That's correct. Lack of evidence isn't enough to disprove a theory; what you need is evidence that directly contradicts the theory.
We are approaching the point where the lack of evidence becomes evidence of non-existance. But as of yet, I know of no alternative theory.
There are two projects I think are well suited for this purpose. A CC stripe reader or a SIM card reader. Both are very simple circuits, both require exactly one specialized piece of hardware (the SIM reader or the tape reader--and old cassette player head works fine). Both can provide data to the COM port to any computer, and need only very simple software to manipulate.
I've never been canoeing before, but I imagine there must be just a few simple heuristics you have to remember... Yes, don't fall out, and don't hit rocks.
