Not so long ago, my baby son asked me - what experiment do I consider the most important one conducted in the 20th century? He needed it for a school essay.
This simple question put me into a stupor for several hours. Because the choice was really difficult. With the nineteenth century it is easier - there it is immediately clear that the double-slit experiment *.
And with the twentieth?
Of course, if you choose by significance, then everything is simple. This "Trinity" - the world's first nuclear weapons test, which took place on July 16, 1945. Without exaggerating at all, we can say that after this test the world woke up different.
But, for all the significance of this experiment, it did not bring new knowledge. Before that, everyone knew that the bomb would explode. The experiment did not add any new knowledge.
On reflection, I decided that I should choose one of the social experiments - in the twentieth century, scientists first turned their attention to themselves - starting to study human behavior. For a person, understanding his nature is much more significant than understanding the structure of the atom.
Having considered the Stanford Prison Experiment, Milgram's experiment and Universe-25, aka Rat Paradise, I chose an experiment to breed the friendly fox of the Soviet scientist, Academician Dmitry Belyaev.