Are you puzzled pedants?

Copied from the BBC on-line newspage today.

Maximum number of face turns needed to solve Rubik cube - "God's number" - is 20. This proof was arrived at in 2010 by team of researchers led by Tomas Rokicki, a programmer from Palo Alto, California.

I must be pretty good, I can use far more than this “Maximum”.

I think that makes sense if you think like a mathematician, but it's been compressed by a journalist from what was probably a clearer original text. The researchers presumably proved that, starting from any arbitrary configuration, if you make the most efficient possible move each time you never need more than 20 moves to solve the puzzle. Of course, that doesn't tell us what the most efficient next move actually is.

Which it says: "Maximum number of face turns needed to solve"

Seems clear?

http://www.cube20.org/

Apparently the term "God's number" comes from the notion that this is the maximum number of moves an omniscient being (who of course has memorised all the optimum solutions) would need to solve the puzzle.

Shouldn't it be the minimum number needed to solve…

No, because if the cube has been shuffled randomly it may be solved in one, or even zero, moves. It's saying that no matter what the initial state of the cube a perfect player will need at most 20 moves.

Ah, the subtleties…
Thank you for the explanation.

>8 BoMag:
In 1980 everyone had a Rubik's cube.

(Resists the temptation to Photoshop a bit of the Sistine Chapel ceiling)

>12 BoMag:

fewer

>12 BoMag:,>13 Noisy:
Both wrong. It should be "no more than twenty"

You can, but you have to enter it as an html entity (&lt;): < 20
But the value twenty is also possible, so it should be ≤ 20

So........Instead of all that nonsense of:

Maximum number of face turns needed to solve Rubik cube - "God's number" - is 20.

What they mean is: The number of face turns needed to solve Rubik cube - is (less-than symbol) 20.

The Maximum/Minimum bit just confused everyone. And these are journalists?

>2 thorold: I think that makes sense if you think like a mathematician, but it's been compressed by a journalist......

So.. .. .. The number of turns is compressed to only 15? :)

I'm outta here...

Wait for me................

No way. Save yourself! ;-)

Simpler: "The Rubik's cube can be solved in 20 or fewer moves no matter how scrambled it is, and there are some starting positions that require the full 20 moves."

It takes me somewhere between 20 and a million. I've never solved one.

Maybe you have one that can't be solved? Always blame the technology.

>25 Amtep: Good re-frame, thanks!

The puzzle, surely, is to work it out for yourself. (I have not yet managed but I'm close.)

The idea of getting a video to learn how to do it is counter-productive.

Then GOD Had one back in those days.

I saw the subject heading for this thread and vainly hoped it might be about crosswords. Hey ho. I'm with PhaedraB on this one: my parents bought me an unbranded knock-off Rubik's cube back in the 80s and I never managed to solve that. Because it wasn't a genuine jobbie I've never been sure whether my lack of success with it was down to my not-very-analytical brain, or it being unsolvable.

>29 dtw42: So.. .. .. You reckon the reason you couldn't do it was.. .. because it was a fake? Nice try. :)

Yup. That's my excuse and I'm sticking to it.