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New Model Solves Grandfather Paradox
goldfishy writes "If you went back in time and met your teenage parents, you could not split them up and prevent your birth - even if you wanted to, a new quantum model has stated. Researchers speculate that time travel can occur within a kind of feedback loop where backwards movement is possible, but only in a way that is 'complementary' to the present. In theory, you could go back in time and meet your infant father but you could not kill him." From the article: "Quantum behaviour is governed by probabilities. Before something has actually been observed, there are a number of possibilities regarding its state. But once its state has been measured those possibilities shrink to one - uncertainty is eliminated."
Just watch Quantum Leap
In other words, even if you take a trip back in time with the specific intention of killing your father, so long as you know he is happily sitting in his chair when you leave him in the present, you can be sure that something will prevent you from murdering him in the past
This means that you cannot be killed when you go back in time, nor can you kill or destroy anything! That's just perfect!!
Go back in time and be able to observe, only... no ability to interact with anyone either... it should be kinda like ghosts... we go back in time and observe and be like ghosts in the sense that we cannot interact and change anything that has already happened but only observe!
Imagine the possibilities of history classes of the future... maybe there are already a lot of ghosts watching us right now... the future students studying history!!
Destiny, it had to happen. Which now make me realize the importance the several episodes of time travel in Futurama had to the plot. It miss it....
And the knowledge that they fear is a weapon to be used against them...
"Clearly, the present never is changed by mischievous time-travellers: people don't suddenly fade into the ether because a rerun of events has prevented their births - that much is obvious."
That's not clear at all. If I went back in time and killed the baby George W Bush, it's like he would disappear in the middle of a speech. Rather the entire course of history branching from that moment would be changed, so that in the "present" no one would ever know GW had existed.
-Alex
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How can that even be remotely possible? Anything and EVERYTHING (no matter how small or big of an event it is) will change SOMETHING in the future.
Sci-fi writers have had two main theories for a long time. Either you can go back in time and change things, or you can go back in time and "fulfill" the past you expireinced. Just because you have an influence on the past doesn't mean your influence didn't shape time into the way you remembered it.
Anyone who thinks any differently needs to go back to school.
Yes, because I'm sure these quantum physicists haven't spent any time in school...
Clearly, the present never is changed by mischievous time-travellers: people don't suddenly fade into the ether because a rerun of events has prevented their births - that much is obvious.
;)
So either time travel is not possible, or something is actually acting to prevent any backward movement from changing the present.
So let me get this straight, BBC reporter. Your proof that time can't be changed, is simply that you don't remember it happening?
There are just so many flaws in that reasoning.
First, time changes could be happening everywhere, but perhaps you have not witnessed one. Wait! How about this? How about time changing, and altering your memory at the same time?
What's the matter with you? Do you believe that it is impossible for something to occur, without you being aware of it?
Is this a God complex?
What unmitigated self-importance, BBC reporter!
Now sure, I know this reporter was likely trying to parse some marlaky that they were told, but this has to be the worst use of logic I have seen.
Um Doc... how about we test on a monkey first?
0110100100100000011000010110110100100000011000100
It could be happening all the time and you wouldn't be aware of it (by definition).
Sounds like bad fiction to me.Sounds like the techno-babble "justification" in the bad fiction.And the easiest way to not change it is for time travel to be impossible.If, for example, you knew a picture would be taken, you could reflect light from your body and appear in that picture, thereby altering the future.
So, travelling back in time, you cannot reflect light, and, by the same token, you cannot absorbe light.
And it just moves up from there for all other physical effects. Nothing touched, no air breathed, no light disturbed, nothing.
So, how would you even know you were in the past?
One of the major problems encountered with time travel is not that of accidentally becoming your own father or mother. There is no problem involved in becoming your own father or mother that a broadminded and well adjusted family can't cope with. There is also no problem about changing the course of history - the course of history does not change because it all fits together like a jigsaw. All the important changes have happened before the things they were supposed to change and it all sorts itself out in the end.
