The theory of general relativity predicts that if traversable wormholes exist, they could allow time travel.[12] This would be accomplished by accelerating one end of the wormhole to a high velocity relative to the other, and then sometime later bringing it back; relativistic time dilation would result in the accelerated wormhole mouth aging less than the stationary one as seen by an external observer, similar to what is seen in the twin paradox. However, time connects differently through the wormhole than outside it, so that synchronized clocks at each mouth will remain synchronized to someone travelling through the wormhole itself, no matter how the mouths move around.[17] This means that anything which entered the accelerated wormhole mouth would exit the stationary one at a point in time prior to its entry.
Could be because it wasn't powerful enough. 
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