Science experiments

thumb|Apollo 15 astronaut [[David Scott performs a gravity test on the Moon with a hammer and feather (1971).]] thumb|right|160px|Even very young children perform rudimentary experiments to learn about the world and how things work.

range of air temperatures that most people prefer for indoor settings

famous randomized experiment

Cold War-era US nuclear aircraft propulsion experiments

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thumb | Diagram of a small form closed system mesocosm thumb | Different components of a successful mesocosm

experimental element which is constant and unchanged

The '''Acali expedition (or Acali experiment or the Sex Raft''') was a 1973 social experiment that aimed to investigate interpersonal relationships in conditions of limited space and social isolation. The experiment was conceived by Mexican anthropologist Santiago Genovés, who had previously been a crew member of Thor Heyerdahl's Ra expedition. The participants showed a restraint towards aggression, which frustrated Genovés and led him to start to try to create conflict, and at one point he took command of the float. Despite these attempts, the group remained peaceful.

1919 observational test which confirmed Einstein's theory of general relativity

evidence of any kind that suggests something is missing or that it does not exist

methodology of software-engineering research