• Philosophy and the Twin Paradox
    No, you're wrong. It's not conjecture, it's proven. The truth of it has been demonstrated to me as true, through evidence and logic, therefore it is proven. Aristotle thoroughly explained this thousands of years ago.Metaphysician Undercover
    The view to which I refer (positing no preferred moment in time) was probably not something Aristotle was aware of. The argument you outline assumes the opposite point of view (yours) and argues for a distinction between past, present, and future. I have little against the argument, but it is irrelevant to proving its assumption, that there is a present moment.

    So we're back to unproven conjecture. You need a proof that does not proceed right up from an assumption that a present moment exists, as both you and Aristotle do.

    It has been proven, and now you need to demonstrate that what has been proven to me as true, is actually false if you have any desire to lead me in another direction.
    As I said, the argument isn't particularly invalid, but it assumes your premises right up front. Aristotle can be forgiven because to my awareness the alternate position would not be proposed for around 14 centuries.

    The alternate view does not describe a different experience, so there is no distinction. There is still past and future, but they're just relations between events, not actual states of events. — noAxioms
    "Relations between events" does not produce a past and future, it produces a before and after.
    Pretty much yes. To be a little more precise, if you assume a preferred frame, then there is an objective before/after/simultaneous relationship between any two events. If you assume neither a preferred moment nor a preferred frame (mainstream view), then there is a relationship of before/after/ambiguous between any two events (the 'ambiguous' meaning the relation is frame dependent). No event is in 'the past' or 'the future'. Thus any references to such properties in any demonstration of inconsistency of this view would be begging a different set of assumptions.

    Until you model this difference, your model has no past and future.
    If A is before B, then B would be in the future of A and A would be in the past of B. This illustrates the usage of the terms as relations instead of properties.
  • How Do You Know You Exist?
    Every person, as a self, body, or both, knows they exist.Unlimiter
    Why ask the question if every person knows the answer?
  • Philosophy and the Twin Paradox
    Fundamental facts, proven by hundreds of years of application of the scientific method, are what you call "biases".Metaphysician Undercover
    You cannot back this assertion. Science has done no such thing, especially since what I called a bias (the lack of a present moment) is strictly a philosophical premise.

    I am actually very capable of putting aside such biases, when they are demonstrated to contain contradictions and inconsistent premises.
    Wrong. You should be able to set them aside when considering an alternate point of view. It doesn't mean you have to change your personal belief to that alternate PoV. The exercise is done simply to recognize that your favored 'proven' view is not proven fact at all, but merely conjecture.

    That there is a difference between future and past is easily proven. Past events are remembered, and future events are anticipated. Furthermore, past events cannot be changed while future events can be created, or avoided. Therefore there is a fundamental difference between past and future. That this difference cannot be measured is irrelevant to the proof We do not need to measure things to prove that they are different, we only need to describe the difference.
    The alternate view does not describe a different experience, so there is no distinction. There is still past and future, but they're just relations between events, not actual states of events.

    - - -

    The problem here, as I've already explained, is that the field is the medium.Metaphysician Undercover
    Still assuming the conclusion I see.

    Feynman, as a physicist, is very good at tutorials, putting things into words which non-physicists can understand.
    Then you're summarizing his argument completely wrong. You really need to find that reference as jgill requested. I don't think Feynman would make commit such an obvious fallacy as blatant begging.

    The field exerts force on the particles through the means of the waves
    The quote you originally made said something different, and I agree with the former only:
    Changes within the field are described as waves,Metaphysician Undercover
    The waves convey changes to the field, but not the force. Gravity waves for instance are not generated for a mass exerting a force at a distance. Gravity waves are energy, and energy expenditure would quickly deplete the mass of an object. But gravity waves do this. Earth for instance, due to its acceleration around the sun, emits about 200 watts of power in the form of gravity waves, far less than the energy given to even a small rock falling to the surface. Thus the force upon and kinetic energy gained by the falling rock does not come from waves of any kind.
    Ditto with EM force and energy. The waves do not carry the force, only the minor energy of the changes which has negligible effect on other masses. LIGO is sensitive enough for instance to detect this, but any object can measure gravity.
  • Philosophy and the Twin Paradox
    I believe that some physicists such as Feynman have produced very convincing arguments which demonstrate that electromagnetic fields must have real physical existence, i.e. substance.Metaphysician Undercover

    Please do. I am curious. :chin:jgill

    An electromagnetic field is necessarily a real object (what I call substantial) because it exerts a force on particles (exemplified by iron filings). This is the energy of the field. Changes within the field are described as waves, and this is how energy moves from one place to another through the field, by means of waves.Metaphysician Undercover

    So you are attacking the soundness of my argument, not the validity of it.
    -- Meta
    Only when your argument is in fact invalid.
    noAxioms
    jgill bumps an excellent example of an invalid argument which in this case begs two different conclusions by assuming them both true in order to conclude them. It begs the field being a real object, and it also begs a medium for EM waves.
    To illustrate that, let's assume otherwise and see if a contradiction is reached.

    The force on particles (iron filings) is exerted by the magnet nearby. Changes within the field are described as EM waves which require no medium. It works just fine with the opposite assumptions, therefore the argument demonstrates nothing.

    As for energy, your comment seems to equate force to energy, which is just wrong. It makes it sound like the field itself has energy, and if that energy was consumed by something, it would be gone, leaving the magnet with no field. Gravity is like that. There's no gravitational energy of an object or its field. Nobody quotes some number representing the gravitational energy of say the Earth or its gravitational field (which is neither an energy field nor a force field, but rather an acceleration field).

    Anyway, if Feynman did actually argue for this, and it was in any way convincing, then you've not summarized it very well.
  • Philosophy and the Twin Paradox
    The problem is you have not presented anything which makes sense.Metaphysician Undercover
    It make sense to those that understand it. I'm sorry that you're apparently not one of them.
    Present me with contradictions and it's intelligent for me to attack them.
    Your contradictions come from twisting my statements out of context. Maybe spell out the contradictions more clearly so I can point out where you didn't get it right.

    Your approach is fruitless if you cannot demonstrate why the thing which is extremely obvious to me might be false.
    I cannot demonstrate it to you. It's like trying to convince my cat. I've spent whole threads discussing this with you. I know where it goes. You are incapable of setting aside your biases, and hence you see contradiction where there is none. You already know the answer, so any premise that contradicts it must be wrong, and is thus not worthy of consideration.

    If your claim is that a similar empirical experience could be produced without the present, as in "a simulation",
    A simulation has a present, and a dualistic experience for that matter.. Not at all a good model of what I'm talking about.

    On the contrary, there seems to be no measurement that can be made to distinguish between the premise being the case or not, which makes hundreds of years of nothing. They've tried too. I've seen many attempts, mostly logical, to disprove one view or the other. I've never seen a successful one. I even have my own argument, but it rests on premises that cannot be proven. — noAxioms

    I went through this with you already, it's called "refraction".
    I'm talking about the existence of a present moment, which has little if anything to do with refraction.

    I don't see how this is relevant. The patterns exist in a medium. If they simply look like waves, but are not actually waves, they are still an activity of the medium.
    No, they can appear and move with no activity of what you might consider to be the medium. That's why I brought it up.
  • Absolute rest is impossible - All is motion
    Just a thought and the connection to the topic title is the possibility of an object/objects that could be at rest relative to everything else in the universe.TheMadFool
    Not possible. Beyond a certain distance away, the Hubble expansion prevents any object from being stationary relative to something over here.

    If two objects A and B have the same velocity relative to another object C, then the two objects A and B must be at rest relative to each other.
    Seems correct to me.

    If that's the case then since all objects in the universe have the same velocity relative to light
    They do not. Read what I said above about light not defining a valid reference frame. Also, light doesn't all have the same velocity since it is moving in all different directions
  • Do thoughts require a thinker?
    Do thoughts require a thinker?Kranky
    Kind of by definition, yes. I think it safe to use such a definition.

    If they do, and thoughts occur, then I exist?
    Doesn't follow the way it is worded.
    Give the above definition, try: "if thoughts exist, then the thinker exists". That seems to work for any definition of 'exists' one cares to use.
  • Philosophy and the Twin Paradox
    Then you clearly have inconsistency, contradiction, if you model gravity waves as wrinkles in the fabric of spacetime, and you maintain that things do not travel through spacetime.Metaphysician Undercover
    Wrinkles in fabric are not movement, so 'clearly' hasn't exactly been spelled out.

    And if you say that nothing moves because spacetime is an eternal static block
    I didn't say nothing moves. Your refusal to understand the view isn't evidence that it is inconsistent. Read up on it and attack it intelligently.

    know you have a consistent history of inability to understand that view, as again evidenced by your statement above.
    — noAxioms

    That's right, I cannot understand principles which appear fundamentally contradictory, and the appearance of contradiction is only made to go away when the obvious is denied.
    There you go. You admit that you cannot let go of at least this one particular bias long enough to comprehend a view that doesn't posit it. Yes, the view indeed becomes contradictory if this additional 'obvious' premise is made, but the fact is that there is a different set of premises that predict the same empirical experience and these premises deny the existence of the present moment. Hence the truth of that premise is not obvious.

    You might say this, but you attack my premises, not my logic
    I only attack your premises if you insist on applying them to a view that doesn't posit them. Otherwise, when have I ever asserted your premises are necessarily wrong in any way? Maybe some of them are. I forget.

    so you are really demonstrating that you think my arguments are unsound.
    I meant invalid, and if they're invalid, then they're also unsound, which is why I kind of used both words.

    For example, here's my argument. P1. Light exists as waves. P2. Waves require a medium. C. Therefore there is a medium for light, "the ether". The logic is valid, but you consistently attacked the truth of my first premise.
    Sorry, but I never attacked that line of reasoning. I might attack your assertion that those premises are necessarily true.

