Dear Cameron,

Thank you for your replies. It is only a short answer now as an opening to a more detailed response.

Time for me is only what physical clocks can indicate.

Gravity and acceleration may slow down a clock, and the fastest it can tick is in an inertial frame free of gravitational influences to my best knowledge.

So in a quick and dirty reasoning regarding your last question:

When one clock travels in an incredible space filled with gravity, rotating dust and/or forced to rotate and accelerate, then all it can happen to it is to get out of synch with the clock it started with.

My conclusion is if the two unite in space again (I said again) then they both advance somewhat although it cannot be decided without detailed record of history of each which will indicate lower elapsed time.

If you can say the clocks can meet when at least one of them has negative time prior to their synchronisation at 0 or even prior to their existence that is science fiction.

If calculations support this kind of reunion, then there is a serious problem in interpretation of time and clocks somewhere.

And this is basically the purpose of my question to find if one can prove on clocks they could reunite prior to their existence or at or before departure in general.

I did not quite understand the following statement by Andrew Wutke: 

"... if the two (clocks -MF) unite in space again (I said again) then they both advance somewhat (correct! -MF) although it cannot be decided without detailed record of history of each which will indicate lower elapsed time (? -MF)".

I think, the second half of the quoted statement is not exactly accurate. Assume that time, when quantified, is just reading of a clock. Then it is natural that readings of the two initially synchronized clocks, meeting second time, may now be different, depending on their respective interim histories. For a physicist, the "reading" may be, e.g., the number of oscillations in a vibrating system. If so, then both meeting clocks can indeed, only advance in time (the number of oscillations in either one, starting from zero, may be albeit different, but both positive). In this respect, I could never understand what "travel into the past" really means. But getting to the initial point, I would say that we do not need the history records of each clock in order to decide which clock will indicate lower elapsed time. It will be the clock with lower reading (smaller number of oscillations since their first meeting). Or it may be the one of two twins who will be aged less upon their reunion. It is true, however, that the reading (proper time) of a clock is intimately linked with its specific history. And in all cases it is the traveling clock returning to its inertial counterpart, that will show the lower reading (if you want to age slower, travel more and faster!). In this sense, if you know  individual history of each clock, you can predict its readings without looking at it. But the opposite is also true - by just looking at the clocks, you can correctly describe some basic features of their histories without studying the records.

Moses Fayngold 

Thank you Moses.

I meant that after spatial reunification of the two clocks it is not possible to predict without knowledge of all influences on each clock which clock's time is lower. I do not necessary constrain any particular time value. Referring to history was unfortunate as it implies post mortem inspection while I was thinking of prediction. 

Dear Cameron

Your question:

"Are you sympathetic with Gödel's interpretation of the results?"

It may take multiple lifetimes to answer formally the question if time exists. But I can say within my limited lifetime that nonexistence of time as an omnipresent physical entity that makes all things move, makes much more sense than the other way round. Therefore I am sympathetic to Godel's interpretations such as:

"As we present time to ourselves, it simply does not agree with fact.

To call time subjective is just a euphemism ... An entity corresponding

in all essentials to the intuitive idea of time ... in relativity theory ...

exists only in our imagination"

"A relative lapse of time, however, if any meaning at all can be given to this phrase, would certainly be something entirely different from the lapse of time in the ordinary sense, which means a change in the existing. The concept of existence, however,

cannot be relativized without destroying its meaning completely."

This is not only because I believe or like these statements, but also because I have determined the real nature of relativistic time thanks to my preliminary study on simultaneity or as I prefer to call it - temporal coincidence.

The numbers for t and t' are just results of a particular clock synchronisation and the fact that an object which has moved from rest, will undergo relatively slower change than its stationary counterpart . This is in the same way as frozen meet ages less than that exposed to the sun.

For every clock in the stationary system there exists a clock in the moving system that momentarily coincides with it and their indicated times are generally different but all coexistent at once not in anyone's past or future.

Once misinterpretation of time in special relativity proliferates to general relativity, the oddities like time travel can happen.

This is not to say that relativity theories are wrong. This is about naive and idealistic interpretations of time that are superimposed on simple relationships between  states of  moving or gravitationally influenced clocks.

The depth and accuracy of information on time travel that is available is limited and incomplete. I did a report for select members of U.S. Congress that was meant as both a tutorial and a report on the coming reality of time travel. It's now a book and it does answer all of the issues concerning the subject.

Marshall

It would be good to have reference or access to the book or the main conclusion. 

I hope that this is impossibility of such thing as time travel.

When time is only a reference state in a closed system it may reverse if the state chosen for reckoning can itself reverse.  And if it is not depending on other states it has no bearing on evolution of the closed system. Same clock in separated closed systems may get out of sync simply because there is no common physical state called time. It is just an arbitrary reference clock.

