Gettiers in software engineering (2019)

Physics has kinda-solved what it means to know something.

- JTB is not enough, for something to be “true” it needs _testability_. In other words, make a prediction from your knowledge-under-test which would be novel information (for example, “we’ll find fresh cow dung in the field”). - nothing is really ever considered “true”, there’s only theories that describe reality increasingly correctly

In fact, physics did away with the J: it doesn’t matter that your belief is justified if it’s tested. You could make up a theory with zero justification (which doesn’t contradict existing knowledge ofc), make predictions and if they’re tested, that’s still knowledge. The J is just the way that beliefs are formed (inference)

Testability as you describe it seems to give you more than just knowledge, but also some amount of understanding: understanding of consequences (not necessarily understanding of causes) — you mentioned the ability to make predictions about the consequences of actions (e.g. 'tests'). (Aside: it seems that you can say you know something, it's a narrow enough concept to be sharp, while understanding something can only ever be true to a degree: it's broad without limit!)

But you may have conflated 'testability' and 'tested'. Can I know there is a cow in the field if I don't check? Seeing it was already evidence, testing just collects more evidence, so how can that matter? Should we set a certainty threshold on knowledge? Could be reasonable.

Maybe prediction-making is too strong to be necessary for 'knowing', if we allow knowing some fact in a domain of knowledge of which you're otherwise clueless. Although very reasonable to not call this knowledge. Suppose I learn of an mathematical theorem in a field that's so unfamiliar that I can't collect evidence to independently gain confidence in it.