After the recent news of the new ongoing Wonder Woman-Superman romance - now getting its own book - it leaves me with one question. What of the events of the Justice League International Annual where Booster meets Rip for the first time in the new 52 and everything is revealed as being wrong somehow? There are no real answers as of yet, but it did get me thinking as to the difficulties of writing realistic time travel.

Time travel is of course a tricky concept to write because of what is known as the grandfather paradox (basically what would happen if you killed your own grandfather in the past). This is one of the fundamental problems with writing time travel that is grounded in logic and science. I looked up a short article that I read some time ago (it is here if anyone is interested in reading it.) The basic problem with time travel basically is one of entropy and determinism (explained in much greater detail in the article.) Essentially it boils down to, that if you are going to travel through time that it is going to be in a way that is pre-determined just as our present reality is (providing you believe in determinism versus free will.) The simple explanation here to justify time travel is to create time travel which is not scientifically based but rather to create it which is supernaturally based. As those that believe in a higher power have a different perspective on determinism (that it is controlled by a deity) then mankind traveling is not necessarily inconsistent with this. Though it is still inconsistent with hard science, and if that is the approach then it is not going to work.

The only option that I can conceive of to make something somewhat hard in terms of science is the bending of time itself. As described in the article time is another dimension, but it is maybe reasonable to think that time would only be bent locally. This is the base of a black hole. They bend the space continuum in a localized spot (defined by their event horizon) but beyond that things are relatively normal. This is why we can have a supermassive black hole at the center of a universe, but being outside of its event horizon we are not really in danger of being swallowed up. So if space and time can be bent in a localized place, might this mean that an observer can have an effect outside of that localized area? I am not sure of course, but maybe this is a realistic place to start, that if mankind is to time travel that we would not do it on Earth. Or to put that another way if Rip and Booster are going to save the world, they would not be doing it from Earth.

ANd there is that theory that says the past, present and future are all happening simultaneously and that's when things get really confusing

@jonny_anonymous: Right, but that is inconsistent with entropy.

This makes me think of the Looper movie... and how it did everything wrongwrongwrong....

@joygirl: I havent seen it yet.

it's very good

@razzatazz: It has absolutely no concern for any rules of time travel. It breaks pretty much ALL of them, to the point where I drew a diagram to show how badly they butchered their respective timelines.

Don't listen to him it's terrible.

@joygirl: Ah ok, I guess I will keep avoiding it.

Just create a time travel paradox and kill your father. Done. You survive. Like in Doctor who.

It's not, it's a great sci fi noir film

@pyrogram: That wouldn't be hard science fiction though, the challenge is to write hard science fiction with time travel.

It's a decent movie if you pay absolutely no attention to the time travel aspects, which make up 90% of the plot.

@razzatazz: It's easy, Use metaphysics time distortions and create a parallel time-line/paradox. In theory, real life theory. It works.

if you say so

Time travel is a fictional concept, so there's really no right, or wrong way to do it. The grandfather paradox is actually more complicated than most think. If you killed your grandfather, then you no longer exist. If you don't exist, then you couldn't have traveled back and killed him in the first place. If you didn't kill him, then you do exist and travel back, kill him, cycle repeats. This creates a paradox. Black holes are the key to moving forward in time. Then again, so is light speed.

I don't think there should be a set rule for time travel. Joygirl says Looper did it all wrong. I disagree. Since there's no possible way of doing it right, how could they do it wrong? What dictates the laws of trime travel? I'm open to all sorts of theories and interpretations of time travel, but fact is, there is no definite answer yet.

On my phone. Don't expect my comment to be at all clear.

@pyrogram: I think you should read that article I attached. That violates entropy.

@awesam: Hard science fiction has to at least acknowledge the limitations of fiction to fit within a factual world.

@razzatazz: How? Entropy?

@pyrogram: The article explains it better than I can, but basically time travel still depends on an equilibrium of the breakdown of matter to a chaotic state (which is what entropy is.)