    So you are attacking the soundness of my argument, not the validity of it.
    Only when your argument is in fact invalid.

    However, my first premise is well supported by hundreds of years of scientific experimentation, empirical evidence, so you haven't gotten very far with your attack.
    On the contrary, there seems to be no measurement that can be made to distinguish between the premise being the case or not, which makes hundreds of years of nothing. They've tried too. I've seen many attempts, mostly logical, to disprove one view or the other. I've never seen a successful one. I even have my own argument, but it rests on premises that cannot be proven.

    Also, you or others, have made some attempt at creating ambiguity, and obscuring the separation between P1 and P2, by saying rather that light is "wavelike". This allows P2 to appear unsound, because there could be a "wavelike" thing which cannot be called a "wave" because it does not require a medium.
    P2 might be true by definition. It depends on how a real wave is defined. But yes, the logic goes pretty much along the lines of what you say here. Known real waves do things that light doesn't, and light does things that known waves do not. That doesn't demonstrate that light is not a wave, but it does demonstrate that your premises are not necessarily true.

    The ambiguity as to the criteria of "wave" allows for something which we would normally call a wave, to actually not be a wave, only "wavelike", and therefore exist without a medium.
    As an example of something wavelike: Take interference patterns, which are formed by things other than waves. Moire patterns are a good example of this. The patterns move in apparent 'waves' without an obvious medium carrying the waves, as evidenced by the fact that there seems to be no limit to the speed at which they move.
  • Absolute rest is impossible - All is motion
    What about light? No matter who the observer, where the observer, relative velocity with light is always 186,000 mph.TheMadFool
    The speed (not velocity) of light is constant. Each photon has a different frame dependent velocity.

    Isn't this kinda like saying that all object in the universe, because they're moving at the same velocity with respect to light,
    Light does not define a valid reference frame, so no, it's not like saying that. If one was to attempt consideration of such a frame, the universe collapses into a singularity and there is no space or time in which to define motion at all.

    I am wondering what any of this has to do with the topic title. Absolute rest (of a given object) is conceptually possible, and it means that the object's absolute location is unchanging, and has nothing to do with what any of the other objects are doing. It requires a definition of absolute location, which isn't trivial.
  • Absolute rest is impossible - All is motion
    Correct. Thanks for pointing that out. Motion is always relative. What I meant to ask was if there exists an object that's at rest relative to everything else in the universe? There is no such thing, right?TheMadFool
    If there are only two objects in the universe moving relative to each other, a third object might be stationary relative to one of them, but it would be moving relative to the other at the same velocity as the thing relative to which it is stationary. This is pretty trivial geometry. Yes, you describe this in your lower paragraph.

    Another way of wording it: For an object to be a rest relative to the rest of the universe, everything in the universe would need to become stationary relative to the one thing. All motion everywhere would need to stop. That's not going to happen.

    In some of your posts you talk about the distance between things changing or not. That's not the same as relative motion. Given two objects in relative motion (like a pair of masses A, B in eccentric orbit say), one can find a 3rd point (not stationary) that is always some unchanging distance from them, forming a constant length AC and BC despite the ever changing AB. That's still relative motion, but unchanging separation. It might even work for 3 objects, but not 4.
  • Philosophy and the Twin Paradox
    Your proposition, "Spactime is not something that anything can travel through", is not a sound premise.Metaphysician Undercover
    It isn't a premise at all, but rather a conclusion from a different premise, one a thousand years old, that time is a 4th dimension, even if the 'spacetime' term and the mathematical description were introduced far more recently, by Minkowski if I have my history correct.
    If the premise is accepted, then spacetime isn't something that things travel through. If not, there is no spacetime at all through which a thing can travel.
    I know you have a consistent history of inability to understand that view, as again evidenced by your statement above.

    Do you understand the difference between soundness and validity?
    A sound one is valid, and in addition, has all true premises. I probably used the word incorrectly there. We have no easy way of knowing which premises are true if they contradict each other but each lead to the same observations.

    My point was that your arguments are very often not valid.
  • Philosophy and the Twin Paradox
    Not arbitrary. In all such cases, the speed of the waves is pretty much fixed (isotropic) only relative to the medium.
    — noAxioms

    Right, this is one reason (amongst others) why, as I explained, objects must be conceived of as part (features) of the medium.
    Metaphysician Undercover
    If you can actually follow the argument presented in that exchange, you see the opposite position is suggested.

    Your [...] lack of ability to formulate a sound logical argument,
    — noAxioms
    When you deny science, and the truth of obvious premises, as you were doing, you cannot distinguish a sound argument from an unsound one.
    If science was about asserting 'obvious' premises, the sun would still be going around the Earth. Science is not about premises at all. It is about models that correspond to empirical observation.
    As for the sound argument, you illustrate my point above with your response. The soundness (validity if you will) of a logical argument has nothing to do with the premises chosen, but rather what conclusions are (and are not) drawn from those premises.

    Your commitment, that light exists as a particle
    I never said that. Strawman fallacy, getting at least two things wrong about what I've said. Wait, three things wrong. Not bad for 8 words. Kindly refrain from putting words in my mouth.
  • Information Theory and Simulated Realities
    To a solipsist, the only universe that exists is one in which their self is the same with the world. Does that make more sense?Wallows
    Guess I'd make a lousy solipsist because no, that doesn't make sense to me, and here I am, an idealist of a weird sort.

    That's true; but, we can measure models and traits of the original universe through measurement and observation, yes? Kinda, Plato's cave.
    You're saying the original universe is simulating the experience of something with the same rules as itself. How might you know that?
  • Information Theory and Simulated Realities
    Are you also considering the multitude of multiverses also?Wallows
    No, but do those exist to a solipsist? Why count them? Why simulate them?

    Any solipsistic universe can be (potentially) uncountably infinite, as per the pre-existing universe from where the solipsist derives their solipsism.
    You talking about the scale of the container universe simulating this one? The properties of that are completely undefined, so I can offer no opinion.
  • Information Theory and Simulated Realities
    Continuously expanding or not, I can conceivably count the electrons in it, so it seems countably infinite, no?

    As for the solipsist thing to which you seem to be leaning, the universe need not be simulated at all, only your experience of it, which is within the capability of the sort of machine we can envision.
  • Information Theory and Simulated Realities
    An infinite universe expanded say 10% does not require more state spaces any more than a busload of new guests requires expansion of Hilbert's hotel.
    — noAxioms

    I think it more as an issue of countably infinite alphabets versus uncountably infinite alphabets as an analogy.
    Wallows
    It goes from countable to uncountable when growing 10%?
    If not, what do you mean by that reply?

    The universe is not the sort of thing that can be run on any computer as we know them, even given infinite resources. Approximated, sure, but even then only a subset of it. So the thing doing the simulating is not anything to which we can really relate.

    As for being a deterministic universe, that all depends on your quantum interpretation of choice, but most of them are actually pretty deterministic with no fundamental randomness.
  • Information Theory and Simulated Realities
    Well, the question is pretty straightforward. If the universe is expanding, then new state spaces are arising and hence information.Wallows
    An infinite universe expanded say 10% does not require more state spaces any more than a busload of new guests requires expansion of Hilbert's hotel.
    Also, I have personal doubts about there being a specific state for any particular location, but there are interpretations of the universe that posit it, so I cannot say it is wrong.

    Think of a solipsist arising within a simulated world.Wallows
    That's different. As the visible universe expands, it seems that matter exits it over time, leaving less to simulate. More space for a while, but eventually even that begins to collapse as the event horizon encroaches.
  • Philosophy and the Twin Paradox
    A crisp shadow is not inconsistent with a wave, as an object in a wave tank demonstrates.Metaphysician Undercover
    Alrighty then.
    Designations such as "inertial medium" are arbitrary because motion is relative.
    Not arbitrary. In all such cases, the speed of the waves is pretty much fixed (isotropic) only relative to the medium.
    OK, so you do recognize the need for a medium.
    Not a need for it, but a reference to something like one. Spacetime is not something that anything can travel through, so it doesn't really correspond to the function of an actual medium like rope, water, or air, all of which are mediums through which waves travel .
    people like you will deny this need
    Yes, I deny the need, even if I don't deny the medium.
    and speak of people like me as if we're "cranks"
    Your're a crank probably mostly due to the lack of ability to formulate a sound logical argument, and not so much for the views you choose. I never used the word, but I see it coming up quite a bit now. Doubtless there are those that consider me one for whatever reason. The views I hold (not a realist for one) are not exactly mainstream, but at least I can defend them.

    The assumption of "stationary" is arbitrary, and really quite false.
    Arbitrary, but the assumption of its existence is mandatory for the view you hold.

    The preferred frame, what Leo called the "absolute inertial frame" ...Metaphysician Undercover
    I pointed out why the preferred frame cannot be an inertial one, so Leo hasn't thought it through. Have you? I suggested some violations of thermodynamics as well for other suggested preferred frames. Maybe the lost energy I pointed out accounts for the source of 'dark energy'. That would at least resolve that problem. Not claiming to be a cosmological expert, but I can do 4D math at least.
  • Philosophy and the Twin Paradox
    Continuing with the denial of science I see. The activity of light is described by a wave-function. Where's your evidence that light does anything which is not wavelike?Metaphysician Undercover
    You're ignoring my posts above. Surely you're aware of the dual nature of light. Yes, light refracts, which is very much swimming like a duck. Not denying that. The mathematics of waves can be used to compute angles of diffraction for instance.

    But like also throws crisp shadows given a small light source, and that is very much not quacking like a duck. The conclusion you should draw from this is that the nature of light is not exactly like a classic wave in a medium with a known velocity, and thus isn't necessarily best expressed as a function of such a medium. No wave in an inertial medium throws hard shadows or is measured at a single point instead of spread-out, and all waves with known mediums behave differently in frames other than the one in which the medium is stationary, and thus drawing a conclusion of the existence of a medium is premature.

