Symmetrick

Tomas Lindén’s IPP32 exchange was a devilish little puzzle designed by Vesa Timonen. Consisting of only two flat pieces of wood, the goal is to make a single, symmetric shape... Tomas kindly gave me a copy of his exchange puzzle and it has taunted me for the last few months – it is evil! Be warned!!

 

I had a quick bash at it while I was at IPP, and got nowhere...

Then I tried it while I was on holiday in NYC, and got nowhere...

Back at home, I put it on the vast shelf-of-puzzles-to-be-solved, and every now and then I’d take it down and fiddle around with it, and get nowhere...

During MPP7 several folks played around with it, and solved it, and I gave it another bash, and got nowhere... 

(Let me know if you aren’t sure where this one’s heading!)

OK, how hard can it be? You have two flat pieces that are virtually identical, and you’re told that they both need to be flat on the table and you have to make a symmetric shape.

At one point on my journey with this puzzle I found myself trading emails with Tomas, and making sure that he really meant both pieces literally flat on the table (yip!) and that it wasn’t some sneaky answer that relied on negative space (nope!) – this time (!) it really was a straight forward solution (hard to picture given this was the same guy that bought us the Black or White!)

Straight-forward it might be – simple it is not!

At one point I resorted to a feeble attempt at using some arithmetic, and measured the edges and played around with various sums and differences, trying to work out which bits needed to be combined or aligned to result in symmetric remainders ... and failed miserably. 

Some helpful soul mentioned that he’d eventually found the solution and then realised that he’d seen that shape a few times before, and not recognised the symmetry in the shape – GREAT! Now I know I’m going to kick myself when I eventually find the solution!

Months later, I found myself out and about having dinner with a bunch of puzzlers in The Hague, and this puzzle’s been doing the rounds and I’m literally the only one left who hasn’t solved it yet, so they give it to me and I try (yet) again! 

AND I GET NOWHERE!

...and eventually one of them takes pity on me and shows me the answer, and my first reaction is “That’s NOT symmetrical!” – only it IS ... but until you ‘see’ it, you’ll be convinced it isn’t, and merrily move on to the next experiment.

For me, this has to be one of the best little bits of puzzling value for money (even if I HAD paid for it!) around at the moment ... I’ve heard stories of one or two gifted puzzlers finding the solution in mere seconds, but most folks take a decent amount of time to work it out ... and some of us took forever! 

Be warned – it is evil. But if you really do want one, I'm sure Tomas will sell you one over here...

Double Squared, a.k.a. Black or White

When I received my first order from Sloyd, there was a little note in the box saying “Free gifts from our own series. Very different types of puzzles. Hope you’ll enjoy them!” along with a couple of additional puzzles – one of which was Vesa Timonen and Tomas Lindén’s Double Squared. 

I’d spotted it as one of the entries to the 2010 IPP Puzzle Design Competition and wasn’t sure if it would be my cup of tea or not, but since I’d just been given one, it would be rude not to play around with it at least a little, right?

So the goal sounds reasonably simple: make square of white or black (OK brown!) – your choice. There’s another version that says “Arrange the six pieces (without any support) to make a white (or black) square.”  There may be a subtle difference in there, and it might be useful, or it may be a total red herring, you’ll need to work that out yourself. 

It consists of six pieces of doubled up birch – light on one side and dark on the other – putting them together in the obvious manner produces an odd coloured piece left behind, or alternatively, the right coloured piece that’s the wrong shape.  OK, so it is a puzzle after all ... so you start experimenting with other concoctions for making squares – but every time you end up with an odd shaped or coloured piece left behind ... 

 

Hmmm ...

It turns out that the pieces are helpfully provided with what I’d call (probably incorrectly – see the ensuing comments section below in due course!) a parity problem – there’s always one wrong shaped or coloured piece, and the only way to get around that is to get rather creative!

The eventual solution is a real killer – you’re not going to stumble across this one by accident. It’s definitely worthy of an entry into the Puzzle Design Competition.

Thanks Sloyd for the freebie!

[I need to add a little note about Sloyd’s own range of wooden puzzles – they’re not expensive and rather nicely made – all in light woods – birch and the like, and they come very cleverly packaged – the card backing and hanger includes a separately stapled solution sheet – so it’s there if you want it, but you have to make a conscious effort to open it – very clever! – and yes I did...]