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Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
First post that addresses my questions. +1 So time rescaling as it passes is equivalent to space expansion due to a scale factor at that time. But what determines how much of that change is attributed to which case? In other words, how much of a redshift measurement is due to space expansion and how much is due to time dilation? According to the FLRW metric, it is ALL due to space expansion and there is a zero, or at least a netzero, time dilation effect. Take in the extreme case where there is no space expansion at all, and all the redshift is caused by time dilation, and the recessional velocity is caused by a dilation in time rather than by an expansion of space Why is this such an absurdity? Right, but that is just an artifact of orientation of your coordinate system. A neat trick to simplify a model. If you orientate the model to where certain dimensions on a manifold do not vary and other dimension do vary, that does not mean that the dimension that does not vary cannot vary in other models. So we orientate our redshift observations to one where the temporal dimension does not vary. That does not mean it cannot vary. The FLRW metric is orientated towards no allowance for time dilution in flat spacetime  of course it is not going to vary, its orientated that way! That does not mean there is no time dilution in flat spacetime. So we go back to my original questions. Where are the other interpretations / orientations  ones where time dilution can occur in flat spacetime? Why have we all towed the line fro 100 years with the one accepted orientation where there is no time dilation in flat spacetime? But more importantly... what are the limitations and consequences of such an orientation? What might we be missing because of this orientation? 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
I have no model to develop. I'm only asking questions that we've had for over 100 years since establishing the accepted model. There's a giant elephant in the room saying "Spacetime is a single manifold". There's another giant elephant in the room saying "Space is different from time because we have conditions in flat spacetime where only space expands and time does not dilute". There is a clear contradiction here. 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
But why do we allow space to expand and not allow time to dilute in flat spacetime? 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
But if there was a cosmological, nonrelative motion sourced, time dilation effect, could the universal still be homogenous and isotropic wrt mass distribution? Ignoring a number of observations that could be argued as violations to homogeneity and also ignoring the violations of isotropy for now (https://en.wikipedia.org/wiki/Cosmological_principle), why or how does homogeneity and isotropy directly refute time dilation in flat space? What makes the premise of homogenous and isotropic mass distribution irrefutable and sacrosanct? Where is the evidence, other than ΛCDM model which is based (not solely) upon the FLRW metric and inherits the same premises? We cannot use models and equations to prove their premises, despite the models and equations matching many observations and predictions. The implications of the premise that space can expand but time does not dilate when spacetime is flat (not the premise of homogeneity) are enormous. And the only evidence we have is redshifted measurements of wavelengths that have been travelling cosmological distances and times. Why has so little scientific attention been paid towards a critical point in our progression of knowledge since 1922, such that there are NO viable alternative interpretations of what is a conflated and ambiguous observation. We have the Many Worlds and Copenhagen interpretations of observations in quantum phenomena. But we only have the space expanding interpretation of cosmological redshift and absolutely forbid any time dilation in flat space, when GR is screaming spacetime is continuum? Just seems like an enormous elephant in the room to me. 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
Yes the relationship between frequency and wavelength automatic. But wavelength is a measure of space, which we allow to expand as described by the FLRW metric, and frequency is a measure of time... which apparently cant expand (specifically in the case of cosmological redshift and not in the case of dilation). Why? Spacetime is a continuum. Why, in the case of interpreting cosmological redshift, is it not a continuum? If there are no viable alternatives, then it is the only viable interpretation. Which is rather surprising considering there is no evidence for space expansion other than cosmological redshift observations. We observe cosmological wavelengths redshifted in 1912, we theorise space can expand, we develop a model (FLRW) to match redshift observations based on that in 1922. We can use the model to match subsequent observations based on the same assumptions. But we cannot then go and claim the model and the mathematics proves space expands. In analogy: Newton observed an apple fall, he theorised gravity as a force, he developed models and maths to match his "falling" observations. We can use the model to match subsequent observations and make predictions rather accurately in most circumstances. But you cannot use Netwon's law to claim gravity is a force. Why is that? Why must there be no time dilation? What is it about cosmological redshift observations that says space expands but time does not dilute? If relative motion can dilate time, why should nonrelative motion not? Why are we applying "classical reasoning" to cosmological redshift observations? 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
I'm not even really asking to justify the FLRW metric. It is perfectly justified  given its assumptions and premised. I'm asking to justify why space expansion is the only interpretation of cosmological redshift. You've said for me to suggest a different interpretation and then explicitly repeated it. Stop derailing my thread please. 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
That's the FLRW metric. One of it's premises is that space is expanding. After that assumption it then describes the expansion. But ill say it again, we can tear apart the FLRW equations all day, you can never use it to justify its own premise. So please, stop using the FLRW to justify that space is expanding. The FLRW describes how it expands. It does NOT justify it. We have to go back to observational evidence  cosmological redshift. It is very logical why cosmological redshift is interpreted as space expansion  it makes a lot of sense. But spacetime is not commonly sensible. And having a sensible interpretation does not mean that there are no alternatives. 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
I'm not suggesting anything. I'm asking questions. All of the answers so far have missed the real crux of my questions. "There is only one metric, the spacetime metric" and yet it is called space expansion and not spacetime expansion. Why? 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
Right. So.... why is the metric of space expanding and the metric of time NOT changing, in the specific case of the widely accepted interpretation of cosmological redshift. 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
It is used in the FLRW metric, AFTER the interpretation of space expansion. Space expansion is a premise of the FLRW metric You cant use a metric to justify its premises. Once we assume cosmological redshift is the observation resulting from space expansion, the FLRW metric ensues. Before that, it is meaningless to talk about the FLRW. I'm not asking about the GR used within FLRW, I'm asking about its premise that space is expanding. Show me where GR is used in the interpretation of cosmological redshift as something other than space expansion. If the equations assume space expansion exists in order to describe it, then they wont help question space expansion only reinforce and it. Where is the evidence for space expansion other than cosmological redshift? What are alternative interpretations of cosmological redshift other than space expansion? 
Cosmological Redshift and metric expansion
AbstractDreamer replied to AbstractDreamer's topic in Astronomy and Cosmology
Show me where. It is, but show me where cosmological redshift is interpreted as a decrease in frequency then. This is how the FLRW fits observations of cosmological redshift and interpretation of it as space expansion. You can't use a parametisation to prove it's assumptions. 113 replies

