Tuff Up - the up side
Let the rocks tell their story
Red hot ash from a volcano, falls from the sky and welds together to form
thick layers of rock.
We can determine which way is "up" in the ash by looking at any curved
fragments in the ash layers.
If you drop a saucer into water - the curved surface will always point
Similarly ash fragments will orient curved side downwards
Space craft returning to earth enter the atmosphere curved side downwards
as this is the most stable confiruration