Laser
In the "War of Worlds" written before the turn of the last century H. Wells told a fantastic story of how Martians almost invaded our Earth. Their weapon was a mysterious sword of heat. Today Wells' sword of heat has come to reality in the laser. The name stands for light amplification by stimulated emission of radiation. Laser, one of the most sophisticated inventions of man, produces an intensive beam of light of a very pure single colour. It represents the fulfilment of one of the mankind's oldest dreams of technology to provide1 a light beam intensive enough to vaporize the hardest and most heat-resistant materials. It can indeed make lead run like water, or, when focused, it can vaporize any substance on the earth. There is no material unamenable2 to laser treatment and laser will become one of the main technological tools quite soon. The applications of laser in industry and science are so many and so varied as to suggest magic3. Scientists in many countries are working at a very interesting problem: combining the two big technological discoveries of the second half of the 20th century laser and thermonuclear reaction to produce a practically limitless source of energy. Physicists of this country have developed large laser installations to conduct physical experiments in heating thermonuclear fuel with laser beams. There also exists an idea to use laser for solving the problem of controlled thermonuclear reaction. The laser beam must heat the fuel to the required temperature so quickly that the plasma does not have time to disintegrate. According to current estimates, the duration of the pulse has to be approximately a billionth of a second. The light capacity of this pulse would be dozens of times greater than the capacity of all the world's power plants. To meet such demands in practice, scientists and engineers must work hard as it is clear that a lot of difficulties are to be encountered on route4. The laser's most important potential may be its use in communications. The intensity of a laser can be rapidly changed to encode very complex signals. In principle, one laser beam, vibrating a billion times faster than ordinary radio waves, could carry the radio, TV and telephone messages of the world simultaneously. In just a fraction of a second, for example, one laser beam could transmit the entire text of the Encyclopaedia Britannica. Besides, there are projects to use lasers for long distance communication and for transmission of energy to space stations, to the surface of the Moon or to planets in the Solar system. Projects have also been suggested to place lasers aboard Earth satellites nearer to the Sun in order to transform the solar radiation into laser beams, with this transformed energy subsequently transmitted to the Earth or to other space bodies. These projects have not yet been put into effect5, because of the great technological difficulties to be overcome and, therefore, the great cost involved. But there is no doubt that in time6 these projects will be realized and the laser beam will begin operating in outer space as well.
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Superconductivity
According to the prominent scientist in this country V.L. Ginz-burg the latest world achievements in the field of superconductivity mean a revolution in technology and industry. Recent spectacular breakthroughs1 in superconductors may be compared with the physics discoveries that led to electronics and nuclear power. They are likely to bring the mankind to the threshold of a new technological age. Prestige, economic and military benefits could well come to the nation that first will master this new field of physics. Superconductors were once thought to be physically impossible. But in 1911 superconductivity was discovered by a Dutch physicist K. Onnes, who was awarded the Nobel Prize in 1913 for his low-temperature research. He found the electrical resistivity of a mercury wire to disappear suddenly when cooled below a temperature of 4 Kelvin (269 C). Absolute zero is known to be 0 K. This discovery was a completely unexpected phenomenon. He also discovered that a superconducting material can be returned to the normal state either by passing a sufficiently large current through it or by applying a sufficiently strong magnetic field to it. But at that time there was no theory to explain this. For almost 50 years after K. Onnes' discovery theorists were unable to develop a fundamental theory of superconductivity. In 1950 physicists Landau and Ginzburg made a great contribution to the development of superconductivity theory. They introduced a model which proved to be useful in understanding electromagnetic properties of superconductors. Finally, in 1957 a satisfactory theory was presented by American physicists, which won for them in 1972 the Nobel Prize in physics. Research in superconductors became especially active since a discovery made in 1986 by IBM2 scientists in Zurich. They found a metallic ceramic compound to become a superconductor at a temperature well above3 the previously achieved record of 23 K. It was difficult to believe it. However, in 1987 American physicist Paul Chu informed about a much more sensational discovery: he and his colleagues produced superconductivity at an unbelievable before temperature 98 K in a special ceramic material. At once in all leading laboratories throughout the world superconductors of critical temperature 100 K and higher (that is, above the boiling temperature of liquid nitrogen) were obtained. Thus, potential technical uses of high temperature superconductivity seemed to be possible and practical. Scientists have found a ceramic material that works at room temperature. But getting superconductors from the laboratory into production will be no easy task. While the new superconductors are easily made, their quality is often uneven. Some tend to break when produced, others lose their superconductivity within minutes or hours. All are extremely difficult to fabricate into wires. Moreover, scientists lack a full understanding of how ceramics become superconductors. This fact makes develop ing new substances largely a random process. This is likely to continue until theorists give a fuller explanation of how superconductivity is produced in new materials
The International Space Station
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The International Space Station (ISS), the most complex and expensive structure that has ever been launched and built in space, is expected to be a permanent off-planet extension1 of human civilization. When completed, it will be a multi-room hotel and research facility orbiting the Earth every 90 minutes. By that time, resupply and assembly flight by shuttles or rockets will have become routine. The Russians and Americans are partners in this international enterprise. The three-person multi-national crews will be alternately composed of two Americans and one Russian followed by a Russian majority. Later a six or seven-person crew will occupy the station. Some astronauts may stay on the ISS up to 187 days, but there are no plans yet for longer missions. The official life expectancy of the station itself is 10 years, but it should last much longer. Five times the size of the Russian space station Mir, the ISS will be one of the biggest objects in the night sky, looking like a supersize Lego set2, almost as long as a football field. Only the Moon and Venus will be bigger and more visible. The fifth-generation station's complexity is as awesome3 as its size. Built by a partnership of 16 nations, the ISS will consist of 36 modules and hundreds of individual elements that come from all over the world. The station involves the most technologically advanced nations - - Russia, the United States, Canada, Japan, Brazil, and 11 European nations. There will be many interconnected parts from so many countries that it would be impossible to predict how they would interact. Hence, it is very important that all of these elements made by different suppliers should fit together properly and work exactly as planned. But even if all the parts fitted perfectly, the assembly process itself in orbit would be risky. The space station is flown while it is being constructed and each new building block added might change the way the station behaves in flight, which could result in serious trouble. The ISS may be the world's most ambitious engineering project in history, but it could not have been realized without previous extensive experience in operating the Russian Mir space station. Mir was a great achievement. Russia learned how to build and maintain complex structures in space. Mir also gave citizens of more than a dozen countries their first opportunity to explore space. It should be noted that Mir has proved to be the perfect training ground for the ISS. For more than a decade, at least two humans were always in low Earth orbit. That is why it was planned that Russia would supply and deliver 12 modules for the future station, each being a key module among its 36 ones. They are: the basic power module, the control, the life support, the service modules and others. What is the purpose of the ISS? It is a political program as well as a science program. This program is no longer only about conducting scientific investigations in the absence of gravity, or about learning how to build a massive project weighing 400 tons in orbit, or about establishing the base for a future trip to Mars. The ISS is more than merely the next great adventure of the space age. It is also about promoting international cooperation and creating thousands of peacetime jobs for highly skilled workers and engineers. The implementation of the broad international program would require more than $40 billion. Some space experts would like to attract commercial users such as, e.g., biotechnology companies in order that the cost of the station should be lowered. And some specialists have even suggested that the station be used for advertising and Hollywood filmmaking.
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