typodupeerror

## Rubik's Cube Algorithm Cut Again, Down to 23 Moves202

Bryan writes "The number of moves necessary to solve an arbitrary Rubik's cube configuration has been cut down to 23 moves, according to an update on Tomas Rokicki's homepage (and here). As reported in March, Rokicki developed a very efficient strategy for studying cube solvability, which he used it to show that 25 moves are sufficient to solve any (solvable) Rubik's cube. Since then, he's upgraded from 8GB of memory and a Q6600 CPU, to the supercomputers at Sony Pictures Imageworks (his latest result was produced during idle-time between productions). Combined with some of Rokicki's earlier work, this new result implies that for any arbitrary cube configuration, a solution exists in either 21, 22, or 23 moves. This is in agreement with informal group-theoretic arguments (see Hofstadter 1996, ch. 14) suggesting that the necessary and sufficient number of moves should be in the low 20s. From the producers of Spiderman 3 and Surf's Up, we bring you: 2 steps closer to God's Algorithm!"
This discussion has been archived. No new comments can be posted.

## Rubik's Cube Algorithm Cut Again, Down to 23 Moves

• #### I still can't do it. (Score:5, Funny)

on Thursday June 05, 2008 @07:09PM (#23675935) Homepage
Call me when it's down to 10 moves! :)
• #### That's quick (Score:5, Funny)

on Thursday June 05, 2008 @07:10PM (#23675947)
And here I used to think my method was faster; but since there's more than 23 stickers on the cube I guess it ain't any more...
• #### Re:I still can't do it. (Score:5, Funny)

on Thursday June 05, 2008 @07:11PM (#23675965)

Call me when it's down to 10 moves! :)

I can do it in one .... I outsource it.

• #### Re:That's quick (Score:3, Funny)

on Thursday June 05, 2008 @07:12PM (#23675987)

And here I used to think my method was faster; but since there's more than 23 stickers on the cube I guess it ain't any more...

Try spray paint.

• #### I can always do it.... (Score:5, Funny)

<brad1138@yahoo.com> on Thursday June 05, 2008 @07:13PM (#23675995)
in 48 moves or less. Luckily the center sticker is always in the right place so I don't need to move that one.
• #### Re:That's quick (Score:5, Funny)

on Thursday June 05, 2008 @07:19PM (#23676065)
And here I used to think my method was faster; but since there's more than 23 stickers on the cube I guess it ain't any more...

This would definitely faster than my method of taking it apart and reassembling it in the correct order.
• #### LET THERE BE THREE moves... (Score:3, Funny)

on Thursday June 05, 2008 @07:23PM (#23676101) Homepage Journal
1. Pour paint on Cube
2. Let Dry
3. PROPHET

• #### Re:I still can't do it. (Score:5, Funny)

on Thursday June 05, 2008 @07:26PM (#23676131) Homepage
I can do it in zero, I just declare that it's fine just the way it is and accuse anyone that tries to argue otherwise for being segregationists trying to keep all the different colors apart.
• #### Re:Solvable? (Score:5, Funny)

<j@jjcm.org> on Thursday June 05, 2008 @07:28PM (#23676149) Homepage Journal
It may not be a rubiks cube, but it would be quite humorous if strategically placed in an "Obsessive Compulsive Puzzle Solvers Anonymous" meeting.
• #### Re:I still can't do it. (Score:5, Funny)

on Thursday June 05, 2008 @07:31PM (#23676177)

Call me when it's down to 10 moves! :)

I can do it in one .... I outsource it.

I can solve it faster .... I defenestrate [merriam-webster.com] it.

• #### I can do it in 2... (Score:4, Funny)

on Thursday June 05, 2008 @07:32PM (#23676191) Homepage
1. Take apart
2. Put back together (wait... why are there parts left over????)
• #### Re:I still can't do it. (Score:5, Funny)

on Thursday June 05, 2008 @07:48PM (#23676357) Journal
Yes, but does the window run Linux?

• #### Re:LET THERE BE THREE moves... (Score:4, Funny)

on Thursday June 05, 2008 @07:51PM (#23676391)

3. PROPHET
That must be part of the God's algorithm the summary mentions.
• #### Only one move required... (Score:5, Funny)

on Thursday June 05, 2008 @08:02PM (#23676515)

There, saved you from another 22 pointless moves.
• #### Re:I still can't do it. (Score:4, Funny)

on Thursday June 05, 2008 @08:18PM (#23676649)

When I was a kid I had a rubix cube which one day resulted in this,

Angry Kid + Teacher(target) + Rubix Cube = defenestrate + one half rubix cube + dozens little pieces of a cube.

