What if we changed our timeline already?

BoardsUser836

What if this... all this... what if this wasn't supposed to be our life? What if we... we had some other life and for some reason, we changed things?

GLaDOS

Do you mean we should have died out as a race awhile ago but we've managed to extend our existence?

Or something more metaphysical?

Conor108

I think he means if future people went back in time to some key event and changed it then the whole timeline after that event would be changed. Is that what you mean?

kumate_champ07

question makes zero sense

Nabber

Then we never changed our timeline :rolleyes:
What ever timeline you think we 'changed' was always meant to be the timeline anyways.

Gary L

1. no timeline is more or less legitimiate than any other potential

2. It would be ironic if they stopped something trivial and accidentally caused the holacaust

doncarlos

Gary L wrote: »

2. It would be ironic if they stopped something trivial and accidentally caused the holacaust

Or that time travel episode of red dwarf where JFK is the second shooter in the JFK assassination.

krd

Or a better question. A hypothetical question that can drive people bananas

If you were able to travel back in time, and stop yourself from being born. Would your future self vanish in a puff of nothingness. Or would your future self still exist in the past?

Gary L

krd wrote: »

Or a better question. A hypothetical question that can drive people bananas

If you were able to travel back in time, and stop yourself from being born. Would your future self vanish in a puff of nothingness. Or would your future self still exist in the past?

Often tried to wrap my noggin around that one. I dont think the train of causality would follow you back into the past but rather it would sever any connections you had in your original time. You'd essentially be parentless, at least from their perspective.

Capt'n Midnight

Gary L wrote: »

It would be ironic if they stopped something trivial and accidentally caused the holacaust

Time lines where the cure is worse than the disease.

http://en.wikipedia.org/wiki/Making_History_%28novel%29 by Stephen Fry no less

http://en.wikipedia.org/wiki/Pastwatch:_The_Redemption_of_Christopher_Columbus

krd

Gary L wrote: »

Often tried to wrap my noggin around that one. I dont think the train of causality would follow you back into the past but rather it would sever any connections you had in your original time. You'd essentially be parentless, at least from their perspective.

How would the train of causality not follow you back into the past?

I remember seeing a discussion on this go on for a long time elsewhere.

There isn't really an answer. Or to come up with an answer you would have to make assumptions about things we don't, or can't know.

Capt'n Midnight

One of the problems with time travel.

May also apply to time lines

krd

Capt'n Midnight wrote: »

One of the problems with time travel.

May also apply to time lines

And how do you know that, Mr. Time Traveller - have you got your Dolorean parked outside?


You're assuming, that time travel must occur in absolute space, and not relative space.

Something that struck me recently. The early expansion of the cosmos. Matter had to be able to travel faster than the speed of light straight after the big bang to get where it did. Which made me think - there may be a way to time travel.

bnt

"Supposed to" implies that there's "something" out there doing the supposing, who knows how it's "supposed to" be. I don't see any evidence of that.

southcentralts

What if "What if" meant something else?

bogwalrus

krd wrote: »

Or a better question. A hypothetical question that can drive people bananas

If you were able to travel back in time, and stop yourself from being born. Would your future self vanish in a puff of nothingness. Or would your future self still exist in the past?

Peter Griffin solved this quite easily

southcentralts

bogwalrus wrote: »

Peter Griffin solved this quite easily

using the Marty Mcfly method

Mayor West: Have the boys in the lab check this out.
Boys in the lab: Sir we report that Peter Griffin is greater than or equal to Marty Mcfly!.
Mayor West: CHECK IT AGAIN!!!

Cork boy 55

I have a simple rule for live regarding time travel

(1) Do not think about it it will wreak your head.

Cork boy 55

As Stephen Hawkings said

A possible way to reconcile time travel, with the fact that we don't seem to have had any visitors from the future, would be to say that it can occur only in the future. In this view, one would say space-time in our past was fixed, because we have observed it, and seen that it is not warped enough, to allow travel into the past. On the other hand, the future is open. So we might be able to warp it enough, to allow time travel. But because we can warp space-time only in the future, we wouldn't be able to travel back to the present time, or earlier.

This picture would explain why we haven't been over run by tourists from the future.

...........
The conclusion of this lecture is that rapid space-travel, or travel back in time, can't be ruled out, according to our present understanding. They would cause great logical problems, so let's hope there's a Chronology Protection Law, to prevent people going back, and killing our parents. But science fiction fans need not lose heart. There's hope in string theory.

Since we haven't cracked time travel yet, I have run out of time. Thank you for listening.

http://www.hawking.org.uk/space-and-time-warps.html

pbowenroe

Capt'n Midnight wrote: »

One of the problems with time travel.

May also apply to time lines

can someone explain this please?

Gurgle

pbowenroe wrote: »

can someone explain this please?

If you travel in time but not in space, the earth is somewhere else on its orbit and you arrive in open space.

pbowenroe

ah, thanks

seamus

let's hope there's a Chronology Protection Law, to prevent people going back, and killing our parents

This and tbh the phrasing of the OP are bit non-sensical because they presume that changes in the timeline occur chronologically, i.e. that the timeline doesn't change until someone travels back in time.

