History of smallpox centuries, the WHO certified the global eradication of smallpox in December 1979. Smallpox is one of two infectious diseases to have been eradicated, the other being rinderpest, which was declared eradicated in 2011. It has been suggested that smallpox was a major component of the Plague of Athens that occurred in 430 BCE, during the Peloponnesian Wars, and was described by Thucydides. Galen's description of the Antonine Plague, which swept through the Roman Empire in 165–180, indicates that it was probably caused by smallpox. Returning soldiers brought the disease home with them to Syria and Italy, where it raged for
Human extinction Robin Hanson argues that a refuge permanently housing as few as 100 people would significantly improve the chances of human survival during a range of global catastrophes. Some 21st century pop-science works, including "The World Without Us" by Alan Weisman, pose an artistic thought experiment: what would happen to the rest of the planet if humans suddenly disappeared? A threat of human extinction, such as through a technological singularity (also called an intelligence explosion), drives the plot of innumerable science fiction stories; an influential early example is the 1951 film adaption of "When Worlds Collide". Usually the extinction threat is