I was watching TV Sunday and forgot what channel (maybe Fox News) and an EMP expert was being interviewed regarding NK (or Russia or China) being able to use a nuke create an EMP over US that would wipe out all our advanced electronics. That is of course a serious threat to the US. It is only our ability to retaliate that prevents this from being done. (Military electronics is EMP hardened, and also many military installations are underground exactly to prevent EMC or nuke attacks.) However I thought this example of a natural EMP was interesting enough to share it with all: Note that CMEs take several days to arrive at the Earth, while it takes about 500 seconds for light from the sun to reach the Earth, so you could see this coming for quite some days.