• Time Travel
    204 replies, posted
I remember watching a show about this like 5-10 years ago or something. Also. [img]http://www.science-blog.com/wp-content/uploads/2009/07/time_machine21.jpg[/img]
[QUOTE=bravehat;22345013]People probably said that the internet would never transport more than 56k :v: Make it big enough and give it enough power and it could do it. If it works in the first place :v: EDIT: And I can't be the only who has realised that if that stays on for say, 100 years, whoever is in the future operating the machine could send particles back in a sort of code, and relay scientific discoveries back to us, and super accelarate our scientific progress, and then when our advanced selves reach the future in 100 years repeat the process and we have this fantastic jump.[/QUOTE] I do assume that's one of the central purposes of this machine. In fact, now that I think about it, I remember watching a documentary on this where the inventor specifically stated what you just said.
[QUOTE=bravehat;22342503]Yeah it does bend space time, a lot, so it is a big deal. It's effectively a genesis device in a way. Make it big enough for people keep it powered at all times and if something cataclysmic happens in the future, we have an escape to keep the species going. And who knows, when this thing actually gets turned on for real someone MAY pop through[/QUOTE] What are you on about? There's no difference between matter bending space-time and EM radiation doing it, get enough light in a confined space and you'll get a black hole. Going near a black hole just makes time run slower than it does from the greater distance from it, this has nothing to do with travelling back in time whatsoever.
[QUOTE=Darkcoder;22347090]What are you on about? There's no difference between matter bending space-time and EM radiation doing it, get enough light in a confined space and you'll get a black hole. Going near a black hole just makes time run slower than it does from the greater distance from it, this has nothing to do with travelling back in time whatsoever.[/QUOTE] ...it was stated that this machine with enough power could transport someone who went into in the future, back to when the machine was turned on. That's all I'm saying, I didn't mention methods of warping space time, only that this would do it with light instead of a high mass. :colbert:
[QUOTE=Darkcoder;22347090]What are you on about? There's no difference between matter bending space-time and EM radiation doing it, get enough light in a confined space and you'll get a black hole. Going near a black hole just makes time run slower than it does from the greater distance from it, this has nothing to do with travelling back in time whatsoever.[/QUOTE] Actually it does. It would create a 'frame dragging' effect which could be used to make someone travelling along with its rotation appear to move faster then SOL from the perspective of someone external to it. If this happens then when you leave the black hole you would have travelled back in time. That is the basis for this whole effect, but instead of a black hole, this scientist is using energy (photons). Since mass and energy are interchangeable both can be used to warp space-time.
I approve of the discussion in this thread.
[QUOTE=Kade;22347629]Actually it does. It would create a 'frame dragging' effect which could be used to make someone travelling along with its rotation [b]appear to move faster then SOL[/b] from the perspective of someone external to it. If this happens then when you leave the black hole you would have travelled back in time. That is the basis for this whole effect, but instead of a black hole, this scientist is using energy (photons). Since mass and energy are interchangeable both can be used to warp space-time.[/QUOTE] But not actually faster, which is the crucial difference. This is practically identical to the ergosphere of a blackhole, and if that allowed matter to travel back in time then don't you see the instant paradox this creates? Let's say you have a rotating black hole and some photon is on a trajectory to pass through the ergosphere(but not the event horizon), let's say the trajectory was such that the photon travelled back in time by an amount slightly greater than it took to pass through it, this means before the photon has even entered the ergosphere there is already a clone of itself exiting it, and because this photon hasn't yet entered there's going to be yet another clone when it enters but that means the clone will appear in the past as well, so in fact you'll create infinite photons which will create a black hole that consumes the whole universe?
