Turtles all the way down

“Turtles all the way down” refers to a infinite regression belief about the nature of the universe.

The most widely known version today appears in Stephen Hawking’s 1988 book A Brief History of Time, which begins with an anecdote about an encounter between a scientist and an old lady:

“A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the Earth orbits around the sun and how the sun, in turn, orbits around the centre 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.”

Tartarugas até lá embaixo

Outra expressão semântica muito legal, mas sem paralelo em português.