Christmas puzzles

I don’t know about Anglo-American or Taiwanese culture, but in Sweden, collaboratively solving puzzles (mostly jigsaw ones) seems to be a tradition, or at least it used to be. I’ve never liked jigsaw puzzles and I don’t have a flat surface big enough for that even if I wanted to. There are other puzzles though, such as Rubik’s cube, which has mostly been something I fiddle with at the same time as doing something else (listening to the teacher, going by bus to Taipei, and so on). The 3×3 requires almost no mental effort nowadays, if I stick to what I already know.

However, on Christmas Eve, I visited friends in Taipei and found out that Gunnar is also interested in solving puzzles like this, although I have a feeling he’s on an altogether different level when it comes to real understanding rather than familiarity. I can understand what I do, but I find it hard to create entirely new algorithms, for instance. Anyway, he lent me a Megaminx, which I solved last night before I fell asleep. It took only a couple of hours of serious thinking, because I reused and adapted lots of algorithms I was already very familiar with either from normal cubing or blindfolded cubing (those algorithms were extremely useful!).


Solved Megaminx.

As is the case with the 3×3, the only difficult part of the Megaminx is the last layer, everything else I could solve without thinking about it too much and at reasonable speed. I ended up correcting last-layer edge orientation the same way as in Petrus’ 3×3 method (i.e. swapping bad edges at an earlier step), and then correcting edge permutation. Corner permutation was done using a variant of Petrus’ 3×3 again, but for the corner orientation, I relied entirely on the quite long algorithms from blindfolded cubing. In all, I would say the Megaminx is a lot easier than the 4×4, for reasons explained below.

During this semester, I’ve also bought and solved a 4×4 (even though that was three months ago now). The problem with the 4×4 is that the centres aren’t fixed as they are on a 3×3 or Megaminx, but rather have to be constructed. Figuring out how to do this is rather easy, and after that, the rest is identical to a 3×3.


My 4×4, exceptionally good quality.

With one exception. Sometimes you end up with an edge pair flipped, which is impossible on a 3×3. The problem is that solving this last edge is really, really horrible. I cheated and got the algorithm from the internet (r ² B ² U ² l U ² r ‘ U² r U ² F ² r F ² l ‘ B ² r ²), and I think I wouldn’t have been able to find this on my own, even given years of time I’m in reality not prepared to waste. Flipping the edge pair earlier is also difficult, because it’s hard to spot this phenomenon early on. With this shortcut, it took me less than an hour to solve the cube the first time. I don’t say this to boast, I do it because I want to show that if you know the 3×3 well, 4×4 is no biggie.

In other cubing news, I’ve also taken a look at a really cool concept, which looks impossible, but turns out to be mechanically identical to a 3×3 (and is thus solved the same way), but uses shape instead of colours. This means that it’s very easy to solve if you can already solve a 3×3, but the feeling in doing so is still extremely odd and well worth the money even if you do it only once. This is what it looks like…


..scrambled


…and solved!

I should also note that my new 3×3 record is 39 seconds, but on the other hand, I’ve almost forgotten how to solve the cube blindfolded. Well, even if it’s Christmas, I suppose I can’t have everything.

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