    There also seem to be a lack of working model using such a medium, since I've seen no links to one, only hand-waving and assertions of how it would work if such a model was created.

    Gravity waves are probably the closest analogy. They are sort of modeled as waves in the 'fabric of spacetime'. That wording suggests a frame-independent medium of spacetime itself. If there was a necessity for some preferred frame, it would be called the 'fabric of space'.
    There is no spacetime in the 3D view, but there is no movement through 4D spacetime, so said gravity waves are more ripple distortions in spacetime, which in any choice of frames manifest as waves that travel through space. This would not work with a 3D medium since it would change the properties of the waves in any frame that doesn't match the one in which the medium is not stationary.
  • Philosophy and the Twin Paradox
    If for example I tie one end of a rope to a tree and then take the other end out to some distance and move it rapidly and forcefully up and down, I can easily establish a standing wave in the rope. Or, such a thing is the simple operation of a guitar string. The medium, if you want to call it that, is air, but the air - the medium in this case - is irrelevant.tim wood
    The medium in this case is the rope, not the air. The air carries resulting sound waves perhaps, but not the wave in the rope, which would be there even if the exercise was done in a vacuum.

    Yes, light acts like a wave in one way, but it acts in other ways like no wave acts. If it swims like a duck but honks like a goose, it's probably not a duck. To assert it being a duck by only considering the swimming property and turning a deaf ear to the honking is a blatant example of selection bias. So no, Meta, it does not look and act like a wave.
  • Philosophy and the Twin Paradox
    Fairly good description there, but the phrase 'waves of probability' hardly fits that.
    Yes, there is a wave function, and yes, the function is probabilistic, but that doesn't make the function a 'wave of probability' traveling through a medium. It simply means that the probability of any particular measurement can be computed from the wave function.
  • Philosophy and the Twin Paradox
    The only models I can think of are those of particles physics, in which the particles are a feature of the fields..Metaphysician Undercover
    None of those require a preferred frame for the fields. Any theory corresponding to the ether would need to.

    Empirical evidence indicates that there are waves and this necessitates the conclusion of an "ether" or some such substance which the waves exist in.
    All empirical evidence for real waves (like in water) have an obvious medium, and no real waves behave like that which the M-M experiment is measuring, so this is just your biases talking.

    Your objection about the two clocks, or two billiard balls is not applicable when the objects are conceived of as part of the ether. Each is a different activity of the ether. The two clocks cannot be said to have the same activity (therefore as 'clocks' they are not the same), nor can the two balls be said to be the same, in any real way. It makes no sense to refer to these distinct things involved in completely different activities, as the same. That's all I wanted to explain, and I think I've finally succeeded.
    I agreed to that, yes.

    waves are an activity of the mediumMetaphysician Undercover
    Kind of by definition, yes. What jgill was questioning not that definition, but where you assert "Empirical evidence indicates that there are waves". That part does not hold up.

    What is the medium through which probability waves in QM travel?jgill
    QM does not posit waves of probability, through a medium or otherwise.
    Meta's answer to this is a statement of his personal beliefs, but nothing about what QM theory says.
  • Philosophy and the Twin Paradox
    You don't seem to understand. The objects, billiard balls now instead of clocks, are features of the ether. I've explained this over and over, but you don't seem to get it. It's what we can take away from the M-M experiment, as what is likely the case, objects are not independent from the ether. The existence of an object is a feature of the ether, like a particle is a feature of the field in particle physics. So if one ball is moving at a high velocity in relation to the other ball, then the activity of the ether cannot be the same at the two locations. The movement of the ball is an activity of the ether.Metaphysician Undercover
    OK. Sounds a little like Conway game of Life which has an objective medium, undetectable directly, but the activity of which determines the physical properties of the 'matter'.

    I am unaware of any actual model that has been fleshed out that works this way for our universe. Is there one, or is this just your contribution here?
    The M-M experiment results do not suggest this case is particularly likely since there are actual fleshed out models that don't involve the ether which are still entirely consistent with the M-M results.

    The only thing I'm trying to demonstrate is that the objection you made to what I said, is baseless.Metaphysician Undercover
    You seem to be failing in your demonstration of that. Yes, I agree that you are trying.
    I suspect the thing to which I've objected here is probably that 'one cannot deny the reality of waves', but light also behaves in ways that waves do not, such as throwing crisp shadows, so light seems in reality to be something that is best described as neither particle nor wave.
  • Philosophy and the Twin Paradox
    Yes, I was talking about the activity of the ether. You introduced to that discussion, "clocks". Now a clock is itself a form of activity, and you asked how it is possible that two clocks (two specified activities) at the same place, at the same time, with one of them moving at a high velocity in relation to the other, could be "the same".Metaphysician Undercover
    I never said they were the same. You can make the two things billiard balls if you like. The moving one is half the length and twice the mass of other (a physical change), but the 'activty' of the ether is the same at those two locations, hence it seems that the ether activity there has nothing to do with the different properties of the two balls. If the contraction is caused by the ether, then it must be its speed through the ether, or the ether's speed through it. If not, the ether seems unnecessary for the view at all and there's just a preferred frame for whatever reason.
    Correct any holes in my logic, since I'm arguing about a theory I don't hold, so I might misrepresent it. I certainly don't know how all the absolutist interpretations word it, but I know some posit relative motion with the ether as the cause of the physical change.

    There is no physical change to the balls in the mainstream view. The differing length measurements are due to spatial separation of different things, not a change in the thing itself.

    I just pointed out to you how this notion, this scenario you created, is in fact contradictory. If one is moving at a high velocity relative to the other, then clearly the two clocks are not each the same "activity".
    Again you use the word in a different way than your original usage. I never spoke of the activity of the clocks, but since you seem to dwell on it, I made the two objects into balls. The ether has physically changed one of the balls, which sort of kills the absolutist's claim to being the more intuitive view. Relativity isn't intuitive no matter how you look at it.

    They might represent something real that simply isn't actually a wave.
    — noAxioms
    Sure, and a rainbow doesn't involve the refraction of waves either.
    That's right. Maybe it doesn't. Hence your assertion that we can't deny the reality of these waves being fallacious. Yes, light has a dual nature, and of course you gravitate towards rainbows where it is most wave like, but you've not demonstrated that matter is actually waves, so one is free to deny it. I'm personally open both ways. I don't know.
  • Philosophy and the Twin Paradox
    One clock is moving at a high velocity relative to the other. It is next to the other "momentarily". Therefore there is no such thing as the same "activity" of the two distinct clocks at the "same" location.Metaphysician Undercover
    The term 'activity' comes from you, and you did not seem to be referring to the activity of each clock, but rather to the ether or something else in the environment:
    The "absolute inertial frame" cannot be produced without a proper representation of the ether flow, which may not be a flow at all, but some other unknown type of activity.Metaphysician Undercover
    So I am reacting to that usage of the word 'activity'.

    That's why 'speed relative to the ether' works better because the two clocks are in the same ether but have different velocities to it.
    — noAxioms
    This scenario ought to be impossible according to Michelson-Morley experiments. That's what was disproven, the idea that a physical object moves relative to the ether.
    If the ether is undetectable, then the M-M experiment proved nothing about it.

    It's not that the ether is moving "through" you, but that you, as a physical object, are a property of the ether. That's why I said it's better to conceive of the ether as changing rather than flowing.
    The ether is changing (instead of 'activity'). There are the same two objects in proximity, one heavily length contracted. The cause seems to be the object's speed and not a difference in how the ether is changing. Same argument. The object's speed causes the contraction, not the ether causing it.

    Ether is necessary to account for the reality of waves.
    That the state of a system can be represented by something called a wavefunction does not mean that the system is necessarily a wave, or that a medium is required for it. The Schrodinger equation does just fine with the future evolution of a wave function without requirement for an ether.

    A wave is in a substance. We can deny the reality of these waves, but then fields and wavefunctions don't represent anything real.
    Fallacious reasoning. They might represent something real that simply isn't actually a wave.
  • Philosophy and the Twin Paradox

    I mean one clock stationary and another right next to it (momentarily at least), but moving at high velocity. The 'activity' at that location is the same, and yet one clock is dilated (runs slow and is length contracted) and the other not, so thus it isn't the local 'activity' that causes it.
    That's why 'speed relative to the ether' works better because the two clocks are in the same ether but have different velocities to it. But if speed through ether is the explanation, then ether must be moving through me if I'm in a gravity well, but there are cases where it clearly shouldn't be. So the 'dilation by motion relative to the ether' also seems to fall apart.

    It seems the theory proper doesn't have an answer to this (why ether is necessary at all) and other issues, because if it had answers, you absolutists would tell me how they've been resolved. If the issues haven't been resolved, it would explain why mainstream relativity is taught in schools and not the absolute interpretation.
  • Philosophy and the Twin Paradox
    I said I'm not going to be available for a while, I shouldn't be here now, but I guess the urge to respond is too strong, so I'll be quickleo
    If this is a quick note I'd hate to see one of your long ones.

    There really is a medium permeating all space that is detectable
    The evidence for stuff in supposed vacuum is not evidence that said stuff acts as a medium. You may posit the medium, but all efforts to detect one have so far failed.

    Now consider an atomic clock at rest in that medium (isotropic radiation coming from all around) and an atomic clock in motion (anisotropic radiation). An atomic clock is based on the behavior of atoms (and electrons), that behavior depends on their environment, why should we expect that the two atomic clocks behave the same when one receives isotropic electromagnetic radiation and the other one anisotropic electromagnetic radiation?
    We can subject said clock to radiation of our choice, and none of it being the medium you speak of, none of it has any effect. I say this because what you suggest is easily tested, and would completely violate both theories if said anisotropic radiation had any effect.

