
A machine has figured out Rubik’s Cube all by itself - mpweiher
https://www.technologyreview.com/s/611281/a-machine-has-figured-out-rubiks-cube-all-by-itself/
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peapicker
Inaccurate article on one point - they say that in 2014 it was proved the
smallest number of moves to solve is 26... but in 2010 it was proven to be 20
moves actually. [1]. (And the article they linked to was from 2008 anyway and
said that 25 moves was the max needed as of 2008 best knowledge)

[1]
[https://www.bbc.com/news/technology-10929159](https://www.bbc.com/news/technology-10929159)

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throwaway37585
The maximum number of _face turns_ needed is 20, and the maximum number of
_quarter turns_ is 26.

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peapicker
Would have been nice if they mentioned the quarter-turn metric, and hadn't
said "moves" then, which in speedcubing almost always refers to face turns.
Especially when the article they linked to was regarding face turns as well.

Both of course are mentioned at cube20.org ...
[http://www.cube20.org/](http://www.cube20.org/)

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kshcon
They clearly refer to quarter-turn metric: “Finally, in 2014, it was shown
that any valid cube can be optimally solved with at most 26 moves in the
quarter-turn metric, or 20 moves in the half-turn metric [26, 25]. The
quarter-turn metric treats 180 degree rotations as two moves, whereas the
half-turn metric treats 180 degree rotations as one move. For the remainder of
this paper we will be using the quarter-turn metric.”

