Letting go of Inertial Reference Frames | Sociology of Physics | N J Wildberger
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- čas přidán 27. 07. 2024
- Einstein's theory of Special Relativity has at its core the notion of an "inertial reference frame". Unfortunately this is an overblown concept which immediately distorts our understanding of our position in the world, and does not jive with the reality of our experience as galactic observers.
This is especially relevant when applied to cosmological issues involving spaceships travelling at uniform velocities with respect to each other and measurements that such inertial observers can make, and deductions they can infer about the relations between these measurements.
We need to think a bit more carefully, and be prepared to reconsider some fundamental assumptions here.
This video is part of the Sociology of Physics playlist. A big thanks to all my Patreon supporters!
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Norman, I do not dispute your viewpoint. However, a viewpoint (yours being I am "here" and everything I observe is what I see "here") is not a model upon which one can predict and then test experimentally. As to Special Relativity, it's model assumes Newton's second law of motion, which we now know is invalid over large distances due to universal expansion and acceleration. Plugging terms for universal expansion and acceleration in to solve for the transform between coordinate systems initially moving at relative velocity Vo no longer gives the Lorentz transform. Instead it gives (although I haven't bothered to work out the terms) a transform that necessarily includes the time and distance dependent increase in relative velocity between observers. So that is a function of not just time and Vo as in the Lorentz transform, but also of initial separation distance at "t=0" and additional terms depending on Vo. (Note the Hubble constant is only about 74 Km/s-Megaparsec, so any measurable deviations from the Lorentz transform for terrestrial scales should be immesurably small. But the mathematical deviation from Lorentz should introduce new physics.)
We do not actually know that the universe is expanding. There has been a lot of hand waving about the cherry picked segment of the observable radiation spectrum they call the CMBR, but pretending noise is a signal is just horrible methodology. Additionally, they did not account for the fact that much of that radiation could be coming directly from earth instead of from the cosmos. There has also been a lot of hand waving about the "cosmic red shifting of light," but they cannot prove that the universe is expanding, or that the red shift is not being caused by one of the other numerous possibilities. We are not directly observing any expansion anywhere. Galaxies are not getting larger. Stars are not continually getting fainter. They literally have nothing. Their cosmic distance ladder is broken. Both methods for measuring the size/age of the universe directly contradict each other significantly and cannot be reconciled while continually growing more divergent as better equipment is produced which provides better observations. Almost none of their theoretical predictions for the JWST observations have been correct with quite a few observations shocking and/or downright contradicting theory. They have now had to double their estimated age of the universe since galaxies were much more developed than expected. Their fundamental premises are wrong, which is why they had to provide a 1900% ad hoc correction to the universe's estimated mass via contriving dark matter and dark energy just to make general relativity match observation. It takes no genius to point out that they have completely abandoned the scientific method long ago in their paltry attempt to salvage general relativity and their egos. It is time to give up the charade. The gig is up. Einstein was so wrong you people cannot hide the fact any longer. It is time for a paradigm shift and a return to the scientific method.
You might like the paper "an order-theoretic origin of special relativity" by Knuth and Bahreyni. They assume only a partially ordered collection of events, with some distinguished chains standing for clocks. They still *technically* use a rigid frame, but it's a frame made of only 4 clocks. From this they derive coordinates and the metric. It's quite neat.
Wonderfully explained
Amen, Norman! The current crises in cosmology suggest way too many unjustified assumptions (essentially global geometric ones) are in play. We keep trying to construct a God's eye view, but the plain fact is we don't have one.
George
Professor Wildberger,
Thank you for the video. I have to say I am initially very sympathetic with your own view. This is more or less the view that I (a mathematician and philosopher with no physics training beyond highschool) had assumed modern physics was operating under for as long as I have understood relativity from a pop-science perspective. One is naturally inclined to inquire as to the role of presenters and popularizers of science in the sociology here.
From this discussion, I am somewhat reminded of Kant's attempt to reconcile the Newtonian idea of absolute space/spacetime with his phenomenology of experience. The transition to a zero-dimensional "point perspective" understanding of physics is very much in step with the Kantian movement toward Transcendental Idealism-in the sense that there is a certain agnosticism about the "true nature" of the absolute reference frame. In this sense Kant and Einstein are analogous.
