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The Quantum Experiment That Simulates a Time Machine
KentuckyFC writes One of the extraordinary features of quantum mechanics is that one quantum system can simulate the behaviour of another that might otherwise be difficult to create. That's exactly what a group of physicists in Australia have done in creating a quantum system that simulates a quantum time machine. Back in the early 90s, physicists showed that a quantum particle could enter a region of spacetime that loops back on itself, known as a closed timelike curve, without creating grandfather-type paradoxes in which time travellers kill their grandfathers thereby ensuring they could never have existed to travel back in time in the first place. Nobody has ever built a quantum closed time-like curve but now they don't have to. The Australian team have simulated its behaviour by allowing two entangled photons to interfere with each other in a way that recreates the behaviour of a single photon interacting with an older version of itself. The results are in perfect agreement with predictions from the 1990s--there are no grandfather-type paradoxes. Interestingly, the results are entirely compatible with relativity, suggesting that this type of experiment might be an interesting way of reconciling it with quantum mechanics.
No Steins;Gate green bananas for me! Tuturu!
Restore the madness of youth's lechery
> The results are in perfect agreement with predictions from the 1990s--there are no grandfather-type paradoxes.
There is no time travel citizen! Go on about your lives.
Meanwhile the military starts researching chrono-troops. Because, you know, Australia has always controlled the world with its benevolent Empire...
You don't need grandfathers to have paradoxes
This isn't news. They already did the same experiment in January 2015.
It's amazing, that if you know the starlings are flying east to west, and you can only detect a starling as a complete *flock* of starlings, and not see the individual birds, then the flock can jump back east, i.e. back in time, interacting with the previous version of itself. Gosh!
Its like the starlings are simulating quantum mechanics!
Well either that, or we're looking at a system (starlings/photons) and its just that our mechanism for detecting them (sight/interaction with matter), means we can only see the flock and not the individual (bird/?). So the thing you know as a photon, is actually a flock of something smaller that is sufficient in density to promote an electron. If it couldn't promote the electron we could not detect it. Hence you're not seeing what you think you are, its just that you refuse to accept the divisibility of photons despite the evidence slapping you in the face.
But lets keep making those equations describing the weird time travelling/ trans-dimensional world of starling flocks. It makes for better science fiction.
tell me who wins the Superbowl.!
Time travel is possible but not in the way you think about it. It exists going backwards but is tied to alternate realities, or tied to multiple universes. When the quantum particle loops back on itself, it's going back to an alternate universe which is similar but slightly different. The farther it loops back on itself the closer the alternate universe is similar to ours. This is because of the Big Bang, and we all originated from the same point in space. if you keep going farther back eventually all universes converge. On the flip side, the farther ahead in time one travels, the more random a universe. The present time is the only constant
If the particle were to kill itself, it would only kill the version in the new universe it is in, not the original from which it originated. One can never travel back in time in their own universe, and if they travel forward, it will never be their original universe but a similar one, and the farther in time they go forward, the more different the universe would be from their original one.
The universe and everything we know follow a set of laws, and it was designed in a way that we could not alter our own universe. At least past universe. However, you could change your original future universe by gathering knowledge from other universes and returning at the exact moment in time you left if you could find the correct signature of your own original universe before you traveled in time. So Leave original universe, gather info, return to exact universe using a signature you already know about gathered at the exact moment you left. If you return a few seconds later, your signature would be off as things could have happened different in those few seconds somewhere in your universe, and would not be your true original universe.
Obviously we have a long way to go to be able to accomplish such tasks, but that's the general theory, and with this article this is the beginning steps of time travel.
Yes, I have traveled back in time already and am here in an alternate universe. However I cannot return to my original universe as we didn't have the means to capture signatures in my timeline yet when I left. I came here knowing that. No I will not tell you about your future, because your future is not my future, so I don't know it yet.
The results are in perfect agreement with predictions from the 1990s
So they built something that thought cloning would be the wave of the future? And that we would save the rainforest?
from an unreadable hipster site
The results are in perfect agreement with predictions from the 1990s--there are no grandfather-type paradoxes
Nice first step, but I'll be more impressed when the results are in agreement with predictions from the 1890s
/. posts from Colorado have gotten stranger and stranger...
"Various physicists have discovered solutions to Einstein’s field equations that contain loops that return to the same point in space and time."
What a lazy bit of reporting! Mr. Kurt Friedrich Gödel first discovered the Einstein's general relativity allowed for closed timelike curves. He presented a paper describing this solution to Einstein as a birthday present, while they were both working at the IAS. It grieves me when Gödel is not given the recognition he is certainly due.
Or not. Until we can find or set up a region with a closed timelike curve, we won't be able to test such things, and it all is, well, entirely theoretical. There are several possibilities.
PHEM - party like it's 1997-2003!
Pretty sure this experiment was done before in 2013-14 areas, everyone was going crazy about how we invented time travel.
But really all it shows is that any possible actual time travel likely does conform to these self-correcting closed timelike curves that prevent paradoxes globally across time all at the same time rather than locally.
So, in other words, you already never went back in time to not kill your grandfather because you already never done it.
