... shown in Fig. 5- 14. In distributed systems, name servers in the global and administrational layer arethe most difficult to implement. Difficulties are caused by replication and cach-ing, which ... large number of days and taking the average before divid-ing by 86 ,40 0. The resulting quantity was called the mean solar second. With the invention of the atomic clock in 1 948 , it became possible ... anything to do with papal decrees and did notaccept the Gregorian calendar for 170 years.Figure 6-3. TAl seconds are of constant length, unlike solar seconds. Leapseconds are introduced when necessary...