What is a theory?How do we know a theory is true?
Nobody knows, and you can never know it's "true" for sure. You just gotta do that do which you can for it to do, and so do it be, thoughsomuch.
>>16972702A theory is what seeks to relate laws with observations and/or data. Theories are embedded into models, which are interpreted as explanations for how reality operates. It thus follows that a theory is true if its accounting for of observations (the explanation aspect) accurately describes what happens in reality for that data to come about, though this is just tautologically true. I would argue that unless one is dealing with a theory of everything, there are varying degrees of how true a theory is within a given context. Take Newton's ideas of motion and compare them with General Relativity. As you get closer to the speed of light, Newton's theory errs more from reality. But for automobile safety engineers and the like, his laws work just fine and are "true enough".
>>16972702Theories are things scientists make up in order to earn some shekels.Donald Trump would make a far better engineer/scientists than the rest of them since he prefers simplicity over overcomplicated, unproductive, useless "science laws".
A theory is the "how" that accompanies the "what."If you see bird poop falling from a bird's anus, and you also see bird poop lying on the ground elsewhere, then one may conclude that a bird pooped on that patch of the ground. That conclusion is your hypothesis. You may test this hypothesis by predicting that you'll find more poop in areas where birds tend to poop. After you collect sufficient evidence, you may develop a broad reaching principle that governs the world we live in: the source of bird poop is the anus of birds, so where bird poop is found indicates a place that a bird has pooped.This broad principle is your theory. It explains why there is bird poop on the ground. You can rely on it to adequately explain how the poop got there.How do we "know" it's true? That depends on your perspective on the nature of knowledge. It could very well be that there is another source of bird poop unrelated to birds. Maybe there's a fundamental source common to both birds and the ground independently. But all the evidence points to the aforementioned theory as presented and said theory has been validated for predictive power. Without any contradicting evidence or competing theory with equal or greater predictive power, the "bird poop comes from pooping birds" theory is the vest we have.
>>16972702In science, 'theory' is pretty damn solid, it's like a nuclear-powered supercarrier, almost impossible to sink. To become a theory, it has to:1) explain all observed phenomena2) predict new phenomena3) the predicted new phenomena has then been verified by testingA 'theory' does all of (1)+(2)+(3), while 'hypothesis' is just (1)+(2).The layman's use of the word 'theory', even in the best case, is about the same as the scientist's 'hypothesis'.In most everyday use it is just (1), and often fails even that.
>>16972702That's easy: all of them are false. In the end it all boils down to formalizing patterns and later discovering the conditions under which those patterns hold (which usually happens by way of the theory getting falsified).
>>16972747>>16972839>>16973125What about underdetermination?
>>16973278Only applies if there is an equally supported rival theory presented.In which case, both are observationally equivalent until one of them is falsified.
>>16973280https://en.wikipedia.org/wiki/Duhem%E2%80%93Quine_thesis