be the first one done, but I do have about 50% done and all algorithms ready. Having just got out of a particularly difficult year of college (junior math/engineer double), I’ve been having trouble dedicating enough time to sitting here nd solving it ;)
Perhaps I can beat you in moves? ;) How many was yours?
As for the 120Cell, as I mentioned before, I believe it took me roughly 150 hours, based on some random samples of how quickly I was solving pieces on average. I only used 2 permutation algorithms, very similar to eachother, and of only 8 and 12 moves and after doing them a couple of times, they easily become memorized. The actual process of clicking through the moves of these algorithms only took me about 16 seconds for the short one and about 30 seconds for the second. Although I never memorized setup moves, it was simple enough to abuse the undo feature to see exactly what setup moves I used and remember them for the 10 seconds it took to redo back to the end of the current solve. So my point here is that having the macros isn’t as big of a handicap as you may think. In fact, I’ve barely used any macros so far in my 24Cell solve. Especially in the beginning, they actually really hurt your flexibility in move count and setups.
Congratulations again on the solve. You have too much free time and dedicaton!!! :D
Hopefully I’ll be able to finish my solve and provide some great competition for lowest move count ;)
-Matt Galla

On Sun, May 15, 2011 at 1:07 AM, schuma <> wrote:



Let me tell the story of solving the 24-cell. Everybody knows that 24-cell is much sexier than 16-cell. So after solving the 16-cell, I looked at the 24-cell. There are only five types of pieces to solve in the 24-cell, compared with eight types for the 16-cell. The 3-cycle algorithms are similar to the counterparts for the 16-cell. So it didn’t take long to find them. Unlike the 16-cell, I prepared many different rotation algorithms to fix the orientations of corners and edges, so that whenever I need any of them, I can directly pull it off the shelf without thinking. I don’t want to go into details because that would spoil the fun to those who wanna analyze it by themselves.

After I prepared all the algorithms, I still don’t know if I can face the main difficulty of the 24-cell. The main difficulty is, of course, there are too many colors. This time I use shift+left, shift+right a lot. Basically I’m using them to find pieces. I never trust my color identification ability because there are too many close colors. I only claim two pieces have the same color when they are highlighted at the same time when I use shift+right. In the beginning I wasn’t sure if I could really handle 24 colors. So I used the first step, the face centers, as a test for me. The face centers don’t need complicated algorithms. Finding pieces of certain color is everything. I started the solve on Friday afternoon, when I finished the work I had to do for the week. I solved all the face centers intuitively. It meant that I could handle the colors.

After dinner I resumed the solve from about 9pm. By 2am, I solved all the pieces except for the side-face pieces. I thought I should go on to finish it, if the side-face pieces could be solved quickly. Then I used a stopwatch to time myself on solving one such piece. In that trial I was nervous and it took me 40 seconds to spot the colors, find the place it should go (using shift+right), setup, call the macro and reverse setup. A simple calculation told me that I needed three more hours for all the pieces. So I gave up and went to bed. On Saturday I got up earlier than in weekdays and indeed spent three more hours to finish it.

This one is my longest solve to date. There are six hundred pieces or so and I can use macros. I really don’t know how someone can solve the 120-cell without macros.


— In, Melinda Green <melinda@…> wrote:
> Congratulations, Nan!
> The 24 Cell is a very unique object. I’m sure we will all enjoy hearing
> your story.
> -Melinda
> On 5/14/2011 12:13 PM, schuma wrote:
> > Hi guys,
> >
> > I just solved the cell-turning 24-cell. The log file can be found here:
> >
> > <>
> >
> > This is probably my longest solve ever. It took me 9 hrs and 25 min. I’ll probably write about my experience later today.
> >
> > Nan