Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Does time exist?

12357

Comments

  • Registered Users Posts: 4 EnderValentine


    Time is a relative term as proposed by Einstein. The average human mind has the effective capability to theoretically slow time enough in a subconscious ability that an event occurs much more slowly or rapidly based on the overall appeal of the event. Take for instance when you were a child and the clock for school seemed to run slower the more you looked forward to something and the opposite is also true. While Einstein's theory of relativity does not address this particular occurrence, one has the mental capability to understand that the cognitive functioning of the brain is relative to time and so as a parallel to this theory yes time does exist.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Time is a relative term as proposed by Einstein. The average human mind has the effective capability to theoretically slow time enough in a subconscious ability that an event occurs much more slowly or rapidly based on the overall appeal of the event. Take for instance when you were a child and the clock for school seemed to run slower the more you looked forward to something and the opposite is also true. While Einstein's theory of relativity does not address this particular occurrence, one has the mental capability to understand that the cognitive functioning of the brain is relative to time and so as a parallel to this theory yes time does exist.
    As you mention, Einsteinian relativity doesn't make any reference to such a perception of time; but I would agree that "time" is relative in that sense.

    That is, our experience of the present moment can vary such that processes we don't enjoy can seem to take longer than processes we enjoy; but at no point do we experience any part of the process outside of the present moment.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    If we conclude that absolute rest might not exist, then intrinsic motion might not exist either. It is perfectly consistent.
    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.

    RoS is based on the kinematical formulation of Einstein's relativity. The constancy of the speed of light comes from Maxwell's equations. No circular reasoning is present, unless we try and use RoS to prove the kinematical formulation of Einstein's relativity.


  • Closed Accounts Posts: 352 ✭✭Masteroid


    The only time is 'now'. 'Now' is the current configuration of the universe and change occurs through deterministic processes. Only 'now' is the energy of the universe useful and usable.

    In line with the second law of thermodynamics, all deterministic processes dissipate energy. That dissipated energy is related to the amount of change that has taken place and, in its current state, can effect change further.

    Interaction --> Energy Dissipation --> Change. Change can only occur by this means. Which implies that only what happens now can have any deterministic consequences. Energy and matter which do not interact cannot effect outcomes, only that which does interact can.

    The whole universe is but a moment in perpetual change and 'time' is a notional line that represents nothing more than the direction of that change.

    In other words, the only reality is now.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Masteroid wrote: »
    The only time is 'now'. 'Now' is the current configuration of the universe and change occurs through deterministic processes. Only 'now' is the energy of the universe useful and usable.

    In line with the second law of thermodynamics, all deterministic processes dissipate energy. That dissipated energy is related to the amount of change that has taken place and, in its current state, can effect change further.

    Interaction --> Energy Dissipation --> Change. Change can only occur by this means. Which implies that only what happens now can have any deterministic consequences. Energy and matter which do not interact cannot effect outcomes, only that which does interact can.

    The whole universe is but a moment in perpetual change and 'time' is a notional line that represents nothing more than the direction of that change.

    In other words, the only reality is now.
    Although I'm not as knowledgeable on some of the more technical aspects of your post, I think I am in full agreement.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    If we conclude that absolute rest might not exist, then intrinsic motion might not exist either. It is perfectly consistent.
    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.
    Morbert wrote: »
    RoS is based on the kinematical formulation of Einstein's relativity. The constancy of the speed of light comes from Maxwell's equations. No circular reasoning is present, unless we try and use RoS to prove the kinematical formulation of Einstein's relativity.
    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    No, we can conclude that the notion itself is not a logical necessity.
    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.

    Intrinsic motion is in no way implied. In fact, physical indistinguishability is the very thing which allows us to reject intrinsic motion as a logical necessity.
    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.

    Again, you are losing track of your own line of reasoning. What you have done above is simply restated the postulate of Lorentzian relativity, instead of arguing, as you were doing before, that Einstein's relativity is circular reasoning.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    No, we can conclude that the notion itself is not a logical necessity.
    Where intrinsic motion is required to account for relative velocity, then it is a logical necessity.

    Morbert wrote: »
    Intrinsic motion is in no way implied. In fact, physical indistinguishability is the very thing which allows us to reject intrinsic motion as 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.

