That all said, I still don’t see why a microwave beam weapon is implausible in principle. It might not be the most practical thing ever - that’s why I compared it to polonium and ricin. But for example, using a parabolic reflector you can focus microwaves over the kind of distance between two buildings perhaps across the street from each other. If the beam only has a diameter of a few feet at the target, and only used for a short period, how is that going to be detected? You’d aim it at someone’s head visible through a window, for example, and the source of the beam could be behind a closed window with a curtain.
Btw this subthread seems to have been removed from the OP page at this point, apparently because the comment I replied to was flagged.
We all have fairly compact devices in our kitchens which, if you were to put your head in them and press the start button, would literally cook your brain.
Why wouldn’t a directed version of that make practical sense? Just because it’d be bulky compared to a gun? But that would depend on what you were trying to achieve. Killing people with polonium or ricin isn’t the most efficient approach either, but it’s been done.
Note that I’m not saying that’s what happened in the Havana case. Just questioning the statement I quoted.