Since science is just a guess, weren't we just "guessing" that they were providing us with the correct information? When you're studying existence, everything is "was". Where do you make the cut off between your conception of "is" and "was"? IMO, you have to trust your instruments and your brain or you can't trust anything.No we didn't guess about space. We sent satellites and probes into space long before we sent man into space. It is quite a difference in researching what is and researching what was.Scientific research is quite a bit better than a guess. Space is a vacuum. We "guessed" that when we went, because we'd never been there. Would you have have insisted we save a few bucks on space suits?Knowing what the atmosphere was 800,000 years ago is a guess at best.