Time travel (unsatisfied)?

Time travel is theoretically possible by either travelling faster than light, which would send you into the past. Of course ftl travel is impossible unless you bring an Einstein-Rosen bridge into play (a wormhole). If the mouth of the bridge is in accelerated time, while the other mouth is slowed, anyone entering the accelerated mouth would come out in the past and visa versa. However, whether or not this is possible (even theoretically), is not entirely certain. Furthermore, entering the past could have several serious complications resulting in (possibly) time loops, a tear in space time resulting in obliteration, or the creation of alternate time lines. In addition, it is likely that entering the past could simply allow you to exist yet make it impossible for events to be altered. Entering the future, which would be exponentially more difficult would leave little worry for altering events, though what the future holds could very likely be extremely dangerous to a would-be time traveler.