If someone changes the past would we know it?

[mmntech]

Star Trek had alternative universes. Mirror Universe.

True, but we're dealing purely with time travel here. I'm using the Voyager theory of time travel. While parallel universes exist in Trek, the effects of time travel are only experienced by our own.

 

[sandorski]

You would recall the Change, but not the previous event, because the previous event would not have happened.

 

[HeXen]

i time traveled to post this, its actually hureoday but you guys are in a different universe where that day does not exist, only i'm aware that anything has changed. luckily, the intranets exists in both allowing this communication....well...i have to go fight this giant crab monster now.
wish me luck

 

[invidia]

I would because i see all timelines of the multiverses in the past, present and future

 

[sjwaste]

I read End of Eternity by Isaac Asimov not too long ago. Would be a fun read for anyone interested in this thread.

 

[IronWing]

Gerard Klein - Overlords of War

Pretty much the best SF account of time travel and the implications there of.

 

[coloumb]

I think it works a bit like this:

http://www.youtube.com/watch?v=Z86V_ICUCD4

How the heck does something like that generate 6+ million views?

 

[sandorski]

How the heck does something like that generate 6+ million views?

This is better

 

[drebo]

If you were to go back in time and change the past, that change would erase the need for you to go back in time to change the past, thus you would never go back in time to change the past. So the answer is no.

At least, in the timeline of reference. However, I believe that there are infinite timelines (one for every single possible decision). So, there is no need to go to the past and change anything, because a timeline would have already existed in which said change would have already occurred.

This is why visiting the past would be "read-only" and visiting the future would be impossible (too many possible timelines for any man-made computer to ever compute).

 

[drebo]

True, but we're dealing purely with time travel here. I'm using the Voyager theory of time travel. While parallel universes exist in Trek, the effects of time travel are only experienced by our own.

Not really. If you recall the episode with Red Foreman in it, everyone outside of the timeship was oblivious to any change because in their timeframe of reference, the decision had always been made...the present just was, and the past was how it had always been for them. Yet there were infinite other possibilities which could have been the case depending on their decisions...hence the calculations.

The same is even really true if you look at the Captain Braxton episodes...the effects of time travel outside the people who affect the timeline are unknown, as they are oblivious to any other potential timelines.