Further to Carlo Rovelli’s views on time travel (only a technological problem, not a scientific one) and the order of time in general, views, as set out in The Order of Time, our color commentator Rob Sheldon offers,
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If I can speculate about what goes on in physicist’s heads, this issue about time is an attempt to force symmetry on the universe. Sorta like the 2-yr old who wants to regularize irregular verbs. “Mommy not home; she goed to the store.”
Einstein’s Special Relativity (SR) argued that time was a fourth dimension and should not be treated any differently than height, width, and length. To get the units right, one only needed to multiply time by the speed of light–c*t. Only it was a negative dimension, so if distances are measured by r = sqrt(x^2 + y^2 + z^2), then SR distances were s = sqrt[r^2 – (c*t)^2].
Just to add some pizzazz, we can use that remarkable little constant “i” defined to be “sqrt(-1)”, and write this as: s = sqrt[r^2 + (ict)^2], so now it looks like
a normal distance (Eulerian measure).
But what does it mean?
No one has a clue. But it looks neat and tidy. And it makes physicists believe that time is just another coordinate like space once it is multiplied by “ic”. And since space can go from -infinity–>+infinity, then why can’t time do the same thing? So if there isn’t any “flow” to space, why should there be any “flow” to time?
Just for starters, if you multiplied length by i, and talked about “imaginary length” would anybody have a clue what it meant? So why should “imaginary time” have any more relation to length than “imaginary length” has to time?
In addition, if you don’t allow time to flow, if it is static, then it destroys causality. This has to do with how modellers try to put “tetrads” of 4-D spacetime together and derive physical laws from it. It is absolutely essential that time “flow” for laws to exist, for causality to work, for thermodynamics to make sense, for Newton’s laws of motion to work. Therefore it is sheer nonsense to say that “flowing time” is an illusion–because if it is, all of physics is an illusion too. Just crazy talk. Like “Mommy goed to the store.”
Here is the opening paragraph of chapter 6 from G. K. Chesterton’s Orthodoxy:
THE real trouble with this world of ours is not that it is an unreasonable world, nor even that it is a reasonable one. The commonest kind of trouble is that it is nearly reasonable, but not quite. Life is not an illogicality; yet it is a trap for logicians. It looks just a little more mathematical and regular than it is; its exactitude is obvious, but its inexactitude is hidden; its wildness lies in wait. I give one coarse instance of what I mean. Suppose some mathematical creature from the moon were to reckon up the human body; he would at once see that the essential thing about it was that it was duplicate. A man is two men, he on the right exactly resembling him on the left. Having noted that there was an arm on the right and one on the left, a leg on the right and one on the left, he might go further and still find on each side the same number of fingers, the same number of toes, twin eyes, twin ears, twin nostrils, and even twin lobes of the brain. At last he would take it as a law; and then, where he found a heart on one side, would deduce that there was another heart on the other. And just then, where he most felt he was right, he would be wrong.
Rob Sheldon is the author of Genesis: The Long Ascent
See also: Carlo Rovelli: Future time travel only a technological problem, not a scientific one. Rovelli: A starship could wait [near a black hole ] for half an hour and then move away from the black hole, and find itself millennia in the future.
News, RS is fundamentally right. Time is intimately tied to causal succession. KF
“If I can speculate about what goes on in physicist’s heads, this issue about time is an attempt to force symmetry on the universe.”
Mmmm. I see it more like the difference between Newtonian mechanics and quantum mechanics.
Except we don’t have a quantum mechanics equivalent model of time yet, so we’re stuck using the simpler model and associated maths of our newtonian mechanics model of time.
And we all know there are intractable problems with every theory we currently hold and use, because we all know our knowledge is incomplete. But they’re what we have.
And when people take these frailties and push the model beyond its useful range, that is exactly when its inaccuracy is most obvious.
Like the precession of the moon; you cannot extrapolate it backwards indefinitely or you get a moon revolving around the surface of the earth just above your head … and similar absurdities abound. Even if it is true that the universe is expanding (I personally am not convinced but who cares), you cannot take 50 years of measurements and extrapolate backwards 15 billion years.
