If time machines existed

From everything I've heard, there are two simple ways to think about time travel and the consequences of traveling through time.

1) Fate
Everything that's going to happen is set in stone. If you go back in time and kill someone, then you're not actually changing anything. You were meant to go back in time and kill that person. This has been done a number of times in media, with my favorite example being a child witnessing a murder, then traveling through time in the future and discovering that the murder he witnessed as a child was his own (he saw himself get killed).

2) Multi-verse
There are different universes. If you kill your grandpa, then either that creates a universe where your father was never born, or you traveled to a universe different from your own, thus making any actions you made there not affect your universe at all. This was done in Dragonball Z, with Trunks and Cell changing the past but really just affecting different universes and not their own.

I don't know anything about the actual science stuff, except that it's all out-there stuff that cannot be tested in a laboratory at this time. Those two ideas are just what I've picked up from science-fiction media and what other people have said.

i wouldnt want to use a time machine. If i had a choice i would rather take over my own body back when i was a baby and relive my life.

Really? Hmm, it seems to me by stepping foot in the past (or future) you're changing Destiny, Fate, or this movie real. Am I missing something here? >_>



Maybe our "movie" is the only place where it actually get built? I don't know.



Yes :D

if a time machine ever been build then i will use it to travel back to time and offer some of my advice to GOD.

I'd rather go forward in time then back, just to see if I actually become someone successful, so that if I messed up somewhere, I can fix my mistake.

yeah then you just killed your future self.

Oh well, he'll still exist, just as a successful person.

Personally I favor a parallel time lines type of time travel where you could in fact go back and kill your own granpa but still exist. This would be because either you'd stay in the new timeline you created and your existence doesn't need to be supported by the timeline you're now in because you come from another one that does support your existence or you go back to your original timeline where you didn't kill your grandpa. Of course going back to your original timeline is pretty much for the "oh ok I've screwed things around too much, let's go back to how things were before I started messing around" because otherwise there's no point in you going back in time and changing things because the changes don't happen in that timeline so they'd effectively not have happened.

I like this type of time travel because 1) it sets up infinite parallel universes. 2) because paradox is a non-issue. Your existence in a timeline where you couldn't have come into existence isn't a paradox because you're just some guy from a parallel reality where you did exist. 3) Because you could harvest the resources of other timelines for your own thus having a world where there is unlimited resources. (Bonus points for stealing food from yourself in the past that you ate so you can eat it again.) 4) You're just as likely to encounter people fucking with your timeline who come from other ones so it's fair. 5) Things get really really weird if multiple timelines have time machines and are aware of each other.

Sweet! So many cool replies! So many that I can't reply to them all. RBZ's prof has a cool and realistic view on the topic! If you will try to kill your grandparents, then you failed! XD


anyway, as for all of the replies. What if you can travel back in time, but the things around you is intangible?

Large Hadron Collider. At least, it has the potential, via the creation of a Black Hole.

The Large Hadron Collider (LHC) is the world's largest and highest-energy particle accelerator, intended to collide opposing particle beams of either protons at an energy of 7 TeV (1.12 microjoules) per particle, or lead nuclei at an energy of 574 TeV (92.0 microjoules) per nucleus. The term hadron refers to such particles that are composed of quarks. It is expected that it will address the most fundamental questions of physics, hopefully allowing progress in understanding the deepest laws of nature. The LHC lies in a tunnel 27 kilometres (17 mi) in circumference, as much as 175 metres (574 ft) beneath the Franco-Swiss border near Geneva, Switzerland.~wikipedia

wow. hmm. I guess this topic is unanswerable after all... x.x

Technically speaking, if you want to look into the past, all you have to do is look into the sky. All the light from those stars are hundreds, thousands, or even millions of years old. Even light from the sun takes 7 minutes to arrive on earth.

Anyway, this is the perfect opportunity to talk about something that I saw in a Barnes & Noble bookstore. While I was walking around aimlessly, looking for interesting books, something caught my eye. It was about unexplained phenomena, mysteries, etc. One of the chapters of the book talked about a person named John Titor. They say he was a time traveler from the year 2036!! I kid you not.