    The question ... talks about being in a dense hollow shell, a region of a flat gravitational field (no acceleration, but still in a well).
    — noAxioms

    I don't know, the ether flow model works well in many cases but it seems to be problematic in the kind of situation you mention.
    Maybe the reason the mainstream view is taught in schools is because GR has a clear answer for this situation. If LET was fully generalized, why are you guessing instead of looking it up? If not, is has no business being taught. If the moving ether model can't account for observations in the case I mention, then the moving ether model is incomplete or wrong.

    Meta (in the post following the one to which I'm replying) calls it 'activity' instead of motion, but activity doesn't explain two clocks in the same place running at different speeds. The flowing ether model does, but it seems to come up short in some cases.

    I suppose Lorentz's theory has been generalized then? I wonder how black holes are handled since they don't seem to exist under LET.
    — noAxioms

    I gave a link to an example of such a generalization, but it could be generalized in other ways.
    Oh, so if that 2-page paper is the general theory, you should be able to answer the questions based on that particular work. It seems to mostly just refer to gravitational field theory (Einstein) for all the mathematics. I don't even think it makes a suggestion for the choice of frame.

    As I said I don't consider that time 'flows',
    You said 'runs' I think. Same thing. Anything that isn't a 4D spacetime view is a preferred moment, and if change doesn't progress, well, that's kind of like a Boltzmann brain situation, and very few people argue for that view.

    but in order to compute absolute time dilation one would have to have detected the absolute frame in the first place
    Let's assume the comoving one like everybody else does. We're only moving at around 350 km/sec in that frame. Hardly any dilation due to motion. It's the gravity part they always shy away from. Problem is, the equation doesn't converge.

    Yes strictly speaking they don't 'see', I explained that in another post, what they see is mostly Doppler not the real rate of the other clock. But when each of them assumes that light travels at c in all directions in their frame, each of them infers (computes) that in their frame the other clock is ticking more slowly.
    No paradox there.

    One can do it the complicated way (the non-inertial frame in which the traveler is stationary the whole way), but then the twin back home ages mostly during the time taken to turn around.
    — noAxioms
    And that's exactly the kind of stuff that confuses people.
    Rightly so. Besides the needless complication, a person's point of view is not the cause of events, remote or not. Mike Fontenot doesn't seem to realize this, wording his assertions as if a PoV is such a cause.

    The idea of an instant "remote age change". If there is no acceleration, there is no "during the acceleration".
    No, there's just 'at' the acceleration. Mathematically, an extended object (anything not a point mass) cannot instantly accelerate without distortion, so instant acceleration isn't possible even if infinite power was theoretically possible.

    Consider that we don't even need to talk about twins, we can simply talk about the clock readings.
    I've said the same, but everybody seems incapable of visualizing things unless they're 'identical' human observers of some kind. For one, pregnant women make far better biological clocks.

    In that way there is no need to jump to another ship and accelerate, whatever reading the clock of the first spaceship indicates can be transmitted to the other spaceship going the other way when they pass by one another, and the clock of the second spaceship can be synchronized to it. In that way it is as if the clock had been transferred to the second ship without any acceleration at any point. Sure there is a change of inertial frame.
    Yes, this tag-team method illustrates the point without worry about acceleration at all. There isn't even a change of frame since each ship just keeps right on going.

    But still, at any moment, it is as if from the point of view of the moving clock, the staying clock is always ticking more slowly.
    I don't get what you mean by that. From the PoV of any thing, the thing is not moving.

    We may be in a privileged location (how would we know we aren't), but let's assume we aren't anyway, and that the Hubble law applies from the point of view of other galaxies, that redshift of distant galaxies is proportional to their distance. Even if that redshift/distance law applies to arbitrarily large distances, the velocity/distance law doesn't, or at the very least there is no reason it should apply.
    Redshift is a function of the increase in separation over time of the observed object and the observation. No increase in that rate means no increase of redshift.
    LET supports this, using the same coordinate system as does GR. Notice I don't say 'velocity' because that rate is only velocity under a relational definition of the word.

    If we assume no superluminal velocity, then arbitrarily large redshift doesn't translate to arbitrarily large velocity, as the redshift increases the velocity approaches the speed of light, just like in a given inertial frame if you have a projectile with a very high redshift its velocity is close to the speed of light not above.
    ...
    The absolute frame can be inertial. See the problem with the mainstream narrative? Pushing beliefs as if they were truths.
    Dark matter and energy aren't incompatible with an absolute inertial frame.leo
    You obviously haven't thought that through. Nobody seems to support the inertial model/mapping of the universe. I've never seen a picture of it, but you claim to have drawn one. I drew one myself because I could not find one published anywhere. It didn't support dark energy. It can have no event horizon, and that makes it a contradiction with reality.
    Ignoring the problems with dark energy, absolute interpretations really fall apart under the inertial frame model since it can be demonstrated that the universe is probably older than any arbitrary finite age you can choose.

    The problem is that it takes infinite energy to accelerate the last bit, so it cannot be sustained. What can be done is indefinite proper acceleration of 1G like that, in which case light speed is never reached.
    — noAxioms
    I know that isn't true, yet that's exactly what they do when they say that the recession velocities of galaxies are proportional to their distance no matter how distant they are.
    They don't take into account how velocity approaches the speed of light as redshift increases.
    Now you're talking nonsense. Redshift is about observation, so irrelevant. I'm saying continuous acceleration (defined as a constant change in velocity in a given frame) would take you over light speed and is impossible only because infinite energy would be required for the last bit. Continuous proper acceleration on the other hand (defined as a constant value on the onboard accelerometer) is quite possible, and occurs in reality, and indeed, light speed is never reached in any inertial frame because of the way relativistic velocities add up.
    Know the difference between acceleration and proper acceleration before you make such statements.

    I actually tried to draw a picture of the whole universe using an inertial frame, including these 'superluminal' objects.
    — noAxioms

    I did that too,
    Got a link to it somewhere?

    That sounds stupid only because you assume special relativity is true
    It sound stupid because if any of it actually worked that way, the mainstream view would be easily empirically falsifiable.
  • Philosophy and the Twin Paradox
    You would have called the kinetic theory of gases a metaphysical interpretation of thermodynamics, back when molecules hadn’t been observed yet.leo
    I think not since that theory makes predictions. I suppose that explains the hunt for the ether, even though I don't think it is posited to be detectable.

    That's far more of an explanation than Lorentz's story. If it derives from empirical observation, then it's fully explained.
    — noAxioms

    So in the same way you consider that thermodynamics provides far more of an explanation than the kinetic theory?
    About the same actually. The explanation is that light actually goes the same speed in any frame, and doesn't just appear to. That explanation is all that is needed. It isn't provable of course, but neither is the alternate (and more complicated) explanation.

    Or if you assume that gravity is an ether flow you can recover many general relativistic predictions. So you can explain time dilation on Earth in terms of this ether flow (since in the Lorentz ether theory processes are time dilated when they are moving in the ether). That’s just an example, point is it can be done, and not necessarily in a complicated way.
    ...
    Indeed this might be a problem of the ether flow theory, I would have to think more about it. In any case not much research has been done in that direction, but I’m confident it should be possible to come up with a simple and accurate theory of gravitation without invoking curved spacetime.
    Keep in mind I'm just asking here since I'm not totally familiar. If the ether moves/flows, where does the ether go when it gets to say the center of say Earth?

    Also how does it explain dilation in a gravity well with no acceleration? I'm inside a hollowed out space inside a planet and my clock runs slower here than out in space, but I'm completely inertial, not accelerating in any way. Which way is the ether going if it is the explanation of the dilation going on there? I ask because the vast majority of our current dilation (compared to a hypothetical stationary clock at zero gravitational potential) is due to this kind of thing.
    — noAxioms

    You mean if you’re at the center of the planet?
    No, the question above talks about being in a dense hollow shell, a region of a flat gravitational field (no acceleration, but still in a well). Let's assume the ball is stationary so the dilation is completely due to gravity and not the ball moving through the ether or being in an acceleration field.

    Also, I don't see the LET guys explaining the twins using an ether calculation. They all do it the SR way, but keeping to one frame of their choice the whole time.
    — noAxioms

    As I said it can be done, it’s just tedious.
    That was my point. I'm not suggesting it can't be done, but the tedium is part of why it isn't the mainstream view.

    Okay, maybe I’ve been on the wrong forums then, the few ones I used were extremely dogmatic and totally not open to alternative ideas.
    I've been on some of those like thephysicsforum.com . I abandoned it due to the open hostility displayed not only to those pushing nonsense, but the uninformed asking genuine questions. My post count there is still a single digit I think.

    The validity of doing that can be derived from the Lorentz transformation itself, which existed before special relativity.
    I read that actually, so agree.

    Where is your reference process then? How dilated is your kitchen clock? Ever try to compute that?
    — noAxioms
    That wasn’t my point
    No, but it is sort of one of my points. All clocks anywhere are dilated, no matter their position or velocity. They never compute how dilated these clocks are. Nothing exact is asked for. A single digit of precision would be nice. You'd think the 'time flows' proponents would want to know the objective rate of time flow, but they seem to avoid it like it's something embarrassing.

    Hence Einstein's being the mainstream view. It indeed simplifies everything.
    — noAxioms
    It doesn’t simplify the understanding as it confuses the vast majority of people.
    I am inclined to agree with that. But it's the physicists and engineers that actually need to work with the theory and not just comprehend a description of a couple paragraphs, and to that end the mainstream view is, well, complete for one thing. I suppose Lorentz's theory has been generalized then? I wonder how black holes are handled since they don't seem to exist under LET. That's not much of a knock against it since I could probably argue similarly for any interpretation.

