@jman777: hi there, thanks for bringing up this interesting subject. I'm a physicist working in cosmology and astrophysics, and I'd like to clarify a few things concerning C-14 dating and the Big Bang, if you don't mind. I’d like to apologize in advance for the length of this post.
First of all, carbon-14 dating is used to date biological remnants, not rocks. I haven't looked at WhiteSammy's link, but I'm pretty sure it says the same thing there. It basically measures the amount of the radioactive carbon-isotope carbon-14 in the physical remains of a once-living biological organism. Every living organism on Earth accumulates a small amount of carbon-14 in their cells (along with many other isotopes of carbon, but they're less interesting in this respect) through their normal metabolism, and when the organism dies, the intake of carbon-14 ends, for obvious reasons. Since carbon-14 is radioactive, the amount of the isotope in the organism slowly diminishes through radioactive decay, and this decay rate is well-known through laboratory experiments. By measuring how much or how little of the isotope remains in an organism one can determine how long time has passed since the organism died. The older the physical remains of the organism are the less accurate the method becomes and for remains older than 50,000 years it's basically useless.
The method that I think you meant to refer to is radiometric dating of rocks. It works by a somewhat similar principle, in that it measures the amount of certain radioactive isotopes and their associated decay products in rocks. However, in this case there’s not just one isotope that can be measured but many isotopes of many different elements and they all give the same result: provided the rocks were formed when the Earth formed, our planet is (at least) several billion years old. The exact number of billion of years depends on the particulars of stratigraphy and the processes of rock formation, but even when applying the widest possible margins of error it’s safe to say that the claim that the age of the Earth is in the vicinity of 6,000 years is off by several orders of magnitude and quite simply wrong. The fact that many different isotopes from samples from many different locations all around the globe give the same general result independently of each other should be considered quite compelling evidence to this effect.
I wish to emphasize one thing here: the physical process of radioactive decay and the specific decay rates of the isotopes in question are known to a great degree of accuracy and have been tested over and over again in laboratory experiments since the discovery of radioactivity some 100 years ago. The understanding of these phenomena is also the basis of nuclear power and nuclear weaponry - both endeavours that really doesn't allow for much inaccuracy, if you understand what I mean ;) In other words, there's absolutely nothing inaccurate or poorly understood about radioactive decay, carbon-14 dating or radiometric dating of rocks. It's about as solid as it gets in science, and that's pretty solid. I believe the rest of the scientific community would be extremely interested in hearing more about those incidences of inaccuracy that you claim to have heard of, since they would go contrary to anything we've ever seen or heard of. Indeed, if you're right, it would be safe to say that it's a discovery worth a Nobel prize, so I would be very grateful if you would share the info with me in person ;) I would also like to emphasize that the postulate that the rate of radioactive decay, not just of carbon-14 but of all the isotopes used to radiometrically date the Earth should somehow mysteriously be different at earlier times is completely unmotivated by observations and there’s overwhelming evidence to the contrary. To be perfectly frank, I’ve encountered these and similar claims from ID-supporters a number of times now, and the only thing it demonstrates is really a rather harrowing ignorance of the subject at hand on the part of the ID-supporters.
With respect to the Big Bang: first of all, the Big Bang is not ‘an explosion’ in the normal sense of the word, since strictly speaking an explosion is the release of energy from the rearrangement of chemical binding energies of an explosive material, usually resulting in the sudden release of a large amount of gas, the expansion of which causes a shock-wave as it propagates into the surroundings. The Big Bang, on the other hand, is an adiabatic expansion of spacetime, in which the Universe begins in a super-dense, super-hot, super-energetic state, gradually cools as a result of the expansion, and develops through a series of phase transitions and local structure forming processes into the Universe that we see today. It’s not a density expansion from a certain point in spacetime (such as a normal explosion); it’s an expansion of spacetime itself. To call this an explosion is really a misunderstanding of astronomical (pun intended ;) proportions.
The claim that the Big Bang violates the Second Law of Thermodynamics is also clearly a misconception. The early Universe can be described by fewer parameters than the current Universe can, hence in mathematical terms it was definitely more ordered / had lower entropy than the present Universe. It’s much easier, for example, to envision a simple description of the Universe just before hydrogen / helium recombination, where the Universe could basically be parametrized as a hot plasma subject to certain acoustic oscillations. This would not require many parameters to describe. Compared to that, the current Universe with all its structure, i.e. different galaxy clusters, nebulae, stars, planets and organic life, requires a far larger number of parameters (an infinity of parameters, almost) to describe. So if anything, the Second Law of Thermodynamics supports the idea of the Big Bang, not the other way round. I should emphasize, though, that to apply the Law of Entropy to the Universe as a whole is a very questionable course of action, since we do not yet have access to the full array of cosmological parameters and we don’t know if it can be considered a truly closed system, as Dexter.Morgan also wrote somewhere above.
The ‘tactic’ of claiming that the Law of Entropy contradicts the Big Bang is another clear sign of a lack of understanding of even the most basic principles of the law in question (not to mention the faulty idea that the Big Bang is ‘an explosion’). For some reason, ID-supporters never seem to grasp how devastating this is to their argumentation, and I’m sure the ID-community will go on happily using this so-called ‘argument’ for some time to come before it sinks in…
I will concede that we still don’t know the process by which the Big Bang started and what powered the initial expansion. To me, this is one of the most fascinating questions of modern physics. Our current lack of knowledge is mainly due to the fact that the energy levels at the earliest teeny-tiny fractions of the first second of the Big Bang were so vast that we have no firm understanding of the exotic physics involved and that the spatial dimensions were so small that a theory of quantum gravity needs to be developed in order to describe it. But everything since then, i.e. after the Universe had reached an age of approximately 10^-30 seconds, is really pretty well understood. It’s not like the Big Bang is one of several struggling theories, or that there’s any evidence that constitutes a problem to the theory – it’s really the only game in town and has been so since the theory of the ‘Steady State Universe’ was discarded around the end of the 1960s. By all means, feel free to enter into the ongoing scientific discussion on the subject. I’ve worked in this area for a couple of years now and believe me, there’s still plenty of heated discussions going on concerning the details of the theory, a fact for which I’m thankful, by the way! However, posing lame, obviously misunderstood and simplistic arguments like ‘the Big Bang is contradicted by the Second Law of Thermodynamics’ demonstrates a radically ignorant and conversationally unwise disregard for the last 50 years of cosmological research, so people who go ahead and pose those claims anyway should be prepared to be ridiculed.
I should mention that there are realistic candidate theories for the actual triggering mechanism behind the Big Bang, among others the so-called ekpyrotic models, which are derived from String Theory. So even though we don't know yet, we're certainly not without a clue. Due to the observational limitations mentioned above, however, these models are still far away from being testable, but I like to think we’ll get there eventually. Until then, you are of course free to claim that god pushed the button, or that the flying spaghetti monster or the fairy god mother did it for that matter, but however you bend it that’s really just intellectual defeatism, IMHO.
Sorry for the long post, I hope this has been at least a little bit helpful. If you got this far without taking a break you deserve a cookie ;)
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