just use a time based on light?, like meter is based on the speed fo light in the vaccum, or use atomic based times?, like how long take for the hydrogen atom todo something bla bla bla
The second […] is defined by taking the fixed numerical value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s−1.
Do not matter for relativity though, always same change.
just use a time based on light?, like meter is based on the speed fo light in the vaccum, or use atomic based times?, like how long take for the hydrogen atom todo something bla bla bla
https://en.wikipedia.org/wiki/Second
Do not matter for relativity though, always same change.