What would happen if you went back in time and killed your grandfather?

[SnoringFrog]

Assuming that time travel were possible, what would happen if you went back in time and killed you future grandfather. My friends and I have discussed this a few times, and I want to know your theories. I'm thinking about possibly putting this on a site I might make, and I wanted to hear theories and thougths from more people. So, what are your thougts?

[Nate]

Well...let's think about it.

You invent a time machine. You go back in time. You kill your granddad. Therefore, you cannot be born.

Since you cannot be born, you cannot invent a time machine. Therefore, you cannot go back in time and kill your granddad, since you do not exist. Therefore, you are born.

So since it would result in a never-ending paradoxical loop, I'll have to go ahead and say that something would prevent it from happening, otherwise time would never get anywhere.

[Rogie]

o_O And I thought I focused a little too much on the whole time issue...

Good thoughts, though, kae. But this whole "killing your grandfather" thing is a little morbid to me.

[Warrior4Christ]

It would be like a division by zero error or something... the universe crashes maybe?

[Locke]

The universe pulls a "Donnie Darko" on us.

[Raiden no Kishi]

This is why I don't think God will allow time travel.

.rai//

[Ingemar]

Well...let's think about it.

You invent a time machine. You go back in time. You kill your granddad. Therefore, you cannot be born.

Since you cannot be born, you cannot invent a time machine. Therefore, you cannot go back in time and kill your granddad, since you do not exist. Therefore, you are born.

So since it would result in a never-ending paradoxical loop, I'll have to go ahead and say that something would prevent it from happening, otherwise time would never get anywhere.

You do not consider the possibility that changing the past could produce an alternate timeline, which does not affect your existence. Therefore, yours cannot be the only explanation.

[Dante]

Let's look at this from a far less theoretical standpoint and more from a different standpoint that of the past universe to which you went to, according to that universe you didn't causally come into existence anyways, you *popped* into existence without any cause to begin with. Note however this doesn't eliminate the possibility for time travel, particles pop into and out of existence all the time through use of the Heisenberg uncertainty principle, in a process called pair production and pair annihilation.

In an equally bizarre circumstance but completely the same according to the past universe, your grandfather could have just popped into existence (his anti-particles being later absorbed into a black hole as Hawking radiation) and came together with your grandmother to produce your mother (or father) ... But the situations are the same. In fact killing your grandfather before your mother (or father) was born must act in exactly the same way as killing someone else’s grandfather today, you eliminate the possibility of someone else existence, but the future doesn't require their existence to begin with as we do not live in a fatalistic universe (this is forbidden by Quantum Mechanics by it's probabilistic description of the universe)

But what will happen to you if you do this? Remember that the universe just sees you as matter popping into existence along the four-space coordinate of time (after all time is just like space only that we move forward in it at a constant velocity c!). Therefore your situation is exactly the same as a virtual grandfather, you can react with all of your surroundings as matter with memories that aren't "real" in that they don't come from an actual history, they just happen to be the way the memory cells in your head were arranged upon popping into existence. After all they can't be, there is no such thing as "future" memories. In fact after killing your grandfather you could move back to the future and would notice that you weren't dead, because once again you are a result of pair production and annihilation as far as the universe. Of course your whole imagined family doesn't exist but note that it must be imagined, it never existed to begin with and all of your memories are no more than combinations of matter that popped into existence with you.

But for another interesting perspective let's look at this from your perspective instead of from the universe. When you travel back in time according to you the universe is just energy formed in a desirable manner as your memories recall it in pair production. But even before you have changed anything on your own it immediately begins to change. The quantum nature of things take effect, dice role differently and sways of chance begin to create a different universe than your memory of it holds. Its not there is a different universe, its just that you created a new universe from pair production, you sort of played God with all the energy in the universe and rearranged it to a past memory that existed in your memory of a past universe, but realize that it would appear to be a future universe for you, (your mind would note that these events occurred causally after your birth instead of before them). These effects would be seen in the way that people act and in the way that events occurred by chance, after all people sometimes base their decisions not upon a logical process or on their nature but purely on chance alone (iny meany miny mow). In this manner the universe would be very different from the one you would remember purely on the basis of chaos.