Andrew:

Your understanding of time is in gross error. Time is not only a reference state and in fact such a description is inadequate to describe all the aspects that we find with time. Your referencing the reversal of a state also has no regard to time travel or how it functions, in fact none of what you described would have anything to do with temporal mechanics. 

As a result, it is no wonder that you have such an attitude about time travel when it appears that you have a less than pedestrian understanding of the nature of time. 

My book is called Paradox Lost: The True Geometries of Time Travel (see http://www.blurb.com/b/5622324-paradox-lost-the-public-edition ) and it was written to resolve all of the major issues regarding time and time travel so that select members of Congress who were the original audience wouldn't freak out when they learned that serious time travel research was underway in the private sector. 

Marshall

I appreciate honest strong opinions even if people disagree and call me this or another. I will try to see in what way I am wrong.

That's the purpose of discussions in science

Andrew:

I didn't "call" you anything. If I have strong opinions on the subject it is because I have worked very hard to find accurate and demonstrable solutions to these time related issues without having to reinvent the laws of physics, and I have been successful at it. Time is the number one issue that is so problematic in physics and physicists like Julian Barbour, who mix philosophy with their solutions to the problem, only make the problem worse. In short, the problem with time is that it's like one of those IQ test problems where the answer is in the superficial detail that you overlook trying to solve the problem, like "a rooster is sitting on a roof with sloping sides. It then lays 12 eggs which roll off. How many rolled off each side?".

Andrew:

Let me apologize if you took my comments to be a bet abrasive. The thing is I've spent something like 20 years working on the issues of time and what I mean by that is not the measurements of time but time itself. I take Minkowski and Einstein seriously when they talk about a spacetime continuum. I'm an ardent believer in the Everett/Wheeler hypothesis and I have tackled every issue about time that you can think of and been able to solve them all except the idea that time may consist of 'something' physical. Whether it does or not, doesn't seem to have any effect on the solutions to the problems that most people have with time.

In short, when i hear people say, "time doesn't exist", "time is an illusion", "time is just coordinates on a graph", "time is the changes of of the arrangements of furniture of the universe", "time travel is impossible", "Godel this - MacTaggert that" and on and on and on, it gets tedious because to address all those things requires writing a paper about it, each and every time and I don't have that kinda time which is why i took a year and wrote a book about it. 

So let me just say that space is the dimension(s) that allows for things to be and time is the dimension(s) that allows events to take place. It doesn't mean that they have to, but time is always there so that they can. If time weren't real time dilation wouldn't exist and it wouldn't matter how fast an object were moving - the frame rate of the camera would always get a clear shot. 

I work in a highly competitive area of physics and sometimes it's like the old west, which is fine with me - I grew up with cowboy westerns on TV  7 days a week. I've found more errors that Hawking has made than anyone (was the only person in the world to publicly challenge him over the Higgs when he went public against it in 2008), defended NASA's Harold White against Miguel Alcubierre over Harold's use of proprietary technology, and disproved Julian Barbour's theory of Platonia.  I dare say I'm the world's expert on time travel, which some people may think is an arrogant thing to say but it's like saying I'm the fastest gun in the west. You have to take the risks that someone will challenge you someday to a contest, which is fine with me - it comes with the territory. But when I seen the lay of the land and what everyone else is publishing about time and time travel which continues to fail to resolve anything, yeah, I'll say it and I'll back it up and I have in the past. My problem is that I've solved how time travel works as a spacetime geometry and I have the solution to how it relates to quantum mechanics in a demonstrably observable way, but I just don't want to discuss it in a forum like this until I get a chance to write a technical paper about it. Both ideas, however are in my books.

So, in closing, time is the hardest thing for people to understand. I do because I worked my brain and mind to do so. Few have that mental and psychological dexterity, to attack the problem without their own prejudicial biases getting in the way. 

If you want to see an example of how I attacked the problem of the time machine design of Ronald L. Mallett, being able to identify flaws in both his thinking and design that escaped others, even his critics, then I invite you to see the paper I wrote about it. It's on my profile page and the title begins with "Ring Lasers". You can't miss it.

Thank you Marshall for contributing to this discussion.

This thread did not attract much attention as some others I have posted so far. I think it is uncomfortable to make a position here because of the risk of contradiction between scientific theories and the common temporal logic/the common sense.

No ordinary person or a scientist can refer to common sense after it has been obliterated by Einstein's remark:

“common sense is nothing more than a deposit of prejudices laid down in the mind before you reach eighteen.”

You seem to realise the obstacle of contradiction, this can however be mitigated by parallel universes. I cannot accept this hypothesis invented due to the lack of explanation of contradictions.

If you say you take relativity seriously, I take it too. Starting from the Special Relativity I see the big misunderstanding regarding the concept of simultaneity.