I would be interested in hearing how you might respond to a Fichtean sort of interpretation of your theory in which one understands (from a formal point of view) A's 'framework' or lack thereof as grounded only by A's own existence as such in space. To put it another way, in the Einsteinian picture, there is a sense in which the existence of A's and B's reference frame is somehow grounded or given possibility by some kind of transcendental spacetime that neither have subjective access to-but is rather taken "on faith" or "by assumption" (I think this is what you are getting at when you say Einstein only goes "halfway"). The way Fichte resolved an analogous difficulty in Kant was to posit that consciousness arises through the recognition of its own limited ability to understand its objects (including itself). With reference to inertial reference frames, this corresponds to A's understanding of his role as passive with respect to its objects (data about the universe), *including his ability to reason about his own 'reference frame'* insofar as all of the information about A's reference frame is just data _in that reference frame_.
My own opinion is that to rely too heavily on the sort of transcendental Kantian/Einsteinian assumptions invites too much skepticism about our knowledge, especially in the sciences (which as you point out in an earlier video in this series, are supposed to be formulated as *hypotheses*). While initially appearing far more modest, I think you are right in that "facing the reality" amounts to both acknowledging what we may not be able to discover through investigation, while simultaneously providing the basis for an entirely new set of inquiry unrestrained by the limitations of such transcendental assumptions. I find such a view liberating in this respect.
At any rate, my apologies for going on at such length. Great video!
Cheers,
O. W.
I also find it particularly interesting to be able to distinguish the information received from the information transmitted, especially if there could be a dissemetry in relationship of the moving observer.
Very nice summary. This is a great companion series to the Wild Egg series where you explore the mathematical details, which I am also very much enjoying.
I like your guiding principle of 'modesty' of assumptions. Looking forward to the next one.
In the meantime, I'm still puzzling over how to 'reconcile' the last video's example of 'Euclidean' relativity (amounting to circular rotations in that example) with 'Einsteinian/Lorentzian/modern' relativity (with Lorentz boosts as the 'rotations').
There seems to be an underlying sameness/similarity between these two systems, which I'm guessing must be related to how 'timespace' or 'spacetime' constants are defined, much akin to how you've identified the different types of symmetric bilinear forms that naturally pop up when you delve into Chromogeometry. In this analogy, the Lorentzian relativity would be using, say, a Red form (hyperbolic), and the Euclidean relativity would be using a Blue form (spherical/elliptical). So it makes sense that the 'rotations' are hyperbolic in the one and circular/elliptical in the other.
And, having thus defined your three 'base' geometries, Red, Blue, and Green, you can combine them to generate any geometry with any quadratic/conic, by combining the different bilinear forms appropriately.
What I'm really excited to see is: How could the same thinking be used to basically define/construct your own more-or-less arbitrary (within constraints I imagine) systems of relativity? Can we isolate a Red relativity (Lorentzian, say), Blue relativity (Euclidean), and Green relativity (maybe this one takes the point of view of the 'photon'?)? And then, can we combine these kinds of relativity to generate all sorts of systems of relativity?
And, having done that, can we re-translate what we've done into some (perhaps 'fantasy') world-view where, once again, we can discuss the general example of "Bats in a 1D cave", but this time we can have a 1D Red cave (standard/modern relativity), or a 1D Blue cave (like the last video), or a 1D Green cave? What is required, in terms of the Bats and the experiments they need to conduct (bouncing 'signals' for example), and the set-up they need to have available (mirrors for the Red cave, maybe 'complex/imaginary mirrors' for the Blue cave? Or maybe there's some other way to construct the base 'clock' in the Blue case?)?
What is it like for a bat to live in a Green cave? What about a 'chromatic' cave perhaps defined as some combination of Red, Green, and Blue caves? Like maybe with coefficients [Cr, Cg, Cb]? Something like that?
It might have, rather than circular rotations, elliptical rotations. Or skewed-hyperbolic rotations. Or whatever else. How could we interpret how the bats would make sense of their 'Bats in a chromatic 1D cave' world? How could the establishment of 'clocks' work? Is there always a 'maximum speed' (probably not)? What do these different types of 'rotations' or 'boosts' mean, in terms of the bats' observations?
