"We'd feel it first in the economy and our financial institutions, where everything is digital. Markets will collapse," says Siciliano. "Where's everything backed up -- in a filing cabinet? The economy would collapse, the banks would lock their doors and keep whatever money they had in the vault, because the rest has evaporated into thin air. Once the money's gone, we're resetting the clock."
How long to recover: Unknown. According to a January 2009 report by the National Academy of Sciences, the effects of a severe geomagnetic storm would be felt for years, most acutely in societies that are the most dependent on technology. The U.S. could take from four to 10 years to bounce back, according to the NAS -- if it bounces back at all.
"It will take a tremendous amount of manpower to clean up the mess," adds Siciliano. "Something that catastrophic, the gas pumps won't be operating, so a guy who's supposed to take a part to repair a facility can't get there because he has no gas. It could literally throw us back to 1840. Suddenly we're a third-world country again."
How likely is this to occur: Lord only knows. But consider this, says Irv Schlanger, an assistant professor in Drexel University's Computing and Security Technology program.
"We are all familiar with the 11-year solar flare cycle," says Schlanger. "What most people are not aware of is the 110-year solar flare cycle. The 110-year cycle is massive when compared to the 11-year cycle. The affects of the 110-year cycle would be very similar to that of a nuclear EMP. We are currently due for the 110-year solar flare."
How to avoid this fate: Silent prayer to the deity of your choice.
"Manmade terrorist activity is bad, but as we've seen lately, Mother Nature is a bitch," says Siciliano. "She doesn't give a damn about you or me."
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This story, "Tech apocalypse: Five doomsday scenarios for IT," was originally published at InfoWorld.com. Keep up with everyday tech calamities and comedies with Robert X. Cringely's Notes from the Fields blog at InfoWorld.com.