There is a symmetry between space and time. As one can transform an observation by rectilinear motion (translation), or by rotation, or by a timeline change, so one can transform 3D space into an equivalent 3D time. This is not a continuous change so don’t expect a simple equation. There are four things that must be done to transform 3D space into 3D time, that is, 3+1 spacetime into 1+3 timespace:

(1) The ordering of events should be switched between a timeline (1D time order) and a placeline (1D space order). So a measurement of time, such as the duration from a reference event, should be switched with a measurement of place, such as the distance from a reference event.

(2) Scalars should be inverted: speed ⇒ pace, mass ⇒ 1/mass = vass, energy ⇒ 1/energy = invergy, work ⇒ 1/work = invork, etc.

(3) Vectors that are ratios of base units or products of base units should switch their numerators and denominators such that (a) the denominator becomes a magnitude of the former numerator and (b) the numerator becomes the vector with units of the former denominator: velocity ⇒ legerity, momentum ⇒ fulmentum, etc. This is similar to an inversion since s/t ⇒ t/s = (1/s)/(1/t).

(4) Other units should be derived from these, with new rates relative to the timeline for 3D space and the placeline for 3D time: acceleration ⇒ expedience, force ⇒ rush, power ⇒ exertion, etc.

There should be no time vectors in 3D space and no space vectors in 3D time. The distance from a reference place and duration from a reference event should be the same for both, apart from a change of reference points. The laws of physics should be the same for observation or transportation in each frame.

*Related*