Further musings with respect to knowing if the study you are believing is completely false..
Science doesn't happen in isolation. Each scientist works to produce results for the specific question they are trying to answer, but together the results should correlate with each other and cohere with the theory (if the theory is accurate).
This introduces the concept of
consilience.
When a theory (scientific use of the word, not common use of the word) is supported by multiple lines of evidence from very diverse lines of inquiry, that indicates that the theory has passed a significant test of its validity. This is because while one line of inquiry might be wrong and arrive at an incorrect conclusion (flawed assumptions, incorrect data, manipulation of results to fit an agenda, whatever), that two different lines of inquiry would both be wrong in exactly the same way when they're based on completely different sets of premises and data is unlikely in the extreme.
That's why scientists always look for other lines of evidence to support their conclusions.
So take the age of the earth.. There are various dating methods, many different radiological dating methods, varves, ice cores, astronomical features, geological features, etc etc. And where they overlap they all support the same dates; consilience. Some would argue that a radiological dating method is flawed (based on an ideological desire) and say that the decay rate hasn't always been constant, and they may manage to tweak one dating method to come up with their desired 6000 year old figure, but if you apply the tweak to other dating methods, you'd find that you lose the consilience because the other methods will no longer give you the same dates where they overlap. And the other non-radiological methods (which you can't apply the tweak to at all, they're completely different things) now give completely different answers.
If there's a new theory to be had, the new theory has to be at least as good at accounting for the observations as the old one, and it has to fit within the other theories as well.
When conclusions by geologists, cosmologists, astronomers, biologists, geneticists, anthropologists, paleontologists, chemists, physicists, and other "ists" all working separately all support each other in areas where they overlap, that's consilience, and where its strong you know the conclusions are too.