[QUOTE=Darkcoder;22359212]But not actually faster, which is the crucial difference. This is practically identical to the ergosphere of a blackhole, and if that allowed matter to travel back in time then don't you see the instant paradox this creates? Let's say you have a rotating black hole and some photon is on a trajectory to pass through the ergosphere(but not the event horizon), let's say the trajectory was such that the photon travelled back in time by an amount slightly greater than it took to pass through it, this means before the photon has even entered the ergosphere there is already a clone of itself exiting it, and because this photon hasn't yet entered there's going to be yet another clone when it enters but that means the clone will appear in the past as well, so in fact you'll create infinite photons which will create a black hole that consumes the whole universe?[/QUOTE] You are assuming that time is linear. This is the only reason there would be a paradox. If time is more like a tree, branching off at every possible deviation from our 'reality' then there would be no paradox, as a new time line would be created. Even better still, imaginary time (as popularized by Hawking) makes this a bit easier to visualize. Also, per your example, there would only be infinite photons at that exit point if the photon in question somehow paused in time while an infinite amount of the photons previous states caught up with it in time. In reality this would be a smooth continuous flow of time, albeit in reverse and then switching to forward again, meaning these previous state photons wouldn't catch up - so long as the transition between forward and backward motions in time was instantaneous. [I]Appearing[/I] to move faster then SOL and [I]actually[/I] moving faster then SOL in this case are relative concepts. From the external perspective the photon [I]would[/I] be moving faster then SOL. However, relative to the photon traveling it would only be moving AT SOL through space/time (which would itself be frame dragged along). Once the photon exits the ergosphere, its relative clock wouldn't suddenly jump forward to match the outside one. Einstein showed that all time is relative and everyone's individual clocks are just as valid, hence the whole theory of relativity. Once the photon exits its will be at a previous point in time relative to the external observer. Traveling near to SOL would make time slow slow down, as in time dilation. Traveling faster then SOL would reverse the passing of time (at least this is what general relativity tells us).
May be being retarded right, but wouldn't this mean, by his workings, that the second the working machine turns on, someone from the future will come?
A little silly really, as said, it's time dilation, plus one should consider how much energy you need to actually produce any noticeable effect. Yes, the advantage is that lasers, unlike a gravitation field, are less dispersed, so you'll not need as much, but to produce an equivalent mass with energy is still nearly impossible. To produce the effect of one kilo of mass' distortion of space time is C^2, so 9 x 10^16 So yeah. Shitloads, in fact, 90PW. That's about half the potential solar energy in the world. It's just not feasible. Also, half a seconds of no sunlight for the whole world could only make a kilo of antimatter. Poor show.
[QUOTE=Kade;22343019]Just wiki time-dilation man. Its to do with the speed of light always being constant (always the same) no matter how fast you are traveling. This is because speed is a relative thing - there is no fundamental 'at rest' in the universe, you can only be 'at rest' relative to something else which, from an external perspective, would be traveling [I]with[/I] you. Regardless, light would always be measured to be traveling at the same speed. Due to this, and the equation S=D/T the only thing that vary to accommodate this constant is the passing of time itself. An easier way to think about it. If you shine a torch and measure the speed of its light, and then get in a super fast spaceship and fly towards the light, and then measure the lights speed, both measurements of the speed of light would be exactly the same. I read a Brian Greene book recently, which said that we are all always collectively moving at the speed of light. Its just when we are at rest (relative to something with us) we are moving at this speed [I]through time[/I] (and so 0 time dilation). When we begin to move, this momentum is subtracted from our momentum through time, which causes time dilation. If we get up to 99% light speed our momentum through time becomes 1%. In this sense our combined velocities through time and through space always equal SOL. In this sense its much easier to visualize time as a dimension rather then something which allows change to take place.[/QUOTE] But if you are always at rest compared to the speed of light you can never approach it and then the relativistic effects don't apply.
[QUOTE=Spikesandhands;22365769]May be being retarded right, but wouldn't this mean, by his workings, that the second the working machine turns on, someone from the future will come?[/QUOTE] It's a possibility.
[QUOTE=BmB;22366595]But if you are always at rest compared to the speed of light* you can never approach it and then the relativistic effects don't apply.[/QUOTE] *This is all relative [I]to[/I] the speed of light. Relative to an external observer you [I]would[/I] be approaching the speed of light (though never reach it). This is what causes the time dilation. It's easiest to see using photon clocks (such as below) which would quickly fall out of sync due to the photons in the moving clock having to cover more ground due to the sideways (diagonal) motion (as seen from the external observer). Each party would see their clock as being the correcting one, ticking over time normally, but the observer on earth would see the ships clock slow down, and the guys on the ship would see the earth clock speed up. [img]http://upload.wikimedia.org/wikipedia/commons/6/69/Light-clock.png[/img]
Wait, let me visualize this. If you travel away at the speed of light, light from the origin will reach you at the speed of light meaning it's going twice as fast as it should be from their perspective from your perspective, so you get the same amount of photons at twice the speed making it look like time is passing faster, and they see your photons arriving at the speed of light which is again twice as fast as it should be from their perspective from your perspective but they get? Wait? What?