If there can be length-contraction in one system and length-dilation in another, then what is it like somewhere in between? Does it makes sense to think about the 'chromatic relativity' of these different typse of 1D caves, in the sense that maybe you can meta-rotate between them? For bats in a [3, 1, 2] cave, is there a kind of meta-relative transformation so that they can 'understand' in some sense what's going on for bats living in a [1, -1, 1/2] cave?
Can we 'meta-rotate' relativity systems from a Red cave (standard relativity) to a Green one? Can we humans, as mass-having beings, 'meta-rotate' our world-view to understand what life would be like for some mass-less entities, such as photons? And vice versa? [This may be venturing into general relativity. Or maybe it's something completely different. I honestly have no clue! 😅]
1:40 I have objection on starting postulate: no prove that there is more then one observer. Nobody can jump into other head to prove that other is observer too.
Well, I am an observer (but can't prove it to you). There are proofs in mathematics, that are valid, true as a matter of logical necessity, but proofs that are beyond my own ability to construct originally. So they come from (at least) one other observer. This makes it clear to me, that there are at least two observers, most likely many, as if there are only two then the one other besides myself must have come up with many orders of magnitude more proofs than would be possible at least for my kind of observer.
All this will only prove anything to you, if you are an observer and have made the same experience. Still, for absolute rigour one shouldn't be rash and not just take it for granted, that one is still dealing with real observers when (for example) a parliamentary debate suggests, that one is not in an academy but on the Planet of the Apes or in the middle of a zombie apocalypse..
@@peterjansen7929 I know I am Observer but what is prove that others are not algorithms on aether screen? I think Einstein theory fall on this, because his theory could be called: What would be if I am two Observers
@@alexandartheserb7861 1. Insight into the validity of proofs is not algorithmic. In theory, some others could be algorithmic simulations of observers. It isn't even all that rare, that one hears what looks just like observers do say something that would make them fail the Turing Test but for their outward appearance. They are seemingly made of the same material as you and I, so they don't come from the Stepford Electronics Factory, but in logic you have every right to dismiss that as incidental, as not going to the problem. But coming up with some kinds of reasoning requires insight, thus proving that output (ultimately) comes from an observer capable of such.
I am not sure what any theory by Einstein has anything to do with this, other than perhaps a flippant statement that suggests (if only facetiously) that he partly agreed with you, namely his claim that people who can find pleasure in walking behind a military marching band have only been given brains by mistake as spinal chords would suffice for them.
2. "I am" is singular, the form used where the number is 1
"two observers" is plural, with the number 2 explicitly stated
"What would be if I am two observers?" is a special case of "What would be if 1=2?" I don't think that Einstein ever made THAT claim.
Good! The simpler the assumption the better. Also, relativity means not only no absolute motion but also no absolute distance/size.
Thank you for this video!
But do we need something problematic like a 'one-dimensional space' for this? Wouldn't it be better to accept three dimensions and state, that we simply only consider one of them?
I know, that by bringing rotation into this I go outside the scope of the present video, but it has long seemed to me that in some ways Einstein is taking MORE for granted than Newton. Newton proposed the thought experiment of having a universe with one observer, one planet and a bucket of water standing on it. He proposed to establish from the shape of the surface of the water (I'd prefer using the shape of the planet itself …) whether the planet is rotating with the bucket at one of the poles, while Einstein insisted that the planet couldn't rotate for lack of having anything RELATIVE to which it could do so.
Here we have two physicists asked what would happen on such a planet. Newton takes a modest empirical point of view: "I don't know what would happen. Let's walk around on the planet with a bucket of water and find out." Einstein is the one who wants to settle this matter by dogma!
It also seems to me, that Einstein was mistaken in thinking that his modest reform was incompatible with Newton's system. In essence, his dogmatism about rotation amounts to the assertion, that the angular momentum of the universe is necessarily zero. One would only have to make its linear momentum zero, too, something Einstein would have been compelled to do, given sufficient rigour, to have ONE inertial system that is absolutely true and lots of others that are in absolute uniform motion relative to it.
Moreover, if the angular momentum can't have any value other than zero, there isn't any point worrying about what happens to it if a spinning object falls into a black hole. Saying that the angular momentum of the universe remains zero is then equivalent to considering the angular momentum of the vanished object as having been distributed 'fairly' among the remaining masses around the universe.
We assume that Maxwell's equations fit reality. Maxwell's equations are stated with a constant lightspeed. They fit reality adequately at least in a statistical sense.
