Was reading the possibility of time travel. Now Hawkings states that they haven't invented time travel, because we haven't had a visit from a time machine yet. But he also states that there exists infinitesimal small time portals in real space, but due to their size we are unable to detect them. If it were true and there were these infinitesimal small time tunnels, would they being emitting some type of particle, and that these particles would be able to be detected. So, if you could pinpoint one of these tunnels, and supply enough energy to the wormhole say, that it could expand out. I know it sounds in the realms of the ridiculous, but if you could isolated one of the wormholes, and then shoot a particle say at around the speed of light, particle accelerator, could you supply enough energy to enlarge the wormhole. A black hole doesn't emit any signature, but that is what makes a black hole distinguishable from it surroundings.
Traversable wormholes are formed with mass-energy that is negative. Negative energy has the effect by the Einstein field equation of resulting in geodesics that diverge away from each other. This is in contrast to positive mass-energy that results in focusing geodesics in gravitational attraction. This would mean that if you perturb a tiny wormhole with positive matter that you are more likely to demolish it than to build it up.
Now suppose you were able to build up wormholes. The Casimir effect with a form of parametric amplification or squeezed state process might do the trick. Then suppose you had a coherent state operator that builds up these elementary wormholes into a sort of population inversion. Since these are all in the same state you could then form a condensate that would be one big wormhole. Now I am glossing over some serious problems of course. Chief of these problems is that this negative energy system would have enormous instability. However, this spacetime solution could in some extreme hypothetical sense exist. However, on the moduli space of solutions it is a point, which means perturbing it will not evolve the wormhole into a nearly identical form. It is hideously unstable.
Now suppose we have this wormhole as we are able to Lorentz boost or accelerate one of the openings to near the speed of light and then reverse course and accelerate it back, I am assuming this is done without perturbing it. There is a point where a Cauchy horizon exists between the openings which denotes the point it becomes a time machine. The problem is that vacuum modes would wind around the wormhole and pile up at the Cauchy horizon. This would be a terrible perturbation for certain. So I suspect this delicately built wormhole would explode and cease to exist at this point.