Müs wrote:
http://www.thinkgeek.com/geektoys/games/b1d8/
Bring it.
Bring it.
| The Glade 4.0 https://gladerebooted.net/ |
|
| God's number is 20 https://gladerebooted.net/viewtopic.php?f=2&t=3783 |
Page 1 of 1 |
| Author: | Darkroland [ Tue Aug 10, 2010 10:06 am ] |
| Post subject: | God's number is 20 |
I know some of you guys are into the cube: Every position of Rubik's Cube™ can be solved in twenty moves or less. With about 35 CPU-years of idle computer time donated by Google, a team of researchers has essentially solved every position of the Rubik's Cube™, and shown that no position requires more than twenty moves. Every solver of the Cube uses an algorithm, which is a sequence of steps for solving the Cube. One algorithm might use a sequence of moves to solve the top face, then another sequence of moves to position the middle edges, and so on. There are many different algorithms, varying in complexity and number of moves required, but those that can be memorized by a mortal typically require more than forty moves. One may suppose God would use a much more efficient algorithm, one that always uses the shortest sequence of moves; this is known as God's Algorithm. The number of moves this algorithm would take in the worst case is called God's Number. At long last, God's Number has been shown to be 20. It took fifteen years after the introduction of the Cube to find the first position that provably requires twenty moves to solve; it is appropriate that fifteen years after that, we prove that twenty moves suffice for all positions. http://www.cube20.org/ |
|
| Author: | Lex Luthor [ Tue Aug 10, 2010 10:08 am ] |
| Post subject: | Re: God's number is 20 |
Darkroland wrote: It took fifteen years after the introduction of the Cube to find the first position that provably requires twenty moves to solve; it is appropriate that fifteen years after that, we prove that twenty moves suffice for all positions. This doesn't make sense to me because some positions take less than twenty moves. |
|
| Author: | Darkroland [ Tue Aug 10, 2010 10:21 am ] |
| Post subject: | Re: God's number is 20 |
Lex Luthor wrote: Darkroland wrote: It took fifteen years after the introduction of the Cube to find the first position that provably requires twenty moves to solve; it is appropriate that fifteen years after that, we prove that twenty moves suffice for all positions. This doesn't make sense to me because some positions take less than twenty moves. It's including all moves fewer than 20, they are only proving that there are no positions that require greater than 20. |
|
| Author: | Nevandal [ Tue Aug 10, 2010 11:06 am ] |
| Post subject: | |
When was this discovered? EDIT: nevermind...hooked on phonics. This is impressive stuff. First connect four...then chess....now the cube? What's next to be solved by a computer? |
|
| Author: | Kaffis Mark V [ Tue Aug 10, 2010 11:11 am ] |
| Post subject: | |
That's pretty awesome. My algorithm isn't incredibly efficient, but I remember it, and at one point, had trained myself up to impressive speed at executing it. |
|
| Author: | Lex Luthor [ Tue Aug 10, 2010 12:51 pm ] |
| Post subject: | Re: God's number is 20 |
Darkroland wrote: Lex Luthor wrote: Darkroland wrote: It took fifteen years after the introduction of the Cube to find the first position that provably requires twenty moves to solve; it is appropriate that fifteen years after that, we prove that twenty moves suffice for all positions. This doesn't make sense to me because some positions take less than twenty moves. It's including all moves fewer than 20, they are only proving that there are no positions that require greater than 20. Then what did they find fifteen years after the introduction of the cube? If they didn't know that 20 moves suffices for all positions then what they found is pointless. |
|
| Author: | Nevandal [ Tue Aug 10, 2010 4:15 pm ] |
| Post subject: | |
....what they found is that with a computer they can now solve it in 20 moves or less..no matter what. |
|
| Author: | Shelgeyr [ Tue Aug 10, 2010 5:20 pm ] |
| Post subject: | Re: God's number is 20 |
Darkroland wrote: It took fifteen years after the introduction of the Cube to find the first position that provably requires twenty moves to solve; it is appropriate that fifteen years after that, we prove that twenty moves suffice for all positions. Lex Luthor wrote: This doesn't make sense to me because some positions take less than twenty moves. Darkroland wrote: It's including all moves fewer than 20, they are only proving that there are no positions that require greater than 20. Lex Luthor wrote: Then what did they find fifteen years after the introduction of the cube? If they didn't know that 20 moves suffices for all positions then what they found is pointless. The first discovery was a position from which the cube cannot be solved in less than 20 moves - meaning the "magic number" could not be lower than 20. The second discovery was that 20 is enough moves to solve the cube from any position.
|
|
| Author: | Müs [ Tue Aug 10, 2010 5:30 pm ] |
| Post subject: | |
http://www.thinkgeek.com/geektoys/games/b1d8/ Bring it. |
|
| Author: | Shelgeyr [ Tue Aug 10, 2010 7:55 pm ] |
| Post subject: | |
Müs wrote: http://www.thinkgeek.com/geektoys/games/b1d8/ Bring it.
|
|
| Author: | Micheal [ Tue Aug 10, 2010 8:29 pm ] |
| Post subject: | |
And here I thought the thread would be about a d20 gaming system. Coolness though. |
|
| Author: | darksiege [ Wed Aug 11, 2010 1:01 am ] |
| Post subject: | Re: God's number is 20 |
Lex Luthor wrote: some positions take less than twenty moves. Well if you are a teacher in Wisconsin they are trying to get medicine covered to help with that problem. 
|
|
| Author: | Raell [ Wed Aug 11, 2010 3:39 pm ] |
| Post subject: | Re: |
Micheal wrote: And here I thought the thread would be about a d20 gaming system. Coolness though. This... |
|
| Author: | Lonedar [ Wed Aug 11, 2010 5:00 pm ] |
| Post subject: | |
Chuck Norris could solve it in 19 moves. |
|
| Author: | Micheal [ Wed Aug 11, 2010 6:18 pm ] |
| Post subject: | |
Chuck Norris could make it unsolvable in one move. |
|
| Author: | Kaffis Mark V [ Wed Aug 11, 2010 8:21 pm ] |
| Post subject: | Re: |
Micheal wrote: Chuck Norris could make it unsolvable in one move. This is probably true, given that the solution set for Rubik's cubes are limited to moves on the assembled cube. |
|
| Author: | Nevandal [ Thu Aug 12, 2010 4:30 am ] |
| Post subject: | Re: Re: |
Kaffis Mark V wrote: Micheal wrote: Chuck Norris could make it unsolvable in one move. This is probably true, given that the solution set for Rubik's cubes are limited to moves on the assembled cube. LOL smartass. |
|
| Author: | Rynar [ Thu Aug 12, 2010 4:34 am ] |
| Post subject: | |
Chuck Norris could round house kick the cube, and break it? |
|
| Author: | Kaffis Mark V [ Thu Aug 12, 2010 7:49 am ] |
| Post subject: | Re: |
Rynar wrote: Chuck Norris could round house kick the cube, and break it? Precisely. |
|
| Page 1 of 1 | All times are UTC - 6 hours [ DST ] |
| Powered by phpBB® Forum Software © phpBB Group https://www.phpbb.com/ |
|