Time Travel
What are the possibilities of time travel?
I think we will find there are sadly no possibilities of time travel, because while many people have assumed a thing called time exists, and written about ‘it’ as if it exists, no one seems to have actually bothered to produce an experiment as per the scientific method to confirm their theory.
(how the wormhole billard ball paradox may be solved 'timelessly') se youtube link below, and...
The WormHole Billiard Ball Paradox. - A Brief History of Time-lessness - Matt Welcome.
Firstly, I fyou ask "is time travel possible" on public forums, or of most experts on "time" you will typically get many answers repeating the assumption that Einstein’s Relativity in some way proves time, and suggests time ( as opposed to just space , an rates of change) can be manipulated.
But if you ask for the specific part of Relativity that they think proves time, you will almost certainly find that they have not carefully read “On The Electrodynamics of Moving Bodies” themselves, and cannot show that from the outset the paper does anything other than just ‘assuming’ time.,
(see...
concerning : “On The Electrodynamics of Moving Bodies”
Anyone who refers you to this paper suggesting it provides evidence time may exists (let alone be manipulated )should be able to show you why this is true in the opening section of the paper section 1 of the paper..."Kinematics".
But if you ask any responders here on Quora, I think you may find they have either not read the source paper for themselves, or cannot show where it proves, rather than just assumes ‘time’
Specifically...
In section 1 of the paper..."Kinematics" , the (translated) words are...
"If we wish to describe the motion of a material point, we give the values of its co-ordinates as functions of the time.
Now we must bear carefully in mind that a mathematical description of this kind has no physical meaning unless we are quite clear as to what we understand by “time.” "
But the paper continues...
If, for instance, I say, “That train arrives here at 7 o'clock,” I mean something like this:
“The pointing of the small hand of my watch to 7 and the arrival of the train are simultaneous events.”
So, it is stated.... “If we wish to describe the motion of amaterial point, we give the values of its co-ordinates as functions of the time.“
But in fact, the paper only describes the motion of one material “point”, (a train), to the motion of another “material point”, the motion of the tip of a motorised hand rotating on a numbered dial.
In other words, while many people assume relativity proves time exists... section 1 of the seminal paper on Relativity itself only “assumes” that there is a thing called “time”, thus implying its existence, and “passing” are valid terms, and that a rotating hand on a numbered dial, in some way shows, or proves this. But from the outset the paper provides no logic or proof of the existence or function of “time”.
and, just "calling" the movement of a rotating hand "time", and from that suggesting there "is a thing called time that is needed for things to be able to move" - is imo, the most horrendously weak reasoning.
However, relativity does show how moving things "are" "changing" more slowly, but it does not prove there is a future or a past, or a thing called time that is "passing" more slowly... though many people seem to assume otherwise.
For example if you look at a trpical answer on Quora.
Travelling into The future is possible and theoretically provable. If you moved at the speed of light than you could almost stop time and never age compared to your slower earth counterparts
In fact observation ( e.g. of the oscillators in GPS satellites ) all that is observed is that a moving oscillator is oscillating ( changing) more slowly than a stationary one.
And there is no proof at all that it is “heading into a future”, or that “a future is arriving” as it or you change at different rates ... here... ‘now’ so to speak.
(There is a fair amount to understand, on many levels, to see how this ‘timeless’ pov may make sense, these are the more concise videos I’ve put together so far on the possibility)
‘Time-Travel’
In my carefully researched opinion, time travel is completely moot, because we have no valid reason, or proof of, the existence of a thing called time.
For there to be any chance of time-travel, e.g. from or to “the future”, you would first need some reason to suspect that a thing or place called “the future” existed, and also some experiment, as per the scientific method, to support your hypothesis.
Professor Hawking’s idea of arranging a time travellers party, to see if people might attened ‘from the future’, is rather unscientific because it is pointless expecting people to come from somewhere,(‘the future’) if you have not even established that that place exists.
A Simple experiment.
For anyone to assume time exists, other than as a useful idea, they should be able to disprove that matter just exists and moves and interacts, and show instead that a thing called ‘time’, with a future and a past really exist. But there seems no reason to genuinely suspect this, and no proof of this – consider this simple experiment....
Wherever you are, sit and look around you, and ask yourself...
“do I see any evidence at all of a ‘future’ ‘arriving’ “?
To clarify this question for yourself place any object on a surface and push left to right wit your finger, and look very closely at the object, and ask yourself...
“Do I see any evidence at all, whatsoever, that this object is in some way ‘heading into’ a ‘future’ as it moves”?
“Do I see any evidence at ll that a ‘future’ is ‘arriving’ as this object moves”?
“Do I see any evidence at all, that as this object moves, it in any way at all leave a ’temporal past’ behind it”?
“as the object moves, am I actually seeing a ‘temporal past’, affecting a ‘temporal future’ in an infinitely thin ‘present’ “?
... or are you just seeing your finger to the left of the object, pushing it to the right, where your finger touches it?
Instead of asking does time exist, or is time travel possible, it may be worth first asking
“If everything in the universe JUST exists, moves, and interacts in all directions, would that be enough to mislead me into assuming there is also a ‘past’, and/ or ‘future”?
If you consider the above question carefully you may find what it suggests very interesting, and you may also realise that no other writer on ‘time’ seems to have thought of, let alone considered and been able to disprove the possibility it suggests.
So, for the reasons above, and those in the more technical and detailed video below, I would say sadly time travel is entirely moot.
Matthew Marsden
more general aspects of 'time'
Does Time exist? How 'Time travel Paradoxes' can't happen without "the past".
Considering 'time travel'
Time Travel,Timeless Answers to Prof Cox's Science of Dr Who:
11 Does time exist ? book reviews. >
∆ Time Travel In Einstein’s universe.
∆ Time Travel In Einstein's universe. - A Brief History of Time-lessness - Matt Welcome.
What is Time? Worm hole, billiard ball paradox, Timelessly. (re Paul Davies- New scientist article)