The most accurate timekeeping devices are atomic clocks, which are accurate to seconds in many millions of years, and are used to calibrate other clocks and timekeeping instruments. Atomic clocks use the frequency of electronic transitions in certain atoms to measure the second. One of the most common atoms used is caesium, most modern atomic clocks probe caesium with microwaves to determine the frequency of these electron vibrations. Since 1967, the International System of Measurements bases its unit of time, the second, on the properties of caesium atoms. SI defines the second as 9,192,631,770 cycles of the radiation that corresponds to the transition between two electron spin energy levels of the ground state of the 133Cs atom.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What method do atomic clocks use to measure seconds?
Ah, so.. the frequency of electronic transitions in certain atoms

Much of Tucson's economic development has been centered on the development of the University of Arizona, which is currently the second largest employer in the city. Davis-Monthan Air Force Base, located on the southeastern edge of the city, also provides many jobs for Tucson residents. Its presence, as well as the presence of the US Army Intelligence Center (Fort Huachuca, the largest employer in the region in nearby Sierra Vista), has led to the development of a significant number of high-tech industries, including government contractors, in the area. The city of Tucson is also a major hub for the Union Pacific Railroad's Sunset Route that links the Los Angeles ports with the South/Southeast regions of the country.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Where is the US Army Intelligence Center?
Ah, so.. Sierra Vista

Alexander Graham Bell (March 3, 1847 – August 2, 1922) was a Scottish-born[N 3] scientist, inventor, engineer and innovator who is credited with patenting the first practical telephone.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is Bell famous for inventing?
Ah, so..
telephone