We think of science as a way of discovering certainty in an unpredictable world; experiments are designed to objectively measure cause and effect. Yet science often produces more new questions than answers, and all scientific theories can change with new and better observations. Scientific philosophers say that "objective" observations actually depend heavily on the observer's intuition and point of view.
Einstein overthrew Newtonian physics but like Newton he still believed that physical events have definite causes. Then Niels Bohr, a Danish physicist, joined others in describing a strange new world of uncertainty and mystery. Quantum mechanics has intrigued and confounded many by joining keen insights with apparent contradictions and indeterminacy. Quantum theory also was later used to create semiconductors, the technology of the computer revolution.