I guess that (in the 21st century) I'm tired of YEC so I'd like to discuss the smoking-gun arguments that nail the coffin shut on YEC.
I've always thought that one argument that achieves that is the presence of footprints within rock layers. I can't see any possible way that a year-long flood could result in footprints within rock layers? And a similar problem for YEC would be to have footprints found at different layers (even if they are at different sites).
To believe it's possible to have such things, they'd have to argue that animals were walking around under (at least) thousands of feet of water to leave footprints in soft material, and then the animals drifted off somewhere so that higher layers of sediment would float down to cover the footprints etc., and then somehow the whole lot got to be covered with so much sediment and water that the pressure somehow turned everything to rock. Of course it's ridiculous, but that's the level that YECists have to descend to support their nonsense.
Well, time to fight back. We should be able to come up with a set of examples that are impossible to refute.
To that end, what are some examples of footprints that have been discovered within rock layers? Especially good would be to have examples where there are many layers below the footprints. Video of someone chipping away a rock layer to expose tracks in a layer below would be the best (although that might be pretty rare?).
I also believe that the gene-producing-vitamin-C mutation found in humans and chimpanzees (amongst others) but not in the (for example) lemur is a smoking gun again creationism in general. Why would "god" create the vitamin-C-producing gene and then turn it off in some animals but not others?
Another example might be the fact that it's impossible to get the genetic characteristics and diversity of humans found today based on the nonsense concept that there were only eight humans (after the so-called flood) about 4,500 years ago.
I would really like to hear/discuss other arguments that nail the coffin shut. Please play devil's advocate because we can't leave any parts of the coffin lid flapping open.
Can we create a list of succinctly-stated smoking guns with plenty of examples, evidence and references? We should be able to document those in a way that the layman can read and understand. Happy to help where I can.