If this concept is flawed, then there is no point go to advanced theories that build on it. So I have dedicated all my spare time to clarify the simultaneity issue. There are only three possible outcomes. I will show that relative simultaneity is not real temporal relation or that it is or I will never be able to prove either way.

Based on my preliminary analysis and current work not yet made public I am 80% confident the relative simultaneity concept is flawed. Additionally by realising that one can demonstrate the absolute reference frame necessity without contradicting the mathematics of the Special Relativity but requiring common language interpretations of it to be corrected. 80% confidence is not good enough to claim anything as a scientific fact, but it makes me comfortable to think that someone if not me will finally get to the bottom of it. It is only a matter of time.

With the one world as we know it, nobody or nothing can time travel, and I hope you agree with it under this constraint.

Your article makes some interesting claims but you do not go into details. If my organisation I am working for was in any way interested or involved with my private Simultaneity project, I would ask them to bring your book to our library. Unfortunately I cannot go an buy any book that appears to be interesting unless it is critical to my research. That is, I do not need any result of interpretation of General Relativity while I dispute Special Relativity claims which were in its foundations.

Andrew:

One, it appears you don't understand the concept of non-simultaneity which is a product of SR and due to that fact, as debaters against Einstein often do, have turned it into some big hobby horse that they feel will become a Trojan one. 

Second, you appear to have less than a pedestrian understanding of the topic of time travel so I don't expect you to even begin understand why it is possible. In fact, it would be impossible for you to understand it.

Andrew - I agree with  you completely.  If I travel along a c t-l curve I need another time dimension in which to move and to measure my speed.  This is what convinced philosophers that the flow of time is an illusion, just as the idea of time travel is.

I can understand why journalist persist (or pretend to) but not intelligent, grown-up physicists. What makes them reject an evidently valid proof?  Is it romanticism or a fear of the consequences - such as accounting for a Universe without cause and effect?

Stephen:

The flow of time has nothing to do with time travel, aside from time dilation, which isn't actually evidence of a time flow, though it's framed that way. There are also no "grown-up" physicists who are tasked with solving time travel, so of course none are really in any position to say anything very sophisticated or informed about it. In addition, there is no "valid proof" ruling it out. Others like Hawking have tried and all have failed...

Marshall - I guess it seems to me, as a non-physicist outsider, about the most important issue in science.  Block time eliminates many problems in physics but creates a lot of new, and equally interesting, ones.

Stephen:

Unfortunately, the "importance" a subject has is not only subjective but subjective in the eyes of those in charge of grants, science budgets and the like. In that regard, few physicists have taken the notion of time travel serious enough to rise above the most knee-jerk, and pedestrian level, which is good for me, because it makes it easy to out do them...

All fields of research have the same problem.  I am doing (desk) research into Parkinson's Disease, with which I was diagnosed in 2010. To begin with I was curious to know what happens when you have PD. I asumed that information would be readily available and it is.  But there is almost nothing proved.   The curent theory is implausible and much of the research focuses now on a protein whose fnction is ncertain and whose efffects are conjectured.  This is the yield of annual research budget of £100+M.  In 4 years of fairly desultry research I have put together a more plausible theory that  can at least account for some of the 70 odd symptoms.  

People who are good at research don't want to waste time on administration and poeple who are not so good at research lack the ability too see what needs to be done and rely on scentists to make proposals.  Scientists have careers to develop and make eye-catchngb proposals for using very state-of-the-art technology. No-one represents the peopel who pay for the research, or who might benefit from the results.

I hope Stephen you will contribute significantly to PD understanding and subsequent cure. New discoveries often need non-orthodox approach and outsiders seem to put science onto new tracks. Just to mention Faraday - a book binder and a patent clerk Einstein and a chemical engineer Linus Pauling.

Thank you Andrew!

I hav advised on some projects at Oxford but what strikes me is the necessity to meet the funding agencies requirements.  Not the trivial (and usually reasonable) administartive obligations but (contributing directy to curing - or to finding a cure for - the condition), which means that few proposals to find out what has gone wrong in PD sufferers are submitted because proposers do not think they will be attractive to funders.

Physics is also subject to fashion.  What has happened tt all the physicists who were seduced into working on string theory?

I'm sory I haven't given you much support in the discussion on the two time questons but I cannot stand another set of protracted arguments in topics that have akready been wrestled to exhaustion two years ago with the same people who seem to agree that time does not flow but immediately talk about time as if it is the "means of change".

I just proved parallel universes are real with a physical experiment which mimics time travel and produces decoherence which can be shown to be the result of the retrocausality nature of the experiment. In other words, time travel is real and involves parallel universes as a solution to paradoxes - https://www.prlog.org/12613870-new-similar-experiments-dramatically-achieve-rainer-plaga-suggestion-to-prove-parallel-universes.html