Post by: McQueen on 17/03/2024 03:58:55
Post by: Origin on 17/03/2024 12:08:46
Yet, if one tries to find the exact process by which light propagates from Point A To B, there is very little information.There is a wealth of information on the process of light propagation. Essentially light is a wave that is an oscillating electric and magnetic field and the speed of the wave is dictated by the permittivity and permeability of free space.
Post by: McQueen on 17/03/2024 16:02:44
″Light as it travels from Point A to Point B, ceases to be ″real″ instead it travels as an abstract mathematical wave form, that undergoes disambiguation, (i.e., it exists everywhere and nowhere). During the time in which light is travelling from Point A to Point B, it travels through multiple dimensions, that have no existence, in our world, the solar system or the Universe. When the light is finally detected at point B, it once again becomes real this is accompanied by the collapse of the abstract wave function. The collapse of the wave function results in the formation of multiple Universes.″
It should be noted that this is not something that I have made up, it is an accurate description of how Standard Theory describes the propagation of light. In point of fact, it gets worse than this. Perhaps a poll could be conducted to see if any of this makes sense?
Post by: Petrochemicals on 17/03/2024 17:41:34
″Light as it travels from Point A to Point B, ceases to be ″real″ instead it travels as an abstract mathematical wave form, that undergoes disambiguation, (i.e., it exists everywhere and nowhere). During the time in which light is travelling from Point A to Point B, it travels through multiple dimensions, that have no existence, in our world, the solar system or the Universe. When the light is finally detected at point B, it once again becomes real this is accompanied by the collapse of the abstract wave function. The collapse of the wave function results in the formation of multiple Universes.″It could travel as a wave until it is interupted by matter forcing a particle.
Post by: Eternal Student on 17/03/2024 18:28:36
Perhaps a poll could be conducted to see if any of this makes sense?You can make a poll BUT you need to start a new thread. Choose a forum section and then instead of hitting "new topic", hit "new poll" which is right next to it.
It should be noted that this is not something that I have made up,Although you also stated:
If a layman were to look at what quantum mechanics eventually came up with, this is probably how he would describe it.
However, it doesn't matter too much. If you want a poll, you can have a poll.
Best Wishes.
Post by: McQueen on 17/03/2024 19:21:48
It could travel as a wave until it is interupted by matter forcing a particle.Thankyou Petrochemicals, it could have happened, light could have started off as a wave and been obstructed by a particle and changed, it could have happened in many ways, let us discuss what did happen. Quantum mechanics as the emergent leader in the discipline of physics, needed to find a way of expressing electromagnetic radiation in terms of Max Planck?s discovery of quanta; namely that EMR was made up of infinitesimal, discrete packets of energy. Instead of trying to find a new expression for EMR, quantum mechanics decided to adopt Maxwell?s equations whole sale and to impose upon his theory, a quantum interpretation. Converting Maxwell's equations to a form suitable for quantum mechanics involves a series of processes beginning with First quantization, followed by second quantisation, followed by normalisation and re-normalisation. What do all these processes mean and what is the end result? Here's a brief overview.
First Quantisation: refers to the standard approach of quantizing individual particles, in this case photons. In this framework, particles are described by wavefunctions that evolve according to the Schr?dinger equation. First quantization deals with the wave-particle duality and the behaviour of individual quantum systems. (note) Schrodinger?s wave equation works well for single particle situations, however with each additional particle that is needed, three additional dimensions are required. This is a well-documented fact, freely admitted by both Max Born and Heisenberg. Though recent proponents argue that it is not dimensions that are involved it is multiple degrees of freedoms. This is an evasion rather than an attempt to address the problem. Even a cursory examination of the philosophical implications reveal that it is dimensions that are involved (i.e., actual spatial dimension) and not degrees of freedom.
Second Quantisation: is a different approach used in quantum field theory (QFT) to quantize fields rather than individual particles. Instead of describing particles as discrete entities, second quantization treats particles as excitations of quantum fields that permeate space. This framework allows for the creation and annihilation of particles and provides a more natural description for many-particle systems present in EMR. Quantization of the Electromagnetic Field, involves imposing commutation relations on the creation and annihilation operators to ensure that the resulting quantum field theory is consistent with the principles of quantum mechanics.
