"The future ain't what it used to be."

# Is any time change = Grandfather Paradox?

#### Yankee

Timekeeper
Grandfather Paradox summary: I go back in time and kill my grandfather before he impregnates my grandmother. An apparent paradox, because then I am never born and thus never go back in time to kill my grandfather, thus he lives and impregnates my grandmother and I am eventually born to go back in time...

Seems like time travel theories are invented to "solve for" the various apparent paridoxes.

We use this example because it is simple and fairly easy to understand. My question is whether or not all time changes can be simplified into the same grandfather paradox.

Is any time change equivalent to the grandfather paradox?

I am not so much interested in theory that explains the grandfather paradox isn't a paradox, but rather that all time change creates the same apparent paradox.

Hank

(I wish I had a stronger background in symbolic logic, but then it might be inaccessible to others (like me now))

A time traveler (Hank) goes back in time and makes a change (kill Hank's grandpa) that makes the initial trip not possible (Hank wasn't born).

Is the following situation equivalent?

My dad could really use some money right now, so I go back in time and tell him to go buy Microsoft Stock.

The only reason I went back in time was to tell him to buy the stock because he needed the money. Thus, after my trip, he no longer needs the money, so I don't go back in time to tell him to buy the stock, therefore he does need the money...

Hank

O.K. let's just say for the sake of argument, you "did" go back in Time, with the intent to kill your Grandparents (as a test)

First of all, because you were not even born yet tells us clearly that you have killed somone elses Grandparents that may resemble your own, but are not.

Also the fact that you are still alive afterwards clearly tells us that they are not "Your" Grandparents, so the question remains if this scenario ever were to take place, "Who's Grandparents did you kill then?

Truly this is indicative that what you are participating in is an "Alternate" or "Parallel" Universe, regardless, threfore in spite of the question as to wh's Grandparents you have killed, it is very possible that your "Meddeling" has set forth a cosmic chain reaction in the Time-Line directly associated to that of your own, therefore it is contemptious to believe that after comitting such an act while Time~Travelling, that you would be capable of returning to your original World from whence you came from.

What I am proposing here is that if you were only observing that Time-Line, without creating any "Drastic" alterations as such, it is possible that you may be more capable of returning to your original point of origin with little, or no divergences, however when you participate in such alterations, I believe that this action
for every action, there is an equal, or greater opposing)...action creates a seperation that prohibits your ability to return to your original world, instead, you end up returning to the one that you altered.

<just a thought>

Don't take my word for it though, you can see that I am not the only one out there that shares this view, including one of our world's leading physicists "Dr. Michio Kaku". Check out his website & see for yourself how he negates those paradoxes!
http://mkaku.org

Again, if a 30 year old man travels back in time 25 years, does he become the 5 year old he was back then? And, if that same 30 year old man travels back in time more than 30 years, does he become the man/woman/animal/thing he was in a previous incarnation? That might explain why we don't meet many time travelers.

Again, what I'm asking is if all time change is essentially the same apparent paradox. I am not asking how we develop a time travel theory that explains that those paradoxes are not actually paradoxes.

I want to know if making any change is logically equivalent to the grandfather paradox. I am leaning towards yes, but am not totally convinced.

Yankee: Ok, there's my answer for your question: It starts by "suppose the granfather-paradox is achievable and possible"-then anything else that you may change or do (anywhen) will create a paradoxe: but thoses paradoxes, if they really exists, you never know about it. The way a paradoxe do his job it's in a way that something anormal occur -]then the main question come-]what append then?

So, I believe that anything you do, either now, yesterday or tomorrow, will create changes in the "time line", if you do something that might create a paradox (actually: do the action that makes imposible to you to make this action, by exemple)then I believe (that's further than the answer)-] a big "reset button" is pushed in our brain, and we get back to the point where everything started...

Time02112: About your theory on killing the "wrong grand-parents"; I taught this; If you travel in past, are you able actually to bring your actual body (brain-knowledge...), for shure, going in the futur (by higher speed) is just a "preservation" of the body and the 'soul' - going in the past would maybe be a formula who stands on a relative principle? To come to that point: we already talked about the fact that <if we time-travel thru a machine fixed on earth-time, we won't be able to travel back before the activation of the very machine(...) - where our bodies are actually our time-machine, it's maybe not possible to get back before our born (if the case is, the next question is: so how much control would be have over time in that situation).[P>Oh gosh! I just got a flash... There's too much already here, I'm starting a new topic (inspiration time!)

hope you got something?!!

