For centuries, knowledge was defined as "justified true beliefs". This definition laid the foundation for epistemology itself a cornerstone of many social sciences. Yet, the definition was and is wrong, as shown by Edmund Gettier. Indeed, half a century after the House-of-cards-destroying influence of Gettier's fake cows, epistemology continues to find its foundation and rebuild their house.
Interestingly, natural scientists since the enlightenment have created the most successful knowledge creation apparatus known to man. This apparatus brought light to the dark ages as people realized that through trial and error and diligent documentation, they could outpace the knowledge from the Greek, Roman, and even the Bible. The scientific method, as this apparatus is known, has diligently expanded our understanding of the world and brought our collective knowledge ever closer to the truth.
Note the last sentence. "Closer to the truth" builds on different assumptions than the O.G. definition of knowledge that builds on the truth of a belief as a (externally?) validated element. Outside of maths, science does not do this as there is indeed no entity that can validate our beliefs. Indeed it is the problem of validation that brings me to the second problem I have with the O.G. definition.
Science does not validate nor does it give justifications. Science refutes what is wrong. Just as our brain's main job is to forget and a firm's strategy is to choose what not to do, science gets us closer to the truth by telling us what is wrong. Scientists never get a pad in the back and a realization that they were right, just the Schadenfreude that others were "more wrong" than them.
<parenthesis> And, isn't this what knowledge is all about in a social context? A way of testing whether I am more right than you? It does not have to be perfect, just as economic markets do not need to be efficient just to clear. Knowledge should just provide a foundation for socializing beliefs and pushing forward. Indeed, a contribution to an open conversation has always been a key argument to push a paper forward in the review process. And yes, I know this social epistemological view is novel and debated. Yet, I think it is also true. We live in a post-truth society, where the social elements of knowledge (i.e. who told me?) are valued more strongly than the facts (i.e. did it seem justified?). Post-truth has a bad connotation. But personally, I find it laughable to imagine that someone thought they lived in a truth-based society at any moment of their life. It might be the fact that I know how the sausage of knowledge is put together, that brings my cynicism, but I can try to explain my view more succinctly. </parenthesis>
To me, knowledge is any not yet falsified falsifiable belief. This definition is isomorphic with the definition and process of creating knowledge in science. The scientific method starts with a hypothesis. Hypotheses need to be falsifiable, this is the dividing element of Popper's division between science and pseudoscience. After data is collected about a hypothesis and it fails to be rejected it becomes part of the researchers' knowledge. But only after it is socialized is this knowledge important to science as a whole. With time and if relevant, other scientists will replicate the experiments used to test the hypothesis. These replications won't be one to one and thus the boundary conditions and relevance of the hypothesis will be put to test. Eventually, the hypothesis and others around it will become a theory, our society's most accurate understanding of an aspect of our world.
However, if an experiment is built that falsifies the original hypothesis, then the whole edifice falls apart. Indeed is the lack of falsification of a falsifiable belief that builds our knowledge, not truth, nor justifiability. What builds knowledge is the process of gathering data and getting closer to the truth.
PS: This post just paraphrases VSauce2's video titled: "You don't know time" and posted on July 15, 2020..