Does time exist?

roosh wrote: »

Indeed, but it doesn't assume that anything is actually at absolute rest, and hence, doesn't assume that there exists an absolute reference frame; unless we assume that mathematical reference frames have physical existence.

Lorentzian relativity simply allows for the possibility that an object could be at absolute rest, something which can be deduced from the evidence; what we can't deduce, however, is that absolute rest doesn't exist at all; because, afterall, the earth might be at absolute rest - we just can't tell if it is or not.

If we conclude that absolute rest might not exist, then we are only free to conclude that everything must absolutely be in motion; we can't conclude that absolute rest doesn't exist, because, afterall we could be at absolute rest.

I think RoS might be based on circular reasoning, because it explicitly (or implicitly perhaps) assumes the constancy of the one-way speed of light, which, of course, is circular reasoning; and something which is a cornerstone of Einsteinian relativity.

I don't think we have any reason to deduce that a teapot orbits pluto, but I think we can deduce the possibility that an object could be at absolute rest, as well as the non-existence of time, which would make time dilation, at least, dynamical.

I also wonder if an absolute wave-length of light would account for the absence of fringe shifts in interferometry experiments; but that is for a different thread.

roosh wrote: »

Absolute rest pertains to the intrinsic motion of an object, it isn't necessarily a case of it existing or not; so when we conclude that "absolute rest might not exist" we can conclude that nothing might be at absolute rest. From that we cannot conclude that intrinsic motion might not exist.

Galileo's insight was that we can't distinguish a state of absolute rest from a state of inertial motion; both implying intrinsic motion, because the motion wasn't qualified as being relative to anything - as Galileo's observer was in a closed ship. That we cannot determine one form the other doesn't mean we can conclude neither exists, or that neither might exist; we can conclude that one or the other exists, we just can't determine, by co-moving experiment, which state we are in.

From Maxwell's occasions we can infer the constancy of the measured speed of light. If I measure the speed of light to be 300,000km/s, and you measure it to be 300,000km/s, but my instruments are contracted compared to yours, it means that my measurement of 300,000km/s is not the same as your measurement, and so the actual speed of light, as represented by those measurements would be different.

roosh wrote: »

Where intrinsic motion is required to account for relative velocity, then it is a logical necessity.

Intrinsic motion is implied; Galileo's observer on the ship could not distinguish absolute motion from absolute inertial motion - although he could determine accelerated motion. In both cases intrinsic motion is implied, because the conclusion isn't that Galileo's observer cannot distinguish his state of rest relative to X from his state of motion relative to X. I think the point Galileo was probably trying to make, pertained more to his belief that the Earth actually orbited the Sun, and not the other way around.

The physical indistinguishability doesn't enable us to reject it as a logical necessity, it simply allows us to declare that we cannot distinguish one from the other; the implication is still that it is one or the other. Indeed, the logical necessity of absolute motion to account for relative motion, is what enables us to deduce that it is a logical necessity.

As mentioned, only the constancy of the measurement can be deduced from Maxwell's equations.

Where one observer measures the speed of light to be 300,000km/s and another, relatively moving observer measures the speed of light to be 300,000km/s, but the instruments of one observer are contracted, such that one observers clock ticks slower than the others, and their metre stick is shorter; the conclusion we would reach is that the actual speed of light, as represented by those measurements, does not remain constant.

So, Einsteinian relativity should conclude as Lorentzian relativity does.

roosh wrote: »

That we cannot establish it as a logical necessity does not mean we are free to reject it, because, of course, we can deduce that it might actually exist; we just cannot tell one inertial state from another. We can, however, distinguish between them logically. Of course though, the physically indistinguishable nature of motion only extends to inertial motion; we can, apparently, distinguish accelerated motion from non-accelerated motion.

We mightn't need to go any further though; from Maxwell's equations we can only deduce that the measurement of c remains invariant, not necessarily the actual speed of light as represented by those measurements.

Where length contraction and time dilation are involved, two measurements of 300,000km/s mean that only the measured speed of light remains invariant, not the actual speed.

