spatial
In special relativity, however, the interweaving of spatial and temporal coordinates generates the concept of an invariant interval, denoted as 



Δ

s

2




{\displaystyle \Delta s^{2}}

:




Δ

s

2





=
def




c

2


Δ

t

2


−
(
Δ

x

2


+
Δ

y

2


+
Δ

z

2


)


{\displaystyle \Delta s^{2}\;{\overset {\text{def}}{=}}\;c^{2}\Delta t^{2}-(\Delta x^{2}+\Delta y^{2}+\Delta z^{2})}


