By reading some popular science sites and some popular books I have got that idea. That if we think scientist only make rock-hard conclusions based upon solid observations and experiments that is far from the whole truth. That what they do very often is as much about modelling, hypothesis and "what ifs". As almost all written about life elsewhere in the universe, about possible "aliens", multiverses etcetera, but even ideas of "planet 9." That most of what we learn scientists don´t allow themselves to do, they do it anyway.