If time goes in reverse

[khan2012]

Time is non-linear and if time[for the entire universe] went in reverse, similarly to the rewinding of a video machine, we would not be able to tell the difference from forward time because our memories would be played backwards and they would essentially be erased back to the point of the rewind.

The universe appears to be a living organism or self organizing system, that could expand, then contract in short intervals, similarly to the way many life forms need to breathe by inhaling and exhaling. So while the universe is expanding overall, it could be halting time, then reversing time, before it starts another expansion interval as time goes forward.

When time goes forward again, we sometimes experience "deja vue" as there is possibly some type remnant of the previous future still in our memory somehow, or it could be an echo in time that we sense.

Perhaps history does not repeat exactly, with each reverse then forward-time breathing cycle, things could change. We might not have to be locked in to repeating things twice or even three times.

The reversing of time intervals may be much shorter than the expansion of time intervals, maybe a few days at most. I imagine a giant being slowly inflating the balloon universe, where the breath is time and time is a force, where the being occasionally pauses, the balloon shrinks slightly and then begins to expand again.

 

[recall15]

The best analogy to this problem is in this SCi-Fi works:

CODA

 

[RainmanTime]

You are a being that exists across vast spans of space-time.

It is only an illusion of our (primarily) linear senses that we "exist in a moment of now".

Your memory is "that part of you that speaks to you from your past." And just like any communication, it can be distorted via a noisy channel (see the works of Shannon and Hamming in quantifying noisy channels) as well as modulation and demodulation errors.

In exactly the same way, there is a "part of you that speaks to you from your future."

Whether time moves "forward" or in "reverse" is a trvial question that amounts to nothing more than a convention (much like the "right hand rule" in engineer). Granted, it is a convention that reflects our sensory apparatus... but isn't that, in and of itself, suspicious? We picked the convention for "moving forward in time" merely based on what was convenient to our senses? That, in itself, should prove it is arbitrary. ONLY the second law of Thermo can place a "direction" on time...and it is only loosely related to the time sense imbibed within our consciousness apparatus.

I once again repeat, with deadpan certainty, that the "romantic" notion of time travel that most envision will NOT come to pass. EVER. The only way time travel will manifest (and it necessarily excludes all those paradox-forming hopes and dreams of the TT romantics) is when you start to integrate your true being across space-time. You are NOT a being that lives moment-to-moment. You are a being that spans all of space-time. THE ONLY WAY that physics will allow you to "travel back in time" would be if you ACTUALLY, PHYSICALLY existed as the being you are targeting. The statistics of it being "close but only similar" are so far out as to be impractical, and the physics of replication of the same being, with the same instances of experience, in the same place in space-time, are even less.

RMT

 

[khan2012]

It becomes impossible to travel backwards in time to one's original world-line using a time machine if an infinity of parallel universes exist.

http://en.wikipedia.org/wiki/Path_integral_formulation

quote:

"

The path integral formulation of quantum mechanics is a description of quantum theory which generalizes the action principle of classical mechanics. It replaces the classical notion of a single, unique trajectory for a system with a sum, or functional integral, over an infinity of possible trajectories to compute a quantum amplitude.

"

 

[Twighlight]

Time is non-linear and if time[for the entire universe] went in reverse, similarly to the rewinding of a video machine, we would not be able to tell the difference from forward time because our memories would be played backwards and they would essentially be erased back to the point of the rewind.

There is no such thing as 'time, for the whole universe'. That is the basis of relativity. There is no, one, single 'time' that exists everywhere.

Time going backwards is quite fanciful stuff. I'd like anyone to provide any reason why it should. The speed of time is directly related to the speed of light....and there's not the slightest evidence that has ever changed.

A film running backwards is not a good analogy.....because to run the film backwards, time still has to run forwards.

 

[khan2012]

There is no such thing as 'time, for the whole universe'. That is the basis of relativity. There is no, one, single 'time' that exists everywhere.

Time ticks at different rates in different regions of the universe but it is accepted that time is going forward for ALL of the the observable universe. If it were to run backwards for the entire universe, there is no way we could tell the difference.

 

[elle]

Time ticks at different rates in different regions of the universe but it is accepted that time is going forward for ALL of the the observable universe. If it were to run backwards for the entire universe, there is no way we could tell the difference.

Time ticks! That idea scares me. /ttiforum/images/graemlins/frown.gif Time traveling ticks. Maybe they put the blood back into you?

 

[Twighlight]

If it were to run backwards for the entire universe, there is no way we could tell the difference.

Second hand car salesmen would have a field day....

" This car's a bargain sir ! We didn't need to clock it...as it does that itself. Only 20,000 miles, and getting less by the day."

 

[khan2012]

I once again repeat, with deadpan certainty, that the "romantic" notion of time travel that most envision will NOT come to pass. EVER.

The forum title is TIME TRAVEL INSTITUTE and YOU are a moderator. Yet you do not ...think... time travel is possible.

http://www.pbs.org/wgbh/nova/time/through2.html

quote:

"

Various researchers have proposed ways in which backward and forward time machines can be built that do not seem to violate any know laws of physics. Remember that the laws of physics tell us what is possible, not what is practical for humans at this point in time. The physics of time travel is still in its infancy. While all physicists today admit that time travel to the future is possible, many still believe time travel to the past will never be easily attainable.

Don't believe anyone who tells you that humans will never have efficient technology for backward and forward time travel.

