PFers and Rubik's Cubes: How Do You Feel?

[Ki Man]

I'm wondering how many PFers like solving rubiks cubes (or tearing them to shreds in frustration)

I'm asking for some replacement stickers for Christmas, the ones that come with it begin to peel after a week of heavy use

 

[Danger]

Hate 'em, hate 'em, hate 'em.

It takes me half an hour using the manual. Can't you just paint yours with enamel? It should last longer than new decals.

 

[Ki Man]

everybody is really slow using the manual at first, eventually it just becomes instinct (scary, eh?)

 

[out of whack]

Here! I do, I totally tear them to shreds in frustration. Or at least I did one of them, when they first came out. And by tearing them to shreds in frustration I mean peeling off every bloody sticker from every blasted square, then sticking the bastards back where they should be, then throwing the freaking cube to the bottom of the deepest drawer never to see daylight again. It must have completely decayed by now because I can't find it.

So to answer the question, no.

 

[Moonbear]

Do people still do those? When I was a kid and they first came out, you could just pop all the pieces apart and reassemble it in the right order. That was the only way I could solve it until I got the manual, then realized it was really a quick thing to solve once you learned a few patterns to look for.

Then someone got me one of the ones with 4 squares to a side. I was able to solve the Rubik's Links puzzle (looked like links on a chain). But, I think that was less complicated than the cubes.

 

[Danger]

everybody is really slow using the manual at first, eventually it just becomes instinct (scary, eh?)

Well... I've had mine for more than 25 years, and I ain't feeling no instinct.

 

[Ki Man]

Maybe that's just me personally because when I first got it, after I figured it out I did it almost every waking moment of spare time

 

[Ki Man]

Do people still do those? When I was a kid and they first came out, you could just pop all the pieces apart and reassemble it in the right order. That was the only way I could solve it until I got the manual, then realized it was really a quick thing to solve once you learned a few patterns to look for.

Then someone got me one of the ones with 4 squares to a side. I was able to solve the Rubik's Links puzzle (looked like links on a chain). But, I think that was less complicated than the cubes.

Yeah its making a small comeback, and they've released a new 'rubik's revolution' where there is not turning and the center piece lights up and all you have to do is find the one that's lit up and press on it. talk about a sell out eh?

 

[Zantra]

There's a manual? bah when I was a kid you didn't get no stinkin manual. And you have to solve it hanging upside down adn blind folded. You had to do it through sheer force of will and persistence.

I never did figure out how to completely solve the cube but I had the links down cold. I could go from linked to unlinked in like 20-30 seconds when I was a kid (I had a lot more energy and free time back then).

 

[Ki Man]

For those of you who don't know how and are interested in learning how, the site cubefreak.net is really helpful and is made by the 5 time world record holder

 

[out of whack]

the site cubefreak.net is really helpful

"This site will not display properly in Internet Explorer."

He-he-he, I like that!

 

[Ki Man]

I guess it works in firefox only

 

[cristo]

I've never had a rubik's cube, or even had a go of one; well not that I can remember anyway. I saw one guy complete a 5*5 cube in around 10-15 mins: he was a pure mathematician though!

 

[out of whack]

I guess it works in firefox only

Naw, it's just the layout that is a bit off with IE because this browser does not implement CSS correctly. There is of course a standard for this aimed at making sure that all web sites are properly rendered by all compliant browsers. But the Evil Empire exists in a sphere beyond such pedestrian considerations so they don't try to abide by the rules. This forces webmasters either to jump through hoops and implement hacks to make their sites look as it should, or dumb down the features and/or layout until it works well everywhere. So now it's fun to see someone who decided not to play ball and just state that the site doesn't display right under IE. Live with it or switch browser.

 

[Chris Hillman]

Interesting theory with serious applications

I'm wondering how many PFers like solving rubiks cubes

Do people still do those?

I saw one guy complete a 5*5 cube in around 10-15 mins: he was a pure mathematician though!

It was quickly appreciated by group theorists that these ingenious puzzles afford many opportunities for motivating such important concepts as conjugacy, cosets, stabilizer subgroups, and wreath products. Numerous distinguished mathematicians including J. H. Conway have contributed to the theory of such permutation puzzles. (An earlier puzzle, the 15 puzzle, is another classic.) Rubik's cube is discussed as an important example in one of my favorite textbooks, Neumann et al., Groups and Geometry, Oxford University Press, 1994 (see the last chapter).