Douglas Adams, The Restaurant at the End of the Universe
This is another case of science fiction being well ahead of science.
I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
Actually, according to this theory, that bump would be what causes your particular sperm to be the winner. By this theory, history had already accounted for your interactions in the past in the future that you left from, wether you knew about it or not.
In a way it's kinda scary, means you don't really have free will when you go back in time, since whatever you do has been done already so the probability of it happening that way is already 1. So really, who's to say the present we're in now isn't already predetermined? Really depends on the nature of time itself. Is time 'flowing' or did it happen all at once and our perception of time is just an illusion after the fact.
No, his name is Philip J. Fry. Farnsworth is the last name of his nephew, the professor, many generations removed.
"Stumble before you crawl"
I don't like that. Let's say I travel back in time to two days before today and I land in wet cement, leaving foot prints. However, the day before I left (Which would be the day after I arrive), the cement layer came to work in the morning and saw no foot prints. Doesn't that prevent me from traveling back, because history records show the cement was smooth?
Or...Does it allow me to 'land' back in time *only* where my landing does not affect anything in the future. Where would that be? Wouldn't my biological struture have influence on just about any environment?
The next time someone talks about the difficulties of multiple inheritence, they may not be talking about OOP.
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
We, existing in this universe, are on a crash course toward the future.
There's no stopping it or slowing down of time, in the traditional sense. However, it might be possible (with the help of absolute zero) to stop all things in the area of the absolute zero. This would be akin to stopping time, as nothing could be happening within that area.
Unbaking a cake or uncracking an egg is a good example of going back in time. Hey, if you can take a fully-baked cake, reverse the steps, and make it back into cake-mix-egg-and-milk-inna-bowl, that's good enough time travel for me.
Job? I don't have time to get a job! Who will sit around and bitch about being broke and unemployed then?
There are numerous problems with your "proof". Here are some assumptions that you gloss over:
- You assume that t automatically progresses from -10 to 0, with all other values in tact. That is, you assume that if father is dead at t=-10, then father will be dead at t=0. Pretty wild assumption, considering that you assume just the opposite is true (that if father is dead at t-10, it's possible for father to be alive at t-11). It's a much more logical assumption that if father's state can change from dead to alive going in the negative direction (from t=-10 to t=-11), then father's state can also change from dead to alive in the positive direction (from t=-10 to t=0).
- You assume that it is impossible for father to be dead at t=0 and father to also be alive at t=0. Since parallel universes and probabilistic realities are two hotly debated ideas (by people smarter than you), I'd say that this assumption cannot be relied upon.
You can't just apply math where you want to, and gloss over these huge assumptions. Nice try, though.
- A/C #12345
My point is: "observation" is a meaningless concept. All points in the universe continuously "observe" all other points in the universe. Nothing is *ever* in an "unobserved" state, except perhaps for a duration shorter than plank time.
..." but that's nonsense, really. The position of an electron is continuously measured, as is its momentum, by the space around it. Nothing can ever be unobserved.
You speak of "if I measured the position of an electron, then at the moment I measured it
Or do you propose that a electron only has the property of "having been measured" when a certain sort of thing "measures" it? That seems pretty odd - does the momentum space function of an electron only become uniform when *you* measure its position? Perhaps only when measured by a physicist who has published? Perhaps only when measured by a cat?
Socialism: a lie told by totalitarians and believed by fools.
I've always wondered why that sort of view isn't more popular or at least widely recognized as a reasonable alternative to the "quantum magic" view of the world. It's philosophically more reasonable while being mathematically identical.
When I was taking undergraduate quantum mechanics (about 8 years ago), I recall feeling elated when I ran across a single paragraph in the textbook that referred to the possibility that one day someone might develop a non statistical theory for the workings of the sub quantum world.
It probably would be pure fantasy since there's no way such a theory could ever be tested (right?), but I was happy to see that it was at least acknowledged that the statistics are just a tool and not a philosophical statement about what the universe is.
Cow Cube