    It’s pedagogically much simpler to retain the view that there is an absolute frame like we’re used to, then show that no matter which inertial frame is the absolute one we still get the same result, then use that to simplify the calculations, without going the next step and claim that the absolute frame doesn’t exist and give up our intuitive understanding.
    But the mainstream view is the same in that way: Any frame can be used and the calculations are simple, and if you choose a different frame as the one to use, then a different person is dilated more. We're back to the same concepts that need teaching in both cases.

    If Einstein’s view simplified everything, people wouldn’t still be confused about the twin paradox and others a century later. There is no such confusion when we assume an absolute frame.
    Einstein's view doesn't suggest you complicate things by computing everything in different frames. It is equally simple if you stick to one like you should in such an exercise. The confusion occurs when the situation is deliberately described in mixed frames. Look at the OP of this thread where Mike is doing exactly that: Describing everything in from an idealistic mixed-frame point of view where distant people physically age backwards and such. It's not wrong, but it omits a lot of implicit assumptions and thus is nothing but confusing. He words it like my age is caused by the actions of somebody far from me, which is nonsense.

    I didn’t claim spacetime is inconsistent, I said that it is a mathematical concept, not a physical thing.
    That's your belief, and that's fine. I happen to prefer the view that the physical thing is just like that. I personally find the 3D view logically inconsistent, but relativity theory has nothing to do with that.

    LET (or at least the theory Lorentz worked on himself) also posits time as a dimension. nLET does not. You seem to be in the nLET camp then.
    — noAxioms
    I’m not sure in what way you distinguish LET and nLET,
    neo Lorentz ether theory, that which has evolved from his work by others. The big change was the assertion of the 3D flowing time view, the thing that MTaggart supposedly 'disproved' according to Bartricks' post above. I'm personally unimpressed with the argument. Point is, I am unaware that Lorentz himself supported that. Maybe I'm wrong. His was a preferred frame but not preferred moment model.

    I said “at every moment of the trip each twin sees that the other is aging more slowly than themselves”
    the frame references lie in the “sees”.
    If the twins are approaching each other, they see the other aging faster. Yes, that's doppler, so 'sees' is a misleading choice of verbs. What each actually does is compute the age of the other, and in order to do that, each needs to select a frame, and if they select different frames (there is no reason they need to), then they're going to get different answers of course. Your statement omitted the choice of frames they made, and hence is using obfuscating language. The fact is that they're incapable of determining the age of somebody not in their presence. You know that, but your statement suggests they can. Take away the obfuscating language and the attempted paradox vanishes.

    It isn't true since the turnaround time is not considered in the above statement, and also the frame references (there are multiple frames again) are omitted. You seem to do this deliberately since you know better. Are you really suggesting that the mainstream view is contradictory or are you just pretending to be stupid when it suits your purposes?
    — noAxioms

    I said: “at every moment of the trip twin A sees twin B aging more slowly, yet when they reunite twin B has aged more”, are you really claiming that’s false?
    Obviously, since the reuniting moment verifies otherwise.
    There can be zero turnaround time if you invoke triplets instead of twins.
    There there is no turnaround at all. Yes, I've used tag-team examples for those who refuse to consider an acceleration case, but now you have to explain how there's Louis who is way out there and already seriously younger (in his own frame) than Huey and Dewey at their separation event at age zero. It appears they're not triplets after all.

    From the point of view of the traveling twin
    That point of view is not inertial, which is making the same obfuscating mistake as Mike in the OP. It makes it look like distant people age quickly or possibly backwards which they simply don't. An accelerating person does not define an inertial reference frame. Do it from any inertial reference frame and the ages work out.

    One can do it the complicated way (the non-inertial frame in which the traveler is stationary the whole way), but then the twin back home ages mostly during the time taken to turn around. If it's instant, then the remote age change is instant. Either way, your assertion above that 'at every moment of the trip twin A sees twin B aging more slowly' is wrong. It happens during the acceleration, however long that takes.

    you can even simulate an instantaneous turnaround using a second spaceship.
    Can't jump to the other ship without accelerating. The ship has nothing to do with it. Maybe the traveler takes Earth with him and leaves the other twin in a ship without fuel back home.

    Yet when they reunite the clock of the staying twin has ticked more. Sure you can explain that by invoking different frames, the point is it’s extremely confusing.
    You're making it confusing by using a non-inertial object as your reference. So don't do that if reducing confusion or reducing complication is your goal.

    If you mean the inertial frame in which the CMBR is isotropic here, that is not a valid candidate for the preferred frame of the universe since no inertial frame foliates all of spacetime. In other words, galaxies like GN-z11 (something we can see) does not even exist in that inertial frame since it is moving at well over light speed and thus hasn't yet been born.
    — noAxioms

    The Hubble law doesn’t apply to arbitrarily large distances.
    Oh doesn't it now. Are we in a privileged location in space where it seems to work out to a fixed distance from us in every direction, but if we were near the edge of that, it would only work if we looked back at Earth and not further away from Earth?
    If not, what do you mean by this? The comoving coordinate system (that based on the postulated absolute frame) has the Hubble law continuing forever.

    If you assume it does then you get superluminal velocities.
    No you don't. Velocity is a property under absolutism, not a relation. All those galaxies are nearly stationary. The separation between us and them is growing at a rate more than c, but velocity is not defined as a relative change in position relative to a reference in that view. That's the SR view, and the universe is not described by SR over large distances. That's a good part of why the absolute frame cannot be inertial.

    Just like if you assume that the speed of a car increases by 10m/s every second eventually that car will exceed the speed of light, that doesn’t mean it ever gets there.
    First of all, under SR, this isn't true. The problem is that it takes infinite energy to accelerate the last bit, so it cannot be sustained. What can be done is indefinite proper acceleration of 1G like that, in which case light speed is never reached.

    Under absolute view, the car slows down over time by itself, and at high enough speeds, the slowing balances the proper acceleration and the two cancel out. I'm not making fun of the view. It actually works this way.
    I actually tried to draw a picture of the whole universe using an inertial frame, including these 'superluminal' objects. Under SR, speeds do indeed add up using the relative rule and light speed can never be reached. The picture works fine until I attempted to work acceleration of expansion into it, and I could not do it without violating fixed light speed in the coordinate system. I don't think I can post pictures here or I'd show it to you, but it is a picture of non-absolute physics.

    You can very well pick a global frame in which nothing is superluminal.
    That you can, and they have diagrams of it. All the super-large-scale pictures use it, which prompted me to attempt it using inertial rules since I could find nobody else attempting it on the web.

    See that’s the kind of confusing stuff with the mainstream view, on the one hand they say nothing exceeds the speed of light, on the other hand they extrapolate Hubble’s law to arbitrarily large distances
    Hubbles law is about the increase of proper distance measured over curved lines of comoving time, not about absolute speed, which is assumed to be fixed at zero. Our galaxy for instance moves at I think under 0.002c, but our solar system is well under that figure. The other galaxies move at similar speeds, nowhere near light speed. That's the consequence of a non-inertial preferred frame.

    No. I put a clock in there and it still paces the one on the outside. That's empirical evidence against the dilation explanation of the apple rotting.
    — noAxioms
    Or the apple is time dilated in the fridge but not the clock.
    Time that picks and chooses. Yea sure.

    Also have we ever tested if a mechanical clock gets time dilated at high velocities?
    To my knowledge only atomic clocks have been tested.
    Muons make great clocks. Accurate to at least 2 digits and easy to accelerate.

    Sure they’re more accurate, but then maybe their time dilation has to do with their internal processes, there is no evidence that everything gets time dilated due to velocity.
    Let me know how that works out for you.

    The geometry method for instance explains (and is not just a mathematical convenience) why the height of a flag pole can be taller or shorter depending on your choice of the orientation of the 'up' dimension. That is physical length contraction without any change to the proper dimensions of the pole.
    — noAxioms

    Well a flag pole can certainly appear differently depending on how you look at it, that doesn’t imply that the flag pole physically changes when you do that
    Exactly. Ditto with length contraction. The change is only a mathematical coordinate difference, not a physical change. I think it is actually a physical change in the absolute interpretation. Fast things really do physically change in that view.
  • Philosophy and the Twin Paradox
    Yes the Rømer measurement isn’t a true one-way measurement either, this is actually addressed in the link I mentioned: https://en.wikipedia.org/wiki/One-way_speed_of_light (this is a good Wiki article for once, there aren’t too many like that).

    The Australian physicist Karlov also showed that Rømer actually measured the speed of light by implicitly making the assumption of the equality of the speeds of light back and forth.
    leo
    Yes, it says that, despite no signal going back. Only forth.
    At no point does that page say that the measurement was invalid (cannot be done to arbitrary precision today) or that it in fact involved a round trip signal of some kind.

    In order to measure the one-way velocity of some thing we need to know the one-way velocity of a signal that we transmit back and forth between that thing and us
    This says that in order to know X, you already need to know X. I suppose that's arguably true in this case.


    but since light is the fastest signal we know and we don’t know the one-way speed of light in the first place, then we can’t measure any one-way velocity with perfect precision, even for slow-moving objects.
    We're not asking for perfect precision. Romer was off by quite a bit mostly because of a poor measurement of Earth's orbital radius, something not trivial to measure in the day. The most accurate clock at the time was a sundial. Still, the method works today and easily gets several digits of accuracy. Perfection? No.

