There’s an old but apocryphal anecdote (or very funny joke, if your sense of humour is similar to mine) about a scientist or philosopher (in some accounts Bertrand Russell, in others William James) giving a lecture on modern cosmology. As Stephen Hawking tells it on the first page of A Brief History of Time:
He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: “What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise.” The scientist gave a superior smile before replying, “What is the tortoise standing on?” “You’re very clever, young man, very clever”, said the old lady. “But it’s turtles all the way down!”
Almost by definition there are few bigger or more difficult questions to grapple with than the nature of the universe, and different civilizations and ages have all attempted to provide answers that aligned with both the physical evidence presented to their eyes and with the invisible agents and forces they believed in just as firmly. John F. Ptak, of J.F. Ptak Books, Maps & Prints and the writer of a fascinating blog on the history of ideas, has collected on his site a wide range of cosmological art — a “visual chronology of cosmologies”, from the ancient Hindus to the Greeks, Chinese, and on to the modern world — which is both easy to browse and effectively conveys the diversity and the similarity of humankind’s various essays at answering the question of what that turtle is standing on.