Really? Did they not have science fiction back then, or the ability to imagine impossible things? Didn't Di Vinci draw helicopters and all sorts of amazing ideas? In Dante's The Devine Comedy doesn't the narrative go to other planets, stars and other civilisations?
Yep. Scientists will always say things like 'we believe that there could be....' or 'this leads us to conclude that....'.
Did Karl Popper not say any scientific theory or proposition that claim to be unfalsifiable is psuedo-science? The premise being a theory can be backed by a thousand...
Of course it's hypothetical, science mostly is hypothesis backed by observation and experimentation.
Only religion claim to know the origin of life the universe and everything...