What if this thread is from the past.
So you get light back before it even arrives? ???
[QUOTE=BmB;22366784]Wait, let me visualize this. If you travel away at the speed of light, light from the origin will reach you at the speed of light meaning it's going twice as fast as it should be from their perspective from your perspective, so you get the same amount of photons at twice the speed making it look like time is passing faster, and they see your photons arriving at the speed of light which is again twice as fast as it should be from their perspective from your perspective but they get? Wait? What?[/QUOTE] I really really tried to get what you're saying, but ended up with 'has anyone really been far as decided to use even go want to do look more like?' :P I think you're on the right track tho, its really hard to visualize because you have to try and think about it from two contrasting perspectives. youtube to the rescue! [media]http://www.youtube.com/watch?v=HHRK6ojWdtU&feature=related[/media]
I don't think you can go back in the past. Otherwise it would of already happened, if time is 'non-linear'.
That video is completely inconsistent. It basically says at the end that light has an absolute speed anyway. And it resorts to magic by god how many times. Sorry, but useless. :/
[QUOTE=Kade;22367044]I really really tried to get what you're saying, but ended up with 'has anyone really been far as decided to use even go want to do look more like?' :P I think you're on the right track tho, its really hard to visualize because you have to try and think about it from two contrasting perspectives. youtube to the rescue! [media]http://www.youtube.com/watch?v=HHRK6ojWdtU&feature=related[/media][/QUOTE] 186 thousand miles per second? Fuck off, it's 3*10^8 m/s. Oh wait, I'm kinda getting it now. To the observer, light will move a distance in a certain time. When you are moving fast and give off light, the light has to maintain it's speed so time changes and maintains the lights speed. The observer sees the light move normally at a constant speed while time changes for the second person so it is still moving at that speed. Really trippy stuff.
Ah, I get it now. You have to use a timed signal to understand it. Imagine a transmitter travelling away from another at the speed of light. It sends out a signal which is composed of two beams of light sent at an interval. The transmitter at the other end responds with exactly the same behaviour. Now, when the light leaves the transmitter, it shoots back towards the receiver at the speed of light, with the exact interval. However, from the receivers perspective the light also comes back at the speed of light, rather than at the speed of light minus the speed of the transmitter, this means that from this perspective the light is travelling at twice the speed it did from the other perspective, but if the speed is doubled the distance between the pulses will be doubled as well to fit the interval. Doppler effect? Not quite, since if you imagine that the travelling transmitter were to transmit the signal to trigger a response, the light would arrive at different times from the different perspectives, which means the response would be fired before the signal arrives from the travelling perspective, in addition the response would arrive even sooner, before it would appear that way to the responder. So the response information would have to travel back in time and arrive before it is physically possible for the receiver to to receive the original input. The only way to reconcile this difference is to slow down time on the other end. Meaning that, from the travelling perspective, if time was slower on the receiving end the effect of the greater pulse distance and apparent faster light speed would be justified for the same interval. Likewise from the responders perspective if time was slowed down for the travelling perspective, it would explain the greater pulse distance for the same interval, as well as account for the fact that a response would appear to be slower even though both signals travel at the same apparent speed. Basically, if you halve the flow of time for yourself it will explain how a beam of light will be travelling at double the speed of light relative to an object moving away from you at the speed of light. Likewise if you halve the flow of time for them it will explain how your beam travels at apparently double the speed of light relative to you. However this would have to be a relative effect and I don't see how you would not be exactly back in sync once you are stationary relative to each other. In fact the whole construct exists to keep you in sync in the first place. Time travel in this manner is a ridiculous notion. Time travel would only be possible without time dilation.
The universe. Fucking with your head since the big bang. And since we're on about time dilation time travel and the like, I present to you. The tachyonic antitelephone!!! [url]http://en.wikipedia.org/wiki/Tachyonic_antitelephone[/url]
cause before effect time travel forwards through time dilation is entirely possible, but this makes no sense
Here's a good little analogy I picked up from reading a post from another user after he had read a book about relativity: Let's assume your collective momentum (meaning the overall momentum of all your particles regardless of time) is 100% the speed of light. If you are moving at 1% the speed of light, your momentum through time is 99% that it was previously. If you are moving at 99% the speed of light, your momentum through time is 1%. Thus, the faster you are moving, the slower your perceive time, and vice versa. Hope that helps. [editline]09:26AM[/editline] [QUOTE=ProWaffle;22367748]cause before effect time travel forwards through time dilation is entirely possible, but this makes no sense[/QUOTE] Actually causality violations are impossible with this device because it simply transports whatever is being sent back through time into another timeline, as the moment that reality is altered in one universe by something form the future, that universe becomes a separate timeline and can in no way effect the first timeline.