In this manner I have solved the Grandfather paradox... While I'm not sure that that’s been done before,

Later
Pascal

[SnoringFrog]

Kae, that's what I tell my friends, that's gets us into a loop so we usually end it right there.

Well, here's another thought. Like what Kae said,it would result in a loop that would prevent time from getting anywhere, so let's say that the loop doesn't happen. You killed your grandfather, so then you are never born(that is, if he hasn't had your father/mother as his child yet) but, there is no loop, and he stays dead. You then do not exist anywhere in history, and are now just an object with no origin whatsoever, stuck in that time because you never existed to time travel.

Assuming the above happened, there are a few possibilities.

1- You're stuck, unless you somehow re-invent the time machine and stop yourself. And if you don't, you just live your life in that time, and most likely create your own fake backstory. Legally, I'm not sure how you'd exist though. Anyways, you'd live out your life in that time like it was your normal time, and die there as well.

2-You're still stuck, but since you were never born, then you never lived to the age you were when you time-traveled. Since you never grew up, you woudn't have any memories, and at the point in time that you kill your grandfather, your entire memory is gone. Then, you'd be a [insert your age here] new-born baby, with no knowledge whatsoever.

Those would either alter the timeline completely, or, as Ingemar stated, would result in an alternate timeline. But if it did indeed result in an alternate timeline, what would happen in your original timeline? Would your existence and that of your family disappear? or would it remain the same, with the exception of your absense?
-----

Here's my Dad's theory-- Since your father/mother has not been born yet, you have not been born either. ANd since you have not yet been born, the man you killed wasn't your grandfahter, he was simply some guy that you thought of as your grandfather. Then, what would happen if your possible-grandmother met another person, and had your father/mother? would that child still becmope your parent? or would you never exist, resulting in another paradoxial loop?

EDIT: Wow, Pascal, that's a bit confusing but I do think I get your point. Frrom the first standpoint, when you went back, there was no future from whence you came, you just simply, as you put it, *popped* into existence. So, you became just another person in that time, only with no existing backround other than that contained within your memories, which are now nothing more than that, memories, now not real at all, but somewhat like figments of your imagination even though they actually did happen to your physical self. Because now they never happened anywhere but your mind.

That is what you were saying, was it not? I want to try and understand this, becuase I did not believe there was actually an answer.

Edit Edit

(after all time is just like space only that we move forward in it at a constant velocity c!)

My dad just pointed this out to me after reading your post, Pascal. He said that we do not move forward in time at a constant velocity. There was that one instance in the Bible(not sure where exavtly in the Bible it is, but I do remember the story) where God stopped the progress of time for a while by stopping the movement of the earth. So, according to that, time is not constant, and can be changed. (Although in my opinion this was a supernatural act that could not, except by God's direct intervention, be replicated, and thus does not exactly show that time does not move at a constant velocity when not changed directly by God's hand.)

[~Natsumi Lam~]

well i wouldnt be born..... well unless i killed him after i was born. Than it would be good... he was a very bad man.


~NL~

[Dante]

EDIT: Wow, Pascal, that's a bit confusing but I do think I get your point. Frrom the first standpoint, when you went back, there was no future from whence you came, you just simply, as you put it, *popped* into existence. So, you became just another person in that time, only with no existing backround other than that contained within your memories, which are now nothing more than that, memories, now not real at all, but somewhat like figments of your imagination even though they actually did happen to your physical self. Because now they never happened anywhere but your mind.

That is what you were saying, was it not? I want to try and understand this, becuase I did not believe there was actually an answer.

Yes that is what I meant, however also note another fine detail, there are two reference frames here, and according to yours these memories are results of real things that happened to your physical self, but from the rest of the universes reference frame they are not and are no more than particle orientations in your brain that came along with you.