    Morbert wrote: »
    Again, you are losing track of your own line of reasoning. What you have done above is simply restated the postulate of Lorentzian relativity, instead of arguing, as you were doing before, that Einstein's relativity is circular reasoning.
    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    Since you cannot establish it as a logical necessity without the cases being distinguishable, we can indeed reject intrinsic motion.
    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.

    This, again, has nothing to do with circular reasoning.

    Regarding Lorentz v Einstein: You are just repeating yourself, perhaps unintentionally. You need to be able to recognise that we have been over this countless times before. If I am at my most charitable, I say that the assumptions of dynamical length contraction are at least as big an assumption as the kinematics of Einstein.

    Under Lorentzian relativity, you have to assume that all material, whether it is a bar of steel or a bar of smoke, contract by exactly the same amount, and all processes are slowed by exactly the same amount, an amount that happens to make the speed of light constant. In Einstein's relativity, you don't have to assume all these accidental dynamics. You simply have to suppose that the relations between events exhibits hyperbolic geometry.


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    Since you cannot establish it as a logical necessity without the cases being distinguishable, we can indeed reject intrinsic motion.
    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.

    Morbert wrote: »
    This, again, has nothing to do with circular reasoning.
    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.
    Morbert wrote: »
    Regarding Lorentz v Einstein: You are just repeating yourself, perhaps unintentionally. You need to be able to recognise that we have been over this countless times before. If I am at my most charitable, I say that the assumptions of dynamical length contraction are at least as big an assumption as the kinematics of Einstein.

    Under Lorentzian relativity, you have to assume that all material, whether it is a bar of steel or a bar of smoke, contract by exactly the same amount, and all processes are slowed by exactly the same amount, an amount that happens to make the speed of light constant. In Einstein's relativity, you don't have to assume all these accidental dynamics. You simply have to suppose that the relations between events exhibits hyperbolic geometry.
    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    Yes it does. Or to put it another way: There is no compelling logical argument for absolute, intrinsic motion. You keep reasserting that there is, but you never tender an argument that doesn't tacitly assume it to begin with.
    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.

    You don't need to assume such things in Einstein's relativity. They are all a consequence of the kinematics of hyperbolic geometry. I.e. Einstein's relativity, unlike Lorentz's, has an underlying principle that provides a structure for all observations.

    But do you agree that, at the very least, Lorentzian relativity, and hence presentism, is based on assumptions?


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    Yes it does. Or to put it another way: There is no compelling logical argument for absolute, intrinsic motion. You keep reasserting that there is, but you never tender an argument that doesn't tacitly assume it to begin with.
    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.


    Morbert wrote: »
    You don't need to assume such things in Einstein's relativity. They are all a consequence of the kinematics of hyperbolic geometry. I.e. Einstein's relativity, unlike Lorentz's, has an underlying principle that provides a structure for all observations.

    But do you agree that, at the very least, Lorentzian relativity, and hence presentism, is based on assumptions?
    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    I have corrected you on this before. It is, of course, true that the metaphysical assumption of absolute rest, and hence intrinsic motion, is consistent with relativity. It is also true that the contrary assumption, that no such metaphysical state exists, and that intrinsic motion is meaningless, is also consistent with relativity. Hence, relativity does not assume absolute rest or intrinsic motion.
    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.

    Neither version of relativity supposes coordinate frames exist in Nature. Instead, the issue is the metaphysical assumption that all reference frames but one imply an observer who will be working with contracted/dilated instruments.
    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.

    They require far more assumptions. That is what Lorentzian relativity is missing, an underlying principle like hyperbolic geometry, producing relativistic kinematics. It instead has a wide variety of assumptions. Why, for example, does a bar of smoke contract by exactly the same amount as a bar of titatium, or a neutron star? Why do all the interactions conspire to behave the same way?
    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.

    Presentism is very much an assumption. The assertion that the present is all that exists is inconsistent with electromagnetism unless we assume some undetectable, metaphysical dynamical processes are under way.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    I have corrected you on this before. It is, of course, true that the metaphysical assumption of absolute rest, and hence intrinsic motion, is consistent with relativity. It is also true that the contrary assumption, that no such metaphysical state exists, and that intrinsic motion is meaningless, is also consistent with relativity. Hence, relativity does not assume absolute rest or intrinsic motion.
    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.

    Morbert wrote: »
    Neither version of relativity supposes coordinate frames exist in Nature. Instead, the issue is the metaphysical assumption that all reference frames but one imply an observer who will be working with contracted/dilated instruments.
    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.