[IMG]http://www.ttrove.com/images/Standups/881%20The%20Tardis.jpg[/IMG] On the other hand, Time is man made. We created it as a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify the motions of objects
Ah, no. Time the measuring system was made by man, to measure time the physical entity/property/whatever. It's something real. [editline]03:35PM[/editline] [QUOTE=billeh!;22367752]Actually causality violations are impossible with this device because it simply transports whatever is being sent back through time into another timeline, as the moment that reality is altered in one universe by something form the future, that universe becomes a separate timeline and can in no way effect the first timeline.[/QUOTE] This is what multiversers actually believe. Seriously doesn't Ockhams Razor tell you exactly why that idea is completely off the bat? Come back to me once you can explain how the alternate universes are created and where they are.
[QUOTE=billeh!;22367752]Here's a good little analogy I picked up from reading a post from another user after he had read a book about relativity: Let's assume your collective momentum (meaning the overall momentum of all your particles regardless of time) is 100% the speed of light. If you are moving at 1% the speed of light, your momentum through time is 99% that it was previously. If you are moving at 99% the speed of light, your momentum through time is 1%. Thus, the faster you are moving, the slower your perceive time, and vice versa. Hope that helps. [editline]09:26AM[/editline] Would thinking of it as time being a dimension we are constantly moving through be a good way as well? Like say we have a time axis and for everything naturally it increases in a positive direction (or maybe holds at a steady positive value depending on curvature of space time?) and to stop, slow or reduce this positive value towards 0 we need to increase our speeds, or the curvature of space time in our surroundings. Actually causality violations are impossible with this device because it simply transports whatever is being sent back through time into another timeline, as the moment that reality is altered in one universe by something form the future, that universe becomes a separate timeline and can in no way effect the first timeline.[/QUOTE] [editline]02:38PM[/editline] [QUOTE=BmB;22367867]Ah, no. Time the measuring system was made by man, to measure time the physical entity/property/whatever. It's something real. [editline]03:35PM[/editline] This is what multiversers actually believe. Seriously doesn't Ockhams Razor tell you exactly why that idea is completely off the bat? Come back to me once you can explain how the alternate universes are created and where they are.[/QUOTE] M theory is bat shit insane. But is the closest thing we have to the Grand Unified Theory.
[QUOTE=BmB;22367867]Ah, no. Time the measuring system was made by man, to measure time the physical entity/property/whatever. It's something real. [editline]03:35PM[/editline] This is what multiversers actually believe. Seriously doesn't Ockhams Razor tell you exactly why that idea is completely off the bat? Come back to me once you can explain how the alternate universes are created and where they are.[/QUOTE] But I like M-Theory. :(
M theory is bad ass. Mind you the whole 11 dimensions thing strapping us onto giant branes which clash together to create universes, literally blanked me first time I saw it all laid out in front of me.
[QUOTE=Kade;22365087][I]Appearing[/I] to move faster then SOL and [I]actually[/I] moving faster then SOL in this case are relative concepts. From the external perspective the photon [I]would[/I] be moving faster then SOL. However, relative to the photon traveling it would only be moving AT SOL through space/time (which would itself be frame dragged along). Once the photon exits the ergosphere, its relative clock wouldn't suddenly jump forward to match the outside one. Einstein showed that all time is relative and everyone's individual clocks are just as valid, hence the whole theory of relativity. Once the photon exits its will be at a previous point in time relative to the external observer. Traveling near to SOL would make time slow slow down, as in time dilation. Traveling faster then SOL would reverse the passing of time (at least this is what general relativity tells us).[/QUOTE] I understand this, and using a photon was perhaps a bad example, but if we instead used a point light source(some sub-c mass that just emits light), at no point when passing through the ergosphere would it be moving through space faster than light relative to itself. So are we talking about this object would appear to have gone back in time when it exits the ergosphere? Or that from an outside observer there would appear to be two light sources? I can perhaps understand the second, but the first makes no sense to me.
Sorry, you need to Log In to post a reply to this thread.