Saturday, 16 October 2010

Time Travel or Universe Travel?

Lately my mind has been drifting to the thoughts of time travel. In this week alone, I went and saw Back to the Future in the cinema and I got the majority of my new tattoo finished.

Now, one can only hope that when we discover the time vortex, it is that pretty and colourful and shiny.

So, thinking about time travel, in my opinion, it goes something along the lines of having billions and billions of parallel universes. Time travel is not so much the travel along a linear time path, but a jump into a timeline of a different universe. For example, in Back to the Future when Marty goes into 1955 and ploughs down one of the "Twin Pines" with his Delorean, he changes the future of the shopping mall to "Lone Pine". However, he has entered a new universe. The universe where Marty left continues on, with two pines and a wimp of a father, but without Marty. The parallel universe that the Marty we are following enters, has previously been occupied with a different Marty who disappeared to a new universe when he took off in the Delorean the same way our Marty did. Okay, this gets a bit confusing. Let's try a new one.

So, take Star Trek. Now aside from the brilliant, innovative science behind "red matter" (ha ha) the time travel is quite interesting. We have all happily followed along the adventures of Kirk, Spock, Uhura, Scotty and the other members of The Enterprise with (occasionally) silent devotion. As the timeline continued, with the stories we knew, at one point the Romulan planet gets annihilated in a supernova. Spock and the Romulans travel through a black hole "back in time" (i.e. to another universe) and pop out at the location of the USS Kelvin, starting off the plot of the new Star Trek world. We are now in a new universe where new adventures with the usual gang can take place. The original stories that we all know are still in tact, but in a different universe.

One last example, in The Big Bang Theory Sheldon postulates that if he invents a time machine, he will go back to himself and inform him of the invention, thus relieving Sheldon of ever having to invent it. However, the Sheldon in that universe would have to still invent the time machine; it is the Sheldon in the new universe that will be spared the invention.

These are the things I ponder when trying to fall asleep. It isn't perfect, but it is sure fun to think about. What are your thoughts? How do you think of time travel? Bring it on!

On a side note, Back to the Future was AWESOME in the theatre!


  1. The problem with the multiverse model for time travel in BTTF is that Marty starts to fade out of existence when the probability of his parents getting together starts to fall. It could be that he's just travelled into a parallel universe where things like fading out of existence happen to happen, but otherwise I'm not sure there's really any good model that could explain how time travel works in BTTF.

  2. It seems you're advocating a "Sliders" TV-show mentality for time travel, yes? Infinite plurality of parallel universes? The only problem to me with that rationale is something crying out from a dark recess of my brain about conservation of energy... Assuming the laws of physics don't go completely out the window, having two Martys or two Spocks in one timeline leaves a deficit in the original universe... There's something to be explored there. Something...

    Re: Matt's observations>

    Perhaps time travel in the BTTF universe and "fading" into and out of existence can be explained simply. The observations of time travel effects in BTTF (if we can call them "observations" for the time being, lol) seem to imply that there is a maximum "speed" that the time-change effects propagate through a timeline, hence a "fade" and not a sudden "blink" out of existence.

    So, at least to me, it seems like BTTF's take on time travel says the Twin Pines Hill Valley universe faded out of existence entirely as the Lone Pine Hill Valley faded in, with a somewhat substantial lag time where both existed for a spell, and unaffected elements simply appeared unaffected to someone "time-jumping" between them. Or maybe it is just completely inconsistent...

    (I mean, why doesn't the picture in Marty's hand just disappear instead of the image of his brother's head? Would his parents have taken a picture of a hedge with nobody in front of it? Would they have even been there to take a picture in the first place? Hmm.....)

  3. Literally happened on this by chance tonight and said I'd leave my own meandering thoughts for the internet to enjoy. aaaaaaanyways, I often think about time travel and was nuts about it as a kid up until I thought literally about this stuff e.g. killing your grandfather in the past and could it ever be possible but now I wonder whether our perception of time as having a past and future is where the problem lies and that each of us has our own little time space continuum, so, were I to travel back in time and kill my grandfather then perhaps that would only effect my own subjective perception of time. Dooming myself only, but because I have ceased to have any effect on time/space in my original reality I don't really know if those people perceive any change at all. So were it in back to the future then perhaps and I'm pushing the rationality of this quite a bit but perhaps were marty to return to the past with the pic and his great grandfather die or whatever then the picture and he himself would have completely left their original time space location. I guess in some ways that reality would have been completely destroyed from Martys perspective however the picture would have also traveled back with him so should have also remained unchanged, Either way I always wonder how scientists in these movies can build a time machine that goes both backwards and forwards in time. I just can't help but feel that these would be two completely different technologies. Then again, I guess I'm assuming there's any difference between past and future anyway, as if the universe cares.