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Cosmological Redshift and metric expansion
AbstractDreamer posted a topic in Astronomy and Cosmology
"In physics, a redshift is an increase in the wavelength" https://en.wikipedia.org/wiki/Redshift "One interpretation of this effect (cosmological redshift) is the idea that space itself is expanding." https://en.wikipedia.org/wiki/Redshift "In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single fourdimensional manifold" https://en.wikipedia.org/wiki/Spacetime Why do we use classical physics and not GR to interpret cosmological redshift as an increase in wavelength and not a decrease in frequency? Why do we allow the metric of space to expand, but not the metric of time, when interpreting cosmological redshift as space expansion? What are the other interpretations of cosmological redshift where something else is happening other than space expanding? 
Yes, I had dark energy or space expansion phenomenon in mind. Perhaps "mechanics" is confusing the issue. I had in mind the concept of "micro" vs "macro", or "quantum" vs "classical" as in the OP, when thinking about categories of which there are only two and not three. The introduction of the word "mechanics" open up the number of categories to any number really.

Why do we only categorise only two perspectives of reality, "micro" and "macro". Is that because of the difference between QM and GR? If we can say decoherence makes observations lose their quantum properties (not sure if we can say this), can we also say a fully coherent observable is "beyond the limit of QM"? Why is there not three (or more) mechanics? If there was a third, I would guess it would lie beyond the macro mechanics, "supermacro" rather than beneath the micro, "submicro". It would have to describe phenomena that is beyond the limits of GR, such as the local referenced limit of speed and the apparent superluminal recession speeds at very large distances. Is it possible we need a third set of mechanics to describe observable physics at the supermacro scale, but still within our observable or future observable envelope. Or is the scale of all observations complete with just two mechanics?

Some questions on Blackholes
AbstractDreamer replied to AbstractDreamer's topic in Modern and Theoretical Physics
What kind of oscillation do you mean? Do you mean a physical oscillation, that is, this EH boundary's location/position in space wobbles with some frequency? Or do you mean oscillation in the values of a BH's properties, such as mass, angular momentum and charge? If the position of the EH can "wobble", is it possible the wavelength of this is large enough to allow energy to escape? For example if you were a photon just within the EH, but moving with 99.99999% of your speed directly away from the point of singularity, such that your geodesic is almost parallel with the EH boundary (you are still falling in just very very slowly). If the boundary then wobbles sufficiently, is it possible to wobble "behind" you and momentarily wobble you outside the EH? While it is likely you will wobble back within the EH on the next phase, is it possible to permanently leave the EH in this way? 
"... the photons instead increase in wavelength and redshift because of a global feature of the spacetime through which they are traveling. One interpretation of this effect is the idea that space itself is expanding." https://en.wikipedia.org/wiki/Redshift Wiki even states that space expansion is only ONE interpretation. I am guilty of entertaining another interpretation. Yet despite all your responses you have repeated failed to address the important points; either due to a failure to understand my point, or you are blinded by a desire to be right and steadfast refusal to be helpful.

