First you need some anti-matter,if you can get enough of this in one place you should be able open a hole in space
Then 2 uncharged metal plates
Separate them in space to create a vacuum
vacuum becomes filled with virtual electron-antielectron annihilations
This then creates the casimir effect(net attraction between the 2 uncharged plates)
Then magnify the casimir effect to create a crude time machine
Think a wormhole could connect 2 sets of casimir plates,plates would have to be displaced in space and you then use it as a warp drive system,or if plates were displaced in time then a time machine
if then someone could fall between one set of plates he could be transported to the other set of plates
I suppose you may ask would it be phyisically stable