Spacetime? Time and Space are dimensions of LIFE akin to length, width and height/depth. They may not be things in the tangible manner but they are things in terms of their effect on phenomena. For example, "how could a person perceive 3-dimensions if they were blinded against any one of its parameters?"
Having given the above opening, I posit that 'space-time' is incomplete in the way we represent it. For it to fully equate to our 3-D model of LIFE, a third parameter must be included. I insist it should be 'space-time-form'. Thus you have, "TIME - a representation of transiency/change (rate); SPACE - a representation of awareness/presence (range); and FORM - a representation of force/structure (quality and quantity)."
[Quality and quantity should be understood in analogy to how mass and volume interact to give density. There is a particular quality to every quantity, and vice-versa, so that every part of LIFE is balanced against these two parameters to determine an inherent condition which these two factors represent.]
I hear arguments about time-travel and often wonder why people don't realize how ridiculous they sound. (Perhaps I sound just as ridiculous to them when I refute it!) Anyway, there is a particular theory that I instinctively deny even without recourse to any viable experiments in its support. That is:
"According to relativity, nothing can travel faster than light. If we therefore sent a spaceship to our nearest neighboring star, Alpha Centauri, which is about four light-years away, it would take at least eight years before we could expect the travelers to return and tell us what they had found. If the expedition were to the center of our galaxy, it would be at least a hundred thousand years before it came back. The theory of relativity does allow one consolation. This is the so-called twins paradox mentioned in Chapter 2. Because there is no unique standard of time, but rather observers each have their own time as measured by clocks that they carry with them, it is possible for the journey to seem to be much shorter for the space travelers than for those who remain on earth. But there would not be much joy in returning from a space voyage a few years older to find that everyone you had left behind was dead and gone thousands of years ago. So in order to have any human interest in their stories, science fiction writers had to suppose that we would one day discover how to travel faster than light. What most of these authors don’t seem to have realized is that if you can travel faster than light, the theory of relativity implies you can also travel back in time, as the following limerick says:
There was a young lady of Wight
Who traveled much faster than light.
She departed one day,
In a relative way,
And arrived on the previous night
The point is that the theory of relativity says that there is no unique measure of time that all observers will agree on. Rather, each observer has his or her own measure of time. If it is possible for a rocket traveling below the speed of light to get from event A (say, the final of the 100-meter race of the Olympic Games in 2020) to event B (say, the opening of the 100,004th meeting of the Congress of Alpha Centauri), then all observers will agree that event A happened before event B according to their times. Suppose, however, that the spaceship would have to travel faster than light to carry the news of the race to the Congress. Then observers moving at different speeds can disagree about whether event A occurred before B or vice versa. According to the time of an observer who is at rest with respect to the earth, it may be that the Congress opened after the race. Thus this observer would think that a spaceship could get from A to B in time if only it could ignore the speed-of-light speed limit.
However, to an observer at Alpha Centauri moving away from the earth at nearly the speed of light, it would appear that event B, the opening of the Congress, would occur before event A, the 100-meter race. The theory of relativity says that the laws of physics appear the same to observers moving at different speeds. This has been well tested by experiment and is likely to remain a feature even if we find a more advanced theory to replace relativity. Thus the moving observer would say that if faster-than-light travel is possible, it should be possible to get from event B, the opening of the Congress, to event A, the 100-meter race. If one went slightly faster, one could even get back before the race and place a bet on it in the sure knowledge that one would win."
- A Brief History in Time by Stephen Hawking (Chapter 10).
[The above statement does not represent Stephen Hawking's theory of time-travel, rather, it is one of the more popular notions which he has discussed in the book.]
Firstly, time is not linear. It is a kind of a vector with a shifting magnitude and a variable direction (my own theory). Secondly, there is no theory of relativity which states that, 'nothing is faster than light'. Thirdly, even in Einstein's time, it was known that some light had greater frequencies than others and that the spectrum as they had discovered thus far was still quite incomplete and therefore white light could not be used as a standard of measure. Also, electrons could not be used as a standard of measure because they had begun to realize that they may not be the smallest/simplest organization of LIFE. Fourthly, we know that, any particle, whatever its characteristics, must take time while moving from point A to B which are separated by a certain distance. No matter how fast the movement, there will always be a delay as it traverses the space between the points A and B unless the particle lies over both points and therefore does not move. Therefore the idea that time could run backwards is absolutely absurd.
Lastly, I must reiterate that without understanding the 'Form' factor, those who theorize on time-travel would only be whistling dixie. There is a reason why every form, every body, every system/organization, has its unique inherent qualities. To begin assumptions where spacecrafts and people move at the speeds of light or beyond is in great disregard to the quality of the bodies involved. Even at the low speeds of boats (sometimes canoes), cars, planes, etc, there are people who get affected => sea-sick, car-sick, jet-lag. Why then would they jump to the conclusion that a huge metal chamber or the human system can suffer such torture as being propelled at the speed of light. Not unless they believe once the people were dead then their ghosts will whizz off against the spin of the clock (like in some 'ghost of christmas past' movie).
And for those who think that space-time could be folded or bent, think again. Even if space-time acted as a homogenous material, would it not have properties inherent to itself and its functionality? Then they would also need to be known and manipulated.
Thus, when philosophy hits the reality gong, sci-fi must go bye-bye (I'm still a big trekkie).
To this whole process, I remark that passionate as philosophers may be, they should attempt to keep a tight reign on their fancies else they lead themselves astray, or worse, a horde of fanatics!
THERE IS NO TIME-TRAVEL as we have been led to believe.
* I cannot refute the black-hole or worm-hole theories because I do not know what they (the black/worm-holes) are. However, from what I know about life, creation in six business days is more likely than time-travel.