Post-apocalyptic magic

[clare_dragonfly]

I have a post-apocalyptic world. (The apocalypse in question is a ten-year world war that used physical, chemical/biological, and nuclear weapons.) The world is mostly based on our own, though as it's post-apocalyptic, technology, communications, etc. are broken down and much less common than they used to be. However, now they have magic.

I've worked out that magic is a genetic trait; a long time ago, people with magic existed but were rare. Then they stopped being able to use magic. Now that the war has destroyed whatever infrastructure element kept the magic hidden and dormant, magic users--who are more resilient against modern weaponry and therefore have survived in greater numbers than they previously had--are able to use magic and out in the open again.

My problem is the infrastructure element. The original suggestion I had was cell phone towers/lines, but I think that's too recent. If magic existed up until the time cell phones were invented, the world wouldn't be all that much like ours. I want something that changed longer ago.

Other suggestions I've had are the steam engine and the printing press. The first doesn't seem insidious enough (and now that I think about it, steam engines haven't been widely used for a long time, have they?), and while the second is kind of awesome and I've worked it subtly into a short little story, it seems too nebulous. I guess it's hard to explain. I also thought of using plumbing, and having magic unable to cross running water, but I've been able to find frustratingly little on the history of plumbing, so I don't know how well it would work.

Any suggestions? Reasons one of the other things would work better than I thought? Throw 'em at me!

Comments

[azurelunatic]

What about a population per square mile density point? More people than that per area, and it doesn't work; as the planet overpopulated, the areas in which people could use magic got smaller and smaller?

[bliumchik]

This was my first thought, as well! Population size is the only vaguely linear factor that wouldn't be too obviously linked to specific technology. It also gels with witches in cottages, elves in the woods and wizards in towers, if you're planning to incorporate legends as blurred fact.