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

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!"

I still can't do it.

[ASMworkz]

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

That's quick

[ricebowl]

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.

[Hankapobe]

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

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

Re:That's quick

[Hankapobe]

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....

[Brad1138]

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

[Tumbleweed]

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...

[davidsyes]

1. Pour paint on Cube
2. Let Dry
3. PROPHET

Re:I still can't do it.

[Kjella]

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?

[pwnies]

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.

[fizzup]

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...

[El_Oscuro]

1. Take apart
2. Put back together (wait... why are there parts left over????)

Re:I still can't do it.

[Daimanta]

Yes, but does the window run Linux?

Please, disregard the previous sentence.

Please, disregard the previous sentence.

Re:LET THERE BE THREE moves...

[GoodNicksAreTaken]

3. PROPHET

That must be part of the God's algorithm the summary mentions.

Only one move required...

[FoolsGold]

Blend the fucker - http://www.youtube.com/watch?v=NrqHHBibRvs [youtube.com]

There, saved you from another 22 pointless moves.

Re:I still can't do it.

[Herkum01]

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.

Afterwards I felt pretty bad about the whole thing...

Re:I still can't do it.

[Fishead]

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?

[Deanalator]

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

[Chris Burke]

I just buy a new one.

Easy

[camperdave]

Call me when it's down to 10 moves!

Step 1: Drop cube in can of paint. Done.

Re:Solvable?

[Fred Ferrigno]

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

[felipekk]

Actually, that's more than 10 moves:

1 Drive to Home Depot
2 Buy bucket and paint
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
18 Buy another Rubik's cube
19 Drive back
20 Drop the cube
21 Pick it up

Solved!

Do the math, quick!

[HiggsBison]

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

[KDEWolf]

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.

[khallow]

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

[ami.one]

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.

[this great guy]

What did the verb "defenestrate" apply to ?

• 1. the cube
• 2. the kid

Re:Or...

[this great guy]

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!

[something_wicked_thi]

No.

It's 42.

Trust me.

Re:Easy

[Jay L]

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.

[SQLGuru]

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