Speak for yourself.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
You mean a big ball of wibbly-wobbly... timey-wimey... stuff? Even the light sci-fi tends to be a couple steps ahead of physics.
Let me know when someone builds a Predictor.
but kept up back at the beginning
If I go back in time and kill the old version of myself - is that suicide or murder?
I don't fully understand what they did. But, here's my take. It would seem to me that they may have demonstrated that there is not a single timeline, which kinda goes along with some other assumptions in Quantum mechanics. Relativity assumes that Time is a constant so-to-speak. Quantum Mechanics does not. How this experiment might lead to unifying Relativity with Quantum I don't know, and don't believe, because I think both theories (and they are both THEORIES) are flawed.
The correct answer is 42.
cubs win 2015 outlook not so good unless the cubs sox end up being the only 2 teams left. and even then the cubs will find away to mess it up.
But even if something really bad happen to wipe most of the MLB / USA other then Chicago cubs fans will not give a dam just to see there team in the World Series
Wow, so glad you have all the definitive answers, we can stop researching now!
Terminator, Back to the future, Bill and Ted's... is there any legitimacy here or is it just a bogus adventure?
So what exactly is your solution to the paradox? There are a few possibilities: alternate universes, total lack of free will preventing you from killing your grandfather, some sort of physical conspiracy of the universe always making something happen that thwarts your efforts (gun not firing), etc.) but none of them are as straightforward and obvious as you make it seem.
Lighten up, John Titor.
WOW YOU SURE ARE SMART! This problem has only stumped some of the greatest philosophers who have ever lived but to your LEX LUTHOR LEVEL 19 INTELLIGENCE it's a MERE ABSURDITY! And to think that you spend your days posting to Slashdot as OBIWANKENBLOWME. Please fuck off. Thanks.
Wow, you don't like smart people do you? Is it that you feel threatened by the or you feel that your own intelligence is ignored by others or is it that you had a smart girlfriend that totally broke your heart?
One thing is certain, online bullying of others makes you look like a laughable idiot!
How about you do the fucking off until you have something insightful to add to the conversation?
> I cannot return to my original universe as we didn't have the means to capture signatures in my timeline yet when I left
titor ur such a n00b learnto4D already
Is that you, John Titor? I thought you went back to 2036 from 2003? Why are you back in 2015?
more bunkum theory. Any theory whatsoever can be announced saying anything you want, but it DOES NOT make it true.
"Cats could rule the Universe" is as valid as this time loop announcement and "probably is far more likely" (see what I did there....)
Sorry this quantum stuff is largely just hype bandied about by philistines who just like to get attention
Time travel is possible but not in the way you think about it. It exists going backwards but is tied to alternate realities, or tied to multiple universes. When the quantum particle loops back on itself, it's going back to an alternate universe which is similar but slightly different. The farther it loops back on itself the closer the alternate universe is similar to ours. This is because of the Big Bang, and we all originated from the same point in space. if you keep going farther back eventually all universes converge. On the flip side, the farther ahead in time one travels, the more random a universe. The present time is the only constant
If the particle were to kill itself, it would only kill the version in the new universe it is in, not the original from which it originated. One can never travel back in time in their own universe, and if they travel forward, it will never be their original universe but a similar one, and the farther in time they go forward, the more different the universe would be from their original one.
The universe and everything we know follow a set of laws, and it was designed in a way that we could not alter our own universe. At least past universe. However, you could change your original future universe by gathering knowledge from other universes and returning at the exact moment in time you left if you could find the correct signature of your own original universe before you traveled in time. So Leave original universe, gather info, return to exact universe using a signature you already know about gathered at the exact moment you left. If you return a few seconds later, your signature would be off as things could have happened different in those few seconds somewhere in your universe, and would not be your true original universe.
Obviously we have a long way to go to be able to accomplish such tasks, but that's the general theory, and with this article this is the beginning steps of time travel.
Yes, I have traveled back in time already and am here in an alternate universe. However I cannot return to my original universe as we didn't have the means to capture signatures in my timeline yet when I left. I came here knowing that. No I will not tell you about your future, because your future is not my future, so I don't know it yet.
I have always thought that , in a nutshell, if one were able to travel backwards in time, anything that the did there would only have the result of creating the future that they came from, as absurd as that sounds. I always thought time travel movies where that had been the result were particularly insightful. Movies such as 12 Monkeys or The Time Traveller's Wife.. agrees with this model of how time travel and non-linear causality work to protect the continuity of chronology and create the world we normally live in. I have always suspected that this concept is a cause or an effect of why that superluminal signaling is not possible because it would interfere with the continuity of causality. There are still some interesting predictive mechanisms one can use to utilize this understanding, but it may very well be that going back in time and changing anything that has already happened is simply an impossibility.
First step take all of these 'theorists' and freeze them down to a few thousandths of a degree above Zero Degrees Kelvin ...
And then ... problem solved
This immediately made me think, well what if time travel isn't possible, but a simulation of it, of the past, is, using this.
And of course that immediately made me think of the possible scifi stories that could explore this concept or use this as a literary device.
And then I realized this has sort of been done already, in the episode of ST:NG, The Inner Light (a personal favorite).
