[Chrysalis]

I think time travel might be possible through time manipulation, where by you cheat time in some way making it move faster in some way. For example putting yourself in a deep freeze where a computer takes you out the coma after specified time and you wake up the moment you goto sleep gives you feeling you skipped time, on this theory only going forward would be possible.

If someone went back in time to change something, eg. to stop hitler make the mistakes that lost him WW2, then I believe we would see something like whats explained in back to the future 2, multiple time lines. People in the current would carry on living their lives as normal in their timeline, the person changing history then changes the timeline hes in, so effectively going back creates a new timeline. However I would say that only works when going forward in time and not backwards, reffering to back to the future 2 again, when marty goes back in time he sees himself from when he first went back in time and he sees the grandpa guy from when he went back in time, when really he should be going back in time on his current timeline, when the grandpa guy went back in time he would have created an alternate timeline on my thoery so marty would never have seen him and only his other self so when going to the future again things would still be normal. So my thoery to summarise if going back in time was possible, people would never see anything change in the current as the result because when going back in time a new time line is created, and the results of a new time line will only be seen from then onwards going forwards not back.

Also a weird question to ask, if the universe is infinite wouldnt the concept of a wormhole be impossible as you cannot fold a infinite peice of paper.