In second quantization, the electric and magnetic fields are represented by creation and annihilation operators. These operators create or destroy particles (quanta) associated with the electromagnetic field. During second quantisation the electromagnetic field is expanded in terms of its Fourier modes, which describe the field in terms of different wavelengths and momenta. (note) Each creation and annihilation process involves 1024 MeV approx., since there are an almost infinite number of photons all; undergoing these processes at the same time, it is a staggering amount of energy.
Normalisation: Could be described as a house-cleaning process, used in quantum mechanics to ensure that wavefunctions (or states) are properly normalized. Normalization ensures that the integral of the square of the wavefunction over all space (or some appropriate region) equals 1. This condition guarantees that the probability of finding a particle in any allowed region of space is unity. Normalization is achieved by dividing the wavefunction by a normalization constant, which is determined by integrating the square of the wavefunction and then taking the square root of the result.
Re-normalisation: is a technique used in quantum field theory to handle infinities that arise in certain calculations. In quantum field theory, interactions between particles can lead to divergent quantities, such as infinite values for certain physical quantities. Renormalization involves redefining these quantities in terms of experimentally measurable quantities, effectively absorbing the infinities into the parameters of the theory. Renormalization ensures that physical predictions from the theory remain finite and meaningful. It's a crucial aspect of quantum field theory, particularly in dealing with theories like QED where infinities arise in perturbative calculations.
I wonder if it would be possible to calculate the parameters of a single cell phone call using such a system BUT beauty is in the eye of the beholder.
You can make a poll BUT you need to start a new thread. Choose a forum section and then instead of hitting "new topic", hit "new poll" which is right next to it.
My apologies for such a long post. To rationalize the situation to some extent, I wanted to hold a poll to see what members think about this theory, but eternal student tells me that the poll will be independent of the post, so I don?t know if it will have any value.
Post by: Origin on 17/03/2024 22:39:36
″Light as it travels from Point A to Point B, ceases to be ″real″ instead it travels as an abstract mathematical wave form, that undergoes disambiguation, (i.e., it exists everywhere and nowhere).The first problem I see is that no one, that I am aware of, thinks that light is no longer real when light travels from point A to point B. I think you are mistaking the mathematics that describe light with the actual photons themselves. The light does not travel as an abstract mathematical wave form, the wave form is a mathematical description about aspects of a photon.
Post by: Origin on 17/03/2024 22:45:52
it gets worse than this.Your inability to understand a theory does not make the theory wrong. You do realize how incredibly successful quantum theory is, don't you? Do you find it odd that this 'absurd' theory makes only the correct predictions?
Post by: McQueen on 18/03/2024 02:51:16
The first problem I see is that no one, that I am aware of, thinks that light is no longer real when light travels from point A to point B. I think you are mistaking the mathematics that describe light with the actual photons themselves. The light does not travel as an abstract mathematical wave form, the wave form is a mathematical description about aspects of a photon.
Thank you Origin, I seem to have underestimated the complexity of the issue. So, it is probably better to let things lie. However, I would just like to point to this quote by Max Born, the father of quantum mechanics:
″We have two possibilities. Either we use waves in space of more than three dimensions,..or we remain in three dimensional space, but give up the simple picture of the wave amplitude as an ordinary physical magnitude , and replace it with a purely mathematical concept into which we cannot enter.? Yet one has to wonder how something that can be ethically unacceptable in the ′real′ world can be perfectly justifiable in the abstract ′mathematical′ world. . " Max Born
That having been said, I have no other option than to abandon, this post and the views quoted in it by myself, since it seems to be a vast subject into which it would be difficult to come to any conclusion.
Post by: alancalverd on 18/03/2024 08:52:27
If a layman were to look at what quantum mechanics eventually came up with, this is probably how he would describe it....which is why laymen and chatbots are not useful starting points for understanding physics.
