Where do you get the idea that the ancients thougt the image was small? See for example Ptolemy's Almagest (IIRC) as quoted by C.S. Lewis.
Cheers!
Depends on the Ancients ~ the Hindus may have had a concept of a very large universe, but the fellows in the West and Middle East didn’t ~ maybe a galaxy or two, but nothing like 26 billion lightyears wide. They even thought of the stars as holes in the sky ~ maybe revealing Heaven beyond, but nothing more than that.