Time is a tricky wicky thing and the more we think about it and the more we learn about it, the more malleable it becomes. When you know enough, you can walk right through it as easy as you could walk through your bedroom door. As time passes (this is an illusory concept, but it will suffice for our purposes) and space moves on, as we progress - we tug at the causal lines and change the possible future. We are doing it always, even now. This is how we learn to travel between different eras.
It is happening right now as we read about it, as we discuss it. Everytime we play with time, we break down our resistance to it a little more. Not everyone will be able to come with us on these journeys at first. Many of us are incredibly linear and time is not like that at all.
And the scary thing about the whole time travel thing is that when we break through the membrane, how many other entities will always be trying to stop us from traveling (are already trying to stop us), controlling how we travel and which whens we can go to. But our perseverance in this endeavor is the only thing that will save humankind from our own destruction.
The Universe is much more strange than we can imagine, but that mystery is largely what keeps us going. Don't you agree, Mr. Ransoon?
The following 7 pages are in this category, out of 7 total.