In my worlds vaguely like this (very, very vaguely, so don't worry about idea-borrowing :D ) I have it be simply due to population pressure and/or mobility. If there are too many people in too small a space, magic stops working for them, or alternatively stops working *predictably* (sort of due to an overload/failsafe); once humanity spreads out again, magic starts being relevant again.
Also, in a slightly different sphere, I had my magic users be strongly linked to a spirit of place. That is, a magic user who has moved around a lot in their life, who isn't living on lands bred into them at least a generation or two, or whose ancestral lands have been heavily altered, can't access their magic anymore. So the more mobile society gets (and this started being widespread in Western Europe in the 18th century with the clearances and enclosure acts, and of course in America pretty much since the beginning of White settlement), the less magic there is. Give us a few generations with limited mobility, magic comes back (this might not work with your plot, though.)
Other possibilities, depending on when you're setting your end-of-magic: Radio (which is basically all cell phones are anyway.) Electricity. Speed of communication (reliable, fast communication - whether it's a telegraph or just runners on good roads - changes the way humans interact *so much*.) Fossil fuels being burnt (which would go back to coal, again in the early 18th century/a bit before). Magic users needing their tools (including, say, their clothing and their workspace) to be hand-made from raw materials under controlled circumstances, so that a factory-manufacture culture makes magic very difficult. A vaccine, or a pandemic illness that remains dormant in the nervous system, possibly, could block magic access, and with less travel and communication it could die out in the population (or maybe even that it's a genetic thing that just bred out, if it's gene-linked to something that makes living in a citified culture very difficult, like unblockable psi or multiple chemical sensitivity or something.) Or how about magic that's linked to biodiversity? The less different types of non-human life around you, the less magic there is to use, and the Holocene Mass Extinction event has been picking up momentum for 10,000 years - and the agricultural revolution loves its monocultures.
You are taking into account that pretty much anything that fits your story - except possibly an astronomical conjunction - would've affected the industrialized/post-industrialized parts of the world way disproportionately, right? So that significant parts of the world's population will still have their magic all the way through.
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Date: 2010-12-29 05:28 am (UTC)Also, in a slightly different sphere, I had my magic users be strongly linked to a spirit of place. That is, a magic user who has moved around a lot in their life, who isn't living on lands bred into them at least a generation or two, or whose ancestral lands have been heavily altered, can't access their magic anymore. So the more mobile society gets (and this started being widespread in Western Europe in the 18th century with the clearances and enclosure acts, and of course in America pretty much since the beginning of White settlement), the less magic there is. Give us a few generations with limited mobility, magic comes back (this might not work with your plot, though.)
Other possibilities, depending on when you're setting your end-of-magic: Radio (which is basically all cell phones are anyway.) Electricity. Speed of communication (reliable, fast communication - whether it's a telegraph or just runners on good roads - changes the way humans interact *so much*.) Fossil fuels being burnt (which would go back to coal, again in the early 18th century/a bit before). Magic users needing their tools (including, say, their clothing and their workspace) to be hand-made from raw materials under controlled circumstances, so that a factory-manufacture culture makes magic very difficult. A vaccine, or a pandemic illness that remains dormant in the nervous system, possibly, could block magic access, and with less travel and communication it could die out in the population (or maybe even that it's a genetic thing that just bred out, if it's gene-linked to something that makes living in a citified culture very difficult, like unblockable psi or multiple chemical sensitivity or something.) Or how about magic that's linked to biodiversity? The less different types of non-human life around you, the less magic there is to use, and the Holocene Mass Extinction event has been picking up momentum for 10,000 years - and the agricultural revolution loves its monocultures.
You are taking into account that pretty much anything that fits your story - except possibly an astronomical conjunction - would've affected the industrialized/post-industrialized parts of the world way disproportionately, right? So that significant parts of the world's population will still have their magic all the way through.