Message #773

From: David Smith <djs314djs314@yahoo.com>
Subject: Re: [MC4D] If you thought Levi was insane …
Date: Sat, 14 Nov 2009 20:39:31 -0800

Congratulations, that’s incredible!  I don’t think you’re insane at all, considering that I have possibly spent as much time and energy on my own projects and consider myself sane. :)

That macro problem sounds very strange, the only way I can think that could occur in the program is the insertion, deletion, or transformation of a move somewhere in the macro.  Given that there was the other problem with the macros, there might be a very elusive bug somewhere in the program. (I say elusive because I believe Roice has considered MC5D complete, and I know he is a very talented programmer and dedicated to perfecting his work before calling it finished.  Given that the program is a 5-dimensional Rubik’s Cube, its complexity could certainly be hiding some bugs.)

Regarding the 3C pieces, a position could occur with all of them solved except for a single piece which has two stickers swapped.  However, the flipped piece can only be in a particular subset of the 3C pieces, and this situation cannot occur with the 2C pieces already solved.

Again, congratulations on this monumental achievement!  I think we are all impressed to see this unsolved puzzle finally be conquered.  Roice must be especially pleased to see that his program has, through your hard work and dedication, proven to be solvable for all sizes (and enjoyed) by a single person.  By the way, your solution is made even more incredible by only containing 293280 twists.  Well done!

-David

— On Sat, 11/14/09, matthewsheerin <damienturtle@hotmail.co.uk> wrote:

From: matthewsheerin <damienturtle@hotmail.co.uk>
Subject: [MC4D] If you thought Levi was insane …
To: 4D_Cubing@yahoogroups.com
Date: Saturday, November 14, 2009, 7:07 PM

Hey guys,

     If you thought Levi was insane solving the 6^5, I wonder what you will think of me having just finished the 7^5.  That's right, for some reason I started it near the end of May this year, and finished yesterday yesterday on Friday 13th.  I think Levi certainly wins on speed, maybe partially because I never managed to average even close to 6 hours a day, but I took 293280 twists as opposed to his >1.9 million.  And luckily I'm not superstitious or I would have had to have waited another day to finish it!  So at last, the highest peak has been conquered.

In his reply to my log file, Roice asked about my mood throughout the solve. Upon scrambling my first impression was, understandably, fear. Several times during the solve when I was faced with a new section of randomly distributed blobs across the screen the view was terrifying. Sometimes it just became a little tedious (13672 moveable pieces can have that effect). But now and then it was rather fun and interesting when I had to think myself out of a new and mind-bending predicament. I had a bit of a scare near the end of solving the 3C pieces, when I seemed to have 1 piece left which had 2 stickers swapped, which I didn’t think could be solved on its own. Thankfully I managed to find another of the same type of piece which wasn’t solved correctly earlier in the step and I could solve both simultaneously.

He also asked how the program might be changed to help with the solve. I have to say that, for the most part, I found the software to be really useful, but there are a few things which were troublesome. One of the main problems was with the piece finding capability. While it is staggeringly useful for solving, it distinguishes pieces only by colour, and no further distinction is made between various types of pieces with the same colour combination. This isn’t a problem with the 3^5 as every piece has a unique combination, but where the larger cubes are concerned it can make things a little difficult. For the 1C pieces (maybe I should mention that my method was reduction, unlike Levi using cage), I could work around this problem. I used the capability to choose face colours to make the face I was working on yellow, solved faces white, and everything else grey, combined with only showing 1C pieces. Rather than having a mass of 625 pieces strewn
across the screen (I have an interesting screenshot of this, its stunning and also pretty damn scary, I can upload it if anyone is curious) I could only see pieces I needed in the faces i was looking at. However, this wouldn’t work for the other pieces, and this was particularly annoying for the 2C pieces due to number (250 pieces visible is not very useful).

Another problem was (for me, I don’t know if everyone has this problem) a glitchy macros feature. It worked fine usually and was invaluable, but had one predictable glitch, and one bizarre one, which I will leave as an open problem for the community to try and figure out. First, I had to close the program shortly after recording a macro I intended for long-term use, otherwise it would disappear. The second had a long story. When recording macros for matching up 4C pieces I used a commutator withing a commutator (I think it was actually 3 comms.) So I used a macro which affected only 4C pieces (X), moved a few things around (Y), then the usual X’Y’, only to find it affected 3C pieces too. I changed the macro which affected only the 4C pieces to one which had the EXACT same effect, and it worked perfectly. Does anyone know what’s going on here? I’m sure I tried the first several times with the same effect.

Now that I’ve finished solving Everest (I actually named the folder with my log file ‘everest’), I can sit back and enjoy the weird and wonderful new puzzles in 4D, which you now know why I didn’t have enough time to play with before! They look like a lot of fun :)

Since I seem to have written a short novel here, I guess I should finish up. I would like to say a huge thank you to those involved in programming all these puzzles, and making them freely available to everyone. Melinda, Don, Roice and Jay (I think that’s everyone, apologies for anyone left out), you are amazing people for bringing these to life. They have given me, and many others, hours upon hours of enjoyment and I’m sure we all appreciate the effort you have all put in on our behalf. You have also rendered my usual sign-off line ‘happy hypercubing’ useless in the best way possible by making hyper-non-cubes available.

Happy polytoping everyone ;)

Matt

P.S. Hi Klaus, as last time I will have a look at your parity problem and see if I can help any, but it will wait until morning :) Also well done to Remi for staying true to form and beating my 2^4 record by 1 move exactly. Good work!