It's difficult to overestimate the role of science and technology in our life. They accelerate the development of civilization and help us in our co-operation with nature. Scientists investigate the laws of the universe, discover the secrets of nature, and apply their knowledge in practice improving the life of people. Let's compare our life nowadays with the life of people at the beginning of the 20th century. It has changed beyond recognition. Our ancestors hadn't the slightest idea of the trivial things created by the scientific progress that we use in our every day life. I mean refrigerators, TV sets, computers, microwave ovens, radio telephones, what not. They would seem miracles to them that made our life easy, comfortable and pleasant. On the other hand, the great inventions of the beginning of the 20th century, I mean radio, airplanes, combustion and jet engines have become usual things and we can't imagine our life without them. A century is a long period for scientific and technological progress, as it's rather rapid. Millions of investigations the endless number of outstanding discoveries have been made. Our century has had several names that were connected with a certain era in science and technology. At first it was called the atomic age due to the discovery of the splitting of the atom. Then it became the age of the conquest of space when for the first time in the history of mankind a man overcame the gravity and entered the Universe. And now we live in the information era when the computer network embraces the globe and connects not only the countries and space stations but a lot of people all over the world. All these things prove the power and the greatest progressive role of science in our life. But every medal has its reverse. And the rapid scientific progress has aroused a number of problems that are a matter of our great concern. These are ecological problems, the safety of nuclear power stations, the nuclear war threat, and the responsibility of a scientist. But still we are grateful to the outstanding men of the past and the present who have courage and patience to disclose the secrets of the Universe.