    But while for slow-moving objects the precision is very high (since the average speed of light on a round-trip is much higher), when we attempt to measure the one-way speed of light itself the precision drops to zero, meaning that the one-way speed could be pretty much anything (as long as the two-way average yields c).
    There was no two-way measurement. That's the whole point.
  • Philosophy and the Twin Paradox
    The Lorentz ether theory is a theory different from special relativity, it isn’t an interpretation of it. The postulates of special relativity lead to the Lorentz transformation, Einstein called it that way precisely because Lorentz had come up with it before.leo
    Lorentz did not hold to the postulates of relativity. In particular, he denied the first one (that dates back to the time of Galileo). The Galilean principle of relativity states that the laws of physics are the same and can be stated in their simplest form in all inertial frames of reference. Yet LET concludes a violation of that:

    Consider that in the Lorentz ether theory, there is only one frame in which light travels at c in all directions, while in other frames this isn’t the case.
    There you go. That's a violation of the GPoR. Lorentz couldn't accept that principle which is why to my knowledge he never managed to generalize his theory to the actual universe.

    However this is correct only as long as nothing travels faster than light! Obviously if we ever encounter superluminal signals, then the one-way speed of light would no more be a convention, it would be experimentally measurable. And it would allow to decide whether there really is an absolute frame or whether all inertial frames are truly relative.
    OK, I actually agree with this, and have come to a similar conclusion myself. The world of star-trek doesn't work except under an absolute reference system, and since the vast majority of viewers assume such a view, they don't cringe when the Enterprise hits warp speeds.

    But that’s not the only difference between the theories. Consider that special relativity is a principle theory (based on heuristic principles), while the Lorentz ether theory is a constructive theory (provides a picture/mechanism of what is actually thought to be occurring).
    Yes, that being why I call it a metaphysical interpretation. Physics is about what we see (said heuristics), but metaphysics is about what actually is. There is definitely some metaphysical wording in Einstein's theories, especially that taken from Minkowski's work.

    Special relativity doesn’t attempt to explain what causes time dilation and length contraction, it merely derives them as a consequence of heuristic principles.
    That's far more of an explanation than Lorentz's story. If it derives from empirical observation, then it's fully explained.

    While the Lorentz ether theory attempts to give the beginning of an explanation. It says that there is a medium that permeates all space, the ether, which represents an absolute frame, and that objects moving within that medium are length contracted and time dilated by a given factor which is a function of their velocity in that medium. The next step would be to understand what is it about that medium that generates such an effect on matter and processes, Lorentz and others had begun working in that direction.
    I am unclear if this was ever generalized to gravity. How is time dilation say here on Earth explained? I've heard that the ether moves by, giving the impression that it necessarily builds up in places where there is matter, and hence depletes elsewhere. Also how does it explain dilation in a gravity well with no acceleration? I'm inside a hollowed out space inside a planet and my clock runs slower here than out in space, but I'm completely inertial, not accelerating in any way. Which way is the ether going if it is the explanation of the dilation going on there? I ask because the vast majority of our current dilation (compared to a hypothetical stationary clock at zero gravitational potential) is due to this kind of thing.

    Also, I don't see the LET guys explaining the twins using an ether calculation. They all do it the SR way, but keeping to one frame of their choice the whole time.

    everyone remains focused on the principles of special relativity and confused with all its (apparent) paradoxes.
    You seem to know then that it isn't paradoxical.

    That leaves the fairly small percentage of armchair opinion holders like ourselves on these forums, and among them, it seems split pretty evenly.
    — noAxioms

    On most physics forums you will find that in most discussions about special relativity most people do not question the mainstream view
    There are forums that disallow discussions of alternate theories and only exist to give mainstream answers to real questions by people who want to know, and not who want to push their own pet views. If you want to question the mainstream view, these forums are not the place to do it.
    On the other hand, there are forums that are open to it (completely open like Quora where even utterly wrong answers often appear as answers to searched questions) and others that have a separate section to separate mainstream from alternative views. In these forums, the mainstream views are often questioned by more members than supported. I am a moderator on one such forum and the mainstream view seems defended by a small number of people who know it and by several more who don't know it very well, and questioned by countless users that either want real understanding, want to push an alternative (like you), or want to push something of their own.

    Nobody pushing an alternative view gets banned for it. The bans are for abusive language or for purposes of promotion of personal websites. The crackpots often remain, relegated to the children playground. LET is not considered a crackpot view.

    I had done the calculations myself some years back, I believe I’ve seen it done in a few papers, but anyway once we realize that by a specific change of coordinate we can treat the Earth as stationary
    Treating the Earth as stationary when it isn't is valid move because of what Einstein showed.

    and this greatly simplifies the calculations, there is no need to do the complicated ones all over again every time.
    Hence Einstein's being the mainstream view. It indeed simplifies everything.

    Personally I consider that it is a fallacy to say that time runs/passes/flows, as if time was a physical entity.
    There are those that think it does, and that as well is a valid view, although one that Lorentz himself did not seem to hold. He also viewed it as a dimension.

    When we say that a process is time dilated we’re merely saying that it takes longer than it does in other conditions, relative to a reference process.
    Where is your reference process then? How dilated is your kitchen clock? Ever try to compute that?

    Based on that, I consider it a fallacy to treat 4-dimensional spacetime as anything more than a mathematical concept.
    It being a fallacy is not a belief or not. You have to show the logical inconsistency of it. 4-D spacetime is the constructive theory you mentioned, providing an explanation for the dilations and such. LET (or at least the theory Lorentz worked on himself) also posits time as a dimension. nLET does not. You seem to be in the nLET camp then.

    You're dissing an interpretation that you either don't understand or refuse to represent correctly. The theory does not say that each twin ages more slowly than the other.
    — noAxioms

    Not far, it says that at every moment of the trip each twin sees that the other is aging more slowly than themselves.
    Wrong again. In order to make any determination about relative ages, a frame needs to be selected. If they happen to choose different frames, then the results may differ. They each could choose different frames for example and compute that the other twin is always aging faster than themselves. The question of which is older is a frame dependent question. You know this, and yet you misrepresent what the theory says by omitting frame references in a statement that references multiple frames. That's a strawman tactic, or fallacious reasoning.

    And then the real thing that rubs people the wrong way: “at every moment of the trip twin A sees twin B aging more slowly, yet when they reunite twin B has aged more”.
    More strawman. It isn't true since the turnaround time is not considered in the above statement, and also the frame references (there are multiple frames again) are omitted. You seem to do this deliberately since you know better. Are you really suggesting that the mainstream view is contradictory or are you just pretending to be stupid when it suits your purposes?

    I concede that the frame in which the CMBR is isotropic here is not necessarily the absolute frame of the whole universe, but I already conceded that. I shouldn’t have said in an earlier post that “in practice an absolute frame can be detected”. It’s simply neat to pick that frame as the preferred frame.
    If you mean the inertial frame in which the CMBR is isotropic here, that is not a valid candidate for the preferred frame of the universe since no inertial frame foliates all of spacetime. In other words, galaxies like GN-z11 (something we can see) does not even exist in that inertial frame since it is moving at well over light speed and thus hasn't yet been born. Inertial frames are really only locally valid and do not correspond to curved space. Most of the absolutist theories choose the comoving frame as the absolute frame. Even GR does, it being for instance the only frame in which the expansion rate of the universe is the same at every spatial point in the frame.

    Still there is no proof that there is no absolute frame, personally I believe there is one and eventually we will detect it.
    There seems to be the one choice, making it quite detectable. It is objective in that any observer anywhere in the universe would agree with the choice, and they certainly wouldn't agree with the one you chose.

    And so going back to the fridge example, would you say that the apple in the fridge is time dilated?
    No. I put a clock in there and it still paces the one on the outside. That's empirical evidence against the dilation explanation of the apple rotting.

    it would be interesting to explore the idea that special relativistic time dilation is a physical slowdown of internal processes due to some effect that is yet to be understood. What do you think?
    But they've already done that, in two different ways (geometry and ether). The geometry method for instance explains (and is not just a mathematical convenience) why the height of a flag pole can be taller or shorter depending on your choice of the orientation of the 'up' dimension. That is physical length contraction without any change to the proper dimensions of the pole. That's essentially the contructive explanation behind dilation: recognition that measurements of any one dimension depends on the choice of orientation of the coordinate system, without any physical change to the proper properties of the object being measured.
  • Philosophy and the Twin Paradox
    But while he can measure the times of reception, he cannot measure the speed of light in each direction, he only knows that the average speed of light on a round-trip is measured to be c, while the unidirectional speed of light could be anything.leo
    I always wondered about this claim. The first speed of light measurement was done using a one way method. It can still be done today with far greater precision. Are you saying Romer did not actually measure light speed, or that the method he used was in some way not one way?
  • Philosophy and the Twin Paradox
    So you're not reading or not understanding what I say?leo
    You're not being very clear about what you're trying to say. I see you starting a rant about fighting for the truth, which says to me that you claim that your view is the truth and everybody is just being dogmatic for not seeing it.

    I'm not saying relativity is false. I'm saying it's not necessarily true.
    ...
    Because, again, alternative theories account for the same experiments just as well.
    Not being clear.
    'Relativity' is the theory, and while science is not is the business of proving anything, the evidence for the theory is overwhelming. It is effectively necessarily true. There is no competing theory.

    What you seem unable to articulate is that the metaphysics behind that theory is open to multiple interpretations (preferred frame vs. any-frame-will-do, and preferred moment vs. block), and thus no one interpretation is necessarily true. With that I agree, and it isn't truth to be fought for, but rather an open-ended philosophical point left to ones personal preference.

    I'm saying there is no proof it is true. I'm saying there are alternative ways to explain all the experiments that are considered tests of special relativity, without invoking relativity.
    Sorry, but even the interpretations with a preferred frame need to invoke relativity theory else they'd predict different things. This is especially true of SR. There is no CMB in SR since it doesn't model our universe. You have to go to GR for that, and GR suggests (wait for it):
    a preferred frame.