My dad just pointed this out to me after reading your post, Pascal. He said that we do not move forward in time at a constant velocity. There was that one instance in the Bible(not sure where exavtly in the Bible it is, but I do remember the story) where God stopped the progress of time for a while by stopping the movement of the earth. So, according to that, time is not constant, and can be changed. (Although in my opinion this was a supernatural act that could not, except by God's direct intervention, be replicated, and thus does not exactly show that time does not move at a constant velocity when not changed directly by God's hand.)

Not really, he's come to the conclusion to fast. If God really did stop time than noone would have remembered it, after all there would be no time in which the event took place, note that according to Einstein's theory of relativity time goes at the same rate for everyone in their own reference frame even if it can be slowed down outside of their reference frame. Time can only be slowed or stopped for objects outside of your reference frame but it must remain constant for your reference frame. In the situation you are discussing however I believe it is far more likely that time only appeared to be standing still in that things that we normally consider to change with time would be constant (unchanging) but this doesn't mean that time itself stops. As I said, if time actually did stop than no one would be able to realize it except God anyways because all events including perception and thought would cease until it started again. It would set up a very funny situation, (imagines a man challenging God to stop time, God agrees, one second later God replies "there, it is done", the man replies "but nothing happened!", to which God replies "I know". )

Later,
Pascal

[SnoringFrog]

Yes that is what I meant, however also note another fine detail, there are two reference frames here, and according to yours these memories are results of real things that happened to your physical self, but from the rest of the universes reference frame they are not and are no more than particle orientations in your brain that came along with you.

Oh, okay, so those memories that to you you have that seemed to happen to your physical body, are, according to the universe, just imaginative things that have appeared in you brain, however real they may seem to you?

Not really, he's come to the conclusion to fast. If God really did stop time than noone would have remembered it, after all there would be no time in which the event took place, note that according to Einstein's theory of relativity time goes at the same rate for everyone in their own reference frame even if it can be slowed down outside of their reference frame. Time can only be slowed or stopped for objects outside of your reference frame but it must remain constant for your reference frame. In the situation you are discussing however I believe it is far more likely that time only appeared to be standing still in that things that we normally consider to change with time would be constant (unchanging) but this doesn't mean that time itself stops. As I said, if time actually did stop than no one would be able to realize it except God anyways because all events including perception and thought would cease until it started again. It would set up a very funny situation, (imagines a man challenging God to stop time, God agrees, one second later God replies "there, it is done", the man replies "but nothing happened!", to which God replies "I know". )

Alright, I'm trying to figure out how to type my Dad's response here since he doesn't really want to come and type it himself at the moment. I'm not really sure what he said, because he seemed to disagree with what you said, but something ese he said made it sound like he was agreeing with you. I see what you're saying, that it only appeared to be standing still. I'd have to go find the verses again to be more certain, but my theory is that God simply stopped the earth from revolving around the sun for however long time seemed to stand still, and while it was stopped (Earth) the rest of the universe and planets and everything continued on their normal paths. My Dad said something about 'Why do we have leap years?' and that it's because we have to make up lost time. My take on that is that the time ws not in fact lost; it was merely unrecorded in our history, adn to avoid a 1/4 of a day each year, we simply record that extra amount of time once every 4 years. He was also saying that even if time did indeed stop, because God was doing the stopping, he could have allowed thepeople involved with this instance to remember it. I'm assuming that would mean that He stopped time for the universe, but added extra time into the lives of the Israelites adn whoever they were fighting, so that they could continue to move along in time without time itself actually moving. At least, I belive that is waht he was trying to say.

[Myoti]

Question:
































Why would I want to kill my grandfather?

[SnoringFrog]

Why would I want to kill my grandfather?

I'm not sure, seeing as how I am not you nor am I a mind reader. So, now I ask you, why would you want to kill your grandfather?

[Myoti]

I wouldn't, and doesn't seem to matter as he's already dead, but that would mean me trespassing in fate and killing him before that happened, but for no reason.