Accurately predicting future technology is nearly impossible, and history is filled with underestimates of technology:

"Heavier-than-air flying machines are impossible." (Lord Kelvin, president, Royal Society, 1895)

"I think there is a world market for maybe five computers." (Thomas Watson, chairman of IBM, 1943)

"There is no reason for any individual to have a computer in their home." (Ken Olsen, president, chairman and founder of Digital Equipment Corp., 1977)

"The telephone has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us." (Western Union internal memo, 1876)

"Airplanes are interesting toys but of no military value." (Marshal Ferdinand Foch, French commander of Allied forces during the closing months of World War I, 1918)

"The wireless music box has no imaginable commercial value. Who would pay for a message sent to nobody in particular?" (David Sarnoff's associates, in response to his urgings for investment in radio in the 1920's)

"Professor Goddard does not know the relation between action and reaction and the need to have something better than a vacuum against which to react. He seems to lack the basic knowledge ladled out daily in high schools." (New York Times editorial about Robert Goddard's revolutionary rocket work, 1921)

"Who the hell wants to hear actors talk?" (Harry M. Warner, Warner Brothers, 1927)

"Everything that can be invented has been invented." (Charles H. Duell, commissioner, US Office of Patents, 1899)
"

 

[khan2012]

Time ticks! That idea scares me. Time traveling ticks. Maybe they put the blood back into you?

:D

 

[khan2012]

Second hand car salesmen would have a field day....

" This car's a bargain sir ! We didn't need to clock it...as it does that itself. Only 20,000 miles, and getting less by the day."

There are a few people who can remember the (((echos))) of a previous future. :D

 

[RainmanTime]

The forum title is TIME TRAVEL INSTITUTE and YOU are a moderator. Yet you do not ...think... time travel is possible.

Incorrect characterization of what I said. I never said time travel will not happen. I am only saying it will not take the form that all typical storylines wish to romanticize. You will never jump into a physical time machine and POOF your body is magically transported (unchanged) to the space and time you choose. That ain't how it is gonna go down. And you can take that to the bank.

Time travel will not manifest as a mass-transfer experience. Rather, it will manifest as an information experience. A bit like tuning a radio to a frequency, but on a much more complex level. You will eventually be able to tune-in to specific space-times, but only to observe, not to directly act. The only impact you can/will be able to have through this means of time travel will be to plant or suggest ideas, in the form of information, that may, or may not, be interpreted correctly in that time.

Sacred texts are nothing more than ourselves, talking to ourselves, from both past and future selves. That is the "time travel" that has always been present and always will be present as part of the human experience.

RMT

 

[Darby]

Time is non-linear and if time[for the entire universe] went in reverse, similarly to the rewinding of a video machine, we would not be able to tell the difference from forward time because our memories would be played backwards and they would essentially be erased back to the point of the rewind.

That's the classical thermodynamic interpretation.

Time reversal symmetry postulates that in a thermodynamic system one can't distinguish the difference between a system evolving in the +t or -t direction.

In quantum mechanics the situation is different, even though the outcome still ends with the observer unable to distinguish the difference. If we accept the postulates of QM then we have to accept that if we reverse the process of determining some state of a quantum system that in doing so we lose the information that we originally gained in the first instance of determining the state. Returning the system to its original state involves a total loss of "memory" of the original determinatiojn of the state of the system. There won't be any deja vu because there won't be any information at all about the previous determination of the state of the system. The reason for this is that in QM, especially MWI, the observer "system" is entangled with the system under observation. Returning the latter to its original state requires returning the former to its original state (of ingorance in this instance).

 

[Twighlight]

Sacred texts are nothing more than ourselves, talking to ourselves, from both past and future selves. That is the "time travel" that has always been present and always will be present as part of the human experience.

On a more fundamental level, there's various 'bootstrapping' theories like John Wheeler's feedback loop.....which suggest that we somehow reach right back into the past and create the very conditions that lead to us being here. A more extreme version of that is 'concensus reality'....which speculates that we are making up the universe as we go along.

 

[khan2012]

Time travel will not manifest as a mass-transfer experience. Rather, it will manifest as an information experience. A bit like tuning a radio to a frequency, but on a much more complex level. You will eventually be able to tune-in to specific space-times, but only to observe, not to directly act. The only impact you can/will be able to have through this means of time travel will be to plant or suggest ideas, in the form of information, that may, or may not, be interpreted correctly in that time.

Energy cannot be created or destroyed, so it seems that you are correct in that we cannot transfer mass/matter into the past. By transferring mass to an earlier time period, that mass would in effect be created out of nothing because all of the atoms of the thing going back in time also exist in some other form already, in THAT past. It would be a violation of conservation of energy because something that already exists would be doubled out of nothing.

 

[Twighlight]

Energy cannot be created or destroyed, so it seems that you are correct in that we cannot transfer mass/matter into the past. By transferring mass to an earlier time period, that mass would in effect be created out of nothing because all of the atoms of the thing going back in time also exist in some other form already, in THAT past. It would be a violation of conservation of energy because something that already exists would be doubled out of nothing.

All elementary particles are identical.....so there's no real sense in which one could identify an atom as being part of the same object elsewhere.

However, there's a more fundamental reason why such time travel may not be possible. It appears that even 'stable' particles like protons do in fact have a 'half life'. Incredibly long.....10^33 years.....which is a million billion billion times longer than the universe has already existed. But....it implies that somehow such particles have an 'age'.....that there is some factor that knows how old the particle is since the big bang.

The question then arises as to whether the universe will accept one taking a proton back in time, to a time before that of it's own internal clock.