Going Around In Circles?

A few years ago, having left Victoria BC on a beautiful clear morning, we were just clearing Baynes Channel via Plumper Passage into Haro Strait when, suddenly, we ran smack dab into pea-soup fog. A trawler just ahead of us, which we were comfortably following, quickly disappeared into the fog. Seemingly alone, we continued on, somewhat nervously, heading north for Sydney, trusting our radar, following the contour lines on our fathometer, and with June up on the bow, listening intently (until the cold fog simply froze her back inside) for any sounds.

Soon a tug came on the radio saying that he was just north of us and had made us and another vessel on his radar, cautioning us that he was towing a log raft. (And that's another whole story for a later blog posting!) Giving him our position, he wondered who the other vessel was that was "making dough-nuts" out there in the Strait.

Going round in circles - - not uncommon in such circumstances. But why circles?

An article published August 21st in the TG Daily (with thanks to Captain Mike Harlick for passing this on to me) gives some help.

Tubingen, Germany — People really do walk in circles when they're lost, and it's not because their legs are different lengths.

That's the conclusion of scientists in the Multisensory Perception and Action Group at the Max Planck Institute for Biological Cybernetics.

They dumped people in either in the Sahara desert or the Bienwald forest in Germany and set them walking "for several hours", following them via GPS and probably cackling with glee.

As long as the sun or moon was visible, the participants were able to keep a straight path. But a cloudy day foxed them completely, and they started to walk in circles without even noticing it.

"One explanation offered in the past for walking in circles is that most people have one leg longer or stronger than the other, which would produce a systematic bias in one direction," said one of the authors, Jan Souman. "To test this explanation, we instructed people to walk straight while blindfolded, thus removing the effects of vision. Most of the participants in the study walked in circles, sometimes in extremely small ones (diameter less than 20 metres)."

The leg-length theory was exploded by the fact that the circles were rarely in a systematic direction, with the same person sometimes turning left, sometimes right.

"Small random errors in the various sensory signals that provide information about walking direction add up over time, making what a person perceives to be straight ahead drift away from the true straight ahead direction," according to Souman.

The guys haven't finished yet. In future research, they plan to examine the even more bewildering question of how people use the sun and other cues such as tall buildings to guide their walking direction.

This sounds rather less unpleasant for their volunteers, as they get to use state-of-the-art virtual reality kit, including a cool, new omnidirectional treadmill.

The study is published today in Current Biology.

So, are we any wiser? Or are we still going around in circles. Your call.