[SnoringFrog]

Well then, I believe that would be the answer to your question. However, other people might want to kill their grandfather for some reason (I am not one of those people).

[Myoti]

Those people are freaks. Unless they gain some sort of great wealth and inheritance or special power like Itachi killing his best friend.

They're not freaks.










They're greedy psychopathic nimrods.

[Dante]

Oh, okay, so those memories that to you have that seemed to happen to your physical body, are, according to the universe, just imaginative things that have appeared in you brain, however real they may seem to you?

Yes, but do note that they are real to you, even if they aren't real to the universe, and they aren't real to the universe even if they are real to you. , It's a conflict in timelines but this is common in such things as length contraction and time dilation as seen in special relativity.


1.

I see what you're saying, that it only appeared to be standing still. I'd have to go find the verses again to be more certain, but my theory is that God simply stopped the earth from revolving around the sun for however long time seemed to stand still, and while it was stopped (Earth) the rest of the universe and planets and everything continued on their normal paths.

2.

My Dad said something about 'Why do we have leap years?' and that it's because we have to make up lost time. My take on that is that the time was not in fact lost; it was merely unrecorded in our history, adn to avoid a 1/4 of a day each year, we simply record that extra amount of time once every 4 years. He was also saying that even if time did indeed stop, because God was doing the stopping, he could have allowed the people involved with this instance to remember it. I'm assuming that would mean that He stopped time for the universe, but added extra time into the lives of the Israelites adn whoever they were fighting, so that they could continue to move along in time without time itself actually moving. At least, I believe that is what he was trying to say.

I would agree more with item 1 than item 2, leap years do not actually suggest increasing the amount of time in the universe any more than daylight savings time does. When we discuss years, we are directly referring to the time it takes for the Earth to revolve around the sun. If the sun were to blow up though and we were to go spinning out into space we could still measure time in years, we just wouldn't be spinning around the sun. It is a length of time that we create that is directly correlated to period functions followed by the sun. This is the same way in which we define a day. We could have real fun in discussing big bang cosmology in this manner by noting that this is what WE call a day while GOD refers to what WE call light as day. But such things would cause a giant argument and soon CAA's servers would crash and the mass amount of information entering the system would cause a black hole that would destroy life as we know it rendering the entire thought useless.

But back to the other argument, how can God cause others to "remember" a lack of time. It is sort of like imagining a universe without hypothetical circumstances. I can imagine a situation where each individual could imagine all other reference frames as having time stopped, but not the individual having time stopped for himself, as I said lack of change doesn't mean lack of time, in the end there would be nothing to remember. This would sort of be like what happens when you take a picture but when you look at the picture later, you note that you are still experiencing time even if the picture isn't "changing" this is because time is changing for you even if it isn't changing for the picture. But the inverse is impossible. Time stopping for other reference frames however isn't impossible but do note that your explanation is far more likely. For stopping time for all other reference frames occurs only in the light like reference, and because of the coupling of space and time, the poor individuals would have a rather strange experience and time stopping in other reference frames would be the least of their worries. First off all energy in the rest of the universe would blue-shift to infinity as all other stars appeared to be approaching them roasting everyone in this reference frame instantaneously by the now incredibly powerful photons. (blue shifted photons means higher energy, the higher the blue shift the higher the energy through E=hf). Also note that for them to be in the light-like reference frame requires them to be mass-less causing their bodies to turn into pure energy and finally they would experience the universe flattening into a infinitely thin pancake.

It's all rather weird if you ask me, , but seeing as God is God, I guess he could break the laws of physics if he wants and not cause these unfortunate events to take place. But I still can't believe that he could cause them to understand what time would look like stopped in their reference frame any more than you or I could imagine a true tesserac in all of its 4-D glory (I am not talking about a 3-D cop out either so keep your hypercube gifs). We're just not built for that nor do we need to be, its requiring God to do far more work and make the situation far more complicated than he really has to and in the end all it would do is probably confuse the poor people involved anyways. It just doesn't make logical sense if you think about the way God works.

