Regarding these, Professor Michael Howard concludes: “The peoples of Western Europe and North America seemed to have every reason to greet the twentieth century as the dawn of a new and happier age in the history of mankind. ”
पर आइये, अब हम देखें कि इस 20वीं सदी में विज्ञान ने क्या - क्या करिश्‍मे किए हैं ।