For an excellent overview of the basic theory, see these blog entries from John Armstrong:

• Rubik’s Magic Cube,
• A few more facts about group actions,
• Rubik's Group Notation,
• Restrictions of Rubik’s Group,
• Rubik’s Group and the solution to the cube
• Rubik’s Cube Wrapup

I myself have often pointed out a close connection with information theory.

See Brian Hayes, "Sorting out the genome", American Scientist Sept-Oct 2007, 386-391, for discussion of some further examples of permutation puzzles (flipping and reordering a stack of pancakes using a griddle) plus important applications in genomics.

"This site will not display properly in Internet Explorer."

He-he-he, I like that!

There is of course a standard for this aimed at making sure that all web sites are properly rendered by all compliant browsers. But the Evil Empire exists in a sphere beyond such pedestrian considerations so they don't try to abide by the rules.

I don't want to give it away, but if you can find the Brian Hayes article, one of the references is highly amusing in the context of a favorite activity among those who use Another Operating System, namely bashing Microsoft products

Here is another virtual cube from rubiks.com (Seven Towns, Ltd., London), which works fine for me if I enable that site to have my browser execute a javascript.

 

[Office_Shredder]

I can do rubik cubes twice on tuesdays*

*bastardization of 'any day of the week and twice on tuesdays' written for brevity and cool sounding alliteration. I'm trying to get everyone to use it[/size]

 

[moe darklight]

I'm with the tear them to shreds team.

I bought one a few months ago after I saw this guy on tv solve it in like a minute behind his back. it's a cheap knock-off that I bought for a dollar. they had a basket filled with them at the dollar store. it always gets stuck and stuff.

I spent like 40 minutes on the thing and couldn't finish it! I could get the first two layers ok, but couldn't figure out any pattern for doing the last layer without screwing up the first two I completed. every time I tried to solve a square for the last layer, a layer from the first two would get scrambled up!

eventually I got angry at it and threw it out my door. it was the single most horrible and humiliating experience of my life and I wish to never go through it again.

there it is now... sitting on my desk as I type... taunting me... laughing at me...

THEY'RE EVIL I TELL YOU! EVIL!

the thing is probably made in china and will give me lead poisoning.

 

[Donski]

I first figured out the cube back in 1980. I bought it on Monday and had it figured out by Friday even though I was high as a kite the whole time. What I can't figure out is how to read those stupid manuals, simply doing it is a lot easier. It takes me around 3 minutes.




I have the Homer Simpson one, it's the same as the simple 2x2 but confuses people because of the shape.
http://www.bigboystoyz.com/affiliate_images/mo_simpsons_rubiks_cube.jpg

[/URL]
I have the Rubik's Revenge (4x4), takes me around 15 minutes. Took me a day the first time.
http://db.stuffkidslike.com/mas_assets/thumb/100939.jpg
The Professor (5x5) takes me around 30 minutes. It took me only 1 1/2 hours the first time.
Doing the 3x3 & 4x4 gives you the insight on how to solve it.
It's still my favorite though. I even used this picture as my avatar for a couple years.
http://images.funagain.com/cover/small/18058.jpg
Square One around 15 min.
http://webplaza.pt.lu/public/geohelm/myweb/images/square1.jpg
I've had this round one for 20 years and I don't think it's all that hard, I never timed myself on it but I would say around 15 min.

I also have the link the rings with 3 rings and the one with 5 rings, and I even have the one you fold into a cube.
Took me a long time to figure these out the first time, but now they're easy.
[PLAIN]http://www.zwahlendesign.ch/images/documentation/rubiks_magic_puzzle8_solved.jpg[ATTACH=full]196365[/ATTACH][ATTACH=full]196366[/ATTACH][/URL]
The Rubik's clock is way too easy.
It's not a matter of whether or not you can do it, it's how long it takes you.
You get bored with it too quick.

