[QUOTE][b]i meant that it is easy to observe and it doesnt have any parts left to be filled in. those parts cannot be filled in by opinions, assumptions, beliefs, etc.[/QUOTE]
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It is the role of science to not just "observe" natural phenomena but to
explain it. That means that assumptions and opinions and sometimes even beliefs are part of the process so long as the scientific method is followed and these are allowed to be questioned and rejected if the data requires it.
"Proof", as you define it, does not exist in science, there is only tentativity.