Physics is the business of constructing mathematical models of stuff that happens. We have two models that are useful when dealing with high frequency electromagnetic radiation: a wave model describes propagation, and a particle model becomes increasingly useful when describing the interaction of emr with particulate matter above 1012 Hz.
Post by: Zer0 on 18/03/2024 17:57:28
& Thanks for dropping that " Poll " idea.
ps -
" Fools are in the Majority, and they never lack confidence because a fool Believes that being in the Majority is Proof that one is Right. "
(Rozoff)
Post by: McQueen on 19/03/2024 03:39:46
Physics is the business of constructing mathematical models of stuff that happens. We have two models that are useful when dealing with high frequency electromagnetic radiation: a wave model describes propagation, and a particle model becomes increasingly useful when describing the interaction of emr with particulate matter above 1012 Hz.There shouldn't be two models.
Post by: hamdani yusuf on 19/03/2024 11:47:53
Thank you, Origin, you have given a concise and accurate description of Maxwell′s ″A Dynamical Theory of the Electromagnetic Field″ and of how electromagnetic radiation propagates. This is where the problem begins, Because, Maxwell's theory is a purely wave theory while quantum mechanics wanted a particle theory or at least a wave-particle duality theory. If a layman were to look at what quantum mechanics eventually came up with, this is probably how he would describe it.The experiments below show that light doesn't cease to be ″real″ during the propagation, even in the case of double slit experiment.
″Light as it travels from Point A to Point B, ceases to be ″real″ instead it travels as an abstract mathematical wave form, that undergoes disambiguation, (i.e., it exists everywhere and nowhere). During the time in which light is travelling from Point A to Point B, it travels through multiple dimensions, that have no existence, in our world, the solar system or the Universe. When the light is finally detected at point B, it once again becomes real this is accompanied by the collapse of the abstract wave function. The collapse of the wave function results in the formation of multiple Universes.″
It should be noted that this is not something that I have made up, it is an accurate description of how Standard Theory describes the propagation of light. In point of fact, it gets worse than this. Perhaps a poll could be conducted to see if any of this makes sense?
The Real Double Slit Experiment.
Quote
This video was edited 30-12-2022. I removed everything but the experimental parts of the original video. The reason for this is that I was no longer behind the way I explained the experiments, especially the quantum aspects.
In the video I show you how you can use a microscope to visualize the EM- wave propagation after light has passed the slits.
Post by: Origin on 19/03/2024 12:07:14
There shouldn't be two models.Interesting opinion, I guess.
Just to let you know, hamdani is probably the most confused person on this site.
Post by: hamdani yusuf on 19/03/2024 16:08:15
That's an interesting opinion on its own right. Did you find inconsistencies in my arguments?There shouldn't be two models.Interesting opinion, I guess.
Just to let you know, hamdani is probably the most confused person on this site.
Post by: Origin on 19/03/2024 18:32:40
That's an interesting opinion on its own right. Did you find inconsistencies in my arguments?I wasn't responding to you, but I didn't see an argument just a video.
Post by: Origin on 19/03/2024 18:36:40
There shouldn't be two models.Do you realize that 2 different gravity models are taught in all universities?
Post by: alancalverd on 19/03/2024 22:08:13
There shouldn't be two models.Like we shouldn't have boats and cars. But we do, because amphibious vehicles aren't terribly good at doing either job.
Post by: hamdani yusuf on 20/03/2024 02:06:05
We also have submarines, jetski, trains, bus, bicycles, roller blades, aeroplanes, and helicopter. Seeing this way, 2 looks like a small number.There shouldn't be two models.Like we shouldn't have boats and cars. But we do, because amphibious vehicles aren't terribly good at doing either job.
Post by: McQueen on 20/03/2024 04:03:59
Do you realize that 2 different gravity models are taught in all universities?I do realise that there are two models of everything in physics, now-days. Two models of gravity, two models of electromagnetic propagation, two models of radio-waves etc., One model is used for performing calculations and the other for philosophical speculation. All I said was why two models?
Post by: McQueen on 20/03/2024 04:10:21
We also have submarines, jetski, trains, bus, bicycles, roller blades, aeroplanes, and helicopter. Seeing this way, 2 looks like a small number.
