A week ago, for science Wednesday, I wrote about   THE WORST CATACLYSM EVER FOR PLANET EARTH .  Today, what was the worst event for Humanity? Here is one viewpoint, with the gray bar indicating how many people would have died today if projected to our current population: The second world war only comes in at #11, mostly because it was too recent. China seems to monopolize this list. Not taking current population as the base,  Wikipedia  says the Khans might have disposed of 80 million, and so did Mao and Deng.  But various Marxist-Leninist leaders did away with nearly 150 million. Adolf Hitler?  "Only" 25.5 million. The  Black Death  around 1350 might have killed up to 200 million. The world population then was 370 million. Doing the math, this means if the same percentage of people in the world died, the equivalent today would be 4.3 billion, which is more than half our current population. Genghis Khan killed the equivalent of fewer than 0.8 billion. There is some speculatio