On Jan 25, 2021, at 5:33 PM, art wagner <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:
For the first time in the literature, specific dynamical 4-dimensional solutions are presented that satisfy the NEC and WEC everywhere and everywhen.    https://arxiv.org/pdf/2008.04013.pdf

Good, but the energy conditions are no longer of any importance or relevance to practical Tic Tac Tech Metric Engineering Physics of Low Power Warp/Wormhole Machines.

They were only important given the assumption that the stiffness of spacetime cannot be changed.
Tic Tac has shown that conclusively to be false to any physicist sufficiently competent in Einstein’s General Theory of Relativity.
The point is that the coupling of source stress-energy currents to gravity inside artificial metamaterials is not G/c^4, but is (G/c^4)|S(x)|cos(argS(x))
Tan(argS(x)) = ImS(x)/ReS(x) ~ (dissipative inelastic scattering)/(reversible forward elastic scattering)
S(x) is the local frame invariant scalar electromagnetic susceptibility response function of the meta-material fuselage of Tic Tac that controls the resistance of gravity to the stress-energy current densities inside the fuselage.
Note that
G/c^4 = 1/(string tension)
String tension = space-time stiffness of vacuum
c^2 = 1/(electrical permittivity x magnetic permeability of virtual electron positron pairs in the Dirac Sea) to a good approximation.
The stress-energy currents also have imaginary dissipative parts, usually ignored.
The effect of dissipation in the source currents is to induce a relative phase shift between source INPUT and the gravity warp field OUTPUT.
This allows us to switch between attractive and repulsive generated gravity fields at will by modulating the ratio between dissipation and reactance (in electrical engineering parlance). 
That is why we do not give a fig about energy conditions for the design of Tic Tac Tech Machines.