Does this mean time travel is possible? Yes and no. To travel back in time, I don't think so. Each dimension may be ahead or behind ours, but it is still the same universe time, I think we can see the past if we could travel faster than time. In other words, we'd have to make time stand still. If we could go from earth, with no time passing, to any point in the universe, we could see that far back. For example, if we could go from here to Jupiter with no time passing, then we could see as many years into Earth's past as we are lightyears from earth. The further the distance, the further back into our history we could see. But that time is all we would see, nothing before or after, like a freeze frame of a movie. Why could we see it but not go back into past times? because it is only an energy signature of light. You can record a video, rewind or fastforward it, but you can't go into it and interact. Am I confusing anyone yet? Is it possible to travel forward in time? Yes, we know the theories but not the technologies or even if we can do it. To travel forward in time is only to be able to travel at the speed of light. But the speed of light can't be accomplished yet, and may never happen. Some believe that if you travel at the speed of light as we understand it, then the speed of light is still faster. Others believe that the speed of light can never be achieved, that we could only make it to a tiny bit less. However, let's say we can travel at the speed of light. We aim for outerspace, fly one light year out and one light year back. Are we two years older or two million? How much older is the earth? But we can't go back in time so we would be stuck in whatever future time it is. Who wants to be the first to try it?
Here's a thought to ponder-- are aliens really alternate humans who can travel interdimensionally? In other words, are they just our alternate selves from another dimension of earth that have found a way to travel back and forth? Honestly, I think it would be easier to master traveling within dimensions of the same earth as travel would be instantaneous, rather than to think of any long distance space travel or being able to travel faster than the speed of light.