    Morbert wrote: »
    They require far more assumptions. That is what Lorentzian relativity is missing, an underlying principle like hyperbolic geometry, producing relativistic kinematics. It instead has a wide variety of assumptions. Why, for example, does a bar of smoke contract by exactly the same amount as a bar of titatium, or a neutron star? Why do all the interactions conspire to behave the same way?
    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.

    Morbert wrote: »
    Presentism is very much an assumption. The assertion that the present is all that exists is inconsistent with electromagnetism unless we assume some undetectable, metaphysical dynamical processes are under way.
    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    No you have not. You jump topics. Whenever we are close to wrapping up one of your misunderstandings, you introduce another. Whatever issues you might have with relativity, it does not imply intrinsic motion. This has been categorically demonstrated by myself. You can either address this, or we can move on to analysing the logical consistency and veracity of relativity itself.
    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.

    There are several issues with what you have said above. Your understanding of time in Einstein's relativity, for example, is still incorrect (an intrinsic, physical "time" is as meaningless as an intrinsic velocity in relativity). But, from your last post, it seems you now at least acknowledge that, however you might view relativity, presentism requires untestable assumptions about dynamics.


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    No you have not. You jump topics. Whenever we are close to wrapping up one of your misunderstandings, you introduce another. Whatever issues you might have with relativity, it does not imply intrinsic motion. This has been categorically demonstrated by myself. You can either address this, or we can move on to analysing the logical consistency and veracity of relativity itself.
    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.

    Morbert wrote: »
    There are several issues with what you have said above. Your understanding of time in Einstein's relativity, for example, is still incorrect (an intrinsic, physical "time" is as meaningless as an intrinsic velocity in relativity). But, from your last post, it seems you now at least acknowledge that, however you might view relativity, presentism requires untestable assumptions about dynamics.
    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    And when a particular angle has been investigated, you must acknowledge this. Instead, you change angles, only to come back to it when you figure it has been forgotten about.

    For example, we previously concluded that hyperbolic geometry reconciles the postulates of relativity with our intuitive understanding of how events are viewed from different perspective. See out "pole and centre of light sphere" discussion. Now, in another thread, you are drudging up the issue again, presumably forgetting what we have talked about before.
    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.

    This is another issue we have dealt with before. Presentism, if it is to be considered consistent with electromagnetism, does require additional assumptions about dynamics.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    And when a particular angle has been investigated, you must acknowledge this. Instead, you change angles, only to come back to it when you figure it has been forgotten about.

    For example, we previously concluded that hyperbolic geometry reconciles the postulates of relativity with our intuitive understanding of how events are viewed from different perspective. See out "pole and centre of light sphere" discussion. Now, in another thread, you are drudging up the issue again, presumably forgetting what we have talked about before.
    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.

    Morbert wrote: »
    This is another issue we have dealt with before. Presentism, if it is to be considered consistent with electromagnetism, does require additional assumptions about dynamics.
    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.
    For an object moving directly towards (or away from) the observer at 9e3669d19b675bd57058fd4664205d2a.png metres per second, this light would then be expected to still be travelling at 5b1be7eb33dcabd1921c413ae3188698.png ( or 1e808aad9132c1e4c6a9ae9599a71dd6.png ) metres per second at the time it reached us.

    Willem de Sitter argued that if this was true, a star in a double-star system would usually have an orbit that caused it to have alternating approach and recession velocities, and light emitted from different parts of the orbital path would then travel towards us at different speeds. For a nearby star with a small orbital velocity (or whose orbital plane was almost perpendicular to our line of view) this might merely make the star's orbit seem erratic, but for a sufficient combination of orbital speed and distance (and inclination), the "fast" light given off during approach would be able to catch up with and even overtake "slow" light emitted earlier during a recessional part of the star's orbit, and the star would present an image that was scrambled and out of sequence.
    De Sitter - wiki



    The "brand" of emission theory it appears to deal with can be summed up as
    according to simple emission theory, light thrown off by an object should move at a speed of 4a8a08f09d37b73795649038408b5f33.png with respect to the emitting object


    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    And the answer is still the same. Causality is preserved under Lorentz transformation. Two people disagreeing over which clock is ticking faster is no more a paradox than two people disagreeing over which radio sounds louder.
    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.

    Yes it does. Inductive inference 101.
    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.

    Hence, you are guilty of the very thing you are arguing against: Unphyscal assumptions
    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.

