Ancient puzzle, solved by abstract algebra?

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Discussion Overview

The discussion revolves around a puzzle involving the rearrangement of a sequence of numbers in a specific order, with a vacant space used for movement. Participants explore the feasibility of solving the puzzle and the implications of group theory in relation to the problem.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant asserts that the puzzle is impossible to solve after extensive trial and error, seeking proof or disproof of this assertion.
  • Another participant agrees that it is impossible, referencing the need for an even number of swaps to maintain the empty space in the bottom right corner, which contradicts the requirement to swap certain numbers.
  • A third participant expresses appreciation for a resource that provided insight into group theory, indicating a connection to the puzzle's solution.
  • One participant attempts to clarify the problem's presentation and shares various configurations they tried, suggesting that they are close to a solution but ultimately give up, humorously proposing the use of Riemann Space as a fantastical solution.

Areas of Agreement / Disagreement

Participants generally agree that the puzzle is impossible to solve, but the reasoning and proof methods are not fully settled, with some uncertainty about the problem's presentation and the implications of the moves allowed.

Contextual Notes

The discussion highlights limitations in the problem's description and the assumptions about the movement of numbers, particularly regarding the parity of swaps required for certain configurations.

MathematicalPhysicist
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i reackon youv'e seen it already, the problem is to rearrange the next numbers in the fixed order:
1 2 3 4
5 6 7 8
9 11 10
when you have at the last entry a vacant place you need to put it in order.
this is from the text of edwin h. connell, and i think it's impossible (after a lot of trial & error on my behalf), now my question is how do you prove/disprove my assertion?
 
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It's impossible. I've seen it before but I couldn't remember how to prove it until I looked here
http://members.tripod.com/~dogschool/permutation.html

If on each move you could make a swap between _any_ two numbers (or between a number and the space) then to swap the 11 and the 10 while leaving the other pieces the same requires an odd number of swaps. But the way the game is set up, the empty space can only be at the bottom right if you have made an even number of swaps.
 
oh, this old dogschool site is indeed great, this was my first insight into group theory.
 
loop quantum gravity said:
i reackon youv'e seen it already, the problem is to rearrange the next numbers in the fixed order:
1 2 3 4
5 6 7 8
9 11 10
when you have at the last entry a vacant place you need to put it in order.
this is from the text of edwin h. connell, and i think it's impossible (after a lot of trial & error on my behalf), now my question is how do you prove/disprove my assertion?

i did not understand the problem until i quoted it. it is poorly written...the 9 11 and 10 appear to be as long as the first columns. Okay...everyone says it is impossible but...

5 6 7 8
9 11 10

9 6 11 10

5 7 11 8
9 6 10

5 7 10 11
9 6 8

1 2 3 4
5 6 7 10
9 8 11

almoust...almoust...

5 6 10 11
9 8 7

5 6 11
9 8 10 7

1 2 3 4
5 6 11
9 8 10 7

1 2 3 4
5 6 7 10
9 8 11

once again...close

5 8 6 10
9 7 11

5 7 8 10
9 6 11

that 10 just won't go down!

i give up. I'll let you with this lengthy post maybe someone uses a Rhiemann Space to teleport it into place.
 

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