On February 4, 2014, Science Guy Bill Nye debated Creation Science Guy Ken Ham. The event lasted over two hours. A day later, Mark Stern argued in Slate Magazine that Mr. Nye had lost the debate when he showed up. Mr. Nye must have known that facts will not shake the faith of a zealot and that members of the audience, exposed to two articulate advocates, will fortify the beliefs they brought to the auditorium. Mr. Nye played along and patiently followed the script that was laid out for him; he tried to argue from the evidence. Anything he could offer as evidence refuting a literal reading of Genesis, Mr. Ham would dismiss as inconclusive, given his assertion that evidence is irrelevant for an understanding of the past. This assertion amounts to an a priori commitment to the idea that evidence challenging Genesis cannot exist. Once this is made clear, why would Mr. Nye keep talking?
Mr. Nye is nice. He respects the power of evidence. Mr. Ham entrapped him by challenging him to produce ever more evidence, only to then claim again that this evidence is not good enough. Mr. Nye should have claimed the initiative. He could have asked Mr. Ham what kind of evidence might get him to doubt the literal truth of Genesis. Mr. Ham would not have offered a definition of such evidence (and to say that he would accept God speaking out of a cloud, saying that He didn’t really mean it because He wrote Genesis during a bout of back pain, does not count; why should it?). If Mr. Ham concedes that all evidence questioning Genesis is irrelevant, the debate over Genesis-challenging evidence is over. Mr. Ham could be asked what evidence there is for the literal truth of Genesis. Mr. Ham did suggest that there is some evidence supporting Genesis (e.g. the genetic similarity of all humans), but to say that there is supporting evidence means nothing if you are on record as saying that this is the only type of evidence that can possibly exist (by the way, the genetic similarity of contemporary humans—not extinct species of hominids—is also compatible with evolution).
Mr. Ham therefore had to move on and appeal to divine revelation. But why would he believe anything that claims to be divine revelation, and why would he believe this particular one? After Abraham, believing a presumed divine revelation is not what it used to be. God—I think—has not spoken to Mr. Ham himself. Mr. Ham has no direct access to divine revelation; he has access to a text, which the people around him claim is divine—and they say so because they were told by others, and so on. Mr. Ham’s faith is a social product. He has no direct evidence for the text being an eyewitness account and for the eyewitness being truthful. Mr. Ham should be challenged to explain why the creation story in Genesis (or the two creation stories, if you read the text carefully) is the only valid one. Wikipedia lists about 100 different creation myths. Why not believe the creation myth of the Mapuche (Chile) or the Mande (West Africa)? What if Mr. Ham did not debate a nice scientist like Mr. Nye, but an equally zealous advocate of the Hindu creation myth? Then Mr. Ham would have to argue that his revelation is truer than the Brahman’s—who would presumably return the favor. Their stalemate would reveal (as it were) the staleness of their belief systems. To them, evidence counts for nothing, and that’s why their beliefs should not be confused with science.
Note. Mr. Ham's debate strategy was a Gish Gallop designed to drown Mr. Nye in a flood of claims too big to be refuted in its entirety in the time available. If just one claim remains unrefuted, the galloper claims victory. It's Popper's principle of falsification turned on its head.