The world has waited with bated breath for three decades, and now finally a group of academics, engineers, and math geeks has discovered the number that explains life, the universe, and everything. That number is 20, and it's the maximum number of moves it takes to solve a Rubik's Cube.
Known as God's Number, the magic number required about 35 CPU-years and a good deal of man-hours to solve. Why? Because there's 43,252,003,274,489,856,000 possible positions of the cube, and the computer algorithm that finally cracked God's Algorithm had to solve them all. (The terms "God's Number/Algorithm are derived from the fact that if God was solving a Cube, he/she/it would do it in the most efficient way possible. The Creator did not endorse this study, and could not be reached for comment.)
A full breakdown of the history of God's Number as well as a full breakdown of the math is available here, but summarily the team broke the possible positions down into sets, then drastically cut the number of possible positions they had to solve for through symmetry (if you scramble a Cube randomly and then turn it upside down, you haven't changed the solution).They then borrowed some computing time from Google (one of the principals is an engineer there) and burned about 35 core-years to solve all the possible positions. The number 20 has been the lower limit for God's Number for more than a decade, but the team was finally able to whittle away at the upper limit (which was trimmed back to 22 in 2008).
So far the algorithm has identified some 12 million distance-20 positions, though there are definitely many more than that. Click through the source link below if you want to see what some of the hardest positions are, and how God would sort 'em out.
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"...That number is 20, and it's the maximum number of moves it takes to solve a Rubik's Cube...."
I think we can take a few more moves than 20 to solve the cube. Just sayin'...
Sincerely,
RainyDayInterns
"We Entertain When It Rains"
pressing issue>? need to proof read reports first...
I'll give everybody a hint:
The first move is green, counter-clockwise.
;)
@RainyDayInterns
It is supposed to mean the maximum number of moves God would take if he was solving the cube. The article describes that they had already gone as low as 20 but it could take up to 22 to solve. But now they have narrowed it down to just 20 as the minimum and the maximum...so theoretically if God were to solve the puzzle it would take God exactly 20 moves to solve it, with the cube as scrambled as it could get. That's at least what I got from the article. This does not mean that no one would take more than 20 moves. I can personally say I have spun sections around endlessly and still not solved one of these puzzles without cheating.
Chuck Norris can do it in one round house kick.
Back on topic. What else can we use the number 20 for, other than solving the Rubik's cube.
I wanted to write a really creative post about which "god" this article was referring to and how each religion would go about solving this puzzle (with different historical references) in a different way ... but then I decided it would take way to much effort for a wen morning. Oy veh
how many moves would it take if you allowed moves: remove 6 center stickers, unscrew the cube, rearrange the pieces, reassemble the cube, replace the 6 center stickers.
ok i know that if i started with afresh cube and did 20 moves, then those same 20 moves in reverse, that i could solve the cube in 20 moves. but does this mean that if i go past 20 moves it will take less than 20 moves to solve it? perhaps they were dealing with rubiks cubes that were only shuffled 20 times or less.. eh, what happened to :42:
Yeah, well, I tried following the links in this and other articles... still can't find the list of 20 moves. "20" is all well and good but how does it help me?
There must be missing criteria in the article for "randomly scrambled." For instance, in straight up random configurations, 1 would be solved, more would be only 1 turn away, even more would be 2 moved away, etc. So what defines scrambled? At least one of each color on a side? No 2 of the same color side by side? Both?
Funny.....I would have figured it to be 42...
"Because there's 43,252,003,274,489,856,000 possible positions of the cube, and the computer algorithm that finally cracked God's Algorithm had to solve them all."
By scrambled, they mean that they similuated every possible state it could possibly start in, and in every one of them they could solve it in 20 moves or less.
Yea nevermind my earlier comment, I'm an idiot. Amazing how a cup of coffee will free ones mind.
Thats crazy it took that long to figure that out. Also thats a gigantic number of possible way to solve. I wonder why they call it God's number because God's number is 7.
So they did all the combinations.
Is that a proof? Maybe, but can it be generalized? What happens with a 16 squared face cube? What is the number then? 25 faces? 36 faces?
I conjecture that it is part of a fibinocci series. Just a thought.
Er, "god" will only need one move; a whisk of his finger and it's solved. It might not even need to move its finger at all..
I feel like this would make more sense as the lowest possible moves necessary to solve a rubik's cube. In my opinion, math doesn't apply to God.
awesome!
@madcat07
its not exactly 20 every time, its what it says, a maximum of 20. the cube could be scrambled so that in 2 moves the cube will be solved.
43,252,003,274,489,856,000 has 20 digits. I CAN SEE THE CORRELATION!!!1! However, I am a more powerful god who chooses not to solve the cube. However, if I was going to solve the cube, I could TOTALLY do it with my MIND and always in 19 moves or less. I mean, who is this god anyway? I bet he/she/it is still wearing a Member's Only jacket and doing 8 minute abs mullet flopping in the breeze listening to Led Zepplin.
In the "old language" say, biblical, this called a "SCORE", get it?
Bagpipes100 - Deep Thought assured us that the answer indeed IS 42. They just can't count properly.
that would be I can do that.
Chad_Is_Rad: Which god? God's nature implies that their can be only one god. It's a bit like how many birth fathers can one person have?
The 35 CPU-years sounds awesome until you realize that the computer they ran it on probably had 1000+ CPU cores on it- about 2 weeks.
Just putting that into perspective... It didn't take a computer 10 years to solve- it just took some poor guy 10 years to make the program and a week at Google.
This always works for me htt p://howtohacklife101.blogspot.com/2011/10/how-to-solve-rubiks-cube.ht ml
Awesome! Our math teacher explained us how they proved this, yak..
He suggested us the Rubik's Cube solution for who interesting.
http://www.rubiksplace.com
I'm trying, how hard it could be?