[dreadgeek]

"...ordinarily, we think that on a factual question like the one about American prehistory, there is a way things are that is independent of us and our beliefs about it--an objective fact of the matter, as we may put it as to where the first Americans originated. We are not necessarily fact-objectivists (emphasis original) in this sense about all domains of judgement. About morality, for example, some people, philosophers included, are inclined to be relativists: they hold that there are many alternative moral codes specifying what counts as good or bad conduct, but no facts by virtue of which some of these codes are more 'correct' than any of the others...These sorts of relativism about value matters are debatable, of course, and still debated. However, even if we find them ultimately implausible they do not strike us as absurd. But on a factual question such as the one about the origins of the first Americans, we are inclined to think, surely, there is just some objective fact of the matter. We may not know what it this fact of the matter is, but, having formed an interest in the question we seek to know it..."

Paul A Boghossian -- Fear of Knowledge: Against Relativism and Constructivism

I quoted him at length because I think this goes to the core of the matter (and, quite honestly, for the purposes of this discussion I want to keep to the issue of epistemology, in part, because it's the more tractable problem). I have often wondered if people who claim that all knowledge is relative and socially constructed *really* believe that or are they saying something that they haven't thought through all the way. If the former, then one might expect folks who believe that to, say, walk off of tall buildings. If all knowledge is relative, if there really isn't a world 'out there', then gravity should be culturally constructed as well. Yet, in all cultures, and in all times, human beings have been subject to 1-G of gravity. It wasn't until, what, 1962 or 63 that a human being ever experienced weightlessness for any length of time. Our bodies are products of 1-G of gravity pulling on us and 14.5 psi pushing us down from the weight of the atmosphere.

Now, some might claim that there are other, equally valid explanations for why things fall to the ground when dropped that doesn't invoke Einsteinian gravity but I think this is a kind of dodge. Take the two models (whatever they might be) and determine which of them is best able to deal with the behavior of various systems subject to the model. For example, the Einstein model of gravity allows us to account for things like gravity lensing where a star appears somewhat out of phase from its actual location relative to us because the light from that star is bent around a large gravitational mass (and yes, the universe really does work like this. It's been confirmed numerous times from observations taken during eclipses). The only model of gravity that can explain this is Einstein's. Newton's model can't although, for most ordinary purposes, we use Newton and not Einstein. The reason being is that Newton's approximations work well enough for the kinds of purposes we typically apply gravitational physics to. However, there is an exception--GPS. Because satellites are in motion and because the Earth is *also* in motion, GPS satellites have to take into account relativistic effects or else the GPS would be off--now, for your TomTom the amount of error isn't going to matter very much (I believe it's a matter of feet) but for military and aircraft navigational applications a few feet is all the difference in the world.

No other system of knowledge can account for this--the fact that other cultures don't *have* this problem is irrelevant here. Once a culture reaches a certain level of technological sophistication, they will have a problem that looks very much like the GPS problem and the solution will have to take into account relativistic effects. That's what I mean when I talk about a world 'out there'.

Do people who believe in strong epistemic relativism think that the Earth has existed for ~ 4.5 billion years? Do they think the universe has existed for ~ 14.5 billion years? If so, who was constructing the knowledge?