Can We Really Travel Back to Our Own Past?

[aaryan0077]

Our past is not our past? Or Does past changes when we travel fast enogh?

We have a light cone
http://img7.imageshack.us/img7/6463/lightcone3.jpg
Vertical and horizontal axis representing time and space respectively.
Here L1, L2 & L3 represent path allowed for massive bodies, light and path not allowed respectively.
I know we can't get to speed of light or more ( atleast for now, unless we don't have any sort of startrek or skynet technology ) but we know that when we get closer and closer to c, time starts to dilates (& I know there are many threads on time dilation here, but my question is different) and we are "said to" (whatever this means) travel into future (remember twin paradox) and if (by any means) we cross the speed limit of c we'll travel back into the past, atleast that is what is supposed to happen.
But any object (here WE) faster than light will follow L3 (or any path between L2 and horizontal axis) and so we'll get to else where region and not our past, contrary to what is supposed that we'll travel to past.
So will that elsewhere be our past if we traveled like this?
Or is our own past not our "own" as we accept it to be?

 

[tiny-tim]

Hi aaryan0077!

… and if (by any means) we cross the speed limit of c we'll travel back into the past, atleast that is what is supposed to happen.

No, that's mathematical rubbish.

The time-dilation formula is √(1 - v²/c²) …

if the formula was (1 - v²/c²),

then you'd be right … for v > c, time dilation would be negative, and a traveller would go back into the past

but it isn't, and for v > c, the correct time-dilation formula becomes imaginary, not negative …

I suppose you could say that means that a traveller goes into imaginary time!

 

[Entropia]

The concept of time travel and its implications on the past is a fascinating topic to explore. While it is true that as we approach the speed of light, time dilation occurs and we can theoretically travel into the future, it is important to note that this does not necessarily mean we can travel into our own past.

Firstly, the concept of time itself is a human construct and is relative to the observer. This means that what is considered the past for one person may not be the same for another person. Our perception of the past is also influenced by our memories and experiences, which are constantly changing and evolving.

Secondly, the light cone diagram provided in the content shows that there are certain paths that are not allowed for massive objects, known as L3. This means that even if we were to travel faster than the speed of light, we would not be able to follow a path that leads back to our own past. We would simply end up in a different region of space and time.

Furthermore, the concept of causality also plays a role in this discussion. The idea that an effect cannot occur before its cause is a fundamental principle in physics. If we were able to travel back in time, we would be able to change events that have already happened, creating paradoxes and disrupting the natural order of cause and effect.

In conclusion, while it is possible for time dilation to occur and for us to theoretically travel into the future, it is unlikely that we can travel into our own past. Our past is constantly changing and evolving, and the laws of physics prevent us from traveling back in time. Our past is our own, but our perception of it may be influenced by our experiences and memories.