From The Chronicle of Higher Education on March 2, 2017 —
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These days, in a world totally dependent on microprocessors, lasers, and nanotechnology, it has been estimated that 30 percent of the U.S. gross national product is based on inventions made possible by quantum mechanics. With the booming high-tech industry and the expected advent of quantum computers, this percentage will only grow. Within a hundred years, an esoteric theory of young physicists became a mainstay of the modern economy. It took nearly as long for Einstein’s own theory of relativity, first published in 1905, to be used in everyday life in an entirely unexpected way. The accuracy of the global positioning system, the space-based navigation system that provides location and time information in today’s mobile society, depends on reading time signals of orbiting satellites. The presence of Earth’s gravitational field and the movement of these satellites cause clocks to speed up and slow down, shifting them by 38 milliseconds a day. In one day, without Einstein’s theory, our GPS tracking devices would be inaccurate by about seven miles. — Robbert Dijkgraaf, Director, Institute for Advanced Study, Princeton |
The above paragraphs are clearly propaganda, not physics.
For "It has been estimated," see …
The "without Einstein 's theory" statement may or may not be correct.
See the lengthy discussion at …
http://physics.stackexchange.com/questions/1061/
why-does-gps-depend-on-relativity .