# Rubik's Cube

Discussion in 'Off-Topic' started by Georacer, Feb 21, 2013.

1. ### Georacer Thread Starter Moderator

Nov 25, 2009
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I 'd never touched the toy. It seemed like a mundane, boring, show-off action.

Recently an aunt of mine got herself to solve it, so she bought one. She failed in trial and error, so I decided to give it a try. Child of the 00s as I am, I googled for the algorithm and sure enough it popped up.

It took me about half an hour to understand it and a day to memorize it.

Now knowing how to solve the puzzle, I must admit that it gives a sense of content each time you solve it. It's like reciting a short poem or a song or a gymnastic exercise.

Isn't life weird?

Apr 5, 2008
15,648
2,348
Hello,

That was a long time ago that I have heard of it.
We also had one at home.
You could spent hours with it.

For those who do not know the toy, here is the wiki page about it:
http://en.wikipedia.org/wiki/Rubiks_cube

Bertus

3. ### DerStrom8 Well-Known Member

Feb 20, 2011
2,428
1,328
I bought one about 8 years ago. It took a friend of mine to help me figure out how the parts moved, and how I could move so-and-so a side to keep so-and-so blocks in the same place. Since then I have been able to solve it every time.

I don't know why it's so fun. I suppose it's everyone's look of amazement when you do manage to solve it. Makes you look really smart, I guess

Matt

4. ### ErnieM AAC Fanatic!

Apr 24, 2011
7,394
1,606
Back in the day... it was summertime (sweet summertime) and I came across Douglas Hofstadter's Metamagical Themas column in Scientific American on The Cube. Looked like an awesome puzzle so I got one. With no classes to attend and the "mechanical solution" well in hand (you can disassemble and reassemble a cube without any tools) I took the notation for moves Hofstadter described and looked for interesting things. Within a week I could solve the cube about half the time, the other half I had to mix it up. A day later I found a simple "mix up" that always worked so made it my third move, and with just three moves one can solve any cube.

My times are around 1:30. Twice I broke 1 minute on the iPad app.

A "move" is a canned sequence that moves just certain pieces, and they fit onto your solution method. My method is to solve one layer (face and the sides together), then the opposite 4 corners (they all come up together), middle edges, the top edges. Thus my corner move will mess up edges, but I don't care as I have not solved them yet. My edge move just moves 3 edge cubies, and I use it forwards and backwards: I count it in my head but it's mostly finger memory.

Notation: Hold the cube between your thumb and index finger: your thumb is on the Front (F) face, finger on the Back (B) face, other faces are Top, Left, and Right... I never move it so I don't remember the name for the bottom. I don't move the back or left either. So R by itself is a 1/4 clockwise turn of the R face, R' is same but counter clockwise. R2 is a half turn (either direction, it's symmetrical!).

Here's my moves:

EDGE 3-cycle:
R U R U R' U' R' U' R' U

CORNER 3 CYCLE:
F n*(R U R' U') F'

where the part in parenthesis is done 1,2 or 3 times. I've since discovered this shortcut for the n=3 case:
R2 U2 R U2 R2

CORNER SWAP:
R U R U R U R U R U R U R U R U' R2 U2 R

I've since found the following transform replacement:
R U R' U' F' U' F

Now also R2 U2 R2 U2 R2 U2 is also interesting (useful) as it can be used (with transformation and conjugation) to flip all 4 top edges.

Transformation and conjugation you ask? A transform is a "move." A conjugation is a small set up move done before a transform, and again in reverse after. It extends what a transform can do.

I currently own 3 or so cubes. I just had to toss out my favorite as it was just worn out, but it turned so nice! Most cubes (especially when new) are very difficult to turn.

An interesting cube I got as a present has no colors, it is entirely metallic in color, but the cubies are different sizes. I can solve it by my normal means, but it takes lots of concentration (solving the standard cube is mostly finger memory and the occasional observation).

I also have a ball cut into 8's, marked with rings. Another present I unfortunately uttered "oh, it's just the corners of a cube!" in excitement when I saw how to solve it... which I did in a few minutes. Those together made the gift givers upset thinking they gave me a simple puzzle... but I really like it and it's more of a challenge to me then a straight out cube as it needs more thought each and every time.

5. ### DerStrom8 Well-Known Member

Feb 20, 2011
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I think my record speed was 1:10, but that was a long time ago.

Nov 25, 2009
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1,266
7. ### maxpower097 Well-Known Member

Feb 20, 2009
795
388
I'm too dumb for it. I tried when I was a lil kid, probably too young, then never tried again as a teen or adult. I still play with my slinky though.

8. ### tshuck Well-Known Member

Oct 18, 2012
3,531
675
This is a family site!

Never had a desire to solve a Rubick's cube once I realized there is an algorithm for it. Don't know why, just felt a little less impressive to me when there was a set of rules that could solve it regardless of whether or not I picked it up...

shortbus likes this.
9. ### spinnaker AAC Fanatic!

Oct 29, 2009
4,887
1,016
It's easy just take the stickers off and paste them in the right places.

I'm with you. I never get most of those puzzles.

10. ### ErnieM AAC Fanatic!

Apr 24, 2011
7,394
1,606
My Cubes:

If you twist a layer 45 degrees you can pop out an edge cube,
and the rest falls apart.

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Georacer likes this.
11. ### Sparky49 Active Member

Jul 16, 2011
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Have you seen the 4D cube?

12. ### DerStrom8 Well-Known Member

Feb 20, 2011
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Do you mean the 4x4 or the computer generated version?

13. ### Sparky49 Active Member

Jul 16, 2011
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DerStrom8 and Georacer like this.

Feb 20, 2011
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15. ### jaygatsby New Member

Nov 23, 2011
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I think that the thing was invented with the intention of people solving it without looking at teh intertubes... cheating != accomplishment.

16. ### #12 Expert

Nov 30, 2010
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I've seen replacement sets of colored stickers in a store. Just buy a sticker kit and you can solve it any time you want to.

17. ### DerStrom8 Well-Known Member

Feb 20, 2011
2,428
1,328
I agree with that. Cheating takes all the satisfaction out of it for me. While I learned what moves do what from a friend years back, I didn't google the algorithm. However, since I did learn from a friend, I don't get as much satisfaction as I would if I solved it without the "lessons".

I truly admire the people who can do it just by looking at it. That takes skill.

18. ### maxpower097 Well-Known Member

Feb 20, 2009
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388
I used to remember people doing that when they first came out to seem smart. Hahahaha thats funny!

19. ### DenzilPenberthy New Member

May 28, 2012
20
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I'm with Spinnaker on this one. I got one for christmas when I was about 8. I disappeared off with it and showed it to my mum solved within 15 minutes. Cue much amazement. After a while I came clean that I'd figured out pretty quickly that you can peel the stickers off without them ripping and stick them back on.

I've used that in a few job interviews to illustrate my 'practical approach to problem solving' and it's always gone down well

20. ### maxpower097 Well-Known Member

Feb 20, 2009
795
388
I have to wonder the results if you were to just bring one and solve it on site? I'd be impressed.