Random Blindfold Cubing Discussion

Whoa... I just had a crazy realization. For both 3x3 speedsolve and 5x5 BLD I consider my times to be fast/medium/slow exactly the same way in each event if I just replace "seconds" with "minutes" (or vice versa) for my times. Cool!
 
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I recently completed my first 100 4BLD solves (I do most events in "sessions" of 100), and I got 43/100. Which is pretty interesting since my first 100 3bld solves ended up 43/100.

I was just wondering how I'm going in terms of success rate. If some experienced 4BLDers remember how yours was at my stage.
 
I recently completed my first 100 4BLD solves (I do most events in "sessions" of 100), and I got 43/100. Which is pretty interesting since my first 100 3bld solves ended up 43/100.

I was just wondering how I'm going in terms of success rate. If some experienced 4BLDers remember how yours was at my stage.

It's not bad actually. Mine was probably a bit less, but still much better than my 5BLD success rate (which was about 20%, if that, for a long time.) I'd say nowadays it's about 70% for 4BLD and 50% for 5BLD.
 
Thought I should share some thoughts about 3op corners:

I've been reading a bunch about 3op corners. The method seems in some ways antiquated, but I'm faster with it than classic pochmann, for memory reasons. Anyhow, every approach to 3op corners that I've read about defines correct orientation the same way: solvable with <U,D,F2,B2,L2,R2>. Given the fact that most approaches to sighted solving define corner orientation similarly, this is to be expected. However, the algs that I find easiest to use fluently are much easier to use when correct corner is defined as: solvable with <F,B,U2,D2,L2,R2>.

3-cycles... (these cover all possible 3-cycles)
- Caltech Cycle: Bx [(RU'R'U)*3,By]Bx' where 0<=x<=3 and 0<=y<=3 and all of its U/D F/B L/R reflections. Note that RU'R'U *3 preserves FB orientation in both transpositions, so 3cycles could be formed as D2x [(RU'R'U)*3,D2] D2x where 0<=x<=1, +reflections.
- A-Perm: R2'D2RUR'D2RU'R and all of its U/D F/B L/R reflections. Everyone uses this with rotations, but when orientation is defined in this new way, no rotations are needed and it and its reflections cover all 3cycles that the caltech cycle doesn't)

Some double transpositions... (need to be used with conjugates in the <F,B,U2<D2,L2,R2> subgroup)
- (RU'R'U)*3 + reflections: preserves <F,B,U2,D2<L2,R2> orientation in both of its transpositions
- E-perm minus rotation, and its FB reflection (and possibly its UR->DL reflection, but I do not use this)
- X-perm+U2 - obviously preserves <U,D,...> orientation, but also preserves <F,B,..> orientation

So, my general point is that <F,B,...> corner orientation may have some advantages over the commonly used <U,D,...> corner orientation.
However, I have found it slightly harder to visualize cycles in this orientation, but I believe this to be due to transition difficulties rather than the nature of how the brains visualize cubes.
Of course, though, I am not an experienced 3bld solver. So, there could be disadvantages that come with FB corner orientation that I have not come across yet.
 
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I was just thinking about things one could do while memoing/solving blind. I know of Mike Hughey juggling, Noahaha skiing, and Mr. Pochmann holding his breath. Am I missing any existing videos?
I'd really like to see someone recite a poem or even carry on a conversation, but I think it would be extremely challenging.
 
I was just thinking about things one could do while memoing/solving blind. I know of Mike Hughey juggling, Noahaha skiing, and Mr. Pochmann holding his breath. Am I missing any existing videos?
I'd really like to see someone recite a poem or even carry on a conversation, but I think it would be extremely challenging.

It took a lot of DNF's but I finally got something like this. The pauses are bad and I needed to use images for everything without sub-vocalizing the pairs in the same general location as the pi images.
.
 
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I was just thinking about things one could do while memoing/solving blind. I know of Mike Hughey juggling, Noahaha skiing, and Mr. Pochmann holding his breath. Am I missing any existing videos?
I'd really like to see someone recite a poem or even carry on a conversation, but I think it would be extremely challenging.

One-handed, blindfolded, while driving is fun :)

*Disclaimer*
I am not responsible if you die while attempting this.

I do this on long road trips sometimes. Basically you hold the cube in one hand, the steering wheel in the other. You hold the cube up high while memo'ing so you can still see the road. After memo you put the cube behind the steering wheel/column where you can't see it and solve.

*Disclaimer*
Obviously your safety while driving is more important than solving, so pay attention to the road the whole time. Also, don't die while attempting this. It's not as bad as it sounds *IF* you are being safe about it. No matter how careful you are about this, realize that you are driving in a distracted state.
 
Rubik's cube talk at CNU in Newport News, VA

I gave a 30 minute talk tonight to the CNU Pi Mu Epsilon Math Honors Society at Christopher Newport University (CNU)! There were about 60 people attending, with 10 inductees, their family members, the math department faculty, and other math enthusiasts at the school. The talk was more math based than other talks I've done before, but I was told to make the talk entertaining to a lay audience as well. I did a demo speedsolve and demo blindfolded solve at the start too, and the audience loved those!