Someone gave me this one as a present, it wasn't that hard.
http://www.chrisandkori.com/_filelib/ImageGallery/Cubes/dinocube.gif
Don't even bother with this pyramid one, you can stumble upon solving it just by turning it at random.
http://masterblog.front.lv/wp/files/willbe_clock_52_rubik.jpg
This one I figured out the first time at a party when I was extremely drunk.
Then later I worked it out for each starting hole in my head before I cut out a piece of wood to make my own.
http://www.hancock.net/~diana/pegs.gif
This one my father taught me how to do when I was just a little kid, and I was addicted to puzzles ever since.
You start with the center hole empty
http://stores.brilliantpuzzles.com/catalog/Solitair_MarbleN.Small.JPG


Here's the one I'd like to get next, but I just haven't gotten around to it yet.
http://www.chrisandkori.com/_filelib/ImageGallery/Cubes/megaminx.gif

 

[Ki Man]

I've yet to try any of the variations of the original cube yet but the 3x3x3 cube usually takes about a minute, my record is 56 seconds

 

[Edgardo]

Maybe that's just me personally because when I first got it, after I figured it out I did it almost every waking moment of spare time

I think that's normal :) It was the same for me and sometimes only a cramp stopped me.
I've been cubing since 2003 and my time now is 45 seconds and on good days I get averages in the 38 seconds region.

What method do you use? I use Jessica Fridrich's method but with the cross on bottom.

 

[OrbitalPower]

Do people still do those?

Yeah, the last world record for the 3x3x3 was set at the Rubik's Cube World Championships and Ernő Rubik even made a public appearance at the event.

For those of you who don't know how and are interested in learning how, the site cubefreak.net is really helpful and is made by the 5 time world record holder

I like this beginner method and am working on advanced methods. I still sometimes use a cube notation page because I still sometimes screw up like R and R' or B and B'.

I'm wondering how many PFers like solving rubiks cubes (or tearing them to shreds in frustration)

I'm asking for some replacement stickers for Christmas, the ones that come with it begin to peel after a week of heavy use

Might want to look for the original Rubik's cube on ebay, the one by ideal, not the one by winning moves. That's the one I have and the stickers haven't come off yet.

Have you ever tried the Pocket Cube

 

[OrbitalPower]

I first figured out the cube back in 1980. I bought it on Monday and had it figured out by Friday even though I was high as a kite the whole time. What I can't figure out is how to read those stupid manuals, simply doing it is a lot easier. It takes me around 3 minutes.

What's your fastest time for the mini-cube?

 

[robphy]

From the PF blog... https://www.physicsforums.com/blog/2007/08/16/rubiks-in-26-or-less/

Some competition results:
http://www.worldcubeassociation.org/results/
(recent CNN video on one-handed speed record holder)

More YouTube:
(3 Year Old Solves Rubik's Cube in 114 seconds)
(6 Year Old kid Solves Rubiks Cube in 37 Seconds)

(solved with feet)
(...not)

http://www.youtube.com/watch?v=CruqZhN_5D8&feature=related (supposedly a 100x100x100 solution [you might want to turn off sound])

BobG's PF post on higher dimensional rubik's cubes:
https://www.physicsforums.com/showthread.php?p=1268096#post1268096

 

[Moonbear]

Yeah, the last world record for the 3x3x3 was set at the Rubik's Cube World Championships and Ernő Rubik even made a public appearance at the event.

Hmm...once I knew how to solve it, I lost all interest in it. What's the point then? It just becomes a matter of how fast you are at turning it, and doesn't reflect any better ability to solve it.

 

[Donski]

What's your fastest time for the mini-cube?

I haven't been timing myself. If you're talking about the 2x2 then I'll just say that it's under a minute.

I find that depending on how messed up it is your times can vary greatly. I feel that achieving the fastest times requires a number of different things all at the same time. You would need to lubricate the cube and modify it so that it spins easily, you need the dexterity to manipulate quickly, you need the experience to recognize how and when you can use shortcut moves, and then you need the luck of having an easy route to the solution.

You need to mess it up randomly to be fair, but in that random scramble you can be closer to the solution that other times so one person can have an advantage over another before they even start. With the 4x4 you can begin to solve it and half the time you will get to a point where if you continue to the end you will have just two of the side edge pieces that need to be swapped. This can add a minimum of an extra 9 turns you need to do before you solve it, and the longer you wait the more moves you will need. Therefore the luck of the draw can determine whether or not you have a record time.

If you were to set them up in the farthest most scrambled configuration to start with every time, then you would be able to memorize the steps needed to solve it and that wouldn't be fair either. Any way you look at it, the fastest time required a little luck.

