His reflections on that movement led to his discovery of the law of pendular motion. Newton one day observed the fall of an apple.
All science is discovery.
And the glory of the scientific method is that, shunning a priori assump tions, it insists on observing and learning from things as they are. The true scientist tries never to impose his expectations on objective reality. That everyone has expectations, and that these expectations do sometimes impose themselves, unsuspected, on even the work of scientists, should go without saying. Einstein and Sir Arthur Stanley Eddington, both great physicists, were in disagreement on some obscure point of science. Einstein settled the matter by declaring that it was, after all, only a matter of taste.