• #### Re:I still can't do it. (Score:5, Funny)

on Thursday June 05, 2008 @08:25PM (#23676699)
I like to buy a new one, solved, and in the package, then using some CA (krazy glue) glue it together so nobody can "un-solve" it.
• #### Re:Solvable? (Score:3, Funny)

<pierce403@gmail.com> on Thursday June 05, 2008 @08:28PM (#23676713) Homepage
I once spent and hour or so working on a cube before I realized that one of the two color pieces had two colors from opposite sides of the cube :-(

It is pretty annoying when people do the sticker trick to only solve one side of a cube.
• #### Re:That's quick (Score:5, Funny)

on Thursday June 05, 2008 @08:40PM (#23676829) Homepage
I just buy a new one.
• #### Easy (Score:5, Funny)

on Thursday June 05, 2008 @09:00PM (#23676969) Journal
Call me when it's down to 10 moves!

Step 1: Drop cube in can of paint. Done.
• #### Re:Solvable? (Score:4, Funny)

on Thursday June 05, 2008 @09:10PM (#23677063)
My friends decided to flip two pieces without telling me, thinking that would really annoy me. They were quite disappointed when I solved the cube, as the second flip perfectly counteracted the effect of the first.
• #### Re:Easy (Score:2, Funny)

on Thursday June 05, 2008 @09:35PM (#23677281) Journal
Actually, that's more than 10 moves:

1 Drive to Home Depot
3 Drive back home
4 Open the paint enclosure
5 Drop paint into bucket
6 Clean the floor
7 Clean yourself
8 Drop the cube
9 Pickup the cube
10 Realize that white paint won't make it look solved
11 Drive back to Home Depot
12 Buy a new bucket and dark paint
13 Drive back home
14 Open
15 Drop
16 Clean yourself (you actually learned not to mess the floor)
17 Drive to Toys-R-Us
19 Drive back
20 Drop the cube
21 Pick it up

Solved!
• #### Do the math, quick! (Score:5, Funny)

on Thursday June 05, 2008 @10:13PM (#23677579)

And here I used to think my method was faster; but since there's more than 23 stickers on the cube I guess it ain't any more...

So that would be, um, each face is three by three, um, nine stickers on each face. Then multiply that times the number of sides, so six times nine would be, uh, ...

Forty two.

• #### Re:Easy (Score:1, Funny)

on Thursday June 05, 2008 @10:30PM (#23677723)

Call me when it's down to 10 moves! Step 1: Drop cube in can of paint. Done.
Step 2: ?????

Step 3: Profit!
• #### Re:I still can't do it. (Score:4, Funny)

on Friday June 06, 2008 @02:29AM (#23679015)
This method has firm group theoretic underpinnings too. An alternate way to view this excellent solution is to realize that moves don't matter. Thus, you can say all states of the Cube linked by moves are equivalent in their state of fineness and hence the entire orbit is a single equivalence class of acceptability. This reduces the overly complex and uninteresting problem to a trivial one. Perfectly mathematical thing to do.
• #### my best time -1 min (Score:5, Funny)

<.moc.liamg. .ta. .rhbatima.> on Friday June 06, 2008 @02:40AM (#23679063)
As a kid my best time was 1 min ! Used to just take off all the stickers on all faces and put them back in correct order. Friends were confused though as to why i want to solve it alone in a room and not in front of them.
• #### Re:I still can't do it. (Score:4, Funny)

on Friday June 06, 2008 @04:22AM (#23679483)
What did the verb "defenestrate" apply to ?
• 1. the cube
• 2. the kid
• #### Re:Or... (Score:5, Funny)

on Friday June 06, 2008 @04:25AM (#23679497)
You could share the script you used to output that sentence...

#!/bin/sh echo "Or 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or and 20 moves."

• #### Re:Do the math, quick! (Score:3, Funny)

on Friday June 06, 2008 @06:22AM (#23679983)
No.

It's 42.

Trust me.
• #### Re:Easy (Score:3, Funny)

<jay+slashNO@SPAMjay.fm> on Friday June 06, 2008 @08:29AM (#23680491) Homepage
Drop cube in can of paint.

Paint is so 1987. Sears now sells powder coaters for \$150.

There is nothing that can't be improved with a little powder coating. Pencils, silverware, desks...
• #### Re:I still can't do it. (Score:5, Funny)

on Friday June 06, 2008 @08:39AM (#23680559) Journal
This post intentionally left blank

User hostile.

Working...