    No we don't. The kinematics (not dynamics) are all very well described in any textbook, and not at all mysterious. They have a well established, rigorous, simple framework.
    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.

    Emission theory has been throughly refuted

    http://en.wikipedia.org/wiki/Emission_theory

    If you assume light travels at a speed c with respect to the point of emission, rather than the emitter, then it would not account for MMX (and a variety of other experiments), unless you postulated mysterious dynamics, in which case you would just have Lorentzian relativity all over again.


  • Closed Accounts Posts: 352 ✭✭Masteroid


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


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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?

    Time, on its own, is an illusion, insofar is there does not exist some strict temporal metric or river of time. Instead, physicists talk of a "spacetime" metric that relates all events with each other. This spacetime also plays the role of the gravitational field. So time, as a facet of spacetime, is intimately related to the fundamental force of gravitation.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    And the answer is still the same. Causality is preserved under Lorentz transformation. Two people disagreeing over which clock is ticking faster is no more a paradox than two people disagreeing over which radio sounds louder.
    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.


    Morbert wrote: »
    Yes it does. Inductive inference 101.
    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.

    Morbert wrote: »
    Hence, you are guilty of the very thing you are arguing against: Unphyscal assumptions
    It doesn't necessarily mean that the assumptions aren't phyiscal.


    Morbert wrote: »
    No we don't. The kinematics (not dynamics) are all very well described in any textbook, and not at all mysterious. They have a well established, rigorous, simple framework.
    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.


    Morbert wrote: »
    Emission theory has been throughly refuted

    http://en.wikipedia.org/wiki/Emission_theory

    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.
    Morbert wrote: »
    If you assume light travels at a speed c with respect to the point of emission, rather than the emitter, then it would not account for MMX (and a variety of other experiments), unless you postulated mysterious dynamics, in which case you would just have Lorentzian relativity all over again.
    What mysterious dynamics would be needed?


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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?

    These are the exact same arguments, but in different contexts, that you are making in the absolute motion thread here. The only new subject, which, no offence, is too silly to get into, is emission theory.

    Here's a a deal. When you first at least accept that a foundation of Einstein's relativity is the principle of general covariance, then we can move to other, competing theories.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    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.


    Note: this isn't intended as a discussion on absolute motion, as that is being continued in the other thread, it is simply a question on the nature of light-cones and world tubes, which affect the discussion on the existence of past and present.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    It isn't. We hear thunder later than when it happens. Similarly, we always see things after they happen. A framework does not define the present as "everything the observer sees at that moment".


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    It isn't. We hear thunder later than when it happens. Similarly, we always see things after they happen. A framework does not define the present as "everything the observer sees at that moment".
    It was an either or question; "it isn't" doesn't address it adequately.

    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?


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    You are beginning to tread old ground again.
    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.

    Yes. But again, this is unrelated to the relativity of simultaneity.
    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?

    The locus of all events that make up your history extend through spacetime as a world line.


  • Closed Accounts Posts: 421 ✭✭Priori


    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.


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    In mathematics, "space" has a rigorous definition that is more general than what a person typically means by space. For example, in classical mechanics, systems can be defined on a configuraton space. In quantum mechanics,a Hilbert space is used. Both of these spaces are distinct from a layman's understanding of space. Similarly, the Minkowski space of relativity is not the same as your usual space.

    So it isn't that time is reduced to "space". Instead, both "time" and "space" are understood to be facets of a deeper geometrical/chronometrical form. In the same way, relativity does not reduce electricity to a form of magnetism. Both electricity and magnetism are understood to be facets of a deeper form called electromagnetism.

    This is counter intuitive, but logically consistent.


  • Closed Accounts Posts: 421 ✭✭Priori


    Morbert wrote:
    ...it isn't that time is reduced to "space". Instead, both "time" and "space" are understood to be facets of a deeper geometrical/chronometrical form.

    This is counter intuitive, but logically consistent.

    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.


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    My opinion would be the same as Hermann Minkowski's: Namely that time, on its own, isn't physical, and nor is space on its own. I think the salient word is not chrono-, or geo-, but rather metric. The relationship between events is codified in the Minkowski metric. The physicist Dirac, for example, used this simple form to predict the existence of anti-matter, before it has been detected by experiments. Field Theorists have used the form to predict the fine-structure of molecules with an accuracy of 1 in a billion, and the behaviour of electrons with an accuracy of 1 in a trillion.