We could get a general self-consistent electromagnetic theory if we assume that the velocity of light is a constant added to the velocity of the moving charge that creates it. There are claims that this does not fit observed reality.
There are claims that it does not fit the Michaelson Morley experiment. But if light keeps the same speed when reflected off a mirror, then it does.
There are claims that it does not fit the Sagnac experiment. But maybe it does, and it's very hard to explain the Sagnac results with special relativity, too.
There are claims that it does not fit various astronomical observed phenomena.
Assume that everything experiences the same time and the same space. One charge is traveling toward another at half lightspeed. starting at time zero and distance 1. Its force is moving at lightspeed. When the force arrives, their clocks will say 1 and the difference between them will be .5.
With the same space and time, suppose the receiving charge is traveling at half lightspeed. When the force arrives, the time will be 2/3 and the distance between them will be 2/3. This is a different result. Special relativity handles this by fudging time and distance.
If the light traveled 1.5 times as fast when the source is moving at .5, it would arrive at time 2/3. The moving charge would go 1/3 distance in that time, leaving 2/3.
Special relativity calculates the measured results. So it is as valid as anything else that calculates those results. Physicists can use it even if they don't find it intuitive.
A more intuitive way to get those same results would probably be useful because it might make it easier to think. Different true things might become obvious. Physics would be easier to learn. And it might encourage physicists to look for more intuitive explanations for other things.
What do you mean in 11:37 by "perhaps they [i.e. the rods] are no longer the same"? What could possibly have happened to them?
The acceleration/deceleration can be as gentle as is necessary in order to avoid any bending or other deformation. (This will make the time longer in which the final travelling speed is reached, but - given the enormous distances - not the total travelling time.) Do you imagine some atomic decay, maybe triggered by interstellar radiation, which can affect the rods? For me, the rods are pieces of atoms, say iron atoms, arranged in some regular lattice. The distance between these atoms, a.k.a. the lattice constant, is given by the laws of physics (quantum mechanics in this case) which are the same everywhere.
And if one suspects that such a rod has been affected (damaged? altered?) in this transport, one can just bring it back here for a check. Do you expect it to be different from the original copy kept here? If so, what mechanism in the journey back could undo the change caused by the first journey?
As these are mere thought experiments, I don't see any foundational obstacles to having/building up a system of rods and clocks for some given observer in Special Relativity.
Just adding my own points to consider but would, from one perspective, a unit rod in curved space appear a different size to the initial perspective.
So you bring it back to check and on the way back the rod returns to the way it was when you sent it. Then you send it out again and it changes once more. It may seem unlikely to you, but dismissing the idea is ultimately just an assumption, one that needs to be at least stated explicitly and better avoided altogether when one tries to find out facts about a universe, the 'reality' of which is actually also an assumption.
Making the assumption that this rod is the same at the end point of that journey is perfectly reasonable for me. In my opinion, that is already contained in the assumption that the laws of physics are the same everywhere, i.e. the assumption of translational invariance of spacetime (in SR). Moreover, it is not even necessary to physically transport that rod to a place a couple of light years away: it's sufficient to transmit the buildung plan and let the guys over there execute it. So that might read like "take 10^28 iron atoms (Fe56), arrange them into a lattice with sides (10^10) x (10^8) x (10^8). The longer side of that object will be one meter". (I'm sure the numbers aren't quite exact... and I know that's an old-fashioned definition of a meter.)
@@user-gd9vc3wq2h "Let the guys over there execute it." But there aren't any guys over there. One of the main points of the video, at least as I understand it, is that observers at such a distance are not available to us. If we had colonized another solar system, we would be in a (slightly) different position, but at present we only get REMOTE observations, not LOCAL observations, and it is at best speculative, at worst vacuous, to assert that there even is any other solar system "there". Strictly speaking, we don't even know whether there is any "there"!
To the extent that I can observe observers, the concept of space has such utility, that I would need a drastically better model of reality to give it up, and I find it convenient to extend it to descriptions of postulated places at unimaginable distances, but that has to be on the understanding, that it is a provisional descriptive approach that might fall down tomorrow in the face of evidence to the contrary.