Anyways, I got to go and design a stealth car, Jumping B-2 PAN carbon fibers!

later,
Pascal

[yukinon]

What exactly are the verses for the sun-stopping incident?

[Mr. SmartyPants]

Well...let's think about it.

You invent a time machine. You go back in time. You kill your granddad. Therefore, you cannot be born.

Since you cannot be born, you cannot invent a time machine. Therefore, you cannot go back in time and kill your granddad, since you do not exist. Therefore, you are born.

So since it would result in a never-ending paradoxical loop, I'll have to go ahead and say that something would prevent it from happening, otherwise time would never get anywhere.

On a similar note, but somewhat different. yet the exact same thing

you are born, you cannot go back in time to kill him because then you wouldn't of been born at all

therefore if you do go back in time and kill him, you mess up the laws of thermodynamics and the world explodes. (not really true, just fabrication)

Anyway if time travel is ever possible, wouldnt people in the future come to here? I've never met any time travelers, have you?

You do not consider the possibility that changing the past could produce an alternate timeline, which does not affect your existence. Therefore, yours cannot be the only explanation.

1. What if you killed your direct parents before they had a you.

2. Then you say that by changing the past, we can change what lifestyle we have. Lets say I went back in time with a red GAP shirt. And made sure the gap company never existed. Does that mean the SECOND I do that, my shirt will change to a blue polo shirt? Or maybe even become shirtless?

But I can't do that, because I came to the past with a red GAP shirt. And if I made sure GAP never existed, how did I get the red GAP shirt in the first place? (Then again this doesn't deal with existence, rather an object)


I do have something else to say regarding this, but it involves theology. So I will not say. Ingemar, IM me if you wish

[Alice]

...you would be a very bad grandson.

[Nate]

What exactly are the verses for the sun-stopping incident?

12 On the day the LORD gave the Amorites over to Israel, Joshua said to the LORD in the presence of Israel:
"O sun, stand still over Gibeon,
O moon, over the Valley of Aijalon."

13 So the sun stood still,
and the moon stopped,
till the nation avenged itself on its enemies,
as it is written in the Book of Jashar.
The sun stopped in the middle of the sky and delayed going down about a full day. 14 There has never been a day like it before or since, a day when the LORD listened to a man. Surely the LORD was fighting for Israel!

Joshua 10:12-14

I don't know what this means, honestly. With the speed that the earth rotates, if God had halted the rotation of the earth, it would have flung everyone out into space or something. I just accept it as a mystery and move on with my life. XD;;

[Scribs]

I think that if you went back in time any actions you took would have already happened befor you left for the past, therefor, you would not be able to kill your own grandfather.

Pascals theory sounds relatively reasonable.

[termyt]

I don't think time could be changed. Here's my theory:

We are three-dimensional beings. We exist in three dimensions - length, width, and depth - and we can manipulate those dimensions.

Time is the fourth dimension. We are aware, that is we can perceive, this fourth dimension, but we can not manipulate it. It is an inviolable wall to us. We simply travel along it at its whim.

That probably means we can not invent a way to travel in it in any way we desire, but it is possible that some natural phenomenon could cause us to travel through time in some non-standard way. In other words, through a natural phenomenon, you could find yourself in our past.

If you do find yourself in the past one day, it is not possible for you to change the present – that is you can not make the future come about in a different way than the one you remember. While in the past, you are a part of the past. Everything you do is part of the past that shaped your present. Everything you create, destroy, birth or kill is supposed to be there. If someone is alive during the present, then you did not kill him in the past.

Simple as that.

[mitsuki lover]

Remember the episode of Futurama when they DID go back and Fry
DID kill his own grandfather and had sex with his grandmother thus becoming the father of his father..?
Ok,nothing as strange as that would happen but there would be some sort of correction,perhaps your granduncle would become your grandfather or you would end up descending from a totally different branch of the family.Actually killing your grandfather isn't the question,unless you are adopted and don't know who your birth parents are.What would be problematical would be if you managed to travel back to say England in the 10th century(ok this is for us who have English ancestry).Since most people don't know who their ancestors that far back would be it would be increasingly easier to off one of your distant ancestors without knowing it.

