If the polarity of our Earth magnetic field were to flip (oscillate) at around 1 GHz or 1 billion cycles per second, would it spell disaster to fauna and flora that depends on it for navigation like hunting for found or in search of potential mates? Would such an event throw us (the modern human civilization) back a few decades? I'm imagining what the needle inside the compass is doing...

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    $\begingroup$ Water magnetic resonance is 2.45 GHz, so you are kinda close to making Earth a giant microwave. By the way, where is this energy supposed to come from? And for needle in compass, this would do nothing, it is way too heavy to react to 1 GHz radio wave. $\endgroup$
    – Mołot
    Commented May 7, 2018 at 8:48
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    $\begingroup$ You just ran into the "Hi, I have a High-Concept" trap. Apart from that: what @Mołot just said... flipping does not happen by itself. It takes enormous amount of energy to reverse the processes that cause the magnetic field. Where is that coming from? $\endgroup$
    – MichaelK
    Commented May 7, 2018 at 8:56
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    $\begingroup$ Wanting to know where the energy to cause the geomagnetic field to oscillate at GHz comes from is irrelevant to the OP's actual question. It deals with three related areas of potential impact. Perhaps it might be restricted further, that's often according to taste. $\endgroup$
    – a4android
    Commented May 7, 2018 at 12:36
  • $\begingroup$ You know that that's kinda how an electric stove works, right? $\endgroup$ Commented May 7, 2018 at 12:48
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    $\begingroup$ You need to narrow it down. Chose between animals or humans. You can only save one. Chose wisely. $\endgroup$
    – Vincent
    Commented May 7, 2018 at 18:52

2 Answers 2


Assuming a uncaring god was fiddling with the developer settings in Sid Moider's Earth™ III:

Electronics will catch fire first, life would be extinct within hours and the oceans will boil soon enough. Mołot is right: a GHz turns the earth into a giant microwave. All that energy will need to dissipate somehow and the easiest thing will be all the highly conductive things on the surface (also known as "life").

I'm not good enough with physics to calculate this right now, too many variables involved. It seems that even at a Ghz the power would be several orders of magnitude smaller than a microwave but that will still boil everything within days.

https://en.wikipedia.org/wiki/Dielectric_heating for the mechanism https://electronics.stackexchange.com/questions/339481/how-strong-is-the-electrical-field-inside-a-microwave-oven for another stackexchanger who did a lot of calculations.


At current 3 Hz fluctuation (which is only a percent of field magnitude, and you don't need to actually flip poles to cause power output - you need magnitude change!) power of field is in reality measured by nanowatts per square meter. It scales up with square of amplitude and proportional to e in power of frequency. Level of microwave power output on surface would become watts, which is dangerous even if not on level of microwave oven, but that's on surface! Surface is not where planet's field is the strongest!

Magnetic field is what creates radiation belt and hold ionosphere in grip of planet. Planet would be baked by sun radiation bursts during pole change and world-wide electric storms, everything manmade on orbit would be irradiated and flung away/slammed by torn protuberances of ionosphere.

Even just changeing poles once is exinction event, because it provides a period of intermediate absense of defense. Turning planet into what amounts to pulsar star signs extinction event on scale of solar system


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