I shouldn't really be responding to this post but can't help it. Surely, all of these things you mention such as submarines, jet skis, trains, buses, bicycles, roller blades, aeroplanes and helicopters are based on empirical science. It has long been my contention that if you don't want to depend on empirical science, call it a new discipline call it metaphysical physics. In that way philosophical speculation can get as zany as one likes in order to suit everyone′s taste, and yet the distinction would exist that the one is hands on and the other can be whatever you want provided it doesn't have practical applications.
Post by: paul cotter on 20/03/2024 09:21:17
Post by: McQueen on 20/03/2024 13:47:02
Both the wave and photon models have vast areas of direct application. If you can produce a better theory there are multiple Nobel prizes waiting.
Thank you for your post. I agree not only do both models have vast areas of direct application. At present I am working on a mathematical theory to account for the missing mass in the Milky Way Galaxy.
Post by: Zer0 on 20/03/2024 17:19:48
You are Cordial & Polite.
A Rarity on Science fora.
(very good)
Nowadays, it's mostly seen as a Boxing ring, & laymen used as Punching bags.
Anyways, back to the Topic...
Missing mass!
You not satisfied with the Dark Matter Hypothesis?
Post by: hamdani yusuf on 20/03/2024 21:34:46
Post by: Origin on 20/03/2024 23:26:18
A unification between wave model and particle model of lightIt has already happened, it is called Quantum physics.
either modifying the wave to incorporate explanation for phenomena currently explained using particle model, or modifying the particle to incorporate explanation for phenomena currently explained using wave model.It didn't work out that way. In quantum physics it is known that a photon (like an electron or any other quantum object) is not a particle and it is not a wave, it is something completely different it is a quantum object.
Post by: McQueen on 21/03/2024 02:02:19
@McQueen
You are Cordial & Polite.
A Rarity on Science fora.
(very good)
Nowadays, it's mostly seen as a Boxing ring, & laymen used as Punching bags.
Anyways, back to the Topic...
Missing mass!
You not satisfied with the Dark Matter Hypothesis?
Sincere thanks Zero, your comment is greatly appreciated. I do believe in the Dark Matter hypotheses, especially so after looking into how the measurements are calculated: https://www.astronomynotes.com/ismnotes/s7.htm I have hypothecated a substance that Dark Matter might be made of and tried to calculate if it would fit the missing mass, using data from the net such as the volume of the Milky Way Galaxy, its mass etc., and got surprisingly good answers.
Post by: hamdani yusuf on 21/03/2024 04:11:09
How do you explain refraction and diffraction using quantum physics?A unification between wave model and particle model of lightIt has already happened, it is called Quantum physics.either modifying the wave to incorporate explanation for phenomena currently explained using particle model, or modifying the particle to incorporate explanation for phenomena currently explained using wave model.It didn't work out that way. In quantum physics it is known that a photon (like an electron or any other quantum object) is not a particle and it is not a wave, it is something completely different it is a quantum object.
Post by: Origin on 21/03/2024 12:28:07
I have hypothecated a substance that Dark Matter might be made of and tried to calculate if it would fit the missing mass, using data from the net such as the volume of the Milky Way Galaxy, its mass etc., and got surprisingly good answersInteresting. What is the substance? Could you show the calculations?
Post by: Origin on 21/03/2024 13:02:05
How do you explain refraction and diffraction using quantum physics?I'm sure I have discussed it before on one of your threads. I am not interested in giving you an explanation and then having you spam the thread with 3 or 4 random Youtube videos and proclaiming no one knows anything!!
Post by: alancalverd on 21/03/2024 13:34:46
I do realise that there are two models of everything in physics, now-days. ................................., One model is used for performing calculations and the other for philosophical speculation.
Philosophical speculation is not physics.
Post by: alancalverd on 21/03/2024 13:35:55
How do you explain refraction and diffraction using quantum physics?Only a fool would try.
Post by: hamdani yusuf on 24/03/2024 14:00:48
Is it impossible?How do you explain refraction and diffraction using quantum physics?Only a fool would try.
