Push beyond our limits, we slid into a world of illusions as our brains struggled to make sense of their surroundingsby Cal Flyn / December 11, 2018 / Leave a comment
Two years ago, I had an unnerving experience while winter mountaineering in the Cairngorms. Having woken at a bothy in Glen Feshie to a clear, frosted morning, we climbed above snowline in the watery sunlight to begin what should have been a simple loop—summiting the nearest Munro before following a track north beyond a steep-sided corrie and dropping down to where we’d left the car.
As we approached the peak a bank of snow clouds appeared in the east, moving fast, and soon we were engulfed in the most complete white out I’d ever experienced. The ground, the sky, the boundary between them, all completely obscured and aglow with a flat, white light. The track nowhere to be seen. With visibility down to zero, we bunched together and trudged onwards through a featureless haze, eyes on the compass and counting our steps.
It was dizzying, disorientating. My eyes, searching for a hold on this otherworldly scene, grasped at what reference points it could: cliffs reared suddenly out of nothingness and raced forwards only to transform, abruptly, into thin strands of frozen grass, poking through snow. It soon became impossible to tell whether we were travelling uphill, or down.
Under normal conditions, human perception works so well as to render its workings invisible to us. But in certain circumstances—extreme weather conditions or extraordinary places—we push beyond its limits, sliding into a world of illusions as our brain struggles to make sense of its surroundings.
Depth perception, depending as it does on a number of visual clues, is first to go. In flat light conditions in the Canadian north, 19th-century explorer Otto Sverdrup and his party once spotted a distant herd of caribou. On closer inspection, it transpired to be a group of rabbits.
Polar explorers were well aware of the lies their eyes could tell them. As Frederick Cook wrote of the Arctic in 1911: “Mirages turned things topsy-turvy. Invented lands and queer objects ever rose and fell, shrouded in mystery.”
The invented lands he speaks of are the result of “looming,” or superior mirages. Formed when temperature gradients between strata of air create mirror-like surfaces, distant objects—far beyond the normal horizon—are reflected and produce in the human mind an impression of mountain where there is only…