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Will the Sun's magnetic activity disrupt electronics on Earth?
It seems that solar flares are one of the few things that have any factual weight among the possible causes of a so-called 2012 event.
There is also evidence (wikipedia article) that at least one really strong solar flare did take place in the past (1859) with some practical consequences:
Telegraph systems all over Europe and North America failed, in some cases shocking telegraph operators.
--source: Wikipedia, the article just referenced
A simple search of google or youtube will probably yield you a lot of videos on the subject including some by the pop physicist Michio Kaku.
It could paralyze the economy of planet Earth.
--source: Michio Kaku, on the linked video
There's also a report on the subject authored by the Space Studies Board (SSB) the Engineering and Physical Sciences (DEPS).
The adverse effects of extreme space weather on modern technology--power grid outages, high-frequency communication blackouts, spacecraft anomalies--are well known and well documented, and the physical processes underlying space weather are also generally well understood. Less well documented and understood, however, are the potential economic and societal impacts of the disruption of critical technological systems by severe space weather.
As a first step toward determining the socioeconomic impacts of extreme space weather events and addressing the questions of space weather risk assessment and management, a public workshop was held in May 2008. The workshop brought together representatives of industry, the government, and academia to consider both direct and collateral effects of severe space weather events, the current state of the space weather services infrastructure in the United States, the needs of users of space weather data and services, and the ramifications of future technological developments for contemporary society's vulnerability to space weather. The workshop concluded with a discussion of un- or underexplored topics that would yield the greatest benefits in space weather risk management.
--source: Description of the said report
There are a lot of people (preppers: here and here) who seem to be prepared to, among other things, a solar flare-induced doomsday.
Apparently, a strong enough solar flare would render all electronic (or electric?) equipment useless thereby causing all sorts of troubles that range from mildly annoying (home appliances not working) to very unsettling (banking system collapsing, food production plummeting, governments collapsing, me being out of a job) depending upon the sort of source you get your information from.
Such scenarios are at least consistent, in my opinion, with the effects of the 1859 event.
By "should we be worried" I mean:
- can a solar flare really cause that much damage?
- if so, how likely is it that one such strong solar flare might hit us in the foreseeable future?