I wouldn't ask if I knew the answer. That's the nature of asking questions. You answer as if you aren't reading the question, despite it being asked multiple times. Hubble's law = recessional velocity = Hubble's constant = proper distance Where is the effect of curvature on recessional velocity? In this equation that shows the direct relationship between recessional velocity (cosmological redshift interpreted as spatial expansion) and distance, where does gravity come into the picture? I've been very consistent. There is nothing I can do about other people choosing to be inconsistent with understanding what I'm saying. It's about whether or not cosmological redshift can have an interpretation that includes a temporal contraction/expansion. It's NOT about if I believe that it does or does not. What I believe is irrelevant. Science is not about faith. I never asked about negating expansion. You answered that gravity negates expansion. Your answer was in response to my supposition that gravity affects space expansion... which was simply a juxtaposition of your previous question about gravity affecting time, which to me seemed to carry an implicit meaning that gravity DID indeed affect space expansion, which I didn't know then and latter asked about. You are looking at the FLRW metric model and the evolution of the Universe as a whole; a model that assumes a spatial expansion interpretation of comoslogical redshift and a flat time metric, to explain why gravity negates spatial expansion and not the time metric, and describe how the universe evolved. You're using a theory to justify its assumptions. That is a logical fallacy. Not only that, I'm asking specifically about cosmological redshift interpretation, not gravitational or relativistic redshift. The point was about testability or nontestability. Are you conceding that your argument that my proposal is untestable is moot at this stage? In response to my lack of maths, I'm not denying that. I don't think it is a reason to dismiss the idea entirely at such an early conceptual stage. In response to a theoretical basis, your arguments thus far have largely missed the mark. I'm questioning the completeness of a spatial expansion interpretation of cosmological redshift. Your arguments supporting spatial expansion are all premised on that interpretation. You cant use a theory to justify its premises.

Entanglement decoherence vs waveform collapse
AbstractDreamer replied to AbstractDreamer's topic in Quantum Theory
OK yes, the slits themselves do not have to be entangled. I guess you cant actually entangle a hole. But perhaps you can have two microscopic holes that are blocked by an entangled pair of particles. For the sake of clarity, lets just call it an entangled slit. But this raises another question. What happens if the two slits are not exactly perpendicular to the wave? So when the wave reaches one slit first, it would instantaneously close the other before the wave reaches the second slit, thus showing no interference on the detector, as the 2nd slot is closed by the time the wave arrives. Is this a matter of precision? Could we position the two slits accurately enough to ensure the wave passes both slits simultaneously? So accurate as to match the instantaneous decoherence of the entangled slots? Lets say the wave managed to reach both slits instantaneously. Would the wave managed to pass through both slits before either of the closed and we see interference, or will the slits close before the wave gets through and we see no interference. Does the wave function of a quantum system preserve quantum entanglement in another system it encounters. 
Space expansion is not modelled in Newtonian physics. In Relativistic physics, gravity is a curvature of spacetime 4d manifold, and space expansion is a stretching of only the 3d space metric. How does curvature affect spatial expansion? How exactly is it an even weaker claim, even if I acknowledge that expansion happens? And No. I don't acknowledge that expansion must happens. I acknowledge cosmological redshift is measured. I acknowledge spatial expansion it is a viable interpretation of redshift. It is apparent you are the one that adamantly believes it expansion happens, and perhaps evidentially so. But you need to separate your beliefs, from mine. Space expansion is a proposal  an interpretation  based on cosmological redshift not relativistic or gravitational redshift. Your answer, that gravity is an attractive force under Newtonian physics is nonsense when talking about cosmological redshift. There's no effect of gravity in cosmological redshift. Hubble's Law describes cosmological redshift is related to proper distance and time (Hubble parameter), and NO gravity factors. The FLRW metric describes space expansion is due to proper distance and time, and again NO gravity factors Time metric contraction is related to distance not gravity (me). No. Ill say it again as pedantically as possible, might just work eventually. IF we interpret the cosmological redshift effect as spatial expansion and zero temporal expansion, then the cosmological redshift effect is all due to spatial expansion, according to Hubble Law and FLRW metric. In this case the redshift represents only spatial expansion, and as such it is a measurement of spatial expansion. IF we interpret the cosmological redshift effect as partial spatial AND partial temporal expansion, then the cosmological redshift effect is NOT all due to spatial expansion. In this case cosmological redshift represents more than just spatial expansion, and as such its measurement cannot wholly be attributed to spatial expansion. Like I said before. We can argue whether or not its testable later. We don't know if its untestable right now. Lack of testability hasn't stopped ideas in String Theory.

