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Time Travel - what alot boll'clocks'

  1. Dec 19, 2003 #1
    I've just been through about an hours lecture on the theories of time travel and it just bores me so much [zz)]

    they all talk about how time travel could become real in about 50 years time through the use of general relativity and i honestly couldnt stop laughing.

    now im not saying that im anti-science on this subject but not once have they related it to quantum mechanics.

    now because general relativity states that the faster you move the slower time passes, scientists take this to the extremes and say that to time travel you have to move close to the speed of light (299,792,458 meters per second (in a vacuum obviously)) and the speed of light depends on the material that light moves through.

    but theres one simple point that they havent discussed and thats on a sub-atomic scale (quantum mechanical).

    now you all have to do a little exercise -

    As you all know,everything is made of molecules and cells. (duh)

    now imagine the room you are sitting in just now on a molecular level. your computer's molecules,the walls molecules and your molecules are all present.

    now if you took a quantum picture of a single second in time which en-captured the entire room on a molecular level, every molecule would be set for only a second (in your picture)then by the next second it would be differed.

    now the next year you decided you wanted to travel back in time to the exact second a year before (which is when you took the picture).

    now if scientists used general relativity to speed you up to the speed of light (which isnt physically or theoretically possible) then theres no exact known effects. you could basically end up anywhere or anyplace

    so the only way in which you could REALLY get back to that exact second a year ago was to re-create the picture you took. they would have to process EVERY molecule in the room from scratch then find somewhere to put this picture. now theres trillions upon billions of molecules in this one room so that is a feat upon itself.

    p.s the picture im talking about is a metaphorical term for a state in time.

    also, when you start to think more about the barriers in travelling back in time in this sense, you realise how impossible it is.

    now i know my little exercise was a pile of metaphorical cack so you dont have to tell me. im just trying to get you to understand a different way in which space-time operates. if you want the dynamics then talk to someone else with a week spare to tell you but i have better things to do.

    so what do you guys (and galls) think about time-travel through quantum and relativistic means. i want your opinions on time travel and if you think its a possibility or something that should just stay attached to the sci-fi movies of hollywood?
  2. jcsd
  3. Dec 19, 2003 #2

    Do you mean to reach the speed of light? Or do you mean near it, because there is nothing that says we can't get close to the speed of light. We just don't have the technology to do that at the moment.

    It doesn't really matter what light moves through, the photons travel at c. Only the delay it takes for the said material to absorb/re-emit the photons changes.

    Also, even though there are theories about moving BACK in time, it's more accepted that (special) relativity does slow time in your reference frame as your velocity increase. But don't expect to get back. The whole cause and effect stuff is tricky.

    I'm sure someone can go into more detail than me.
    Last edited by a moderator: Dec 19, 2003
  4. Dec 20, 2003 #3
    Is it true that for something to travel at the speed of light, it must have a mass of zero?
  5. Dec 20, 2003 #4
    Well, for something to accelerate to the speed of light it must have a "real" mass of zero. It can have mass-like effects as seen in photons because of its enormous energy.

    I always thought relativity never allowed time travel as such, it only specifies that an object traveling at near-c velocities experiences a slower passage of time than the world around it, which is very different from time travel.
  6. Dec 20, 2003 #5
    Besides all the defective modeling of QM and GRT , Time is a one way arrow. You cannot travel backwards olny fowards
  7. Dec 21, 2003 #6
    That wouldnt be science, that's Philosophy. More specifically, its a Philosophy related to Compatibilism and p_Realities.

    Essentially, Compatibilism can be dumbed down to mean "Things are not predetermined by fate, however given that the same inner and outer circumstances of an object are recreated, the same future will unfold".

    P_Realities are different. It means if you can create something which is indistinguishable from the object you wanted it to be like, then that p_Object is the original object. More dumbing down: Lets say I create a computer game, the game mimiced the real world in every aspect, in fact people in the simulation behave in a way indistinguishable from that of actual humans (those computer simulations of humans are properly called p_zombies). Now if you killed one of those humans that I created, are you guilty of murder? (Its an interesting question if you dont kill yourself in the process of thinking about it...)

    By taking the picture, you are only creating something which is indistinguishable from time travel... but that doesnt cut it now does it?
  8. Dec 21, 2003 #7


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    Doesn't that same argument show that it is impossible to move forward in time? Yet we do that all the time!

    Do you really think you can make people "understand" something by saying things that you admit are nonsense?
  9. Dec 21, 2003 #8


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    Hmm is it? My definition of (forward) time travel is a machine into which I can step press a button and within minutes be 50 yrs in the future. This is entirelly possible with time dilation in relation to speed of an object. For example if you were take a machine and punch in date, say 2040 you then need to specify how long you wanted to wait for that time to arrive. This could range from minutes to 37 years, the time you set would determine how fast the machine would have to go to achieve the correct time dilation relative to you the occupant and the outside world. So you could meet grandchildren in the future and be younger than them but you couldnt go back and tell anyone about it.