    A lower percentage doesn't mean there are less of them, seeing as probably 1000 times more people follow the mainstream narrative without ever questioning it.
    I doubt that very much. The vast majority buy into some sort of single-frame mentality because it works for them. Most of them wouldn't know the first thing about relativity theory or be able to describe how it differs from say a Newtonian view, if they even know what that was. The majority of the relevant physicists and engineers probably hold the mainstream view, but there aren't very many of them. That leaves the fairly small percentage of armchair opinion holders like ourselves on these forums, and among them, it seems split pretty evenly.

    Those who question the mainstream view are relentlessly attacked, just like you are doing now, without focusing on the arguments.
    You seem to be quite focused on perceived attacks and not on any arguments. I don't recall for instance you asking what beef I have with say neo-Lorentz-Ether 'theory'. I put that in quotes since a view that makes no predictions isn't a theory. Not sure what name to give the mainstream view since 'relativity' is the name of the theory, not the metaphysical interpretation. Let's just say 'multi-frame'. You also seem to be in the 3D space camp rather than the 4D spacetime camp. I must admit that the latter term appears frequently in the theory. The mathematics are far simpler in 4 dimensional space than in 3 dimension, and even nLET uses 4D calculations. For instance, I've never seen the twin scenario (a realistic one with Earth not stationary) described using any absolute interpretation.

    Look at the scientific literature if you want proofs that one version of the Lorentz aether theory is experimentally equivalent to special relativity.
    I consider that to be a different metaphysical interpretation of the same theory. He didn't get his name on it only because he didn't publish first, and never completed the general theory. You don't seem to buy into his view since he did not see time flowing/'running' as you seem to. That's why I reference neo-Lorentz-ether theory, which does.

    But if we ever find superluminal signals there would be ways to distinguish them, and then maybe relativity will turn out to be false.
    Lorentz needs superluminal signals? Why? How about quantum entanglement? Some non-local quantum interpretations require them.


    The mathematics are furiously more difficult. Imagine a speed limit sign at the side of the road if it was to state the limit in absolute terms. Nobody uses the absolute interpretation to do anything practical.
    — noAxioms

    The nice thing is the calculations can be simplified a lot by a change of coordinates. Any inertial frame can be picked as the preferred frame to carry out the calculations, it works out the same in the end.
    But that's all that relativity theory (the theory itself) says. The calculations work in any frame.

    So in the example of the twins, we can pick the frame of the staying twin as the absolute frame, and then the traveling twin is the one aging more slowly all along. If the real absolute frame is the one of the traveling twin on the way out, then the traveling twin ages more quickly on the first half of the trip, but ages much more slowly on the second half, and the end result we calculate is the same. No matter what the real absolute frame is, the calculated outcome is the same.
    That sounds exactly like the mainstream view.

    And the advantage is there is no paradox.
    That's right. Never claimed one in either interpretation.
    Even if you call it an apparent paradox and not a real paradox, the point remains that it confuses pretty much everyone, to the point that plenty of papers were written on it in professional journals (and there are many more other paradoxes).
    Agree with that. If they frame it as a paradox, they're misrepresenting the theory or the interpretation. Don't confuse pop articles with science. The Andromeda 'paradox' for instance isn't paradoxical at all unless you say mix interpretations.

    there is no "each twin ages more slowly than the other".
    Yea, like that. That's the misrepresentation I'm talking about. You're dissing an interpretation that you either don't understand or refuse to represent correctly. The theory does not say that each twin ages more slowly than the other.

    If you don't say anything I have nothing to debunk.
    ...
    Well, you should know that if there is an absolute frame, and there is a stationary object in that frame, then the object a billion light years away whose distance is increasing is by definition in motion relative to the frame, it isn't stationary...
    You've contradicted yourself. You agreed that the inertial frame in which the CMB appears isotropic from here is a different inertial frame that the one where the CMB appears isotropic from a galaxy 8 billion light years away (science agrees with that). That isotropic CMB defines being absolutely stationary according to your definition of the preferred frame (known as the comoving frame), and here you say the distant galaxy isn't stationary. You need to fix something (like the statement immediately above) or you've been debunked yourself.


    Like I said, if there is an absolute frame, then two frames in relative motion
    I'm talking about the one absolute frame, and not any other. I'm referencing no other frame.

    [Two frames] can't both be the absolute frame, so if the absolute frame is the one in which the CMBR is isotropic here then it's not the one where the CMBR is isotropic in other distant galaxies.
    This is only true for inertial frames. Are you suggesting now that the preferred frame is inertial? In that case, the CMB is of no help to you since it is isotropic in a different inertial frame at every point in space, and in no inertial frame is there not a point in space from which the CMB appears isotropic to a stationary object.

    You're changing your story, which indicates you're not very familiar with the view you think everybody rejects.

    In the muon's frame, time is not dilated at all since the muon is stationary. I also would not worded it as 'running' since I don't think time is something that 'runs
    — noAxioms

    But you would say that in Earth's frame the muons are time dilated?
    As you say, we can pick Earth's as the absolute frame and say the muons are time dilated, yes.

    And if you say time doesn't run, would you say time passes? Flows? How would you say it?
    Time is a dimension, orthogonal to space, which is why they call it spacetime. Space doesn't flow either. There is no preferred location that is one place, and then somewhere else.
  • Philosophy and the Twin Paradox
    So you’re saying you have a problem with people fighting for truthleo
    Until you falsify the other interpretation, it's opinion, not truth, and opinion isn't worth the militant fighting.

    Apparently in your view it’s not a good thing to point out falsehoods in the mainstream narrative.
    A great thing if you can, but if you do it by only showing that it contradicts your opinion, then it just makes you look the fool.
    Would you say that relativists attacking ‘absolutists’ aren’t ‘militantly biased’?
    There are some, sure, but at a much lower percentage.

    Personally I would converse on that subject much more calmly if I hadn’t been attacked so many times for simply being a curious and inquiring mind questioning the mainstream narrative and exploring alternative paths, which is what science is supposed to be about in the first place.
    You don't come across as curious. You put up strawman arguments against the truth you believe, and don't bother to actually learn the view you're attacking. Pretty closed minded if you ask me.

    I guess you don’t have a problem with people getting attacked when they question the mainstream narrative.
    But you're not questioning it. You're asserting it to be wrong.

    In this case questioning is not claiming that relativity isn’t consistent with many experiments, it is pointing out that all these experiments can be explained differently, in a much more intuitive way.
    That's not how you've worded your posts. You've asserted that the mainstream view is wrong, and hence must not be consistent with all the experiments. So instead of the rant, chill out and show where it predicts the wrong results. If you can;t, then again chill out and just accept that both views work and neither is necessarily the truth.

    Also note that many ‘relativists’ claim that relativity proves there is no absolute frame.
    Then they're using the same fallacious reasoning as are you. Most of them don't assert this, especially the physicists whose job it is to know relativity. Those physicists may still have their opinions on the matter.

    Meanwhile, I don’t claim that absolute frame theories prove that an absolute frame exists.
    You said you were fighting for the truth. So you seem to at least claim to know the truth without any proof then.

    However it is easier for most people to think in terms of an absolute frame.
    It isn't. The mathematics are furiously more difficult. Imagine a speed limit sign at the side of the road if it was to state the limit in absolute terms. Nobody uses the absolute interpretation to do anything practical. I can think of no examples except a cosmological map of the universe in comoving coordinates. Somehow the inertial frame just doesn't work that scale since no inertial frame foliates all of space.

    No, there's another reason the absolute interpretation might be necessary. I touched on it in a prior post where I mention the three (not two) basic interpretations of the reality of space and time.

    it gets rid of all the confusion surrounding the relativity paradoxes
    There are no paradoxes. Any attempts to present one always involve strawman arguments.
    Relativity is treated as a religion by many of its proponents, that’s a problem.
    * Snort *

    Do you agree that the inertial frame in which the CMB aopears isotropic from here is a different inertial frame that the one where the CMB appears isotropic from a galaxy say 8 billion light years away? — noAxioms
    So? How does that prevent us from selecting the CMBR rest frame here as a preferred frame?
    I said it was the correct choice. I didn't say you shouldn't select it.

    You said you would debunk my statement, and yet when I ask a question, you evade it. Answer the question yes or no or something else. My argument depends on how you answer it. Then you can debunk my argument. You seem to imply 'yes' to that (as you shstraould), but it wasn't clear. If you answer no, then the argument proceeds along the lines of denial of empirical observations. If you say yes, then you should know that the distance between a stationary object here and a stationary object a billion LY away is increasing, which isn't true in any inertial frame.

    If the CMBR rest frame in a galaxy 8 billion light years away ever becomes relevant, then presumably we would have found superluminal signals by then, which would allow us to pick a more accurate preferred frame.
    But they have found 'superluminal' galaxies. The most distant object is something like 32 BLY away, and light from it is 13.4 billion years old. That's means the distance between us and it is increasing at well over twice light speed, despite the fact that both us and it are within a few percent of being stationary.
    It isn't a superluminal signal. The thing was much closer when the light we see now was emitted. That light reaches us now at speed c. Numbers quoted here are all using the absolute interpretation, which I said was useful for such scales.

    Anyway, I called nothing 'strange' — noAxioms

    you get strange effects — noAxioms
    I stand corrected. Yes, I consider a thing slowing down without a force acting on it a strange departure from Newtonian physics, but plenty of GR stuff also departs like that. The conservation of energy thing is a serious problem and either needs to be accounted for or needs to admit that the interpretation does not hold to thermodynamic law,


    I would never have suggested time running more slowly in a muon's own frame. — noAxioms
    So how do you interpret it?
    In the muon's frame, time is not dilated at all since the muon is stationary. I also would not worded it as 'running' since I don't think time is something that 'runs
  • Absolute rest is impossible - All is motion
    This was a reply to me 5 months ago and I never saw it.

