‘The trick is to change the way you think about time. It’s no use thinking in minutes or hours or days, or even generations. You’ve got to adjust the scale, think in terms of millennia. Then everything you see here is temporary, the lakes, rivers, mountains, all in motion, the changes taking place over millions of years. This valley wasn’t always here: it was created, gouged out by a great glacier, because ice is a moving thing, just a couple of feet a day but scouring and chewing away with these great teeth made of stone,
