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The height of frequency standards
Jul 1, 2003
We live in a relativistic world. You might think that longitude is the only factor that determines the time difference between two locations on Earth. But if you were to use the world’s most accurate atomic clocks, you would also need to take the latitude and altitude of the two locations into account. While these effects are unlikely to affect the itinerary of even the most conscientious traveller, they are crucial for measuring the stability of the world’s frequency standards.
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