Well, no. That claim is not true in a way that it's formulated. You may not thought through example, or you assumed that I'll fill in the blanks in your intended meaning, but:
Again not a trick question. To your point, we know how to calculate gravity with respect to two bodies of mass.
1) All objects don't fall towards Earth, especially if they are outside of reach of Earth gravity. I certainly suspect that you've meant to say "in reach of Earth's gravity", but I'm pointing this out to show you that knowledge is a contextual concept.
I never said "all." That was your erroneous assumption.
Gravitational calculations can be derived with respect to any environment.
2) You can't really demonstrate that ALL objects fall to Earth at that rate. We don't have access to all objects in the Universe to test that claim. Even if we did, it would take quite a bit of time to go through all of them.
That's the benefit of models having predictive capabilities, measuring the gravitational pull of all objects is unnecessary. A sound plane built in Russia will travel to the U.S., and vice versa.
All you can do in this case is test a few and make a generalized pragmatic assumption.
Incorrect, as 9.81m/s/s is independently verified and found so sound, that at this point in time, it is no longer considered scientific theory, but a "law."
Thus, knowledge can't always be demonstrable apart from our presuppositions and identity labels we can point to.
Knowledge is always demonstrable, otherwise we refer to it as an unfounded claim. Either I have knowledge of purple pixies farting universes into existence, or I don't.
Nevertheless, let's move on to the next one, because it's more dense of an assumption.
Whenever you're ready.
First of all, I'm not sure how you jump from "we can know something" all the way to scientific models and fallibility principle. You are missing quite a few books-on-epistemology-seized gaps in there.
Adding "quite a few books-on-epistemology-seized[sic] gaps in there," doesn't make our basal fundamental assumptions any less prescient.
Secondly, such assumption was not in play until Popper came along in 1900s. Such idea was not an inherent assumption of scientific or philosophical thought. In fact, plenty of scientists to this day don't make such assumption, and instead argue that it should be retired as as a methodological presupposition. Take Sean Carol, for example.
Edge.org
Great link. I like Sean Carol a lot.
"The falsifiability criterion gestures toward something true and important about science, but it is a blunt instrument in a situation that calls for subtlety and precision. It is better to emphasize two more central features of good scientific theories: they are
definite, and they are
empirical.
By "definite" we simply mean that they say something clear and unambiguous about how reality functions."
The above quote doesn't bode well for those making god claims, does it?
(emphasis mine)
But, before we even get to scientific methodology...
1) I hate to be a stickler for precision, but "describing reality"? Reality is an abstract concept for everything that exists... even something that we may not be aware of as of yet. We can't "describe reality", just like you can't "describe freedom". It's an abstract concept. You can use it as a shortcut to say "everything that exists", but what we end up describing are isolated objects or processes that we assume are real. Reality is too broad to describe. Again, I suspect I understand what you likely mean by "describing reality".
Which scenario better describes reality, in your opinion:
1. People who intentionally seek to illegally defraud the IRS, risk being prosecuted for it, and possibly spending time in jail.
2. People who intentionally seek to defraud the IRS, risk being rewarded with an annual income of @300K per year, for the rest of their life, tax free.
2) Let's grant that you meant just that . Just like Carol, I would disagree with such presupposition without prefacing it with "Generally, but not always". It's a generally good concept, but it can't possibly be applied to all fields of research.
Other than theoretical physics, please describe a situation in which a model making unpredictable predictions is preferred.
Much of our interpretation of history is neither independently verifiable, not it is falsifiable.
Like Jesus Christ rising from the dead? All we can do is provide likely explanations, those that comport with reality. In the case of a dead man resurrecting, well, as they say, extraordinary claims require...
Likewise, many historical models are viewed in hind-sight, so demanding prediction is somewhat futile.
You fail to understand what having "predictive value" means. For instance, when an ancient text claims that millions of Hebrews were lost in a ten square mile of desert for forty years, yet zero archaeological evidence exists to support such a claim, the claim can be considered as having zero predictive capabilities.
In most cases we are limited to subjective accounts of events, but we have no means to independently corroborating those apart from the authors who record these.
Which is why science is better than religion for predicting reality, as it doesn't depend on one person alone. This is what "independently objectively verifiable" means.
The same goes for a wide variety of sciences that rely on complex data to formulate hypotheses and theories... psychology, sociology, linguistics, etc.
I agree that it's a good principle to follow. I disagree that it's absolute to the point of the necessity to canonize it as axiom, especially when it comes to broader scope of research and claims that would be difficult to examine.
Which is why Hume's Maxim and the like are necessary, lest we get carried away and suggest Thor throws lightning bolts from the heavens.