No statistician would except such nonsense except for one thing;
“It’s the best we’ve got.”
Tomorrow, next week, next decade, it doesn’t matter; sooner or later the current model will be displaced by a marginally less inaccurate model that will imply some equally absurd consequence when you push the numbers to absurd lengths.
ScuzzaMan:
“No statistician would except such nonsense except for one thing”
except…except…?
Being charitable:
“It’s the best we’ve got.”
Other interpretations are, of course, possible.
As to the claim of time travel supposedly being “only a technological problem, not a scientific one”,,, Gödel understood his working out of time travel being possible in Einstein’s space-time to ‘undermine the Einsteinian worldview from within’.
As well, the following study, (in a fairly ingenious thought experiment that looked at the differences between ‘photon clocks’ and ‘atomic clocks’), challenged the assumption of length contraction as being valid for ‘photon clocks’. In doing so, they cleared up some loose ends in relativity concerning time’s relation to space. Loose ends that had been ample fodder for much of the speculation of time travel being possible in relativity: As the following researchers commented, “Our research confirms Gödel’s vision: time is not a physical dimension of space through which one could travel into the past or future.”
As to Einstein’s original thought experiment that gave him his breakthrough insight into “Special Relativity’, Einstein’s original thought experiment was when he imagined moving away from the face of a clock at the speed of light.
Would not the hands on the clock stay stationary as you moved away from the face of the clock at the speed of light? This whole ‘time, as we understand it, coming to a complete stop at the speed of light’, (despite whatever philosophical objections some may have against the reality of a ‘timeless existence’), is now confirmed to be true by experimental evidence.
That time, as we understand it comes to a complete stop at the speed of light, and yet light moves from point A to point B in our universe, and thus light is obviously not ‘frozen within time, has some fairly profound implications.
The only way it is possible for time not to pass for light, and yet for light to move from point A to point B in our universe, is if light is of a higher dimensional value of time than the temporal time we are currently living in. Otherwise light would simply be ‘frozen within time’ to our temporal frame of reference.
One way for us to more easily understand this higher dimensional framework for time that light exist in is to visualize what would happen if a hypothetical observer approached the speed of light.
In the following video clip, which was made by two Australian University Physics Professors, we find that the 3-Dimensional world ‘folds and collapses’ into a tunnel shape as a ‘hypothetical’ observer approaches the ‘higher dimension’ of the speed of light.
It is also very interesting to note that many of the characteristics found in Near Death Experience testimonies are exactly what we would expect to see from what we now know about Special Relativity (and General Relativity): For instance, many people who have had a Near Death Experience mention that their perception of time was radically altered:
As well, Near Death Experiencers also frequently mention going through a tunnel to a higher heavenly dimension:
And in the following quotes, Mary Neal and John Burke both testify that they firmly believed that they were in a higher dimension that is above this three-dimensional world and that the reason that they have a very difficult time explaining what their Near Death Experiences felt like is because we simply don’t currently have the words to properly describe that higher dimension:
It is also important to note that although hypothetically traveling at the speed of light in this universe would be instantaneous travel for the person going at the speed of light, this ‘timeless’ travel is still not completely instantaneous to our temporal framework of time. And is therefore not completely transcendent to our temporal framework.
That is to say, speed of light travel, to our temporal frame of reference, is still not completely transcendent of our framework since light still appears to take time to travel from point A to point B from our temporal perspective. Yet, in quantum mechanics, instantaneous travel is not only achieved for the speed of light framework but instantaneous travel is also achieved in our temporal framework.
That is to say, the instantaneous travel of quantum information is instantaneous to both our temporal framework and the speed of light framework, not just the speed of light framework.
Quantum correlations are not limited by time, nor space, in any way, shape or form, in any frame of reference, as light is seemingly limited to us in this temporal framework. Quantum correlations are truly instantaneous.
Of particular interest to all this is that this discrepancy between what Einstein termed the ‘physical time’ of relativity and what philosophers termed ‘The Now’ of the mind is one of the primary reasons why Einstein never received a Nobel prize for Special Relativity.