@razzatazz: Only by one theory. Many, many other theories state the opposite. Travelling FTL creating time distortions for example. Shifting gravity in large amounts also affects time. Something like this.

If you were on earth

and I was next-to a black hole ( alive ) Time would go faster for one of us, I forgot who. Because of the gravity stuff involved...I really really forgot this but it's interesting as hell, Eisenstein and a few others theorized it.

@pyrogram: Entropy is not at all a theory. It is assumed as scientific fact, and one of the laws of the universe.

@razzatazz: I don't see how it relates to time travel at-all.

@pyrogram: I suggest you read that article, it summarizes it a lot better than I can. I am not a physicist after all.

@razzatazz:

I just skim-read it, It's exactly the same thing I just mentioned. Metaphysics and space/time. LOL. And, it's talking about the parent killing thingy stuff. And nobody can say time travel is THIS or that and entropy etc...as its never been done conventionally. Nobody can say it has rules, as the next theory completely contradicts those rules. Entropy is not saying travel is impossible, it says the opposite if you see it in certain ways....

http://www.losfelizpublishing.com/Time%20Travel.htm

@pyrogram: Well entropy does say that it is impossible, but that time space distortions are also only localized phenomena.

When it comes to time travel I just go with the flow. Don't think, it only hurts you in the long run

@razzatazz: ....Go read up on it. It does NOT say that at-all.

@razzatazz: Basically what I was saying is that time travel's impossible. The rest was sort of a reply to Joygirl without actually replying...

@fuchsia_nightingale: If a time machine is ever invented, you stay away from it.

@pyrogram: I read it, but it doesn't deal with entropy as I mentioned, or determinism.

But it's not... -___- It happens every-day when you look at the sun technically, if we go specific.

@pyrogram: I am not following.

@razzatazz: You know we see the sun 8 minutes late? Go to a telescope and we see things millions of years ago, time travel if you will.

If the Grandfather paradox is the problem you could always go with some string-theory to go from timeline α where you went back in time to kill your grandfather, "back to the future" in timeline β (wheras your original timeline might have been δ or another one) where your grandfather is still A-OK.

The concept would be that each time you make a decision a new path opens and two timelines split.

@pyrogram: That is not time travel though, that is just watching the end process of a physical reaction. Photons do take about 8 minutes to reach the Earth, but they actually take between 10 and 170 thousand years to reach the surface of the sun to be released as light. So the atoms that you see now illuminated us, are actually quite old, but that does not mean that you can see what happened 170 thousand years ago.

@warlock360: Sure but that explanation while potentially consistent with some science is not really hard science fiction though.

@razzatazz: ...If we go down too that level things become ridiculous. If I go to a telescope and see a million+ year old nebula. That is time travel, You are travelling back to an event that happened. What is the difference if you are not actually at that location? Still seeing it AFTER it happened.

was it supposed to stay science "fiction"? i thought you were looking for an alternative explanation or something.

@pyrogram: It depends how you look at it. I shouldn't have said it's impossible, but it would be nearly impossible for humans. Especially if it involves traveling at light speed. It would take me a long time to explain my views on it and I doubt either of us have the time, or the attention span.

@awesam: True, its impossible for humans at this time. That we simply agree on.

you could go as far as to call it a fata morgana, since it's only superficial and the actual state of the nebula would be possibly different.

@warlock360: What is superficial? The actual state is different, hence time travel XD

@pyrogram: If you're looking for a debate, then I'll be glad to hear out your views and attempt to disprove them.

@awesam: We agree basically so no point. I don't think humans can time travel.

@pyrogram: if you look at a star far away (like really far away) that would be a superficial insight to a star that might have in reality already imploded. (at the same time you view it, it's not "really there" anymore)

Same time, two different states, one being real the other being superficial.

@warlock360: Hence the time travel. It's looking back in time at its past self.

@pyrogram: That's a dissapointment. I'm going to start one anyway.

What gives you the idea that we can't?

@pyrogram: Well i suppose it is a form of time travel, but then that would also include the same for older pictures of yourself.