Worldbuilding and the Post-Apocolyptic story

I'm on vacation this week, so here are some thoughts on worldbuilding. BTW, there's still time to sign up for my worldbuilding class: http://www.karinafabian.com/index.php?name=Content&pid=24

Every now and then in a worldbuilding class, or when people talk about their sci-fi, you'll hear a story that postulates a "mad Max" world. There's been a nuclear war (or some environmental catastrophe) and the entire world has degenerated to a pre-industrial state with horribly mutated humans and people again having to relearn technology...

I tend to cringe at these stories from a worldbuilding point of view, because I don't think the logic fits. Yesterday, Rob (my sweet husband) sent me some photos that show exactly why:

Hiroshima 64 years ago, when we dropped the bomb:




Hiroshima today:




Genetic mutations from radiation? Here are two articles from a 3-minute Google search:

More apparent in Chernobyl than Hiroshima (see last couple of paragraphs at http://news.bbc.co.uk/2/hi/health/medical_notes/461921.stm)

Here's a nice in-depth look at the effects of the bombs on Hiroshima and Nagasaki. What I got from it was that the effect was devastating for those exposed to the radiation of the blast and fallout--including the unborn. However, later generations were not affected.

The human race bounces back--technologically and biologically. "Blast them into the Stone Age" really is just a saying, IMHO.

My point here isn't to dis someone's story--Mad Max can be fun--but if you're writing a post-apocolyptic world that you want people to believe in, you're going to need to do some serious research and some real thinking about what it would take to knock us so low.