Reminds me of the "celestial spheres" model of the universe where heavenly bodies (orbiting the earth of course) were "held up" because they were embedded into

Reminds me of the "celestial spheres" model of the universe where heavenly bodies (orbiting the earth of course) were "held up" because they were embedded into a sort of matryoshka series of crystal spheres made of a supposed 5th element, a solid æther. Of course this model did little to explain retrograde motion.. ;)