And having skimmed a bit more of the posts that were written since I last logged in, I am not sure if anyone has made the following point yet.
There seems to be some confusion about facts and theories and how that ties in with evolution, cosmology, and science in general. For example, the observation that if you throw a rock, it describes a parabolic arc before hitting the ground (unless you can throw it really, really hard and have it enter low earth orbit) is a fact. The observation that most of the observable mass in the universe is moving away from our perspective is a fact. The observation that certain fossils are always found in certain strata and can be lined up to show changes within a lineage of an organism is a fact.
What a scientist does is take all of these facts and use them to construct a theory such as Newtonian gravity, the Inflationary theory, or the theory of natural selection. So far, this can all be dismissed as idle speculation, as David Henson and Hovind do, but that is because they do not move on to the next step in the scientific method: testing the theory.
You see, any theory worth the pixels used to explain it not only shows how the facts fit together, but also allows you to make predictions about future observations. The scientist can then design an experiment to test these predictions (much like the fertilizer example given earlier). The results of the experiment either weaken or strengthen the theory. So, for example, accurate observations of Mercury weakened the Newtonian theory of gravity since the predictions made by the theory didn't match the observations. Enter Einstein.
To date, all of the experiments and predictions made based on the current theory of evolution have only strengthened the theory, not weakened it. As others have mentioned, there are observations that could be made that would weaken it, but as of yet, those observations have not been made. As long as we keep testing Relativity, the Inflationary Theory (a much more accurate term than Big Bang), and the Theory of Evolution and they keep passing, we can accept these as being strong theories and models of reality.