In fact, Einstein went so far as to say that “The time of the philosophers did not exist.”,,
In fact, Einstein also stated to a philosopher that “The experience of ‘the now’ cannot be turned into an object of physical measurement, it can never be a part of physics.”
Yet, contrary to what Einstein thought was possible for experimental physics, ‘the experience of the now’ is now found to be very much a part of physical measurement.
As the following researcher stated, “It proves that measurement is everything. At the quantum level, reality does not exist if you are not looking at it,”,,, “The atoms did not travel from A to B. It was only when they were measured at the end of the journey that their wave-like or particle-like behavior was brought into existence,”
Many more experiments from quantum mechanics confirming ‘the experience of the now’ to be primary for ‘measurement’ are touched upon in the following video.
Thus, contrary to what Einstein thought was possible for experimental physics, ‘the experience of the now’ is found to be very much a part of physical measurement.
As the following researcher stated: We must explain space and time as somehow emerging from fundamentally spaceless and timeless physics.
One final note: As to the concerns that have been voiced about ’cause and effect’ being undermined with temporal time being regulated to, basically, being an illusion, It should be noted that all of this evidence from relativity and quantum mechanics fits hand in glove with what we should a-priorily expect from a Christian perspective,,
As well as fitting hand in glove into what was ‘predicted’ by Aristotle and Aquinas concerning the ‘first mover’:
Here is a technical explanation and video of Aquinas’ First way argument for God where you can, at your leisure, see just how well the argument from motion dovetails into what we are seeing in quantum mechanics
Or to put Aquinas’ argument much more simply “The ‘First Mover’ is necessary for change occurring at each moment.”:
The validity of this ancient ‘first mover’ argument is beautifully confirmed to be true in the ‘simple’ double slit experiment.
Verse:
ScuzzaMan:
“No statistician would except such nonsense except for one thing”
…except…except…?
or
…accept…except…?
https://www.amazon.com/dp/1483486869
Peter A
Huh. I completely missed that.
Twice.
Thanks for pointing it out.
Again.
Time travel in any direction is nonsense. The speed of motion in time would have to be given as v = dt/dt = 1, which is nonsensical since 1 is not a speed. And no, it is not 1 second per second. It is 1 and it’s nonsense.
There is a reason that Karl Popper called spacetime “a block universe in which nothing happens.” The reason is that time travel is nonsense. Spacetime is a fiction.
There is only the present, the every changing present.
I’ve always liked Augustine’s discussion about time (an excerpt):
“For what is time? Who can easily and briefly explain it? Who even in thought can comprehend it, even to the pronouncing of a word concerning it? But what in speaking do we refer to more familiarly and knowingly than time? And certainly we understand when we speak of it; we understand also when we hear it spoken of by another. What, then, is time? If no one ask of me, I know; if I wish to explain to him who asks, I know not. Yet I say with confidence, that I know that if nothing passed away, there would not be past time; and if nothing were coming, there would not be future time; and if nothing were, there would not be present time. Those two times, therefore, past and future, how are they, when even the past now is not; and the future is not as yet? But should the present be always present, and should it not pass into time past, time truly it could not be, but eternity. If, then, time present — if it be time — only comes into existence because it passes into time past, how do we say that even this is, whose cause of being is that it shall not be — namely, so that we cannot truly say that time is, unless because it tends not to be?”
—Augustine of Hippo, Confessiones lib xi, cap xiv, sec 17 (ca. 400 CE)
Physicists haven’t done much to improve on that in the intervening centuries.
Fasteddious @12,
Thank you for that inspiring Augustine quote. It reminds me that it’s always a good idea to think of everything from a yin-yang perspective. That is, everything comes in complementary pairs and this include the ‘present’. In this light, the present consists of two things, the immediate past (P) and the immediate future (F). At every instant, two things happen simultaneously:
1. F changes into P.
2. P becomes F and is born anew.
This is why some of us believe that the entire physical universe is continually being destroyed and created. This is a Christian idea. Of course, the idea of time as a line along which we are moving in one direction or another is a conceptual disaster.