This is contrary to Einsteinian relativity.

I'm not sure about the idea of a "bar of smoke", but it might be more accurate to say that atoms have to contract by different amounts, and all processes are slowed by different amounts, depending on their intrinsic motion; assuming there is not other, simpler explanation for the lack of a fringe shift in interferometry experiments.

With Einsteinian relativity we only need to assume that time is physical; that a clock measures time; that past and future exist; that the actual speed of light remains constant; that the one-way speed of light is the same in all directions, regardless of the motion relative to the source; that mathematical reference frames have physical existence; that static world-lines can somehow give rise to relative motion; that we exist as worldlines; that a clock can tick both faster and slower than another clock; and that nothing is actually capable of movement.

Or, to put it another way, that the relation between events exhibits hyperbolic geometry, which can contract and dilate, without affecting the dynamics of the phyiscal objects that are contracted.

roosh wrote: »

There is, equally, no compelling logical argument against it; what we have is the conclusion that we cannot tell between different states of inertial motion, meaning that we cannot tell if an object is at absolute rest, or in a state of absolute, inertial motion.

You're taking this to mean that absolute motion doesn't exist, but that isn't a justified conclusion; you're trying to justify it on the basis that absolute rest is the same as absolute inertial motion, and so we can conclude that absolute rest doesn't exist, and with it absolute motion; but we cannot conclude that absolute rest doesn't exist, because, for all we know the Earth could be at absolute rest.

And even if absolute rest didn't exist, it would simply mean that no object in the universe is in a state of absolute rest, all objects are absolutely in motion. That doesn't mean we can't hypothesise about the possibility that an object could find itself at absolute rest - indeed, the Earth might just be at absolute rest - and use the mathematical construct for the purpose of deduction.

In short, the idea that nothing in the universe is at absolute rest, and all things are absolutely in motion, but that it is, theoretically, possible for objects to be in a state of absolute rest, is closer to what is a justifiable conclusion from the experimental test of the principle of relativity, than the conclusion that absolute motion doesn't exist at all.

They are all supporting assumptions, and things we have to assume to be true, if we are to accept the kinematics of Einsteins hyperbolic geometry.

I would agree that there are assumptions in Lorentzian relativity, for example the existence of a preferred, universal reference frame that determines the universal time. I do, however, believe that such an assumption can be removed from Lorentzian relativity simply by recognising that mathematical reference frames don't exist in reality, and that no object has to actually be at absolute rest; we only need to be able to speak about a hypothetical, imaginary absolute reference frame for the purpose of deduction, not for measurement. The need for an absolute reference frame, to define universal time, is further negated when we recognise the fact that time doesn't actually exist.

As for the mysterious dynamics, I don't think they are any more mysterious than the idea of a hyberbolic geometry which gives the illusion of a mysterious dynamics, without actually affecting the dynamics; I just think the mysterious dynamics require us to make fewer assumptions that run contrary to our empirical experience of the world.

I don't, however, believe that presentism is based on an assumption; I know that I have never experienced anything other than the present moment, and I think if everyone is being honest, then neither has anybody else.

You might say that we have to assume that we share the same present, but I don't think this is accurate, because for it not to be the case every observer has to assume that their past continues to exist, and that their future already exists - this would run contrary to their empirical experience of the universe. In the absence of these assumptions about past and future, all we are left with is the present moment.

roosh wrote: »

And I have addressed your corrections; the most recent reply in the absolute motion thread addresses these, so no need to go into them here.

Einsteinian relativity seems to suggest that relatively moving observers will observer mutual contractions, which arguably leads to a paradox - the subject of the other thread - but it also doesn't seem to account for how relative motion actually occurs; it requires the assumption of some mysterious dynamic which means worldlines which are static in spacetime, somehow give rise to the observation of relative motion.

While absolute motion can easily account for a dilated clock, the issue of distance contraction is less straight forward, but perhaps not as damning as a theory about relativity, which doesn't account for how relative motion occurs.