Scenario #1
I get a manuscript in the mail describing how to build a time machine. After ten years of hard work I get it to work, so I go back in time 10 years and mail myself a manuscript with the instructions...
Who invented the time machine?

Scenario #2
I get a visit from an old me, who gives me his pocketwatch. When I am old and grey I go back in time and give myself that trusty pocketwatch.
Who (or what) created the watch?

I think these are functionally different from the grandfather paradox. They both involve the paradoxical existence of something (in #1, information, in #2, a watch), while the grandfather paradox involves the absence of a grandparent. Perhaps these are functional opposites?

Yes, Thank you, NoName. I'd forgotten about that paradox, which I believe is not logically equivalent to the grandfather paradox. I think I've heard it referred to as many different things, but I like the simplistic "free lunch" description.

So, the next question would be whether or not all time change paradoxes are either logically equivalent to the grandfather paradox or the free lunch paradox...

Hank

i think there may be a worse paradox than the grandfather or free lunch paradoxes. if you go back in time, say from june 7 to june 6, and don't make any large changes, then in one day (june 7) another you will try to go back in time, to june 6. however, you were already at that same place (the location of the experiment) at the exact same time (june 6) that the new you is trying go back to. this means the new you will occupy the same point in space and time as you were. isn't this impossible? i think that before you're able to kill your grandfather or do anything at all, you'd be caught in some kind of anomaly or something, maybe blow up the entire universe? =) this paradox assumes no parallel universes, but neither does the grandfather or free lunch paradoxes.

nature has laws to protect against paradoxes, in this case, nature might not allow time travel to be possible. chronology protection conjecture.

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<Corran>

Noname is correct. There are two known forms of temporal paradoxes. They are the consistency paradox an example being the grandfather scenerio you speak of. The second type of paradox is the bootstrap paradox. This type of paradox is like what Noname was saying, if an oldman gives me a time machine and some time in the far future, I go back in time and give my younger self the time machine then who invented the time machine, this is a bootstrap paradox.
I am sure there may in fact be other paradoxes but these are the two general classes which place the most limiting constraint in scientist's minds about whether time travel is in fact possible.

OK then, it is possible to change history without creating a paradox. This is how you do it...
1] Go back in time. For this situation the journey will be back a few hundred years in an attempt to advance technology (that's the original idea that this was for).
2] Give the technology to someone (for preference without them seeing you)
3] The clever part. Along with technology you leave instructions that once technology has reached a level that wll allow someone to travel back in time, they should send back either more advanced technology or EXACTLY THE SAME technology.
In this way the same technology gets sent back, so there is never a time at which the technology has not been sent back so a paradox cannot occur.

To Fred: This would probably creates a paradox too...

Lots of inventions have change our lifes, simple as electricity, cars, airplane. If you put an other invention on top of that (or certain ressources that may create one) you'll change this current time, creating a paradox. By example, you go back in time, about 150 years and give your time travel plans to the genius of the year. He looks at the plan and than understand many electromagnetic "facts" that haven't been discovered so far(...), one day, your encestors may use one of his "new" inventions. If they do that they change the futur, and maybe you grant-grant-mother won't sleep with her men because there's electricity and she prefer to read at night, feaking the "headache". So you will never born, and will never be able to travel back with your time travel machine.

In conclusion, to evitate paradox, the simpliest way would be to travel to the futur or to travel backward in "safe" mode, with less contact and interaction "0", the same "rules" as in 'Back To The Futur'.

It seems to me that you can't change the
past as it is predetermined. To explain
further I will give an example. Say for
arguements sake that you are able to travel
to the past and change something about it.

You haven't actually changed or altered
anything at all as it was always meant to be.
<font color="blue"> [/COLOR]

Here is a time travel situation that involves no paradoxes, and allows for tangible proof to the time traveler that he traveled back in time.
A time traveler, named Marvin, transports himself back in time just to see the past. He brings with him many modern conveiniances such as a lighter, a taser, video equiptment, one of those nifty singing bass things, and anything else he feels he may need. He arrives in Europe appearing in front of a young King Aurthor, Aurthor takes him to be a wizard, as anyone in those days would seeing a man appear from thin air. Marvin decides he likes Aurthor and helps him become king using some of his futuristic devices.
So it is recorded that Marvin the Wizard helped bring Aurthor to the thrown. Through time Marvin's name is changed to Marlin symbolic of the fish he brought with him. Which later becomes Merlin, just because the English love changing a's to e's. (True story, compare names from differant peroids of time in English culture and you will see.)
A while after Marvin returns he reads the book The Once and Future King, and realizes that he is the Wizard Merlin.