• Time Travel, Possibility or Fiction?
    337 replies, posted
I asked a physicist once about relativity, might be of use here. [IMG]http://dl.dropbox.com/u/34696236/dave%20goldberg.png[/IMG]
[url]http://www.bbc.co.uk/news/science-environment-15017484[/url] given this recent discovery, time travel has more of a possibility of becoming a reality
[QUOTE=Hayburner;34047148][url]http://www.bbc.co.uk/news/science-environment-15017484[/url] given this recent discovery, time travel has more of a possibility of becoming a reality[/QUOTE] I don't know if that is going to lead to some breakthrough though. I've read that observing the neutrino going faster than the speed of light is just an optical illusion. It's very cool though.
Well.. they are blasting neutrinos and other things that are like split atoms to light speeds, and we humans need to get to that speed, in some vehicle. So that's a other whole new story
Okay, So this may just be my 2 cents but, Most theory's state that time is like a river, going back and changing something would produce an alternate future, but we are already living in the future, were our past happened. If someone from our future went into the past it would create a completely different timeline. Also time isn't linear, people haven't appeared in the past yet because we would need to make the machine then go back, again effectively creating a timeline we haven't experienced.
I'm just going to chime in and say that time travel is an animal that humans just shouldn't ever mess with. We're too sentimental about past events and we all think we know what's best for everyone. Shit would get fucked up so quickly with that kind of power. Of course, this is assuming it will affect the present, which is baseless and unlikely, but still. I just don't see any value in a technology like this, because even if you use it to "better humanity", at the end of the day you have man (or men) deciding what is "better".
You can travel to the future. But IMO we can never travel to the past.
[QUOTE=booster;34075299]You can travel to the future. But IMO we can never travel to the past.[/QUOTE] This. It seems we've already kind of made this concrete with our current understanding of the universe. In the dimension we experience time, is completely linear. Only going forward, not backwards. Maybe someday we'll have the technology and understanding to embrace a higher dimension and unlock new possibilities. But I don't see that happening soon.
We only perceive time in one direction: forward. But in reality, it could be three-dimensional: there could be multiple time "tracks" sweeping back and forth, up and down. And we don't perceive changes in time, because we exist in it, if time goes faster, our thought processes go faster, and we perceive time as normal. Same if time goes slower. Hell, you could make a graph with a sine wave and say "that's the speed of time", you could be damn right. And time travel could very well be possible. You might say "well if someone 500 years from now went back and changed things and fucked it all up, we'd notice". But perhaps some kind of "time police" 700 years from now will exist and will fix these sort of things, so we'd never notice. So we don't know until we find out how.
People said powered, heavier than air flight was impossible. People said real-time face-to-face communication over vast distances was impossible. People said space flight was impossible. People said walking on another orbital body was impossible. Every single one of those things has been done. So who's to say time travel won't be done either? Scientists have this strange habit of taking "x is impossible" as a challenge rather than a fact, and in doing so I believe we'll figure it out.
[QUOTE=Scoooby;34079461]It seems we've already kind of made this concrete with our current understanding of the universe. In the dimension we experience time, is completely linear. Only going forward, not backwards.[/QUOTE] That's not true though
[QUOTE=JohnnyMo1;34080829]That's not true though[/QUOTE] I'm just saying it doesn't appear possible in our dimension. Perhaps if we were to expand to the 4th dimension or something. Then perhaps. I understand time isn't actually linear. It just is for us in the third dimension. Considering string theory is based on different timelines and possibilities occurring, then I guess you could say it is possible.
I don't think it's very likely that we will be able to travel back in time, but traveling forward in time at increased speeds might be.
[QUOTE=Scoooby;34081460]I'm just saying it doesn't appear possible in our dimension. Perhaps if we were to expand to the 4th dimension or something. Then perhaps. I understand time isn't actually linear. It just is for us in the third dimension. Considering string theory is based on different timelines and possibilities occurring, then I guess you could say it is possible.[/QUOTE] No, even outside of string theory it's possible. [url]http://en.wikipedia.org/wiki/Closed_timelike_curve[/url]
As I see it, if you want to go back in time you'd need to reverse Entropy for the entire universe or something. That would require a lot of energy. Okay guys rate me all your dumbs.
Timetraveling back in time is probably possible. But like some posts state, it would probably create a new universe if one would go back to time since the dimension you came from should by logic(according to me) continue on without you and as you go back in time you form a new universe since it needs to continue with you. Or you'll just vaporize.
[QUOTE=NETVERK;34082899]As I see it, if you want to go back in time you'd need to reverse Entropy for the entire universe or something. That would require a lot of energy. Okay guys rate me all your dumbs.[/QUOTE] time isn't being written as we experience it, you can't "undo it"
[QUOTE=JohnnyMo1;34082447]No, even outside of string theory it's possible. [url]http://en.wikipedia.org/wiki/Closed_timelike_curve[/url][/QUOTE] Yeah true. For some reason I've been including string theory into everything. It makes sense though. "A closed timelike curve can be created if a series of such light cones are set up so as to loop back on themselves, so it would be possible for an object to move around this loop and return to the same place and time that it started. An object in such an orbit would repeatedly return to the same point in spacetime if it stays in free fall. Returning to the original spacetime location would be only one possibility; the object's future light cone would include spacetime points both forwards and backwards in time, and so it should be possible for the object to engage in time travel under these conditions."