The room we were in had a huge projector screen, so after the demos I showed the calculation for the number of positions to a 3x3x3 cube (8!*3^8*12!*2^12) / (3*2*2) and I talked about how the calculation is an overcount which we adjust by dividing by the (3*2*2). I did a very brief overview of cube laws, enough to explain where each factor in (3*2*2) comes from. I showed them the expanded form for the number of calculations (43,252,003,274,489,856,000) and I told them that the number of unsolved configurations to the cube is a prime number :)

After that I talked about God's number being 20 and it's discovery and announcement in 2010. I gave a brief overview of the history of the lower bounds and upper bounds being narrowed down, as well as explaining that it was a computer aided proof and that they split up all the positions of a cube into sub-cases (cosets) in order to prove the result. I didn't do very much detail on the math of God's number, I gave more of a historical overview of how it was proven.

I then brought up Randelshofer's 3x3x3 applet and showed them how you can use the order of a permutation as the base concept to twist three corners in place. Basically (RUR'U')*6 is an identity, and (RUR'U')*2 flips one corner in the bottom layer, I showed them how the alg:

(RUR'U')*2 D' (RUR'U')*2 D' (RUR'U')*2 D2

works to flip corners and explained how it is using the identity property of (RUR'U')*6 mixed with the fact that (RUR'U')*2 only flips the one corner on the bottom layer to flip all 3 corners. I didn't ever show them notation, I just did that alg on the main screen using the applet while explaining as I did it.

Lastly I did show them commutators (but I did not name them at first). I told them that to cycle a small number of pieces they can follow the process:

Identify a slice of the cube then:
1) Find a sequence of moves that destroys (i.e. changes) one piece on that slice
2) Turn the slice
3) Perform the destroy maneuver backwards to restore the piece from step 1
4) undo the slice turn

Again using Randelshofer's applet I showed them (R U R') (D') (R U' R') (D) and how it moves only 3 corners. I left this part very general and just said that these steps were a process to move a small, targeted number of pieces around on the cube. At the end of this segment I did tell them that this process had a name, and that these were commutators, which were a composition of permutations.

And that was the end of the talk! The audience seemd to enjoy it very much. There was enough math to keep the Pi Mu Epsilon inductees interested. A few of them came up and talked to me afterward and said they really enjoyed the talk, and one of them was a cuber! The parents and non-math relatives and friends really enjoyed the demos, and they liked the more interesting trivia info from the talk (# unsolved configurations is prime, God's Number, hearing the explanation that there was a structure for algs like the 3 corner flipper and 3 corner mover even if they didn't grasp the concepts fully).

I had a great time, and the faculty was really glad to have me as a presenter! Yay! I hope I get to go back again for another presentation at some point! I am also doing a cubing demo at a middle school next week for a math camp being held by the CNU faculty. That one will pretty much just be demo solves as I only have about 20 minutes. I may give them a very basic overview of the cube (center pieces determine the color of that face when solved, there are corners and edges not "sides" to solve, etc.). I will let everyone know how that goes afterward too!

Have fun all, and happy cubing!
 
A Lemon: Very impressive! This is going on my list of favorite cubing videos.

cmhardw: I can neither confirm nor deny having ever participated in the type of activity you're describing. :P
 
I gave a 30 minute talk tonight to the CNU Pi Mu Epsilon Math Honors Society at Christopher Newport University (CNU)! There were about 60 people attending, with 10 inductees, their family members, the math department faculty, and other math enthusiasts at the school. The talk was more math based than other talks I've done before, but I was told to make the talk entertaining to a lay audience as well. I did a demo speedsolve and demo blindfolded solve at the start too, and the audience loved those!

Reminds me when I did a 2 hour long talk (yeah, that was long...) about computer solving, namely Thistlethwaite's and Kociemba's algorithm for fellow computational scientists at my University ("just" 15-20 people). I also show them some basic concepts and laws on the cube, the history of the 20 moves boundary, how certain subgroups work like <M2,E2,S2>, and so on. :) I really enjoyed it, and it seemed that they were interested to.

That blindfold demo surely looked astonishing for your audience. :)
 
Ok, here's one: Memo with only one rotation. E.g., look at the U+F+R faces, turn the cube around and look at the D+B+L faces, and then solve without looking back at the first 3 sides.
The way blindsolvers flip the cube back and forth while memoing is so distinctive. This would be really weird to watch.
 
Ok, here's one: Memo with only one rotation. E.g., look at the U+F+R faces, turn the cube around and look at the D+B+L faces, and then solve without looking back at the first 3 sides.
The way blindsolvers flip the cube back and forth while memoing is so distinctive. This would be really weird to watch.

Yes, and they also should solve with CFOP, tracking edges and corners in their mind.
 
Yes, and they also should solve with CFOP, tracking edges and corners in their mind.
I think you're being sarcastic but actually I kind of like that idea too. Well, not exactly that idea, but speedblind where you start with a quick, regular-blind style memo, (or a novelty one-rotation memo), and then work out the CFOP (or whatever) solution in your head... why not?
For the record, the thing I suggested wouldn't be anywhere near as tough as tracking a whole cube in your head move by move. You'd do something like: have 20 "slots" in your mind for the 20 locations on the cube. Each slot would have 24 (either 12*2 or 8*3) possible values. You'd be able to fill in the corner "slots" with no trouble, since 4 of the corners would be discernable from each angle. The edges would be trickier, as 6 of them you'd only see one side at a time. You'd have to temporarily remember one side of each of those until you saw the other sides. Once you had that structure in your mind, it wouldn't be too tough to do a standard blind-style solve. I'm not saying there's any particular reason to do it, but I do think it's possible and would look really weird.
 
Something I found interesting: If you get a successful mean of 3 in a competition, you're in the top 500 in the world no matter how long you take. Only 391 people have ever done a successful mean of 3 in comp before, which goes to show how hard it is to be consistent.
 
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