The Angry Corrie 25: Nov 1995-Jan 1996

Dr Ben MacDoohey, of The Angry University, again answers your everyday Hillwalking Queries

On a winter expedition to Lochnagar, two friends and I looked across from Cac Carn Mor and observed a man walking around the Cac Carn Beag cairn. When we arrived he was gone, and there were no footprints in the snow. What can have happened? - Connie Vale

A fascinating experience, and one which is frequently reported. Sadly, it is almost as frequently drug-related. However, there remains a hard core of sightings which cannot be explained away by the effects of mind-altering substances. Detailed reports of this sort of occurrence have occasionally come from unimpeachable sources, such as ministers, members of the Scottish Mountaineering Club, and parties who have been on the hill for longer than five days (by which time all recreational drugs have long since been ingested and eliminated from the body). Mighty minds have been applied to the mystery, and we at The Angry University believe that you may have witnessed a temporal mirage. All of us are familiar with the more common locational mirage, in which a person or object appears to be near at hand when they are actually elsewhere. This effect is mediated by the refraction of light-rays, which move at differing speeds through layers of warm and cold air, and are thus bent back upon themselves in such a way as to reappear at unexpectedly distant locations. The temporal mirage occurs through an extreme form of the same mechanism. Supercooled air lingering for days on the lofty winter summits is, we have calculated, capable of slowing down the passage of light to an unprecedented degree. In our laboratory, speeds as low as 2 mm/s have been attained (although we have since had some difficulty reproducing this result). Extrapolating this effect to the open air, it follows that the man you observed on Cac Carn Beag might actually have visited the cairn some three days previously; enough time for a subsequent snowfall to have obliterated his footprints. In an effort to confirm this phenomenon, I would like to ask TAC readers to perform the following simple experiment: when arriving at the summit on a cold winter day, simply inscribe the current date and time on a large card, and turn slowly through 360°, holding the card above your head. This will allow future observers to determine the time-lag with greater accuracy.

I have recently spent a few days walking in the Lake District, and was struck by the fact that the three-thousand-footers of that region (Skiddaw, Helvellyn and the Scafells) are all very different in character. Can you explain this? - Anne O'Keegach

May I first say how brave of you it is to make such an admission on these pages. You do, indeed, pose a fascinating question. It has, until recently, been quite difficult to conduct proper geology in Cumbria, since most of it has been built on or paved over. However, the recent "drought" in that region has given geologists unprecedented access to lake floors, allowing them to piece together an astonishing story. Skiddaw, it is clear, is of native English origin: it is of that flat and dreary construction that I understand appeals to some, but the charms of which are lost on me. Helvellyn, however, with its airy Striding Edge, clearly has affinities with the West Highlands of Scotland; and geologists have proven this to be so. It appears that Helvellyn became detached from Scotland (somewhere in the present vicinity of Fort William) during the rifting of the North Atlantic about 100 million years ago. It then wandered rather erratically southwestwards for 35 million years, until it was in danger of providing Northern Ireland with its own three-thousand-foot peak. At this point fate intervened, in the form of the massive asteroid impact that exterminated the dinosaurs, some 65 million years ago. As well as casting up a world-girdling cloud of dust, this impact (at Chicxulub in the Yucatán), also hurled the massive, slaggy boulders destined to become Scafell and Scafell Pike completely across the newborn Atlantic, where they struck Helvellyn island (rather firmly, as one may well imagine). This impact reversed the course of the mountain's wanderings so that, over the next 10 million years, the fused mass of Helvellyn and the Scafells slid briskly down the North Channel, cannoned off the Isle of Man (pushing up Snaefell in the process), and then slid into place south of Skiddaw. As the rocky masses subsequently accommodated themselves to the impact, various other lumps and bumps appeared, creating what we now ironically refer to as the Cumbrian Mountains.

How come the weather stays sunny all week when I'm at work, but turns cloudy and sleety as soon as weekends come? - Benny Hone

The explanation for this mystery has only recently become clear, and the tale of its unravelling is a fascinating scientific detective story. It all began in 1805, when the tiny Portuguese colonial church of Esmeralda, Brazil, burned to the ground. Two weeks later in Scotland, Saturday dawned bright and clear for the first time in living memory. Sunny weekends came frequently for the next five years, until the church was rebuilt. A fortnight after religious services resumed in the tiny Amazonian township, rain returned to the Scottish weekend, and has persisted ever since. No more than a coincidence? So it seemed until 1961, the year in which meteorologist Edward Lorenz launched the new science of chaos theory by his discovery of the so-called Butterfly Effect. Lorenz described the non-linear dynamics of the atmosphere by suggesting that the merest flap of a butterfly's wings might, weeks later, have effects on entire weather systems on the other side of the globe. His publication of this insight coincided, almost to the day, with an astonishing discovery concerning the Esmeraldan Morpho, a brilliantly-coloured swallowtail butterfly which congregates in large numbers in the vicinity of Esmeralda township. These creatures were found to possess a unique sensitivity to sound; the weekly ringing of the church bells causes a vigorous flapping display from all the many thousands of butterflies within earshot. Although the association with our Scottish weekend weather is clear, the devout citizens of Esmeralda refuse to silence their Sunday bells. Fortunately, a solution is at hand: the National Trust for Scotland has bought up many thousands of square miles of Amazonian rain forest in the vicinity of Esmeralda, and is systematically burning off the Morpho habitat. Within our lifetimes, then, we can hope for some fine weekends in the Scottish hills.

Ed. - Two points: (a) "rifting" was, when I was at school, a euphemistic way of describing involuntary (or otherwise) rectal noise-emissions (see also "trumping" ); and (b) the Doctor deserves a slap on his academic wrist for breaking TAC's newly-invented moratorium on mention of the N******* T**** for S******* following all the recent tiresome wittering about it on the letters pages.

TAC 25 Index