Nikola Tesla hypothesized about the use of directed energy weapons back in the 19th century. He even offered to build them for the government, of course they refused and then stole his research notes after he died.
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A bit later in 1940 he offered for 3 million dollars to build a device which could knock every plane out of the sky within a 200 mile radius and would take 3 months to make,he never got the funding-then of course 1 year later Pearl Harbour happened,we now know what he was on about an emp weapon,like
THIS-STARTING AT $400