    What if we assume, in fact it's true that the distance between the earth and the sun keeps changing, that it's the distance AB keeps changing. Doesn't this mean AC and BC should also change?TheMadFool
    You mean the Earth and sun are A and B respectively? The distance between them does change all the time, but not a whole lot. You didn't define what C was. If it's Jupiter for instance, then AC and BC are going to be changing regardless of the stability of AB or not. If its my mailbox, then AC is pretty constant despite the continuous change to AB.

    I used the math tool geogebra and what I saw was (taking three vertices of a triangle ABC) if we move B relative to A then even if AC doesn't change BC does change.
    Well its pretty easy to make a counterexample of that. Just make AC and BC hinged rods holding those points at a constant separation. AB is free to change (B moving relative to A) without changing the lengths BC or AC. It just changes the angles at each of the 3 vertices.

    The mathematical proof would likely use the pythagorean theorem.
    The existence of the counterexample is proof that it isn't the case.

    Suppose there is an object, A, in absolute rest i.e. at rest relative to everything else.
    Oh, you think absolute rest means that either 1) everything is at rest, or 2) the distance between the one resting object and every other object remains the same.
    In fact, the wording (the i.e. part) is a total contradiction. Motion is either absolute or relative, so if it is at absolute rest (assuming it is even meaningful to be objectively at rest), it just means it is stationary, which has nothing to do with what other objects are doing.
    At rest relative to everything else is physically impossible since there are objects too far away to have the same velocity as any object here.
  • Philosophy and the Twin Paradox
    The absolutists tend to be militantly biased
    — noAxioms

    I fight for truth, you got a problem with that?

    When people are told the lies that relativity is true, that they have to give up many of the intuitive ideas they’ve had all their life, that they have to replace them with totally unintuitive ideas because supposedly that’s how the universe really works, when as a result they give up trying to understand the universe or end up blindly believing the authority, when people who have an inquiring mind explore alternatives to relativity and get labeled derogatory names (“crackpot”, “absolutist”) simply because they have a scientific mind and they use it, when they get told more lies (“relativity proves there is no absolute frame”, “the concept of the aether was falsified experimentally”, “light is measured to travel at c in all inertial frames”), I think it’s a disgrace.

    When the normality is to spew lies and when one gets attacked or scorned for correcting these lies and fighting for truth, it’s a disgrace. If you don’t see the problem with that attitude and the attitude you’re having now, that’s a problem too. This is the attitude that makes science dogmatic and stagnate.
    leo
    Thank you for illustrating my point.

    All said, most absolutists correctly do not posit an inertial frame as the preferred one
    — noAxioms

    If there is an absolute frame then by definition there is a preferred frame, even if it may not be detected, again what are you talking about?
    I use the two terms interchangeably. The preferred frame and the absolute one refer to the same thing.

    Also as I mentioned earlier, the cosmic microwave background radiation does select a preferred frame.
    Yes, that's the obvious one. It isn't inertial, and has the problems/properties listed in my prior post.

    and hence you get strange effects like any moving object, in the absence of a force acting on it, will tend to slow down over time.
    — noAxioms

    I wonder where you got that, tell me more and I’ll debunk it for you.
    Do you agree that the inertial frame in which the CMB aopears isotropic from here is a different inertial frame that the one where the CMB appears isotropic from a galaxy say 8 billion light years away? Not sure how far short your understanding is, so not sure where to start.

    Also I like how you don’t bat an eye when you attempt to explain in a convoluted way why the twins are really both aging more slowly than the other, or why light really travels at c in all directions in all inertial frames, if you were consistent you would call THAT a strange effect.
    Illustrating an apparent complete lack of understanding of the mainstream interpretation. Anyway, I called nothing 'strange' and don't deny the validity of most absolute interpretations, but I pointed out some conservation problems with it that need resolution.

    And if you were consistent you would admit that muons decaying more slowly doesn’t imply that time runs more slowly in their frame
    I would never have suggested time running more slowly in a muon's own frame. That's wrong in both interpretations.
  • Philosophy and the Twin Paradox
    You don't get it - the twin paradox in no way implies the relativity of time.
    — Bartricks
    You either know what you mean and can make it clear, or you don't and cannot.
    tim wood
    In this case, he seems to be talking about the absolute/preferred frame interpretation (Lorentz and such) vs the mainstream interpretation that says the speed of light is actually the same in any frame, and doesn't just appear that way.
    The two interpretation make all the same empirical predictions and hence neither can be falsified. That's the point Bartricks seems to be trying to make. The absolutists tend to be militantly biased, and Bartricks and Leo fit right in with that crowd. They even hold conventions for them to help separate them from their money.

    If the two interpretations make the same predictions, why was the Michelson-Morley experiment performed? Its results seems to be a falsification of what those two predicted as an empirical test for the absolute interpretation.

    All said, most absolutists correctly do not posit an inertial frame as the preferred one, and hence you get strange effects like any moving object, in the absence of a force acting on it, will tend to slow down over time. If you find a fast moving thing, it must have been recently accelerated. Photons similarly tend to lose energy over time. Both effects violate energy conservation, and I wonder how they account for that, or if they also need to discard thermodynamic law.
  • Philosophy and the Twin Paradox
    Two people can be equally justified in believing contradictory propositions - and there can be nothing we can do to confirm which belief, if either, is true.Bartricks
    It seems if there are three valid contradictory positions, then nobody can be justified in their belief using any empirical evidence since they're not justified in eliminating the other possibilities. All of philosophy seems to be like that. If you could verify/falsify one position over the other, it would be justifiable scientific fact, not an interpretational choice.

    I justify my choice because I think the 3D interpretation, by putting time outside of the universe, creates the logically incoherent position of the universe suddenly 'happening' at some random time without cause. That works great for say the theists who assign that cause to a decision made by a deity, but then you have the same problem of the deity existing within time or v-v, both of which typically are incompatible with the definition given for said deity.

    But you can't conclude from that that both are true. Yet that seems exactly what you would need to do to derive any substantial conclusion about time from the twins paradox.
    You seem to not understand either interpretation then. Neither requires the other to be true.

    Tim Wood above seems to be mixing the two interpretations just like Edgar Owen does, which leads to confusion since the two views are contradictory. Tim seems to want a 4D relative interpretation and Edgar wants a 3D presentist interpretation even if he resists the label, but each of them borrows from the other interpretation. There is also the 4D absolute interpretation which nobody here seems to support.
  • Philosophy and the Twin Paradox
    So this is not a point about reality, or time, but about justified beliefs, yes?Bartricks
    The differences between the two interpretations of relativity (relative or absolute frames) and the differences between two interpretations of time (block 4D spacetime vs presentist 3D space) are a matter of belief, yes. The fact that the one twin will be twice the age of the other when they meet again is not a matter of belief.

    When my twin travels away from me, it seems to me that he is getting smaller and smaller than me. And from his perspective, as he travels away from me, I seem to be getting smaller and smaller than him.

    Now, what do we conclude? That we are both getting smaller than each other? No, that's clearly impossible. And it remains impossible even if, due to the fact we've both travelling away from each other, we'll never meet to be able to compare body sizes.
    But you can. Simple geometry. I can measure the actual size of something without being in its presence, if I know how far away it is.

    Two people can be equally justified in holding contradictory beliefs - there's no problem with that. What is problematic is holding that something contradictory is actually true.
    Only if you believe both are true at once. They can't both be right if they're mutually contradictory. Maybe everybody's wrong.

    Two people cannot both be older than each other. Two people cannot both be smaller than each other. But two people most certainly can believe that they are older than each other, and be equally justified in that belief
    Nobody I know claims this. I certainly don't. OK, trolls claim this I suppose.
  • Philosophy and the Twin Paradox
    It has everything to do with apples - I brought apples into it and wanted to know why those who think the twin paradox shows us something interesting about time aren't as confused as someone who thinks that because an apple in the fridge decays more slowly than one on the sideboard, therefore time travels more slowly in the fridge.

    So far you have singularly failed to do this - indeed, from your previous comment it seems that you think time does actually travel slower in the fridge.

    If you don't think this, can you explain the difference between my apple example and the twin paradox?
    Bartricks
    With the apples I can open the fridge and set the two side by side and it is clear which one is more decayed.

    With two clocks receding from each other (and no other objects), it is impossible to tell which is running slower. To do that, one must make an assumption about which of the two is more stationary, but it's an arbitrary choice. There is no empirical test for it. There is no doubt with the apples.
  • Philosophy and the Twin Paradox
    Er, I did. And then you said both move.Bartricks
    Motion by definition is relative. I said they both move relative to each other. The absolute way would be relative to some implied absolute frame, so one just says 'this one is moving and that one isn't'. I have a hard time thinking in such terms, as I said, you should go with it.

    What I want to know is why physicists think it tells us something interesting about time. Because it seems to me to tell us nothing more than my fridge/apple example.
    In absolute interpretation, light speed is not frame independent. That's where it becomes complicated. Has nothing to do with apples. How can I measure how long light takes to cross the room if I don't know if my clock is dilated or running full tilt? For one, no clock in reality, even if stationary and compensating for gravity, runs at full speed. They've never computed how slow Earth clocks run, which sort of puts a dent in the claim that there is such a rate.
    Translation, as an absolutist, I have no idea how long it takes the apple to rot since my clock doesn't measure time accurately at all.

    For instance, here's another variation: one twin travels from the earth and the other stays put. Twin one thinks "hm, my twin is getting smaller and smaller than me". Whereas the other twin - twin two - thinks "hm, my twin is getting smaller and smaller than me".

    Are they both getting smaller than each other? No, obviously not. But they both have equally justified beliefs that one is getting smaller than the other.
    Not justified. An object at twice the distance occupies a quarter of my visual field. They didn't take that into account if either concludes that the other is actually getting smaller.
    Similarly, an approaching clock appears to run faster but nobody who knows their physics actually concludes it is. That's just blue shift.