The guy who said the election was rigged won the presidency with the second-most votes.
How about, like QM, it simply doesn't work on the macro level? That while the photon may have been looped back in time (although another explanation might be forthcoming), massive objects cannot.
Interesting page but incomplete. There are far more theories and some of them even makes more sense than what it listed there.
It must have been something you assimilated. . . .
(sorry)
I prefer the oscillating version. You travel back to kill your grandfather, this causes you to not exist which in turn makes you not travel back to kill your grandfather.
Like an oscillation in an electric circuit the oscillation is either stable, reaches an endpoint or is dampened out.
Typically I would imagine that the time will continue to change until it reaches a stable point.
As long as time machines exists, and are used, they will together with the butterfly effect probably cause time oscillations that causes the time traveler to not go back in time.
Because of this reality is always changed to a point where paradox causing time travel doesn't happen.
The only likely outcomes are either that time machines doesn't get invented because every time it is used it changes the past in a way that makes it not get invented, or that it gets invented, possibly used, then locked away in a museum to not cause further time oscillations.
The Vulcan Science Directorate has determined that time travel is impossible.
That's entirely possible, but that's not what the ObiWanKenblowme was talking about. He said there was no problem and compared it with Zeno's paradox.
Ah, but this machine only goes forward in time, so you won't be able to change history or do something disgusting like sleep with your own grandmother. -Farnsworth
You don't know how what a theory is. At all.
The zeno's paradox is resolved by the discovery of the planc distance.
The runner will have a nonzero probability of instantly tunnelling to the finish line after reaching the planc distance. This means zeno's paradox is false.
Take THAT zeno! :P
But oscillations imply some kind of meta-time so that history itself can change. There would need to be some other, perpendicular time-dimension in which these changes to spacetime would take place. History "used to be" a certain way but "now" (measured in meta-time) history is different.
And then we can start arguing about whether or not it's possible to go back in meta-time, etc...
It sounds like they are referring to the Novikov Self-Consistency Principle.
The principle asserts that if an event exists that would give rise to a paradox, or to any "change" to the past whatsoever, then the probability of that event is zero. It would thus be impossible to create time paradoxes....
Events on a CTC are already guaranteed to be self-consistent, Novikov argued; they influence each other around a closed curve in a self-adjusted, cyclical, self-consistent way. The other authors recently have arrived at the same viewpoint.We shall embody this viewpoint in a principle of self-consistency, which states that the only solutions to the laws of physics that can occur locally in the real Universe are those which are globally self-consistent. This principle allows one to build a local solution to the equations of physics only if that local solution can be extended to a part of a (not necessarily unique) global solution, which is well defined throughout the nonsingular regions of the spacetime...
The Novikov consistency principle assumes certain conditions about what sort of time travel is possible. Specifically, it assumes either that there is only one timeline, or that any alternative timelines (such as those postulated by the many-worlds interpretation of quantum mechanics) are not accessible.
This straightforward solution is that time travel does not exist.
[citation needed]
The results are in perfect agreement with predictions from the 1990s--there are no grandfather-type paradoxes.
That is the beauty of time travel experiments. You just go back in time and adjust the predictions. Simple, eh?
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Bah. The BBC has been simulating a time machine for decades.
Time travel is possible but not in the way you think about it. It exists going backwards but is tied to alternate realities...
I see someone read Anathem.
-1, Too Many Layers Of Abstraction
Maybe his Tesla coil burst.
No, just further and further away from your original universe.
Some stoner got hold of a time machine and went back in time and somehow legalized pot in Colorado... Who knows what those time ripples will do to the continuum...
Somebody stop them before they waste all our Universe ammo!
I am wondering whether this has implications for quantum computing. If a qbit has information about a previous version of itself then flow control can occur entirely at the quantum level, because an operation in current time can be compared to, or influenced by, an operation in a previous time.
El. Psy. Congroo.
Andrew Cleland and Aaron O'Connell have demonstrated macroscopic quantum behavior: http://web.physics.ucsb.edu/~m...
Yves Couder et al. have demonstrated Single-Particle Diffraction and Interference at a Macroscopic Scale.
The present time is the only constant
How do you know the present time is the constant and we're not just an alternate universe?
*puts_tinfoil_hat_firmly_on*
"Here we experimentally simulate the non-linear behaviour of a qubit interacting unitarily with an older version of itself".
A quantistic interpretation of Microsoft System Restore.
So if you considered both string theory(?) of multiple universes formed from choices (all simultaneous outcomes exist until one choice is made then the rest collapse) and the paradox problem, it seems that a paradox is not actually a problem, as the logical outcome of that choice ( to kill your grandfather) would collapse itself leaving all the other choices/universes.
So basically, paradoxes cannot exist. what can exist does.
There are no paradoxes; somebody invents time travel, and somebody goes back and changes things, and changes ripple forwards, and somebody else (or the same) goes back and changes things, and changes ripple forwards, and so on and so on, until somebody changes things into a future where time travel is never invented, and that is a stable trap, and everything marches forwards from there.
Star Trek transporters are just 3d printers.
Are you John Titor.