I'm sure this has been asked multiple times, but I couldn't easily find a answer. So in the double slit experiment, with steady source of emission through two slits, we see an interference pattern on the other side that suggests the emission is wave like as it passes the slits. The emission appears to acknowledge and pass through BOTH slits, while its waveform remains uncollapsed. What happens if the two slits are entangled such that when one slit is open the other is instantaneously closed, for each emission. Would the entanglement of the slits cause the waveform of the emission to collapse, or would the waveform cause the slits to decohere? How would a partial decoherence of the slits affect the probability distribution of where the particle might end up being detected?

How exactly does gravity negate expansion, knowing that expansion is a change in the metric and gravity is not? No. My claim is that redshift could be due to BOTH a spatial AND temporal adjustment. If there was no spatial adjustment, then yes, perhaps you can deduce the redshift is entirely due to a temporal change, and to this end, it might be measurable. But I'm not claiming exactly how much of the redshift is due to spatial or temporal expansion. My claim is that some of the redshift could be due to change in the temporal metric, and why is that not a possibility. My claim is also that a change in the metric of time could be measured, if there is a way to "untrap" a frame of reference from the same moment of time as the observation, or vice versa. Which AFAIK is not possible, but I dont know what might be possible in the future. I'm not claiming there is no change in scale. We find solutions where redshift can be explained via not just a spatial expansion, but a spatial AND temporal expansion. The term timemetriccontraction might be imprecise. I simply used the word "contraction" to conceptualise a rotation that is symmetrical to expansion.

Ok I accept that apparent super luminal recession is a prediction of GR given the FLRW solution, and not a violation of GR under that interpretation. And that solution allows the metric of space to expand at any speed. The cosmological constant was supposed to provide a static solution to the field equations. Redshift was then discovered in spiral nebulae. Lemaitre proposed a spatially expanding universe, deriving the Friedman equations with a parameter for the scale factor of expansion, and calculating Hubble's law. Hubble then provided experimental observation evidence to support Hubble's law describing a relationship between the redshift measurements and distance from Earth. Why have we not proposed a spatially and temporally expanding universe to explain redshift? I dont see why it's unreasonable. You cant use the FLRW solution to explain why the universe expands only spatially, because the FLRW solution IS the interpretation of a universe that expands only spatially. If you question the premise of a universe that expands only spatially, you cant use FLRW solution to falsify that question. No, because it's an affect on the metric of time is not measureable (AFAIK). On the other hand, we have the observation that gravity affects space expansion. Under what mechanism? Magic? Space expansion is a stretching of the metric. Gravity, AFAIK, affects the curvature and coordinate values of spacetime, but does not stretch the metric. Hence why gravity is bounded by causality and the speed of light, and space expansion is not. Lemaitre's theoretical basis for space metric expansion was redshift measurements My theoretical basis for time metric contraction is redshift measurements. Sure he managed to derive actual solutions.

Then neither is a change in the time metric. Then String Theory is not scientific, but it still being explored. Then gravity is also the mechanism why there is no observed change in the time metric where gravity is significant, as I have repeatedly explained through inheritance. Then a falsification will suffice.

In the same way that space expansion is explicitly dependent on distance, so too could the proposed timemetriccontraction equivalent  that is, dependent on distance not time. There is no requirement that the dependency needs to be swapped. In addition, is it not true that distance is explicitly intertwined with time? The coordinate system for GR describes a spacetime value, not just a space value or a time value. Anything that is far away in distance is ALSO far ago in time. Something that is 10 lightyears away in distance is also a year away in time. Something that is 20 lightyears away in distance is also twice the time away than something 10 lightyears away in distance. Something that is 1 year ago has some value of distance away based on its motion and potential and background curvature. Anything explicitly dependent on distance is also explicitly dependent on time, and vice versa. So if space expansion is explicitly dependent on distance, is it not also possibly explicitly dependent on time under a specific coordinate rotation? The concern for testability is not a reason to dismiss an idea before consideration, at least not before even a model is framed. Once we have a model, you can argue it cant be tested. Before that, we should be allowed to create a model. Unless you already have all the answers. Please elaborate what this mechanism is. Is there any definitive proof why it must only stretch the spatial axes but the temporal axis must remain constant?

