We dont really know the mass or the radius of the Universe do we?

Answer 1

Nope, not really. It sounds like a simple question, but it's really quite difficult to determine, since the Universe is so large, and there's still so much of it that we can't even see. That's the neat thing about science, there's still so many things to study, so many questions left to answer. We don't know everything, that's what keeps scientists employed!

Answer 2

A little over a hundred years ago, we didn't know germs caused disease, be patient, or turn to something lame like religion. They have all the answers, or so they claim.