Wednesday, December 30, 2009

Isis update


Warning: spoilers follow.









Don Geddis said...

If the video doesn't show it, and if you couldn't really get the ball through the maze even while looking at it with the cover off ... then how did you ever open it to begin with?

Did you somehow just disassemble the thing mechanically, rather than "solving" it?

Ron said...

I wouldn't say that I "solved" it. (I don't think it's possible to actually "solve" the Isis because there's way too much hidden state.) I just got lucky, which I think is really the only way to do it. I had taken the thing into my garage where I could whack on it without spooking the cat. I was banging and spinning and twirling the damn thing and at one point I happened to press on the plunger and it didn't go down all the way, so at that point I knew I had the third ball bearing in the right place. After that it was relatively easy.

I have still not put it back together all the way because despite the fact that I am now intimately familiar with how the Isis is designed I am not confident that I could reliably open it. In particular, I have not been able to figure out a way to tell if you've successfully dislodged the ball bearing from the magnet. It takes an incredibly hard whack to do it.

This is one of the most perverse aspects of the puzzle's design. The amount of force needed to dislodge the bearing from the magnet is well beyond the bounds of the normal unspoken rules of puzzling. As it happens, the Isis is pretty solidly constructed, and you could probably hit it with a sledgehammer without breaking it. But until you've opened it (or cheated by looking up the answer) how are you supposed to know how much force you can apply without risking damage to the internal mechanism?