Post by: alancalverd on 25/03/2024 15:51:30
Post by: hamdani yusuf on 27/03/2024 11:02:29
Post by: alancalverd on 27/03/2024 18:13:43
Post by: Zer0 on 27/03/2024 18:27:48
Please do Allow a few randomly absurd thoughts...
Can " Space " bend over itself?
Could the ' Higgs field ' twist, tangle, entangle in on itself?
Can ' Relativistic mass ' not produce a similar, but not the same, effect such as Gravity?
Post by: McQueen on 28/03/2024 05:53:25
@McQueen
Please do Allow a few randomly absurd thoughts...
Can " Space " bend over itself?
Could the ' Higgs field ' twist, tangle, entangle in on itself?
Can ' Relativistic mass ' not produce a similar, but not the same, effect such as Gravity?
Wonderful thoughts, and as such scope for discussion certainly does exist. Unfortunately, if an argument lacks structure, it turns out to be an exercise in futility, like hypothesising on how many sugars the mad hatter had in his tea.
Take for instance, the detection of ′gravity′ waves by LIGO. Ligo is a two billion dollar plus experiment that is being replicated all over the world, from Italy to India and China. The sensitivity of LIGO has to be something on the order of one ten thousandth the width of a proton or 10^-20 m approx. in order to detect gravity waves. Taking as a very approximate value the fact that the force generated by a man weighing 100 Kg taking a single step in a place 1000 km distant from ligo, would generate a signal of 981 N / (10^6)^2 = 10^-10 N. Or a signal that is 10^10 times greater than the signal needed to detect gravitational waves, one realises has staggering implications.
This raises several problems. How is it possible to distinguish between the myriad (vast understatement) of different types of signal? The only possible answer that makes any sense at all is that Hal must do it, or to put it in other words. The calculations are all done by computer. But how accurate are these computer calculations, when does the computer decide that a signal isolated from the trillions and trillions of different signals, is the one signal denoting gravity? Surely the very noise generated inside the circuits of LIGo should swamp any credible signal? A very dodgy situation. If similar criteria are used to determine the higgs boson and other hard to detect particles, where does this leave science. Even what should be experiments that yield empirical results are more or less hypothetical.
Post by: hamdani yusuf on 28/03/2024 10:27:59
Except it doesn't explain the interaction of light with materials. Photography, photoelectricity.....all require a particle model,Not necessarily. A modified wave model can do the same job.
Quote
and at very low intensities you can even count the photons!You don't really count the photons. Only some activations of sensory equipment, which can also be activated by other stimulants, such as temperature and cosmic rays.
Post by: McQueen on 31/03/2024 05:44:44
The first problem I see is that no one, that I am aware of, thinks that light is no longer real when light travels from point A to point B. I think you are mistaking the mathematics that describe light with the actual photons themselves. The light does not travel as an abstract mathematical wave form, the wave form is a mathematical description about aspects of a photon.
Well, I knew that there was some kind of documentation on the hard interpretation of quantum mechanics made at the 5th Solvay Conference held in 1927 where a decision was made that light travelling from A to B did not exist as something real but as an abstract wave-function: https://www.youtube.com/watch?v=068rdc75mHM&t=768s (https://www.youtube.com/watch?v=068rdc75mHM&t=768s) from 12.18 on.
Post by: Kryptid on 31/03/2024 14:25:41
The calculations are all done by computer. But how accurate are these computer calculations, when does the computer decide that a signal isolated from the trillions and trillions of different signals, is the one signal denoting gravity? Surely the very noise generated inside the circuits of LIGo should swamp any credible signal? A very dodgy situation.
It isn't dodgy at all. The gravitational waves produced by a black hole merger event is predicted by general relativity to have a very distinct pattern to it. I have a book written long before the first gravitational wave detection that details this pattern. The fact that LIGO has two arms at right angles to each other is critical in detecting it because gravitational waves produce a contraction of space along one axis while producing a stretching along the other axis. As the wave passes, this stretching and contraction reverses and then cycles again and again.