But don't get me wrong, I still highly respect people with the ability to solve it in record times.




As far as replacing the stickers, I'm an electrician so I use different color electrical tape. Just make sure to clean it good and use alcohol (IPA) before placing the tape on it or the tape will slide.

 

[Ki Man]

Hmm...once I knew how to solve it, I lost all interest in it. What's the point then? It just becomes a matter of how fast you are at turning it, and doesn't reflect any better ability to solve it.

not entirely, speed of turning can only get you so far, the real challenge is recognizing what algorithm must be done as quickly as possible. the most time is wasted for intermediate/beginners just looking for the next piece to put in.

I first learned it with the method in the booklet, which I call the 'beginner' method because it had no official name, starting with a cross, 2 layers, another cross, rearranging the cross, orienting the corners, and then facing the corners correctly which got me down to 2-3 minutes per solve. I switched to the Petrus method, starting with a 2x2x2 block and expanding to 2x2x3 etc, which got my time down to an average of 1:30 with a personal record of 56 seconds. Now I'm in the process of learning the Fridrich method, although I don't have all of the algorithms down yet I have tied my fastest solve a few times and my average is down 15 seconds

 

[Donski]

the most time is wasted for intermediate/beginners just looking for the next piece to put in.

I first learned it with the method in the booklet, which I call the 'beginner' method because it had no official name, starting with a cross, 2 layers, another cross, rearranging the cross, orienting the corners, and then facing the corners correctly which got me down to 2-3 minutes per solve.

That sounds a little like me, I do it slightly different and I don't care. I do it, full top layer, bottom cross, rearrange the cross orienting the corners to achieve a cross on all sides, then crank the center & spin the top to place the next side edge piece.

Besides, learning how to do it someone else's way takes all the fun out of it. The whole purpose of doing any puzzle is figuring it out on your own, not cheating by having someone show you how. So instead of learning how to do the same old puzzle faster, I prefer to move on and solve the next puzzle.

But that's just me.

 

[Beeza]

A friend of mine solves them in about a minute including the last 15 seconds or so with his eyes shut. There is just a simple algorithm to learn, but I still can't do it-- I don't have the patience.

 

[click]

I solve it at about 10 minutes with my secret technique
Take out all the pieces and arrange them in the right order [/color]

 

[Ki Man]

I solve it at about 10 minutes with my secret technique
Take out all the pieces and arrange them in the right order [/color]

sticker peeling skill?

 

[MeJennifer]

Hmm...once I knew how to solve it, I lost all interest in it. What's the point then? It just becomes a matter of how fast you are at turning it, and doesn't reflect any better ability to solve it.

There are many different solution methods you can learn.

And if you need a challenge try studing a scrambled cube and then solve it blindfolded.

From the Osake open 2008:
http://f.flvmaker.com/mc2.php?id=GtrFdfg95_GKUTAF6Eq.PMq82Bx_Rii1DPOedPRAbhkofdPPLAEkKix&logoFlg=Y

Watch how the WK 2007 winner solves it by simulating the movements while studying:
http://www.youtube.com/v/Hfd5sxW8Clg&hl

 

[binzing]

Ki Man, is that you Nick? LOL. I have a buddy (the aforementioned Nick) who can do these things insanely. He has taught a few of my friends and got them caught in the storm of it, but not me, I can only figure them out slowly. I would like to machine a cube out of solid brass, it'd be soo cool (and heavy) because brass self-lubricates, so it would have the potential to be a very fast cube, assuming the mechanism in the center was up to par with the rest of the cube. It'd also be a lethal weapon.

 

[Schrodinger's Dog]

I'm wondering how many PFers like solving rubiks cubes (or tearing them to shreds in frustration)

I'm asking for some replacement stickers for Christmas, the ones that come with it begin to peel after a week of heavy use

I learned how to do them quickly off a friend when I was 7, since then they kind of lost their fascination. Simple technique and it takes about 4 minutes to do them at ridiculous speed, and about 10 minutes at normal speed, it's not the fastest solution but it works.

 

[hypatia]

I just peeled off the stickers and replaced them on the right sides.

 

[Mk]

I just recently started learning how to do this. I want to get down to about one minute, I would be happy with that.