Oppenheimer, Sagan & Pannekoek

 'It is very difficult to estimate the extent of their [fission products] effect especially as the most important substances would be those of long life, which are the hardest to study under laboratory conditions. It does however seem certain that the area devastated by the explosion would be dangerous to life for a considerable time' (Maud Committee report, 1941).  

Robert Oppenheimer, often described as the 'father of the atomic bomb', called it "Death, the destroyer of worlds."

Scientists at the time did  not forsee one conequence of atomic war - nuclear winter,   'Five scientists, including Carl Sagan, first proposed this theory in a 1983 paper.'

Carl Sagan also observed: ‘For me, the most ironic token of [the first human moon landing] is the plaque signed by President Richard M. Nixon that Apollo 11 took to the moon. It reads, ‘We came in peace for all Mankind.’ As the United States was dropping seven and a half megatons of conventional explosives on small nations in Southeast Asia, we congratulated ourselves on our humanity. We would harm no one on a lifeless rock’.

Moreover: ‘Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate.’ Yet more positively he also stated: ‘Humans have evolved gregariously. We delight in each other’s company; we care for one another. Altruism is built into us. We have brilliantly deciphered some of the patterns of Nature. We have sufficient motivation to work together and the ability to figure out how to do it. If we are willing to contemplate nuclear war and the wholesale destruction of our emerging global society, should we not also be willing to contemplate a wholesale restructuring of our societies?’ (Cosmos, Futura, 1987, p. 358). 

The less well known astronomer Pannekoek, who died in 1960 just as humanity entered the space age, would concur: ‘It is time for mankind to ensure itself of material abundance by establishing a free, self-managed world-society of productive labor, thereby freeing its mental powers for perfecting its knowledge of nature and the universe’ (A History of Astronomy, 1951).