nLab
second

Contents

Context

Physics

physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes


theory (physics), model (physics)

experiment, measurement, computable physics

Contents

Idea

The second is a physical unit of time. It is defined by taking the fixed numerical value of the caesium frequency Δν Cs\Delta \nu_{Cs}, the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom, to be 91926317709192631770 when expressed in the unit HzHz, which is equal to s 1s^{-1}

References

Last revised on April 2, 2019 at 19:57:24. See the history of this page for a list of all contributions to it.