    The only problem is that we dont really know what happens should a human travel at speeds at a significant percentage of the speed of light. but hey back in the 19th century people thought that if you went faster than thirty miles an hour that the air around you be travelling to fast and you would sufficate seems daft now but hey thats what they might say in the future when the look back at some of the things we hold to be true.
  10. Dec 22, 2003 #9
    Um, horses regularly ran faster than 40 miles per hour in sprints, so you might want to recheck that figure Rog.

    As to time travel backwards in time, your quantum snapshot analogy had nothing to do with time travel but re-creating a moment in time molecule by molecule; that's not the same thing as actual time travel. As far as we know, travelling backwards in time isn't possible, but as many stated here on this board, time travel forward to an extent is, because of general relativity.

    My question is, does anyone have the exact figure of the time dilation at the speed of light compared to average earth time? Inquiring minds want to know.
  11. Dec 22, 2003 #10


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    Time dilation at the speed of light is infinite.

    - Warren
  12. Dec 22, 2003 #11
    It is not possible to reinstate the particles to the state they were at the time you put that picture. You will have to leave it to leave it to coincidence.
  13. Dec 22, 2003 #12
    come on guys....

    I wasnt saying that by creating this 'Metaphorical' Picture that it was itself time traveling. You should read the entire Thread because you are all just picking out simple quotes and taking them entirely out of context.


    I didnt say that the speed of light changes dimwit, i said depending on what material the light moves throught, light dilation varies.

    Water is the most known light dilator, which is why when you put your hand in the bath,it seems to be moved from its origonal location. the light bends or reflects.


    I do agree slightly but if planes travel at 300 mph (miles per hour) and MIR space station travels at a few thousand mph, then how lond will it take before we can reach almost 300,000,000 mps (metres per second).....mmmmmmm i dont think ill hold my breath,lol

    and on...

    another particle that scientists know travels with a mass of zero is a Neutrino. so you would basically have to make a spaceship out of neutrinos to even contemlate achieving "E=MC2"'s method of travelling.

    Anything with a mass could never reach the speed of light with E=MC2 in control because anything with a mass going at those speeds cannot withstand the energies involved, its like trying to put a biscuit in a food processor,leave it for three months and then take it back out without the biscuit being degraded in any way,shape or form which of course is impossible.

    deja vu.....

    eh....go and do a course in physics please because you obviously dont understand the theory of General Relativity. The faster you move, the S-L-O-W-E-R time goes 'relative' to space. here is the most common example -

    the MIR space station travels at thousands of miles, but from an outside point of view (thats our view) the station seems to be going pretty slow.

    this applies to anything,from me running by you to an airplane in the sky. they all go relatively slower than you would expect so whoever told you that through relativity you can only travel forwards should be sacked


    Do none of you understand what i was trying to get accross. Reality is only particles,molecules and space-time when you break it down to its quantum level. skip all that philosophical bullsh!t and see the real world for what it is. conscious is only nerve cells talking to each other and time is only ruled by General relativity.

    So if you re-created my metaphorical picture then it IS time travel (in a sense of the word)because even though you havent got in a frickin spaceship and traveled at the speed of light for a year. you still have a perfect recreation on that time.


    eh when was the last time you went forward in time. you must have made a revolutionary advancement from us mere hominids bound by space-time. remember, changing the clocks back and forward twice a year doesnt count ... uh diddums [b(]

    is this quoting never gonna end...

    So do you honestly and fully believe that your morals,ethics and personal thoughts on life can be 100% true?? no-one can seem to say that everything they believe is horse-sh!t and it takes a real person alot to admit this. and of all the people who study physics, the ones who have this view are the ones who make progress.

    plus, i said that my thread was Metaphorical Cack because it wasnt meant to be taken in context but rather looked at differently, ok? (which none of you did)

    last one..yippee...

    well about 20 years ago, people said that you couldnt see someones face on the other side of the world or that you could sit at a desk somewhere and listen to music from another part in the world...well your doing it right now on the net.

    Of course you all do know that it was particle physicists at CERN that developed the technology for the internet (although it was called ARPANET at the time) and they studied recreating images and sounds at different locations around america. so how do you know that in 50 years time, particle physicists at CERN will discover that they can re-create a room anywhere in the world???

    done at last...[zz)]
  14. Dec 22, 2003 #13
    The second half of the title of this thread becomes ever more apt!

    And do we really need to call people 'Dimwit' on a Physics discussion Forum? If you have a valid point, why not let the Science do the persuasion?
  15. Dec 22, 2003 #14
    yeah i do..

    well if people can come on here and just sit there critisizing my thread without even having the guts to put their theories on page. then i have every right calling them a dimwit -

    im only generalizing my theory (as i have stated many times),and i asked people NOT to just come on here and quote EVERY single grammatical mistake i have made. i asked them for their opinions on THEIR views and not one person even had the intelligence to understand that......

    they are DIMWITS

    'Vegestable rights and peace's & Bananas'
  16. Dec 22, 2003 #15
    Re: yeah i do..

