Death rays and high tech weapons were popular fixtures in popular fiction of the 20s and 30s, but it turns out they were also on the minds of scientists at the time, too, who strove to recreate some of scifi's most devastating weapons right here on Earth. Thanks to the PopSci archives, we can look back and laugh at the silly death rays that almost were (especially since, in the end, they weren't). And, of course:
"[I]t's not all doom and gloom. Sometimes the rays rained death upon germs, or cancer. And one brave soul realized that the horrible power of a death ray was too much to entrust a human to wield, so he vowed never to reveal its secret, for the good of mankind."