He wrote about various things, like how there was going to be a civil war here in the US followed by WWIII, all of it happening by 2015. I'm really trying to summarize it cuz I'm too lazy to write it out. What's interesting is that he does describe his "time machine" in some detail.

No, I don't think what he was saying was really literally true. But its still an entertaining story.

Actually if you think about it the presence of Fate is given if you accept that you can't change the past. Eventually your present becomes past so then the whole of history is fixed since if you traveled to the "end" of it it would be unchangeable.

However this doesn't exclude free will. That would mean that you have no control over the result. That's why predestination and so on in religion is so complicated because even your garden variety philosopher had to admit that your choices *did* influence the outcome.

We could also pose the problem as one of the observer: Observed from inside the time-stream there is change since the you can't look ahead and see the future. From outside the time-stream (how a time traveler would look at it) it's all fixed an unchanging, since all the choices have been *already made* by the participants.

This is a linear view of events and how we experience it.
However what if it isn't really like that? What if there are several realities that one can experience one outside the (perceived) time-stream?

What if not only the future but the past could be changing and instead a single "stream of events" you'd get a texture of diverging pasts and futures that converge in various presents.

BTW here's the catch of Time Travel:

Any Faster Than Light phenomenon also holds the potential of Time Travel.
This is why physicists like to address this like this:

"Relativity, Faster Than Light, Casuality - pick two"

Ergo if both FTL/TT and Relativity are true than we're not living in a casual universe where cause and effect follow each other. (It seems to be so... however what if it's only how we perceive it?)

I looked at the John Titor link and saw that he said that UFO's are also time travelers, which I also believe. But anyway, his statements are not quite that believable. I want to see the pictures that he posted to prove his time traveler.


[What if not only the future but the past could be changing and instead a single "stream of events" you'd get a texture of diverging pasts and futures that converge in various presents. ]

Hmmm... true, if the past is also the present and the future is also the present =O.
i mean, if at this point in time if the future is playing (i used that term like for videos) and also the past, then we will have omg..the universe really is infinite.

But anyway, coz if the universe is finite, then we will be stacking up with the other realities.

After watching a bunch of movies related to time travel, I know that messing with time is definitely not a good thing to do. Messing with the past can drastically change the present. Also, I wouldn't want to go to the future mostly because I'd want to keep it a mystery....

I wouldn't want to live my life knowing what happens exactly in the future and live without hope.

Okay, here's how it is.
Time and space are actually like a bit of fabric. Time goes one way, and space crosses it. The observer travels along the fabric, in a linear path based on paradigms set forth by his species.
(Envision that)


Okay, so you're travelling along the fabric, attempting a straight line. The funny thing is, that it's not a straight line. In fact, it looks something like this:

This happened by accident, Black holes (an as a consequence, wormholes) have such strong gravitational pull, that it exerts force on the entirety of spacetime. (place a rock on your mental fabric)
Because the force is so strong, things going into the holes move faster than the speed of light (which is why light cannot escape). This is a nasty state of affairs, and the extreme amounts of energy burn through the spacetime shirt-thing.


With enough black holes, we end up with a ball of....wibbly-wobbly timey-wimey....stuff. It's all linked together (in places where it touches) and certain points are traversable. This equates to time travel, although it is more exact (and less adjustable) than the romanticized version.

That was a shitty sci-fi movie. The title is irrelevant.
As it stands, time is not set. HOWEVER, because changing time changes memories, nobody would notice. Should paradox occur, it will cycle and re-cycle until time travel "never happened".


In order to properly time travel, one would need an encyclopaedic knowledge of history, and a device to remove him from the regular flow of spacetime. I'm thinking of beings existing in five dimensions, allowing them to touch the four we know--but maintain placing when something changes. (Like riding the bus. You move through the city, but are still anchored to your seat.)

If they existed, I wouldnt use them. I dont think anyone should. Messing with time has got to be one of the STUPIDEST things that someone could do.

13