I've always viewed time as entropy. As entropy can't be reversed, so can't time.
[QUOTE=Parja;34094867]I've always viewed time as entropy. As entropy can't be reversed, so can't time.[/QUOTE] when did anyone talk about reversing time
With the knowledge I have now, definitely fiction.
[QUOTE=BananaFoam;33532356]Lets put this in a way that easy to understand. If timetravel is ever invented, we would likely all be dead already. I mean, what's there to stop some dickhead from going back and say, aiding the Nazis to win WWII? How about a barrier to keep them from coming and enacting a nuclear holocaust in the cold war? Fanatics, militants, terrorist, and just assholes could and likely would have gotten their hands on this by now if it ever gets invented. However, time-travel is achievable (and already has been achieved) through different means. If something is going really, really fucking fast then whatever that item is will not age as fast as the world around it. It would technically warp to the future, but visiting the past is impossible. And that "already achievable" thing, guess what, astronauts go so fast when travelling in rockets that scientists have verified that they are a fraction of a second younger then if they had merely stayed on Earth. of course, it's not like that makes a difference, but it shows it's possible.[/QUOTE] The person who did time travel and did X would only see what he caused, we wouldn't as our time wouldn't be affected. It's like a different universe.
[QUOTE=SIRIUS;34100750]when did anyone talk about reversing time[/QUOTE] When you go back in time you reverse it, unless you assume alternate realities.. in which it isn't reversed.
[QUOTE=DanishD;32725766]Time travel, into the future is possible (and has happened). if you had an identical twin, who was the exact same age as you, and you went into orbit around the earth for a couple of years, due to the speed you travel at in orbit, he would be older than you when you got back. I can't really explain it better than that :/ other than this has happened to an astronaut, who was in orbit for a long time, and because of that, "travelled" a few seconds into the future.[/QUOTE] Isn't this just slowing down time? By going into the future you've made all the actions/decisions pre-made that make you who you are or where you are etc. By slowing down time you're still consciously making these everyday decisions therefore I don't count this as time travel in my book. This is sorta like saying inception is time travel. Unless I'm getting this terribly wrong of course.
Time dilation isn't time travel Danish. The bending of SpaceTime has already been observed, but it's unrelated to actually traveling in the past.
Well, if you shot away from earth, faster than the speed of light, wouldn't you pass the light beams going to wherever you land, and then, provided we had a telescope that could see that far, look into the past? It isn't exactly time travel but...
Traveling in time forward is possible by going fast enough - you essentially "fast forward" time, like you would a movie. Going back is impossible, as consider this: I stand infront of a portal that goes back intime and unload a gun from its case. I then go around to the other side of the portal and shoot myself through the portal, since when the bullet hits me i will be back in time - standing infront of the portal. What happens now? For simple reasons it doesnt work.
[QUOTE=iwancoppa;34103391]Traveling in time forward is possible by going fast enough - you essentially "fast forward" time, like you would a movie. Going back is impossible, as consider this: I stand infront of a portal that goes back intime and unload a gun from its case. I then go around to the other side of the portal and shoot myself through the portal, since when the bullet hits me i will be back in time - standing infront of the portal. What happens now? For simple reasons it doesnt work.[/QUOTE] All paradox arguments like this for the inability to go back in time rely on the existence of free will. Nothing physical excludes backwards time travel.
[QUOTE=Bawbag;34101040]When you go back in time you reverse it, unless you assume alternate realities.. in which it isn't reversed.[/QUOTE] That's how I'd look at it. If time travel were feasible, I would assume that going back into time would lead to parallel universes and not the same previous ones we existed in. It wouldn't make sense for us to reverse time, because what we've been learning from quantum mechanics is there's large support for multiple dimensions/universes. I've been trying to understand QM. It's difficult considering I've only been able to understand so much of the mathematical concepts. Matrices make sense, vectors make sense. Scalars seem to focus more on the rotation/orientation. Tensors seem to show that a vector can be split into several more directions. Which adds on to the possibility of alternate dimensions beyond the visible dimension. Or perhaps I'm analyzing it too hard, (I think I heard that from somewhere). Tensors may just be nothing more but to be used to represent momentum fluxes. [img]http://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Components_stress_tensor.svg/300px-Components_stress_tensor.svg.png[/img] (Reminds me of 3D modeling) Spin and Angular momentum are hard concepts for me to grasp too (without ever taking an intro to physics class in highschool). I'm understanding internal and external forces in relation to the conservation of angular momentum, but how that relates to QM and subatomic particles having spins, is where it gets a little hazy. :d Vector's represent x,y coordinate properties (position in vector space). So I'm guessing scalars and tensors expand from there.
You're misunderstanding tensors but I don't see why you're having issue with them? I don't think they generally show up in introductory QM. They're much more related to relativity.
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