Technology’s unintended consequences are things we have learned to be cautious about because they’ve frequently been unfortunate. Here’s one that seems to be working in our favor. Our civilization emits radio waves. The expectation is that the worst consequence would be some malevolent alien intelligence would track us down from our signal. (Possible, but highly improbable because our signals are weak and space is really big.) A nearer threat is solar radiation and high energy particles. Earth’s natural magnetosphere and van Allen belts divert some of that energy – and now appears to be diverting more because of the radio waves. Our radio waves and the van Allen belts are interacting to create an electric shield around the planet, protecting it from more energetic particles. If we tried to design such a system, we’d probably debate it for a long time before getting around to testing it. But, we did it. So, congratulate ourselves on building a shield that we probably didn’t realize we needed, that we could build, that could work so easily.
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