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Results tagged with time
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user 16725
Time is defined operationally to be that which is measured by clocks. The SI unit of time is the second, which is defined to be "the duration of $9, 192, 631, 770$ periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium $133$ atom."
7
votes
What is a clock?
Wikipedia's "arrow of time" article.)
As far as measure goes, time is what is measured by periodic processes. A periodic process is one that cycles in a fixed amount of time. … These relations depend only on cycles (order of time) and on counting (whole number). Therefore this class can underpin time measurement without circularity. …
- 2,095
4
votes
Why do clocks measure arc-length?
Let $\lambda = t$ the time according to inertial $O$, and let $\vec{x}'$ be the spatial position of $O'$ according to $O$ , while $t'$ is the time measured by $O'$. … $t_0$ and $t_1$, then time lapse $\Delta t_B$ on $B$'s clock satisfies $(t_1-t_0)(1-\epsilon) < \Delta t_B < (t_1-t_0)(1+\epsilon)$. …
- 2,095