A general observation I have made is that creationists misrepresent how the scientific method works, either purposefully or unknowingly. One of the big hangups they seem to have is the relationship between hypothesis, observation, and repeatabilityThis is the usual abstract statement that sounds like it means something in answer to what I've said but it only succeeds in garbling the issues further. I can't imagine that I ever said anything to suggest I make the mistakes he's imputing to creationists. But again, the statement is so abstract it's hard to know what he's saying or if it applies to anything I said or anyone said or in fact anything that is done in science by anybody.
For those of us familiar with the scientific method, we know that repeatability refers to the data/observations. For people like Faith, they think repeatability refers to the hypothesis. They think that in order for a hypothesis to be scientific you need to be able to observe the hypothesis in action multiple times.
Of course, you don't observe the hypothesis. You test the hypothesis. Nowhere in the scientific method is there an expiration date on valid observations. A 100 million year old fossil is as valid a piece of evidence as a 1 hour old ELISA plate. Both are repeatable observations, and both can be used to test hypotheses.
What I'm trying to say about the unwitnessed or prehistoric past is that there is no witness IN the past to confirm the interpretation/hypothesis of the observations made in the present about a phenomenon that occurred in the past. No historical documents, no landmark with ancient writing, nothing. With material in the present, a repeatable experiment in physics or chemistry perhaps, or clues to a crime committed within historical time even, there is no such problem. You have multiple witnesses to the events being studied. This is also true in the case of ancient bones of an unknown animal, which Dr. A kept insisting falsifies my claims, but it doesn't if all you are doing is reconstructing this creature from its bones because you have enough actual material for that job and anyone who understands principles of anatomy could do it. The problems with the prehistoric past that I'm trying to keep in view enter when you speculate about events in time: nwhen it lived, what other creatures occupied the planet at the same time, what the weather was like at that time and so on.
So the problems have to do with TIME and with EVENTS in the past, and all that can only be speculative. Events in the past are not repeatable in the present. All you have with respect to EVENTS in the prehistoric past is speculations and interpretations from the point of view of witnesses in the present. In the case of reconstructing time periods in the distant past from the rock layers, first you have the assumption that the layer represents a particular time period, and that's the first thing you can't confirm, that has to remain a speculation or hypothesis.
Then once you've accepted this unconfirmable hypothesis you go on to compound the problem of unconfirmability / untestability by assuming the contents of the rock can reveal the planetary environment of the supposed time period in which the bones supposedly originated. You assume that whatever other fossils are found in that same rock can tell you what other creatures lived during that time period, and plant fossils in particular suggest what sort of climate prevailed, and so on. All based on the unconfirmable assumption that the rock represents a time period, and apparently a worldwide time period at that.
All this was assumed even before radiometric dating came along to confirm the supposed ages of the rocks, in some cases setting them back even further in time. And here's a point I also keep trying to make. These dating methods also can't be confirmed from the past itself because there is no "witness" from that past to confirm their conclusions. The order of the fossils LOOKS convincing, and so does the apparent order derived from radiometric dating, but none of it can be confirmed for sure. It remains speculative. All the more so since the sedimentary rocks themselves can't be dated but only volcanic material that occurs in proximity to them. AND that the results obtained are not as consistent as they often like to claim either.
I'd like to think this clears up a misconception but I know from experience that it isn't going to happen.
UPDATE: And of course I was right. And all I'm going to say here on the subject is that I thought I did answer the weird complaint that I'd somehow forgotten that nobody witnessed the formation of the Grand Canyon either. But in any case so what? I didn't say you can't do science on the unwitnessed past, all I said was that you can't be sure of your results with one-time unwitnessed past events the way you can with replicable testable phenomena and that all you have in such a case is interpretations and hypotheses, more or less plausibility thereof.
Oh, and I also never said that you can't know SOME things about the past. Dinosaur footprints are like Stegosaurus bones, you can show that they are indeed dinosaur footprints. But that in itself isn't what you want to know, which is how and when they got there, and for that all you have is hypotheses.