The _conclusion_ that the Universe is expanding is based on the long accepted premise that the Universe is _flat_. And this premise can not be proven or disproved unless we travel great distances to actually _observe_ if the Universe does, in fact, look the same from any point you look.
The Copernican principle is, indeed, attractive to the modern mind because its neutrality. But it's not neutral. It's just as loaded as any other principle, no matter how crazy it may sound today, philosophical, religious, or merely personal.
The Copernican principle is, indeed, attractive to the modern mind because its neutrality. But it's not neutral. It's just as loaded as any other principle, no matter how crazy it may sound today, philosophical, religious, or merely personal.