Today, August 6th, is the 66th anniversary of the dropping of the atomic bomb on Hiroshima, Japan, the first time a nuclear weapon was used against human beings.

The second, and so far last, use of nuclear weapons against people was the atomic bombing of Nagasaki three days later on August 9th, 1945.

The nuclear arms race began that same year.

The end of the Cold War convinced many people that the nuclear threat had gone away, but there are still more than 20,000 nuclear weapons in the world, possessed by nine different countries (95% of them by Russia and the United States), and thousands remain on hair-trigger alert.

Photo by xiquinhosilva