This painting of my father's Wellington ditching in the Eastern Mediterranean (posting of 18th March 2008, see A Wartime Incident in the Eastern Mediterranean) is by Mark Postlethwaite GAvA, one of the world's leading aviation artists. The painting was commissioned as a birthday present; Paul Wheeler is 86 years old today.
Driving past Mala Chuchle the other day I was struck - like many other people - by the folding of the rocks on the west side of the road. How did that happen? The formation doesn't look 'rock-solid'; more like a pile of cloth or something organic. What kind of time and force does it need to make stone seem plastic?
Geology is one of many gaps in my education, but luckily the answer was only two clicks away: 500 million years. If I have read it right, this is when the deep, hard strata were first laid down which we can see exposed today in various parts of Prague. But the story gets more interesting.
Until about 2 million years ago, the whole area was covered by a flat plain. In this 'short' time the rivers and weather have eroded deep valleys and gullies, leaving table-shaped plateaux (I live on one of these) and a wide flood-plain - all punctuated by cliffs, crags and outcrops made of harder types of stone, some of them 150 metres above the Vltava.
The geomorphology of Prague is a phenomenon, and possibly unique. There may be other places where people in the central city live on the edge of cliffs, but I don't know any. London, for example, has none of this vertical drama. The Thames basin is more or less level, and there are no vistas until you go north to Hampstead and Highgate - or buy a ticket on the London Eye.
How do you imagine 500 million years? Geologists can, but I can't. And this is only a fraction of the age of the land we live on. Very large numbers are always awe-inspiring but, to non-scientists like me, essentially meaningless... until a website connects a vast span of time with the weird appearance of the rocks at Mala Chuchle.