Anything Can Be Taken Too Far.
That means that I live in a world of invisible forces (gravity, for example) but those forces obey certain fairly well sussed out rules. If I drop my pencil, and there are no elaborate measures in place to affect it, it's gonna drop and hit the floor. (Then, it will probably roll under something that's really inconvenient to move so that I have trouble getting my pencil back, but that's a different issue entirely.)
I don't live in a world where some Zeus-like guy with a beard can stop the world for a few days so his precious worshippers can fight their battle all at once. Why don't I live in that world? Because I'm reasonably sure that that's impossible. I've never seen evidence of anything "supernatural" that couldn't be explained by an application of those aforementioned invisible forces. So, being a skeptic, that means that until I see something that violates the established rules of phyics, I'm gonna stay a skeptic.
But, Cor, you say, there are no "rules of phyics"! The universe doesn't have rules written down somewhere. How can you talk about there being rules when we can never really say for sure that there's not something somewhere that, naturally, violates what we think of as the "rules of phyics"?
Simple. I ignore the fact that the Theory of Gravity may be violated some day.
That's right. I ignore it. On a macroscopic, real world, keep-me-in-my-chair level, I can reasonably say that the Theory of Gravity is a "rule". After all, if it didn't hold true, then the Earth would either plunge into the Sun or wander off into interstellar space. Since that hasn't happened yet, I can be reasonably assured that it's not going to happen tomorrow.
Now, this applies to all the scientific "rules" out there. Avogadro's Law? Falsifiable, and therefore subject to someday failing. We may someday find a gas that doesn't have the same number of molecules per a given volumen as hydrogen, but we haven't yet. And we probably never will. If we do, it probably won't be normal matter anyway, so the same rules wouldn't apply. The Moon has yet to crash into my house. It probably will stay in the sky tonight, as well.
Does that mean that there is zero chance of it happening? Of course not. We don't live in a deterministic universe (I think....the jury's still out about that one), so there's always a chance for something to happen. As Douglas Adams once wrote (in Hitchhicker's, of course) "Nothing is impossible, just highly improbable." Does that mean that I'm going to walk around doing a Chicken Little act? No.
So, to all you skeptics out there who are going overboard with the "I'm a skeptic so I don't accept the validity of any statement without massive qualifiers" act, STOP IT. I'm not an intellectual cripple. I understand that we can only give conditional and temporary agreement to any scientific theory, law, rule, whathaveyou, because it may some day be falsified. But I refuse to bog my conversations down with massive strings of qualifiers when they aren't necessary. If we're discussing the nature of science itself, then yes, by all means, load up the qualifiers. It doesn't hurt to be reminded now and again. But when I'm discussing something as self-evident as the continuance of gravity, then don't presume to tell me that the Theory of Gravity is falsifiable, and therefore we can't accept it at face value. The last time I checked, I don't float to work. I have to move against the forces pulling me towards the surface of the Earth.
This extends to all the "rules of physics" and all the scientific theories (of which there aren't really that many) currently extant. When we talk about the Theory of Evolution, I realize that someday it may be disproved (Creationist Alert: No quote-mining, you vultures) but I doubt it. If it is, I'd love to see the evidence, because that would have to be a literal mountain of evidence. But I can sleep at night, snug and warm in my bed, knowing that I can be reasonably sure that I won't float out of it at night and that each generation is a bit different from the last, driving species change, etc. etc. etc.
I had this discussion with a friend of mine recently, and he brought up "spontaneous generation" as being just as self-evident to the people who subscribed to it as evolution is to us. He said that to them, life from decaying matter was self-evident, until it was disproven. And that's a good point. To us, the Theories of Gravity and Evolution seem pretty constant, with only minor modifications occuring as we refine our data. And I freely admit that we could be way off-base. I might just float right out of this chair. We may find some species that has Lamarckian heredity. But I doubt it.
And here's why: "spontaneous generation" was arrived at by laziness. That's right. Aristotle was a lazy old cuss on this issue. He never checked out any of his claims. He just observed the world, and came up with a hypothesis, which he never tested. At least I can't find where he performed any tests. (If someone can correct me, I'd like to see it.) So, he put forward as a "scientific theory" something that had very little evidence to support it, was not predictive and had never been tested. So, my response to my friend is that "spontaneous generation" may have been self-evident to the people who believed it, but so is astrology. That doesn't mean that either of them are backed up by real evidence. Quite the contrary, in fact.
And that's the cool thing about science. As we progressed in our testing ability, so too does our understanding of the world progress. Once spontaneous generation had the scientific method applied to it, it folded like a house of cards. Astrology does, too. (If only we could stamp it out like spontaneous generation!) That's a far cry from Gravity or Evolution. The more rigorously we test and search for evidence to falsify them, the more rock-solid they become, because you just can't realistically knock 'em down.
So, all you skeptic posers out there, drop the sanctimonious claptrap "in the name of accuracy". If I put my hand on my desk, I can be reasonably sure it's not gonna pass through without meeting resistance. h-bar's value just won't allow it.
Get over it.