[Myoti]

So what happens if you go back in time and kill yourself?

[SnoringFrog]

Yes, but do note that they are real to you, even if they aren't real to the universe, and they aren't real to the universe even if they are real to you. , It's a conflict in timelines but this is common in such things as length contraction and time dilation as seen in special relativity.

Alright, I think I've got that part figured out now.

Anyway if time travel is ever possible, wouldnt people in the future come to here? I've never met any time travelers, have you?

Nope, not yet. THis actually occurred to me in the car recently. I was wonering what it'd be like to have some guy pop up and tell me that I'm his grandfather. It would be rather odd.

So what happens if you go back in time and kill yourself?

You die. Unless there's some way to kill yourself and live.

[Dante]

I don't think time could be changed. Here's my theory:

We are three-dimensional beings. We exist in three dimensions - length, width, and depth - and we can manipulate those dimensions.

Time is the fourth dimension. We are aware, that is we can perceive, this fourth dimension, but we can not manipulate it. It is an inviolable wall to us. We simply travel along it at its whim.

Actually you can manipulate time outside of your frame of reference, remember the Lorentz contraction for time goes such that time seems to speed up outside of your reference frame as you approach the speed of light and time seems to slow down in other rocket ships that fly by you as you stand still. You can also change time by curving space-time in general relativity (Joyful Christofel Symbols!). In fact if you were to build a massive enough spheroid around yourself made of lead (to keep out the blueshifted photons) you could go forward in time as much as you want!

Supergravity theories suggest that before the de-unification temperature was reached, it might have been possible for anti-gravity to have existed. Also note that current quantum gravity theories show space-time not as a smooth surface but as a bump foam filled with 4-D loops and all kinds of tesseracs! As this small level it is quite common for time to go backwards and for space to be connected in weird ways as well! I have even heard that at the quantum level particles can briefly become space-like instead of time-like. But this occurs at an incredible small level and by the time we reach larger levels time flows forward just as it normally does.

However, it has been suggested that it might be possible to increase these quantum effects or recreate supergravity, which might open up the possibility of time travel. Note that just because it might not happen naturally now, doesn't mean that under the right conditions it might not have naturally occurred at other times.

This reminds me of something else that is cool that I was finally able to drag out of my teachers. One of the elements in the Einstein Gravitation Field Equation says that the gravitational curvature of space-time increases with pressure. Now note that photons can exert a pressure when they strike something in space. This is because photons really do have a gravitational mass. The statement that they have no mass is actually wrong. They actually have no rest mass, their gravitational mass is purely derived from the fact that they are moving at the speed of light. But this allows for an interesting event. Imagine we have allot of photons, and now imagine what would happen if we shot all of these photons into a single point. Normally nothing would happen, but what if the gravitational mass of these photons was great enough that it caused gravitational collapse (its possible). Then you would have a black hole (from which light can never escape) created by none other than light itself! You would also have a singularity that was purely made up of light! What a weird thought!

So you see, time is something we can truly change, as long as it is outside of our reference frame .

Later,
Pascal

[Kaligraphic]

Every particle has a history - it moves backward and forward in time, like a thread, being woven with many other threads. Imagine a great loom, where a cloth is being woven - if a thread goes back, it is because it has fallen - it will not change what has already been woven.

Time is like this - you cannot go back in time, and if you could, you would see only blackness, because things only interact in the present, where time is being woven. You wouldn't even be able to see, because seeing would require interactions with photons whose courses are already set - you could not breathe, because the course of the particles in the atmosphere have already been tightly woven.

You are only conscious of the present - now, God can show you the past, but you cannot change it - the only way to change your past is to splice yourself to another already existing past. Oh, and that ain't easy, just so's you know.

[yukinon]

What exactly is a singularity?