  • Closed Accounts Posts: 352 ✭✭Masteroid


    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.

    What I find to be counter-intuitive is how we can have an expanding universe if spacetime is quantized.

    I mean, if the quantized particles of spacetime are moving away from each other all over the universe, that would explain expansion but what do we call the space between particles of spacetime? And doesn't this have implications for the constancy of the speed of light? How would a photon get from one piece of spacetime to another?

    It puts me in mind of stepping stones that are moving apart at a constant rate. The amount of energy that must be expended in order to reach the next stone increases on each step. There comes a point where you end up in the water because you simply don't have enough energy to make it to the next stone.

    If it were the case that photons did from time to time end up in non-spacetime space and so could pop up in any part of the universe at any time, shouldn't we be able detect some of them? Wouldn't they sometimes appear as a mysterious light source that just disappears? And wouldn't they distort the cosmic background radiation data?

    Also, it would seem a little disingenuous to claim that the planck-length is constantly increasing in real spacetime and that we just constantly call that increasing length 10^-33 cm or whatever it is.

    And if it were claimed that new spacetime was being constantly created within the constantly enlarging 'intersitial holes', so to speak, maintaining a contiguous arrangement of spacetime particles, then wouldn't that be in violation of the first law of thermodynamics?

    My head really hurts now. I must go and lie down.

    Mind you, if someone were to suggext that photons that are lost in non-spacetime space actually become a piece of new spacetime, I might sleep a bit easier.


  • Closed Accounts Posts: 421 ✭✭Priori


    Masteroid wrote: »
    I mean, if the quantized particles of spacetime are moving away from each other all over the universe, that would explain expansion but what do we call the space between particles of spacetime?

    Reminds me of some of Zeno's paradoxes, which for the most part demonstrate the problems arising from infinite divisibility.
    Masteroid wrote:
    My head really hurts now. I must go and lie down.

    I know that feeling! :)


  • Closed Accounts Posts: 8 Shady93


    Just discussed this in a lecture the last day! I cant remember who it was that said it, but the theory was that time can't exist. "Time" can be split up into three sections: past, present, and future. The past doesn't exist, because it is gone, only in our memories. The future doesn't exist, because it hasn't happened yet. But the argument is that the present can't exist either, because what is the present? It's a moment between the past and the future, but what's a moment? By the time you've focused on the moment, it's already whizzed by and become the past! Confusing stuff here :p


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Shady93 wrote: »
    Just discussed this in a lecture the last day! I cant remember who it was that said it, but the theory was that time can't exist. "Time" can be split up into three sections: past, present, and future. The past doesn't exist, because it is gone, only in our memories. The future doesn't exist, because it hasn't happened yet. But the argument is that the present can't exist either, because what is the present? It's a moment between the past and the future, but what's a moment? By the time you've focused on the moment, it's already whizzed by and become the past! Confusing stuff here :p
    According to Einsteinian relativity, however, past, present and future, all co-exist together in 4D-Spacetime.

    The present doesn't exist in the sense that there isn't a physical thing called "the present". If you stop for a moment and become aware of your experience; just resting in that experience, and being aware of sensations and thoughts, you are aware of "now".

    Assuming that the universe consists of more than just you, that means there are parts of the universe which are a distance from you - even the objects in the room you are in, are located a distance from you. But, resting in the "now" - without making any assumption as to the simultaneity of the objects you observer - and considering that the universe consists of more than just you, such that there are distant areas of space where things, or events, are happening, then you can reason that, as you are resting in that "now", there are events happening in distant areas of the universe which are simultaneous with that "now"; all of these things go to make up your present moment - even if you cannot determine what those distant events are (or were, at some point in the "future").


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    Shady93 wrote: »
    Just discussed this in a lecture the last day! I cant remember who it was that said it, but the theory was that time can't exist. "Time" can be split up into three sections: past, present, and future. The past doesn't exist, because it is gone, only in our memories. The future doesn't exist, because it hasn't happened yet. But the argument is that the present can't exist either, because what is the present? It's a moment between the past and the future, but what's a moment? By the time you've focused on the moment, it's already whizzed by and become the past! Confusing stuff here :p

    There is also the relativity of simultaneity. What one person considers the present can consist of another person's past, present, and future.

    http://en.wikipedia.org/wiki/Relativity_of_simultaneity


  • Banned (with Prison Access) Posts: 3,455 ✭✭✭krd


    roosh wrote: »
    According to Einsteinian relativity, however, past, present and future, all co-exist together in 4D-Spacetime.

