How when you get lost you end up walking in circles

Published on Thursday 20 August 2009 22:01

THE image of a Foreign Legionnaire lost in the Sahara desert, endlessly walking around in circles and failing to find his way home, is no movie myth, research has suggested.

People deprived of navigational aids or reference points really do find it impossible to walk in a straight line.

Scientists carried out the study using global positioning system recorders to track volunteers trekking for several hours in the Sahara in Tunisia and the Bienwald forest in Germany.

They found the participants were able to maintain a straight path only when the sun or moon was visible. As soon as either disappeared behind a cloud, the walkers started moving in circles, without realising it.

Dr Jan Souman, from the Max Planck Institute for Biological Cybernetics in Tubingen, Germany, who led the research, said: "The stories about people who end up walking in circles when lost are actually true.

"People cannot walk in a straight line if they do not have absolute references, such as a tower or a mountain in the distance, or the sun or moon, and often end up walking in circles."

The research, published online by the journal Current Biology, showed that the circular paths were rarely consistent. The same person sometimes veered to the left, and then to the right, or vice-versa.

The best explanation was increasing uncertainty about where straight ahead lay, the scientists said.