Alcubierre warp drive as time machine.

[sshai45]

Hi.

I heard it's possible to use an "Alcubierre warp drive" as a time machine, if they existed. But how, precisely, would that work?

 

[Simon Bridge]

It would normally be called a "causality violation".
In general, traveling faster than light suggests the possibility of setting one up.
Read through: http://www.physicsguy.com/ftl/html/FTL_intro.html
Alcubierre drives would certainly offer the opportunity to experiment in time travel ... though I would anticipate that, should the Universe allow FTL under some special conditions, those same conditions would prevent such a violation somehow.