Rubik's Cube (1 Viewer)

[Ryan T]

My brother can solve the 6X6X6 cube . I think he got his average 3x3x3 cube down to under a min.


Ryan

 

[Cees Alons]

Ah, Rubik's Cube once more.
I loved it, actually I own several of them. Some more facts:

Prof. Rubik created the cube for his students to prove that he solved the problem of the independently moving layers. We were all amazed, like Ed was, to see that it can be done.

The puzzle-aspect originates from adding the six colours to the sides of the cube.

There is a special position that allows you to take the cube apart without breaking anything - starting with one cubicle. It is possible to re-assemble it in a wrong way: so it can never be solved. That's because there are basically 2 different topological configurations given the coloured cubicles. Those two configurations have none of the "views" of the cube in common, so the "solved" cube belongs to only one of them.

Official competions started with a "solved" cube being turned randomly by a judge a given number of times. Normally that given number was 13. So if you think about that, it was always possible, theoretically, to move it back by no more than 13 moves. No one found those moves in time of course.

Official analysis shows that there is a maximum to the number of moves each position is "away" from the zero position. I don't remember it by head for certain, but I seem to remember that number was 53 or so. Perhaps I'm wrong here.

The general solutions given by most books are based on moves necessary to move a single cubicle from position a to (proper) position b, without disturbing already correctly placed cubicles. Of course that leads to many redundant moves.
While you're using this sort of instructions, you most probably start moving the cube farther away from it's solved position instead of getting closer (strictly speaking).

One can try for a fundamental solution for each position. I once wrote an "total analysis" version of a Rubik's Cube solving program using Turbo Pascal. Unfortunately it could only go as deep as 6 moves in about 2 minutes (and needed a time factor of 12 for each further move). Recently, I wrote a Visual Basic version of the program, but it can only solve ... 8 moves in 11 minutes (on a much faster PC). So, we still need C++ or machine code as well as a faster computer.

The puzzle with the rings, known as Rubik's Magic, constitutes a "trick". You cannot solve it until you realize the funny outcome. (I leave it at that, not to spoil it for those who are wanting to give it a try.)

Cees

 

[TonyD]

i used to collect many of those puzzes.
i remember one shaped like a pyramid. it was much easier to sovle then the cube.

i think my rubik's magic fell apart before i solved it.

now i still have a couple cube's left laying around.

including one shaped like homer simpsons head.

a bart one was supposed to come out but i never saw it.

 

[Kevin P]

I used to know how to solve the Rubik's Cube back in the early '80s. I have since forgotten since I haven't done it in many years. My dad got me a Rubik's cube that had writing on the sides; this one was more challenging since not only did you have to align the colors, you had to get the writing aligned as well. The center square needed to be aligned with the other squares. I figured out a move to do this without messing up the colors.

I had a Rubik's Revenge (this was the 4x4x4 cube) but it broke, and the Pyraminx (the pyramid shaped one). I solved the Pyraminx in about 10 minutes after I got it, it's a lot easier than the cube. I also had the Missing Link, which had the rotating cubes with the sliding panels and you had to align the colors to make it look like a chain; and I also had a snake which could be folded into a ball or made into a myraid of shapes (there was no "solution" to this one, you just made different shapes with it).

I remember that the original cube could be disassembled and lubricated with Vaseline to make it turn easier. With a well lubricated cube I could solve it in about a minute.

KJP

 

[Matt Gordon]

This thread jogged my memory so much I ran out to Wal-Mart and got a new Rubik's cube (couldn't immediately find the original packed away somewhere)! Yep, they're still for sale. I paid about $9.50 for it (tax included).

For those looking to buy one, get the cube by Hasbro, not one of the other "Rubik's Cubes" by Oddzon or Winning Moves. The stickers will come off in a couple of weeks. The originals do show up on eBay, at about $10-20 or so. Make sure they state it is an original from the 80's.

 

[Jeremy Illingworth]

For some unknown reason the colour placement (relative to each other) has been changed since the originals. What focus group decided on that?

jeremy

 

[Ren Cola]

I think I have ever solved a rukik's cube, but I remember that I loved messing with them. The bright colors were always fun to manipulate.

 

[Cees Alons]

For some unknown reason the colour placement (relative to each other) has been changed..

That has always been the case. If you bought two cubes from different brands, the colours could be differently placed (relatively) or (partly) even be different at all.

Cees

 

[Patrick Sun]

I also solve it with the white side being the bottom color, otherwise I get confused.

So, no one else makes nifty patterns with their Rubik's Cube?

 

[Cees Alons]

So, no one else makes nifty patterns with their Rubik's Cube?

Made .
Yes, I used to do that a lot.


Cees

 

[Jeremy Illingworth]

After reading up here I realized that the writing must line up (which it now does) because of the need for each piece to be in the correct place. When I was working one side at a time all the letters were misplaced, which would have made solving impossilbe.

jeremy

 

[Yee-Ming]

IIRC, it is impossible for the centre pieces to be positioned wrongly. by design, centre pieces of course do not move (shift place) at all since they are the pivots, but they can be rotated around, and if there is writing across them, the alignment could be incorrect in relation to the other 8 pieces on that face.

I also recall from the book released by the teen whiz-kid that there was a sequence that could rotate the centre piece only and disturb nothing else, but since I never had any cubes other than plain coloured ones, I never needed to learn how to do that.

[edit: it didn't make sense... :b ]

 

[Kevin P]

It only seems that way.
Each and every cubicle of the big cube is unique. It can only go to one place for the solved position. So, if you solve the puzzle, the writing will be there automatically - always the same, the way they put it.

True except for the center square, which can rotate. It was possible to solve the cube for the colors but still have the writing on the center square out of alignment (rotated) relative to the writing on the surrounding squares. I devised moves to rotate the center square without altering the positions of the other pieces.

 

[Jeff Bamberger]

I always went for the "take it apart - put it back together" method.

 

[Cees Alons]

centre pieces of course do not move (shift place) at all since they are the pivots, but they can be rotated around

Absolutely true. I forgot about the central pieces, because "normally" they play no role. Yes, it complicates things a bit!

Cees

 

[Ted Lee]

too funny. we just picked up a cube for my gfriend's son!

i was one of two kids in my school that could solve that damn thing. it was kinda cool but irritating at the same time. people i didn't know would stop me and ask me to solve it...teacher's were asking me to solve the ones they took away from kids during class...it was ridiculous. it also didn't help that the other guy who could solve it was also asian and that (at the time) we both hated each other's guts. people would get us confused and we were always competing with eachother. (we later became really good friends...go figure.)

i even took mine apart and lubricated the insides with vaseline so it would move quicker! i don't remember my speed record, but i'd guess it was under a minute.

anyway, now i can do the first two layers easy. doing the bottom corners is okay, but i'm totally stuck on getting the last two middle tiles in the bottom layer in place. help!