    Yes. But, if you were in the position of the Laplacian demon, where you had an absolute universal frame of reference, you'd see all the contractions and expansions.

    Humans can only, at the most, visualise 3 dimensional Euclidian space. Because we need to be able to percieve 3d spaces to survive. 4d spaces would be confusing. Euclidian transforms only work if the transform is instanteous. The second you bring time into it, Euclidian space breaks down. So, you need expanisions and contractions in space, relative to different obsevers, to get what we experience to work. As long as objects in different frames, with different velocities relative to each other do not interact - the objects experience no spacial or time distortions. When they do interact - the balancing experience is energy.


    If you move forward - and you consider yourself to be a wavefunction - a quantum object on two legs.....Relative to a "stationary" object, the front of your wave will contract. But relative to you, the wavefunction of the front of the object your approaching is contracted. If you collide, both your wavefunctions need to resolve the contraction, because now you're in the same frame. Either you and the object bounce off each other, and have new velocity vectors, or you travel together (which might give the illusion you're both at rest). Once you're at rest in the same frame, time and space distortions vanish - or appear to vanish. Elsewhere, from the position of another observer, your space is distorted.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Just for the posterity of this thread, it is probably worth putting the following quote in here
    Morbert wrote: »
    The conclusion is the ontological existence or non-existence of an extended temporal dimension does not follow from the physical theory. The physical theory makes no ontological commitments. Hence, it cannot be used effectively to argue that time must exist or that time does not exist.

    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.


  • Closed Accounts Posts: 352 ✭✭Masteroid


    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.

    But to be fair, the existence of only the present does not rule out the existence of time. We are still left 'With what causes change?' and time would be no less validated as the mediator of the change-force.

    If time doesn't exist, what is it that does?

    Could Special Relativity account for an alternative phenomena?

    I take the view that the effect of time is caused by the process of change rather than the other way around and the problem for physics lies partly, in my view, from trying to consider time as an essentially linear scale along which systems undergoing change 'mesh'. The linearity too, is an illusion.

    If the time variable's linearity were treated as varying with the constantly changing rates of rate of exchange of energy as they occur in systems being measured, then 'time' would more accurately reflect the thing it actually represents.

    That was a mouthful.

    In my view.


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Masteroid wrote: »
    But to be fair, the existence of only the present does not rule out the existence of time. We are still left 'With what causes change?' and time would be no less validated as the mediator of the change-force.

    If time doesn't exist, what is it that does?

    Could Special Relativity account for an alternative phenomena?

    I take the view that the effect of time is caused by the process of change rather than the other way around and the problem for physics lies partly, in my view, from trying to consider time as an essentially linear scale along which systems undergoing change 'mesh'. The linearity too, is an illusion.

    If the time variable's linearity were treated as varying with the constantly changing rates of rate of exchange of energy as they occur in systems being measured, then 'time' would more accurately reflect the thing it actually represents.

    That was a mouthful.

    In my view.
    What evidence have we got of times existence?

    Would the abundance of energy in the universe not cause systems to change, no?


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    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.

    Note that Occam's razor does not favour presentism, as presentism requires the assumption that strange dynamics physically warp objects and dilate their processes such that the speed of light is always measured to be c.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    Note that Occam's razor does not favour presentism, as presentism requires the assumption that strange dynamics physically warp objects and dilate their processes such that the speed of light is always measured to be c.
    And it does favour the assumption that past and future physically exist?


  • Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    roosh wrote: »
    And it does favour the assumption that past and future physically exist?

    Yes. As I said in my post you quoted:

    "The conclusion is the ontological existence of an extended temporal dimension necessarily follows from the physical theory. The physical theory makes deep ontological commitments. Hence, it can be used effectively to argue that time must exist."


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    Morbert wrote: »
    Yes. As I said in my post you quoted:

    "The conclusion is the ontological existence of an extended temporal dimension necessarily follows from the physical theory. The physical theory makes deep ontological commitments. Hence, it can be used effectively to argue that time must exist."
    That doesn't explain why Occams Razor would favour the assumption that past and future co-exist with the present.


  • Registered Users, Registered Users 2 Posts: 2,553 ✭✭✭roosh


    @Morbert - Just a subsequent question, which I'm wondering about; you've mentioned that the order of events, and simultaneity isn't physical; does this mean that relativity of simultaneity isn't physical, given that it essentially just a concept for saying that the ordering of events is different according to different reference frames.

