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Rubik's Cube Proof Cut To 25 Moves
KentuckyFC writes "A scrambled Rubik's cube can be solved in just 25 moves, regardless of the starting configuration. Tomas Rokicki, a Stanford-trained mathematician, has proven the new limit (down from 26 which was proved last year) using a neat piece of computer science. Rather than study individual moves, he's used the symmetry of the cube to study its transformations in sets. This allows him to separate the 'cube space' into 2 billion sets each containing 20 billion elements. He then shows that a large number of these sets are essentially equivalent to other sets and so can be ignored. Even then, to crunch through the remaining sets, he needed a workstation with 8GB of memory and around 1500 hours of time on a Q6600 CPU running at 1.6GHz. Next up, 24 moves."
What are these magic 25 moves that can solve a rubik's cube regardless of starting position?
Give me Classic Slashdot or give me death!
The correct answer is a hammer.
Just -1, Troll talking to another.
This Green Technology uses 1/26th less energy to solve a rubix cube! When's the IPO?
The more annoying thing was to solve it for real, then transpose two of the stickers, and mix it up again. Let's see 'em solve it now!
Insightful and funny are really the same thing, except one has a punch line.
I consider a Rubik's Cube to be "solved" regardless of its starting position. I subscribe to the Fred Rogers solution: it's fine just the way it is.
--I'm so big, my sig has its own sig.
-- See?
Well, that explains it; considering how fast the technology is changing, they probably didn't have 2.4 GHz versions 62 days ago.
No, just make the rubix cube out of the oled keys of the optimus keyboard. Integrate with bluetooth and "solve" the rubix in a single button press.
Well.. maybe. Or Maybe not. But Definitely not sort of.
And if you put the corner on twisted by a third of a turn, then scramble it up again, you have an insoluble puzzle to leave lying about to drive people nuts. B-)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I painted all 6 sides the same colour on mine.
I am a free slashdotter. I will not be modded, blogged, DRM'd, patented, podcasted or RFID'd. My life is my own.
In my research, I've reduced female behavior to a set of 50 million parameters. By partitioning this space into subspaces and finding equivalent sets, I think I might be able to get laid.
However I've noticed a problem: if I introduce a parameter to model a female's response to this research, the spaces collapse to zero, i.e., a null set.
I find this quite puzzling. Simply by examining my chances of getting laid, I reduce my chances to zero.
Did I mention I can solve the Rubik's cube in 25 moves?
I've been doing some interesting work in the other direction. I've managed not to solve a Rubik's cube in what I estimate to be 1.5 million moves. That seems to be the upper limit after which the stickers fall off.
I started with a solved cube and now it looks totally scrambled.
The sound of the CPU cooling fan at 2.4GHz?
A cooling fan at 2.4 billion revolutions a second would probably sound more like atoms tearing apart. :)
Not funny. I had this cube in my car for years (something to do at traffic lights and when there's an accident during rush hour traffic in Allentown)... could never beat the friggin' thing. I got it in a box from my cousin (along with a commodore 64 and VIC 20).
One day I decided to look up the algorithm to beat it, and you can imagine how I felt when I realized that the stickers had been removed and there was no solution. I nearly pulled a Ballmer, but I happened to be sitting in the only chair in the room. Not that it stopped me from trying to throw it.
If I mod you up, it doesn't necessarily mean I agree with what you've said, sorry.
Hint: For this prank to work, the stickers should be different colors.
After all, I am strangely colored.
If the fan has a diameter exceeding 3 1/8 inches, it would be the sound of fan blades of infinite mass traveling backwards in time.
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I one met Erno Rubik himself.
Nice guy and all, but it took me half an hour to finish shaking his hand.
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