I am using a principle of inheritance to say that without a model. If you can demonstrate that you can drink a glass that is half full in one gulp, then the same glass that is half empty can also be drunk in one gulp without necessarily needing to demonstrate it  because the latter inherits all the properties of the former. If a space expansion explanation of cosmological redshift does not affect the fine structure constant, then neither would a timemetric contraction explanation nor even a massless invisible gorilla explanation affect the fine structure constant. I beg for precision. We know the speed of light is invariant with a constant metric of time. We know the speed of light is invariant using any frame of reference at the same moment as the measurement of that speed. These premises are fundamental and intrinsic to the physics of GR. You cant use a theory to prove its own premises! In the same way we cant explain why there is no (or insignificant) space expansion in volumes of curvature. It's just an observable the redshift only occurs in "flatter" volumes. Anything you can say about why space expansion is observed the way it is can be similarly attributed to any alternative explanation of redshift. I have wildly speculated previously, the measuring of wavelengths are "trapped" in time with the waves themselves. We literally cannot measure something yesterday or tomorrow. We can measure something that was emitted yesterday and travelled a lightday through space to reach us. But we can only measure it "right now". If we did measure it yesterday, it was measured "right then" and not "right now". We cannot measure something "right now" as it was or will be at any other time than "right now". The "fixing" of this time moment requires that the observer and the object be in the same moment. But I propose that redshift is due to the continuum being stretched  not just the space part. It looks like the only the space part (wavelength stretching redshift) is changing because our observations are fixed in time with our objects. What exactly does a constant metric of time account for that a nonconstant metric of time doesnt? AFAIK, GR doesn't even model the metric of time. It just assumes that time over time is constant. It is a fundamental premise of its theory, despite not explicitly stating it. The consequence of this assumption is that it effectively "normalises" the theory to a state where it works where time over time is constant  which of course suitably matches all observations because all observers are trapped in time with their observees. Would a more fundamental model be one that includes a metric of time, albeit one that only matches observations when a solution to the metric of time for the observer is the same as that being observed. Such a model could then interpret redshift as potentially also a stretching of the temporal axes, and not just the spatial axes. While I agree it wont necessarily help with observations and won't be easy to test, its just an interpretation, like the Copenhagen vs Many Worlds interpretation of QM. I'm saying that GR absolutely accounts for the universe we measure, because all measurements are trapped in time with whatever they are measuring and therefore it does not need to model a metric of time. The universe we experience is one that measureably has a constant metric of time. Should it (GR) account for something different than what we observe (measure)? Possibly, but that would be an endresult or a consequence that follows perhaps, rather than the reason to believe so. The reasoning is that GR models spacetime as a single manifold with four dimensions, and with the discovery of redshift measurements, we accommodate this discovery by declaring that the spatial metrics are variable and the temporal metric is constant  for (to me) no apparent evidence, knowing that those redshift measurements by necessity have the same time metric value as the EM waves being measured, which would allude to a constant metric time but not eliminate one that is nonconstant. Why should our measurements (of redshift) necessarily be accounted for only by expansion of space because the limitations in GR on the speed of light and the implicit invariant metric of time. That is, the redshift shows that the receeding exceeds the speed of light, which violates GR, so there must be another mechanism at play; and implicitly, this moment of measurement of redshift is trapped in time with the EM waves themselves, which is a premise of GR. I previously asked the question is there anything that exists that is observable but not (directly) measurable. Perhaps it is possible the universe is more than just what can be measured? Or should we straight up dismiss it because it might not ever pass scientific methodology  "If it cant be seen today, it won't ever be seen in future and so its not there?" That's some fallacious reasoning there. We cant see the extra dimensions of string theory, let alone test them, yet I don't see us outright dismissing string theory. Why should we dismiss a metric of time idea before we even have a mathematical model and before we know whether or not we can falsify it? Surely that is more unscientific than a wild speculation with even just the slightest of reasoning.