You've mentioned the idea of a bar of smoke before, but I'm not entirely sure what you are picturing; how do you have a bar of smoke in absolute motion? Also, I don't see how you conclude that it requires far more assumptions; you seem to be stating different examples of the same assumption and claiming them to be different assumptions; particularly when the notion of hyperbolic geometry requires the raft of, aforementioned, supporting, assumptions.

Also, as has been mentioned before, the idea that the hyperbolic geometry is, somehow, more than just spatial has yet to be demonstrated; without the underlying assumption about the physical nature of time, all you have is a spatial hyperbolic geometry, which conspires to give the illusion of the mysterious dynamics asserted in Lorentzian relativity; indeed, when we take gemoetry as what it is, a mathematical description of the matter in the universe, then Lorentzian relativity could be said to demonstrate a hyperbolic geometry as well, just not a 4-dimensional one, culminating in a eternalistic block, but a presentistic space.

And it is only compatible with Einsteinian relativity is we assume that past and future exist eternally; that a clock measures the physical property of time; that clocks can tick both faster and slower than each other; among others.

roosh wrote: »

I'm not sure where you think it has been categorically demonstrated, but if you want to highlight the particular point then I will re-read it, to see if there is anything that I have missed.

The reason for the different threads is because we have been discussing different, but related topics; that they start to overlap is inevitable, but it serves the purpose of examining the issue from a number of different angles, and narrowing down the possible explanations. The conclusion we are closing in on is that, without implicit assumptions about absolute rest and motion, relativity only has one way of describing 3 physically distinguished scenarios.

I'm not sure where I have given the impression of discussing anything other than the Einsteinian notion of time, with respect to Einsteinian relativity; but if you want to highlight the particular instances you are referring to, we can see if we can clarify the misunderstanding.

Presentism itself doesn't require any assumptions about dynamics, it simply requires a lack of assumptions about past and future.

roosh wrote: »

The error is in thinking that the issue was resolved; we didn't actually conclude that it resolves the issue, it's just that I couldn't see a way to proceed with the point.

The point about the paradox of the clocks is a lot more straight forward.

Presentism on it's own doesn't require any assumptions, it is the absence of assumptions, and, apparently, self-evidently true - unless we make assumptions to the contrary.

If we consider it with electromagnetism, then, assuming our understanding is complete, there are assumptions required about the dynamics of physical objects, not about presentism itself.

If we consider electromagnetism in conjunciton with Einsteinian relativity, then we have to make a raft of assumptions about past and future, and the physicality of time, as well as assumptions about mysterious dynamics which cause static world tubes to give rise to the observation of relative motion.

Would a form of emission theory resolve the issue of the mysterious dynamics by the way? I see that the De Sitter double star experiment is seen as a refutation of it, but it seems that it involves the simple addition of velocities, which appears to be erroneous.

De Sitter - wiki

The "brand" of emission theory it appears to deal with can be summed up as

As mentioned, that seems to involve a simple addition of velocities; if we consider the possibility that light travels at a speed c with respect to it's point of emission, as opposed to the moving emitter, then the idea that the "fast" light from a star, on it's approach phase, would overtake the "slow" light from the star, emitted while receding from us, would require the star to catch up to, and overtake, the light that was emitted while receding from the observer.

It would still be an emission theory, it's just that the speed of light is relative to the point of emission, not the emitter.

Masteroid wrote: »

Morbert, do you regard 'time' as independent of the fundamental forces? Is the notion of 'time' not emergent from the interaction of energy/matter?

roosh wrote: »

The two examples aren't analogous, because time dilation isn't dependent on the proximity of an observer to the clock i.e. time doesn't slow down more the further an observer gets from the clock.

The issue is that you are taking the general loudness of a radio, based on multiple tones emitted over a period of time; instead, it would be more analogous to say that a single note emitted from the radio can, all things being equal, exist at two different pitches. That of course would be a paradox.

Every observer only ever experiences the present moment.