    Hey JACKASS! I didn't crap on thread. I was explaining something to you that I thought you were misunderstanding. If you don't want people to help you, maintain your current attitude and see if people bother to reply to you anymore. Me? I'm done with you if you're going to be a jerkoff.
  17. Dec 22, 2003 #16


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    It is not clear who the "dimwit" is here. What in the world to you mean by "light dilation". We have length contraction, we have time dilation, never heard of light dilation.

    No water is not known as a light dilator. Light takes longer to pass through water (and other transparent material) because it is adsorbed and and re-emitted by the atomic structure, thus a delay. I still do not know what a light dilator is. Perhaps this is opposed to a heavy dialtor?
    Ok.... The saying about a mote in your eye comes to mind.

    It is clear that you do not understand Relativity, either General or Special. First off, to the person on board the traveling spaceship time remains the same. also for people on the "stationary" earth, time remains the same. BUT, if the stationary observers on earth could observe the clock on the moving space ship they would say it is running slow. Thus after 10yrs aboard the traveling space it returns to earth the traveler will discover that his clock has been running slow and really 20yrs (actual time depends on speed) has passed on earth, thus the traveler has returned in his "future".

    I do not appreciate personal attacks and name calling, please refrain from that practice.

    There are several good threads about this on the forums. Please find them and read them. You have much to learn.

    I am out of time so cannot respond to each point of your thread. I have traveled forward in time since I started this thread. Now my time is up and I must go. After traveling forward in time about 8hrs I will be back.

    Get the point, we are traveling forward in time at every instant of our life.
  18. Dec 22, 2003 #17


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    Re: come on guys....

    Yup, Kaspah_2k, I feel the need to jump in here alongside my buddy Integral. First and foremost, we don't generally permit personal attacks here on physicsforums.com. Second, you're mostly completely wrong about relativity, so you might want to think twice before telling someone else they're stupid.

    Don't use the phrase 'light dilation,' since no one will know what you're talking about. The correct term to characterize the behavior is called the 'index of refraction.'
    1) Water is emphatically not the substance with the highest index of refraction.
    2) Light bending is called 'refraction,' not reflection.
    The neutrino cannot be massless in light of the oscillation experiments thus completed. For sure, it has a very small mass, but it is not zero.

    Futhermore, any particle with mass zero always travels the speed of light.
    I don't quite understand the relevance of your biscuit analogy. The reason a spaceship cannot go c is not because it "cannot withstand the energies." A spaceship could in fact travel at any speed it likes, asymptotically approaching c, and the captain on its helm won't notice the slightest problem. The problem is that you can approach c only asymptotically -- you can't ever actually get there. It's not a matter of structural engineering. Furthermore, from the perspective of those people on the ship, the ship has no more "energy" than it would if it were sitting still.
    1) The concept you're dealing with is dealt with entirely by the special theory of relativity. There is no need to invoke GR.
    2) You obviously need to go do "a course in physics" yourself. Time does not slow down for objects moving faster. I'm also not sure what you mean by 'relative to space.' The captain of a relativistic starship will never notice his own time as being dilated. His buddies back on Earth will measure his time as dilated, and he'll measure their time as dilated, but both he and his buddies will notice nothing at all about their own time. The concept that "going fast makes time slow down" is one of the most common misconceptions about the special theory of relativity.
    Should I sack you now or later? You're wrong.
    I believe television has been around for more than eighty years, and radio for far longer.

    - Warren
  19. Dec 22, 2003 #18
    Chroot, he didn't say the captain of the starship or his buddies on it would notice time dilation on their ship, he said relative to space, time moves slower the faster you go. I think what he meant was time moves slower at the speed of light than time in normal space that is stationary. And yes, it is special relativity, but it is within the family of general relativity.

    I agree with most of your other statements though. Just think you might be jumping the gun and assuming what he meant in that one.
    Last edited: Dec 22, 2003
  20. Dec 22, 2003 #19


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    This statement doesn't make any sense.
    That's false. At c, you lose the concept of time altogether. "Time stops," if you want to think of it that way. And I still have no idea why you're involving "space" in this.

    - Warren
  21. Dec 22, 2003 #20
    Mallets time machine

    I was just wondering how you all felt about Ronald Mallets attempt at a time machine. This is very interesting to me, especially after reading this thread.


    Here is a link, although it is not the one i originally read and dosn't seem to be as informative. (I couldn't find the other one)

    Would love to hear some thoughts on this, or if you have already spoken of it on another thread, let me know : )

    ~ Neuro
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