We’ve got a cheap yellow plastic slinky that a supply vendor tossed in with an order years ago… I wonder if toy freebies are less common now that the dot-com boom has gone? Sorry.. total digression from my original thing.
If you’ve every played with a Slinky style toy, you know the biggest hazard is the spring getting tangled up in itself. Well, this happened with the yellow plastic one. I had a few minutes while a poster printed out, so I tried untangling it. Surprisingly, when I was done, the little printed logo on on the side was completely illegible.
It seems that, with a plastic slinky, it’s possible to reverse the direction of the spiral without changing the orientation of anything printed on them. Since the logo was printed on the side of the thickish plastic loops, it rearranged the slices of logo into a sort of warped mirror image.
This got me to thinking about how something like that could be used as a sort of cheap encryption method… Basically, a spy in a hurry would take a plastic slinky, print something on the side, then reverse it and leave it somewhere for his contact to find.
Trouble is, it doesn’t work anywhere near as well with handwriting. It looks pretty much like a mirror image of what you write, unless you write really small and really neatly, a style best described as “not like me.” In my test, I had the best results when I was writing at about a 45 degree angle to the direction of the spiral. Reversing the slinky produced a funky pattern of dots and lines out of that.
On the other hand, you can get some pretty innocuous looking results if you just take a Slinky and tighten or loosen it up a couple of dozen turns before writing. It’d work with metal as well as plastic too. You get a sort of Morse code of dots and dashes on the outside edge when you let go of the spring, and it’s a lot quicker than reversing the slinky.
I suppose you could combine the two methods to really encrypt things. Maybe try writing two messages, one tightened, one loosened, and then reverse the slinky to make it even more difficult for a casual observer to read.
Maybe I should see about ordering some more stuff from that vendor… I may need to do some experimenting.
And now that I think of it, “Reversing the Slinky” sounds kinda dirty out of context.