In reality if someone has travelled back in time and made changes, then that has already occurred, and this is the correct timeline. Any idea of a "Protection Law" is equally absurd because we would never be aware that any change had ever taken place. Things are as they always have been and will be, chronologically. This logically precludes anyone going back and making changes because from their point of view, the change they were going to make, has already been made.

You do have multiverse theories which propose that the timeline is fundamentally unchangeable, and any trip back in time to make changes is just a jump into a different universe. From the point of view of the person who made the changes, they're in a new timeline, but their original timeline continues elsewhere and hasn't "changed".

southcentralts

seamus wrote: »

This and tbh the phrasing of the OP are bit non-sensical because they presume that changes in the timeline occur chronologically, i.e. that the timeline doesn't change until someone travels back in time.

In reality if someone has travelled back in time and made changes, then that has already occurred, and this is the correct timeline. Any idea of a "Protection Law" is equally absurd because we would never be aware that any change had ever taken place. Things are as they always have been and will be, chronologically. This logically precludes anyone going back and making changes because from their point of view, the change they were going to make, has already been made.

You do have multiverse theories which propose that the timeline is fundamentally unchangeable, and any trip back in time to make changes is just a jump into a different universe. From the point of view of the person who made the changes, they're in a new timeline, but their original timeline continues elsewhere and hasn't "changed".

seems like a whole lot of effort to create a new universe (timeline) within a multiverse, already diverging with each decision we make, (should I travel back 10 or 11 years? ANS: both, each one in different universes).

Though seriously seamus, is consciousness a mitigating factor to a multiverse or are the universes randomly different, indifferent to the conscious mind.

seamus

Consciousness is irrelevant as it's a physical manifestation existing within a particular universe.

There are many multiverse theories of course, some that each universe is randomly different, others based on quantum theory where every possible outcome of a given incident (at the subatomic level) represents a new universe.

From the observer's point of view of course, there is no difference between these things; the latter is effectively random.

It wouldn't be so much that "changing" the timeline creates a new universe; that universe already exists but the traveller is moving from one to the other. Of course, the ability of matter to move between universes opens a whole other can of worms.

jigital

If you are interested in this hypothesis you should look at the Wikipedia article "Grandfather paradox." There is even a link within to listen to the article in spoken form. http://en.wikipedia.org/wiki/Grandfather_paradox

Gurgle

jigital wrote: »

If you are interested in this hypothesis you should look at the Wikipedia article "Grandfather paradox." There is even a link within to listen to the article in spoken form. http://en.wikipedia.org/wiki/Grandfather_paradox

Isn't the grandfather paradox defeated by polychronologic grammar?

i.e. you did always will have been your own grandfather or neither of yourself would exist.

Dave!

What if we're all just brains in vats, being fed what we perceive as reality?!

It's fun to throw around crazy hypotheses, but they're not testable so there's not much point really

Gurgle

<turns down power to Dave's vat>

CiDeRmAn

If you subscribe to the many-worlds interpretation of quantum mechanics then all realities are real, if you go back in time and change things you just create another branch in the infinity of possible universes, the problem happens here not if you can travel in time but if you can't universe hop back to your timeline, otherwise you just return to your present, except with the changes intact, so you wouldn't exist.
This will probably mean that for every successfully departing timetraveller we probably won't get too many back!

Also, time may be a feature of our brain chemistry and hence our consciousness, therefore a direction to time may be meaningless at other scales, certainly at the subatomic scale times direction is, well, relative.
If we can cope with the idea that time as a sequence of events, one after the other, isn't arbitrary it may, ultimately, be nonsensical to talk of time travel at all.

Who the heck knows!

Time travel appears to be only possible in a universe with a time machine in it, it's like fax machines, they only make sense when you have a transmitter and a receiver, otherwise it's just a paperweight.
So it is with a time machine, unless you have a receiver as well as a transmitter it won't work.

Please watch Primer for all your time travel questions answered!

Masteroid

krd wrote: »

Or a better question. A hypothetical question that can drive people bananas

If you were able to travel back in time, and stop yourself from being born. Would your future self vanish in a puff of nothingness. Or would your future self still exist in the past?

No, you wouldn't have any effect on your past at all and would only effect the future of your parents et al.

You might have a problem obtaining a birth-cert though and the you couldn't make a claim on the social and would lack a PPS number. That's how we can detect time-travellers.

Masteroid

Even if you support the many worlds hypothesis the existence of this universe is yet to be sufficiently explained.

I think there are many problems with time-travel the main one being that 'time' itself does not exist as an entity. The phrase 'travel back in time' would be more correctly stated as 'reverse all the processes in the universe that have occurred since the time we want to travel back to'.

Another issue might be that even if all events exist as an infinity of unique universes and time-travel were merely a process of hopping from one universe to another, since the universe is expanding, wouldn't a universe in the past be smaller than the universe of the present? We might be giants in yesterday's universe.

Then there is the first law of thermodynamics. If time travel occurred then energy that is present in the universe would be removed to another time and there would be extra, new energy injected into the universe in some other present.

ScumLord

I don't really see time travel as possible, I see time simply as a measurement of distance and movement so to reverse time you'd have to make everything go back the way it came along the exact path it went forward on. That would seem impossible to do to an entire universe, the past is gone as far as I'm concerned it simply doesn't exist anywhere.