Another proof of Rev 16:18-21 is the WW2 era, is in verse 21 21 "And there fell upon men a great hail out of heaven, every stone about the weight of a talent: and men blasphemed God because of the plague of the hail." The weight of a talent was about 100 lbs. 100lb bombs dropped from planes were common during WW2. WW1 bombs were about 20lbs and were limited due to aerial abilities still being developed. Much heavier bombs were common in the post ww2 decade, though 500lb bombs were also common during ww2.