2018-12-14 02:02:11 Source: Daily Science and Technology
History of science
Time is one of the most important things in human life. Since the old time, China has had the slogan of "one inch of time and one inch of gold." Britain's famous physicist Hawking, a popular science book "A Brief History of Time", is popular throughout the world. The Chinese song is popular "Where's the time?" Also being widely sung, showing people's attention and time attention. Time not only plays an important role in everyday life, but also plays a key role in scientific research. A study of celestial bodies and even a movement of different earth objects is impossible from measuring time. So Newton's main modern science discusses and defines time in his book making the Mathematical Principles of Natural Philosophy. He believes that the time is "absolute, real and mathematical" and that "uniform flow" is "independent of anything external", but it can be felt and measured by offering the object.
In fact, a long history measures time by movement of objects at home and abroad. After people have experienced timing methods, such as prey, dropping, eight hours, pumpkin, quartz oscillations, etc., in the late 1940s, American scientists invented a method of timing by measuring the change between atomic energy levels. After that, he entered the "Atomic Clock Age".
The timing of the atomic clock is a method of measuring the frequency of transition between a fixed atomic level. After improvement, this timing method is much more detailed and stable than a previous astronomical clock and a quartz shock clock. Thus, in 1967, the International Pressures and Measures Conference decided to use atomic clocks to define the base time unit, which is the length of circles 9192,631,770, the radiation that corresponds to the transition between two hyperphine levels of state of the isotope land only 铯 -133 atom. The length of time is taken as 1 second. By the end of the 20th century, on the one hand, by strict regulation of the use of atomic clocks, on the other hand through technological improvements, such as the use of laser cooling and atomic collection, and the more sophisticated laser spectroscopy technology, the accuracy of the atomic clock has been bigger. Improving. This precise timing device makes a more uniform and accurate measure of time, and brings great convenience to scientific and technological research, modern production activities and people's everyday life.
In the twenty-first century, scientists do not continue to work on the accuracy of atomic clocks, but they also work hard on reducing miniature and energy saving atomic clocks, enabling the new generation of Atomic clocks to reach chip level jumps, and the necessary energy is reduced, stabilizing it. Once again, the aspects of sex and accuracy have been optimized and have gone into the commercialization phase.
Currently, atomic clocks have started to diversify in terms of working substances, and it is no longer restricted to strontium elements, but it also includes lead, hydrogen, antimony, bismuth, antimony etc. The approach is split into a variety of different methods, such as optical atomic clocks and quantum atomic clocks. The atomic clock has even broken through simple atom boundaries and has started moving towards kernel measurement and individual ion property. In this sense, the atomic clock appears to be not fully suited to its combination, called "particle clock". A particularly important development is that today's atomic clocks are not limited to being used as an accurate timing device, but also a new type of tool for scientists to study the wider scientific fields of cosmic objects and even topography.