It is the accelerated development of modern scientific and technological achievements and scientific and technological information, and it is the calculation of any measurement index (national scientific research funds, number of scientists, number of scientific and technological papers, etc.). ) according to the law of exponential development.
In the 60 years since the 20th century, the total amount of funds spent on scientific research in the world has increased by about 400 times. By the end of 2 1 century, the number of scientists in the world is expected to account for about 20% of the total population.
Extended data
Traditionally, at the beginning of Einstein's theory of relativity, people used whether the question under discussion involved a non-inertial reference system as a symbol of the classification of special and general relativity. With the development of the theory of relativity, this classification method shows its shortcomings more and more-the frame of reference is related to the observer, and it is considered that dividing the physical theory with such a relative physical object cannot reflect the essence of the problem.
The difference between special relativity and general relativity lies in whether the problems discussed involve gravity (curved space-time), that is, special relativity only involves those problems that have no gravity or gravity can be ignored, while general relativity discusses physics with gravity.
In the language of relativity, the background space-time of special relativity is flat, that is, the four-dimensional ordinary flow pattern matches Min scale, and its curvature tensor is zero, which is also called Min space-time; The background space-time of general relativity is curved, and its curvature tensor is not zero.
At present, in the observation of gravitational waves and the study of some high-density celestial bodies, general relativity has become one of its theoretical foundations.
On the other hand, general relativity also provides a new tool and perspective for people to re-understand some ancient problems such as cosmology and time travel.
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