The quantum-mechanical model, besides revolutionizing chemistry, shook the philosophical world because of its implications regarding determinism. Determinism is the idea that the outcomes of future events are determined by preceding events. The trajectory of a baseball, for example, is deterministic; that is, its trajectory-and therefore its landing place-is determined by its position, speed, and direction of travel. Before quantum mechanics, most scientists thought that fundamental particles-such as electrons and protons-also behaved deterministically. The implication of this belief was that the entire universe must behave deterministically-the future must be determined by preceding events. Quantum mechanics challenged this reasoning because fundamental particles do not behave deterministically-their future paths are not determined by preceding events. Some scientists struggled with this idea. Einstein himself refused to believe it, stating, "God does not play dice with the universe." Explain what Einstein meant by this statement.​