    Also, isn't it the ordering of events that lead to the conclusion that what is the present for one observer could be the past for another; if the ordering isn't physical can we conclude that the past isn't physical?

    Are "the past" and "the future" not just an extension of the concept of "the ordering of events"?


  • Advertisement
  • Site Banned Posts: 385 ✭✭pontia


    how do you tie in they were able to build the newgrange passage tomb that lights up tomb at exact sunrise every year ? calculated by movement of stars ect


  • Closed Accounts Posts: 352 ✭✭Masteroid


    roosh wrote: »
    @Morbert - Just a subsequent question, which I'm wondering about; you've mentioned that the order of events, and simultaneity isn't physical; does this mean that relativity of simultaneity isn't physical, given that it essentially just a concept for saying that the ordering of events is different according to different reference frames.

    Also, isn't it the ordering of events that lead to the conclusion that what is the present for one observer could be the past for another; if the ordering isn't physical can we conclude that the past isn't physical?

    Are "the past" and "the future" not just an extension of the concept of "the ordering of events"?

    I don't know if this will help.

    Imagine you are in a large room whose walls are mirrors and that there is a constant illumination from the centre of the room. As you walk around this room, with its contents remaining stationary, the reflections you observe in the mirrored surfaces will change and would give rise to the illusion that the contents are moving.

    Can you see that?

    If we take you out of the room for a minute, then since there is only one source of light and everything in the room is stationary, all possible paths for photons are occupied. Any reflection that can possibly be viewed exists independently of whether it is viewed or not. At all times there are photons available to form any image that can be seen.

    If we equate the possible set of reflections with the set of time-slices then we can visualise this 4-D block that contains the entire set of possible reflection, or points in time and what we perceive as events taking place is simply the resultant change in reflection. The mirror doesn't change, the light doesn't change and no events other than photons bouncing take place.

    And obviously, reflections make no ontological statements about the rooms contents. The room may be full of real objects but a reflection can't tell you how much they weigh.

    However, it is perception changing that makes objects move and not the other way around.

    So therefore, consciousness itself is a is a single reflection, a small imperfection that forms a local tube that passes through as many reflections as there are in a lifetime.

    It may be that consciousness is almost a standing wave in energy terms and that this wave propogates along the 'time-dimension', from past to future, a constant flow of energy from one side of the imperfection to the other, in the direction settle on by harmonic resolution.

    Scary, that would mean I would experience these reflections over and over. It would have to be this way too because we can't have a one-off event in something that doesn't change. :(


  • Banned (with Prison Access) Posts: 93 ✭✭Berlin at night


    roosh wrote: »
    Personally I believe that time does not exist, that it is merely a figment of the imagination of mankind, and our subsequent belief that it is an external force acting in the universe, makes it, by definition, an illusion.


    I know for people in this forum, that this is probably not a radically new idea, however, trying to discuss it with people who are more scientifically trained than I, leads to the usual dismissal of the notion as "crackpottery".

    As the notion of time has a very real impact on how mankind behaves, and with the impact that the scineces have on the collective psyche, I personally believe that such a question be given serious consideration, as the impact that it has on the collective worldview is very relevant, important and fundamental to the question of existence.

    I would be interested in hearing anyone elses views on whether time exists in reality or is merely the invention of mankind, based on a misperception of naturally occuring phenomena.



    I ultimately see time as a measurement system, as opposed to a force than can be measured. It is often pointed out to me, that time dilation is evidence that the contemporary conceptualisation of time is correct, as per the theory of General Relativity. The issue I have with this however, is that there is a self-contained notion of time that amounts to circular reasoning.

    Ultimately it is assumed that time exists, and that clocks measure time. However, with regard to the clocks, I believe it is erroneous to suggest that they measure an external entity/force called time.

    With regard to the atomic clock, what is measured is the microwave emissions of changing electrons, while the older clocks that give rise to the 24hr clock were the measure of the degree of the earths rotation. To then make the jump to say that these things measure anything other than what was stated i.e. emissions of changing electrons, or the degree of the rotation of the earth, namely that they measure the force that is time, is a non sequitor, it is illogical.

    How I see it, and again this is probably nothing fundamentally new, is that when time is given as a measurement, what is actually being measured is the change that occurs in an object relative to the number of microwave emissions of a changing electron in an atom, or relative to the degrees of rotation of the earth, or relative to some other [almost] constant phenomenon.

