How does the concept of light cones relate to time travel?

[d.smith292]

This is a conversational post, I am looking for others opinions on the diagram below related to time travel. If it is in the wrong room, please move it to the appropriate location. Thank you. I look forward to hearing your opinions.

[URL]http://i901.photobucket.com/albums/ac211/dsmith292/SpaceTimeChart-1.png[/URL]

This post is completely theoretical and I am looking for other peoples views on the topic at hand.

Using the diagram above, I invision the top cone flowing, constantly, into the lower cone. The flowing motion would be time. I then place me at the origin of the two cones, I don't move up or down, I stay in one position. My speed is measured by the slope in which I am on. The speed of light is on a slope equaled to one. The confusing part to me is, I thought at the speed of light, time would come to a halt. According to the diagram time still moves because the slope of c is 1. Time doesn't stop until you reach a slope of zero.

My next thought is, using the Alcubierre Drive theory. If were to place ourselves in a huge bubble and actually make it past the speed of light and into the realm of the unknown. This is a huge gap between reality and the past. My theory is that this would be a huge worm hole. I believe we wouldn't be able to survive this stage of travel without being inside of a bubble for protection. Also i believe that during this worm hole, the smooth flowing motion of the cones from top to bottom will slow like a huge ship slamming itself from drive to reverse. I believe it will begin to slow after we pass light speed and completely stop when we reach the x axis. And then it will start flowing in reverse, from bottom to top.

I also feel that we wouldn't be able to determine what part of time we ended up in. It would just start where we left off and we would view our lives in reverse.

What are your thoughts?

 

[JesseM]

Using the diagram above, I invision the top cone flowing, constantly, into the lower cone. The flowing motion would be time. I then place me at the origin of the two cones, I don't move up or down, I stay in one position.

That's not how light cones work--light cones are defined relative to individual events, not relative to objects or observers. The future light cone of some event E consists of all other events that could receive a signal from E which travels at the speed of light or less, and the past light cone consists of all other events that could send a signal to E which travels at the speed of light or less. Each point on your worldline is a different event (like you seeing a clock reading T=10 seconds and you seeing a clock reading T=11 seconds), and thus has a different past and future light cone. If you draw your worldline on the above diagram, it would look like a curve or straight line--if the diagram was showing your rest frame, it would just be a straight line parallel to the vertical time axis, like the line labeled "no movement" on the diagram. Each event on your worldline would occur at a different time and would thus have a different vertical height on the diagram.