Credit: Unsplash/CC0 Public Domain Your goofy but lovable cousin just told you that you should stop eating eggs because he read somewhere that a study showed they are bad for you. How much should you trust your relative on such matters? More importantly, how much should you rely on one newly published bit of research when deciding what to make for breakfast? To be clear, this is not an article about the health-promoting or health-torpedoing properties of eggs. It's about how scientific knowledge is built piece by piece from many studies. What scientists know is refined over time as new results either do or don't point to the same conclusion. I'm a geographer who's been doing and teaching science for many decades, with a sideline of teaching and writing about how science is done . Many people, quite understandably, take a single experiment or study as the be-all and end-all of knowledge because that's how research is often presented by the press or on social media.…