    The practical implication of this, is that instead of viewing time as a force of nature, it is merely viewed as a measurement system, akin to the metric system, and is afforded no special properties with regard to the "spacetime continuum".

    What adds perhaps, further credence to this is outlined in the following articles Article #1 and Article #2.

    These refer to a solution to the equations for General Relativity, where time seems to "disappear". This is often referred to "as the problem of time" in Physics, and as far as I can gather is represented as Diffeomorphism Symmetry.

    For those that are mathematically minded, there is an online lecture given by Lee Smolin. The first lecture is an introduction to "the problem of time" and doesn't really require much mathematical training. The second would require much better mathematical training in order to understand. That is where I left it, as my maths is only leaving cert level (and first year college).


    Any ideas on the issue are welcome.

    Considering there is no future time as we are always living in the past time.


  • Closed Accounts Posts: 352 ✭✭Masteroid


    Actually, I just had an amazing thought. I might not think so in the morning but I'll write it anyway.

    In the 'Mirrored Walls' analogy above, perception, consciousness, would have to be explained in terms of how photons interact.

    Instead of having an observer enter the system, as we had above, in the block-universe, conscious entities are derivatives of the block itself. My consciousness exists.

    In the mirrored room, my ability to perceive simply as a result of the room's existence may be explained thusly.

    If we map all the points in the space of the room that correspond to the set of reflections I perceive over my 'lifetime' we can define a line in 3-D space.

    If we then take a point and map it to all the points on the mirrors that provided all the photons that are passing through that point in space and then do the same for all points along my life-line then we could create an image that represents the energy distribution along my 'life-line' in terms of numbers of photons that occupy a particular point in 3-D space at a particular time.

    And there is no reason to suppose that the energy distribution is constant along that line. Otherwise, why would the reflection change along that line?

    So far we are only dealing in 3 dimensions but if we treat the photons as a dynamic system, then we could take a series of snapshots, like the one above and create a new diagram.

    This new diagram charts the change of energy distribution at each point along my life-line and any change would be due to a change in photon density, if you will, and the reason for the change may be due to an effect we haven't considered yet.

    Suppose the photon density of a region had a local effect on the photon density around it. If it could then this would naturally give rise to energy systems that exist as eddies around the points of space along my life-line.

    And the evolution of those eddies would be unique to that location, where my consciousness is.

    If we now process the images along with all the points local to my life-line we could create an animation that would reveal the wave patterns in that region. Consciousness exists here. Standing-wave built on standing-wave dancing to a rhythm beaten out as photon density settles its constant battle.

    Would that animation be a map of my consciousness?

    Transfer that to a 3-D block universe, let there be a photon creator and a reflector for all photons, given 'time', and given that all photons must travel along well-worn paths and in that sense are 'confined' to their current path, couldn't interactions between photons give rise to dynamical systems within the confines of that path that could cause a slight 'change' in the path.

    And the reason that the universe appears dark is because the only energy of the universe we can directly experience is the energy that appears as a result of photon induced systems. We can only interact with the changing characterstics of systems that occur on the same scale as ours do. The vast majority of energy, the vast majority of photons, is not taking part in these systems, it simply passes through them having an inperceptible effect on the evolution of the system.

    It's dark.

    Nothing ontological here, I'm just wondering, if you had lots of photons bouncing around the same space, wouldn't systems of patterns eventually evolve that could overcome the force of reflection causing photons to be deflected off their path. And if you just kept pumping photons into the system, eventually the entire space would be occupied by photons, the reflected paths being constantly reinforced, and therefore maintaining a high-density with respect to the number of affected photons, and the only change that can possibly take place is due to the photons, and the fact that they move, themselves. The effects that photons have on each other would be amplified in the systems it produces.

    Perhaps the entire universe as we know it is the result of photons interactions?

    I'm thinking of a boiler that is built to service a food-production company. Some of the heat of the boiler is used for heating the workplace but if you try to account for the energy used by the boiler by how much the workplace was heated, there would be a huge deficit. Most of the energy converted by the boiler is used in unseen processes.

    It's late.:)


  • Closed Accounts Posts: 352 ✭✭Masteroid


    Considering there is no future time as we are always living in the past time.

    Which is persistently 'now'.

    So what is it that you think is actually changing?


  • Advertisement
This discussion has been closed.
Advertisement