@@peterjansen7929 The fear which I couldn't (and still can't) understand is why a measurement device (rod or clock) might "not be the same" after being transported - which includes acceleration and deceleration - to a remote place. This was a question of principle, not a quantitative one. So if a couple of light years is too far away for you, then think of the opposite side of a large accelerator (like CERN, i.e. a few kilometers). Many results of SR are verified or could be falsified at such distances, such as the behaviour of particles in accelerators or the decay of myons on their way through the earth's atmosphere.
The impression that SR deals with huge distances is misleading, even more as the pictures (spaceship travelling to distant galaxies...) tend to touch phenomena of cosmology and/or General Relativity, which is beyond Special Relativity.
The view of the universe in SR is rather traditional for each (unaccelerated) observer: an infinite space invariant under translations and rotations existing forever. Events exist objectively, independently of whether some observer watches them or not, and have well-defined time and space coordinates in each inertial frame (once the units have been set). The non-naive part, namely the fact that the "separation" of spacetime into space and time is not the same for observers moving w.r.t. each other, was revolutionary enough.
So the question whether "there" exists even if nobody has traveled that far is pointless.
In my impression, the large-scale image of SR stems from the fact that one imagines more easily to be on board of a fast train than to sit on some myon or proton. As many of these particles were new, speculative or simply unknown at the time when SR was developed, it was natural to choose trains for illustrating its basic mechanisms.
I would highly recommend checking out New Calculus by John Gabriel.
Wow, I did not expect an existential crisis this morning. So we should accept presentism axiomatically or because you think it's unfalsifiable? Because we already live our life like that and I thought the whole point of this endeavor is to better understand time and our place in it. For my world view to just abandon Einsteins conclusions, the whole Block Univers idea, it would be catastrophic, but I would do it, reluctantly, but I would need some good reasons. Some experimental results would be nice. Until then I'm looking forward to your further analysis. Sincerely, Adam.
You don't need any physical rods or clocks. You don't need to move anything anywhere. You're getting hung up on details that are not important at all.
What you're advocating is just a different accounting method, and if you used SR to make predictions while taking this into account, they would all work just fine.
There is still a fundamental problem with Einstein's notion of time as it relies on a two way trip for light to measure. This will always result in the round trip being the same, even if motion is causing one leg of the trip to take longer than the other leg. Let's say that an observer is flying through space at 0.5c. He has two mirrors equidistant from him in a perfect line with his direction of travel which are both traveling with him at the same exact velocity, with one being ahead of him and one being behind him. He sends a signal simultaneously in both directions. For the mirror ahead of him, the light seems to be moving towards the mirror with 0.5c on the way there and at 1.5c on the way back. For the mirror behind him, the light will travel at 1.5c on the way to the mirror and 0.5c on the way back. The light travels the same overall distance in its round trip and it travels that distance in the same amount of time regardless of which direction it is travelling, thus he concludes that the speed of light does not change. However, the speed of light did change for each leg of the trip. So if he had 3 clocks which were perfectly synchronized, one at each mirror, and one with him, and he sent a signal with a time stamp and then each clock immediately sent a signal with a time stamp when the signal was received back to him he could see the difference in the time it takes for each leg as the signal coming from behind him would be reporting an earlier time than the signal coming from ahead of him. This is not "time dilation." It is simply a result of the light taking longer due to traveling a further distance while propagating in the direction of travel of the system and less time due to traveling a shorter distance when traveling in the direction opposite of the system's direction of travel. Or, you could just make the system a loop and call it the Sagnac experiment, which already disproved general relativity a long time ago.
No, Einstein did not believe in a fixed time coordinate. Both space and time are relative.
In other words:
NORMANS ‘MY VIEW-POINT-A’ replace the Newtonian G-point (G for God/absolutely) with A . More is not possible and necessary.🔵
G-point would be exterior of our world/system meanwhile we know from quantum mechanics that the observers should be considered as parts of the system.
Generalization (waves) is dual to localization (particles) -- quantum duality.
Absolute time (Galileo, Newton) is dual to relative time (Einstein) -- time duality.
Points (singularities) are dual to lines -- the principle of duality in geometry.
Black holes (positive curvature singularities) are dual to white holes (negative curvature singularities).
Singularities (points) are dual in curved space or Riemann geometry.
Elliptic or spherical geometry is dual to hyperbolic geometry.
Bosons (waves) are dual to Fermions (particles) -- atomic duality.
"Always two there are" -- Yoda.
Universals (absolute truth) are dual to particulars (relative truth) -- Hume's fork.