If, as you contend, that the present moment isn't universally shared, it requires an assumption on behalf of every single observer, that both past and future exist.

Presentism doesn't require such assumptions; it's the absence of them.

It doesn't necessarily mean that the assumptions aren't phyiscal.

Which assume that both past and future exist eternally, that a clock measures time, and that static 4-Dimensional world tubes can mysteriously manifest as relative motion.

The refutation of emission theory appears to be on the basis of treating light as a projectile, like a bullet. The De-Stitter double star experiment suggests that light emitted from a star in it's approach phase could overtake light emitted during the regress stage; but that would require the star to first catch up to and then overtake the light that was emitted in the regress stage; if we take the simple addition of velocities, which we know doesn't apply to light.

What mysterious dynamics would be needed?

roosh wrote: »

Light-cone structure
A question which arises again from the statement about the light-cone structure is, how did my eight year old self remain eight years old; given that I was that 8yr old me, and I grew up to be the age that I am now? If it is simply a matter of light from that event not having reached a distant observer, then we can't really say that past and future exist eternally i.e. my 8yr old self doesn't continue to exist, just that a light signal from that event hasn't reached a certain part of the universe. This would preserve presentism, because that ligth signal would exist in my present moment, just in a different part of the universe, and any observer seeing it would effectively be seeing a photograph of the event, not the actual event itself.

In order for the event to be preserved eternally i.e. for my 8yr old self to continue existing, the event must be physically extended, like a tube, in spacetime; but this just brings us back to the question in the other thread about how static world tubes give rise to relative motion.


So, is it just a case of light from an event doesn't reach an observer in a distant part of the universe for a given length of time, or are objects physically extended, eternally, through spacetime; or is there something else at play there.

roosh wrote:

But, the above is precisely the point being made; just because a light signal from my 8th birthday party reaches a distant observer after I have grown up, and he "sees" my 8th birthday party, it doesn't mean that my 8yr old self continues to exist. Similarly, with the thunder example, the conditions which cause the sound waves to emanate outwards can change, while the sound wave exists in the present moment.

But to return to the question; if I interpret what you meant correctly, are you suggesting that the light cone structure, which you say is what relativity says is physical - despite the statement that "objects exist as world tubes" - is not simply a case of light emanating from an event takes time to reach a distant observer? I presume this to be the case, because such an interpretation would not allow us to conclude that past and future co-exist with the present, in Minkowski spacetime.

In order for my past,8yr old self, to co-exist with my present self, and for all moments in between to co-exist; then "I" must be physically extended through spacetime, "like a snake" or "tube" as you put it. Or world tubes must have some other form of mysterious manifestation.


The question is, which is it?

Priori wrote: »

I am always suspicious of time being reduced, or explained in terms of, space. Both are fundamental forms of what Kant would call sensible intuition; the very things that make any experience possible. This includes the experience of physicists in a labratory.

The human intellect cannot analyse time without 'fixing' it, representing it with lines and points (spatial concepts through and through). Time has already been abandoned when this is done.

Priori wrote: »

It's not that I find it counter intuitive at all. In fact I can see how it would have a large degree of intuitive appeal, particularly for those in a scientific discipline.

A deeper geometrical/chronometrical form - just interested to know where you think time fits into this explanation?

Chronometry refers to extremely accurate "clock time", if I'm not mistaken. And no matter how precise and sophisticated measurement becomes, clocks essentially treat time as if it were something extended (i.e. spatial) and divisible into discrete units.

roosh wrote: »

Just for the posterity of this thread, it is probably worth putting the following quote in here

So, Einsteinian relativity, and therefore relativity of simultaneity, cannot be used to effectively argue that time exists, because Einsteinian relativity doesn't make such ontological claims; it therefore cannot be used to argue that the universe isn't presentist.

In the absence of such a counter argument, the lack of evidence for the co-existence of past and future, with the present, should lead us to the conclusion that only the present exists; in the absence of evidence to the contrary.

roosh wrote: »

And it does favour the assumption that past and future physically exist?