As two black holes approach each other in orbit, the strength of this signal slowly increases until the merger event, after which there is a "ring down" period where the newly-formed, merged black hole releases additional gravitational radiation before it settles. The signal then disappears. This known pattern combined with the fact that LIGO and VIRGO are in widely-separated parts of the world can be used to rule out false positives due to local noise.
Post by: McQueen on 01/04/2024 03:09:32
It isn't dodgy at all. The gravitational waves produced by a black hole merger event is predicted by general relativity to have a very distinct pattern to it. I have a book written long before the first gravitational wave detection that details this pattern. The fact that LIGO has two arms at right angles to each other is critical in detecting it because gravitational waves produce a contraction of space along one axis while producing a stretching along the other axis. As the wave passes, this stretching and contraction reverses and then cycles again and again.
While what I have to say may not go down well with certain people, objectivity is one of the most desirable traits in the evaluation of any scientific method. Take quantum computers. For one thing the present generation of quantum computers cannot truly be called quantum computers. Quantum computers are computers based on quantum entanglement of sub-atomic particles. The present generation of quantum computers detect changes in the current of Josephson-Junctions of super conductors and use these signals to serve as quantum qubits, this is more or less a digital process and can by no means be equated with quantum entanglement. Therefore, what may eventually emerge from such a development are better computers but they could not by any criteria be termed to be quantum computers. Google, one of the leading proponents in the field, are offering rewards of upwards of 5 million dollars for anyone who can come up with a practical use for quantum computers. Considering, that Google is one of the most innovative companies in the world, and the fact that research has been going on for at least a decade with unlimited funding, this does not look like a good sign. One useful function that quantum computers should be able to perform, is that of quantum encryption. Surely quantum encryption is such a massive field that there would be no need to advertise for further uses of quantum computers? The fact that no encryption encoding is forthcoming from quantum computers is in itself an indication of the present day wildly speculative nature of science. Huge sums are spent on proving things that cannot be proven.
I would say that in spite of the many reasons that you put forward to justify LIGO that it is a far cry from a certainty. To detect differences of 10,000th the width of a proton in the presence of so much signal noise, is a bit of a stretch. Mere wishful thinking rather than sound (pardon the pun) science.
Post by: alancalverd on 01/04/2024 13:01:22
Please explain photographic reciprocity failure and radiographic quantum mottle using a modified wave model.Except it doesn't explain the interaction of light with materials. Photography, photoelectricity.....all require a particle model,Not necessarily. A modified wave model can do the same job.
Quote
Cosmic rays behave very much like particles in a cloud chamber or a film block, and indeed can be counted individually as particle interactions in electronic detectors. Which is why we call the massless, electrically neutral ones "photons". The effect of temperature on a photocathode will not change when you put a piece of cardboard between your photon source and the detector.Quoteand at very low intensities you can even count the photons!You don't really count the photons. Only some activations of sensory equipment, which can also be activated by other stimulants, such as temperature and cosmic rays.
One common use of photon counting is in x-ray crystallography where we count individual diffracted photons at different points in space them use a wave model to determine the structure of the material that scattered them.
Post by: Kryptid on 01/04/2024 16:34:28
To detect differences of 10,000th the width of a proton in the presence of so much signal noise, is a bit of a stretch.
If it had been determined that the noise was an insurmountable problem, they wouldn't have spent so much money building the thing. Besides, random noise isn't going to generate the telltale gravitational wave signature of two inspiraling and then merging neutron stars in three different locations on the planet and also at the same time that the merger was detected in the electromagnetic spectrum: https://en.wikipedia.org/wiki/GW170817
Post by: Eternal Student on 01/04/2024 17:24:42
Some minor questions from @Zer0 seem to have been missed.
Please do Allow a few randomly absurd thoughts...I'll assume you want short replies.
Can " Space " bend over itself?I'm not sure what you were asking. Here are 2 possibilities:
1. Can space act to bend space? Space isn't as empty as you might think, there is always vaccum energy in every cubic metre of space. All energy contributes to gravitation (the curvature of spacetime). So space will bend spacetime and some of that curvature will be purely in the spatial part of spacetime, so we could reasonably say "yes, space can bend space". Indeed "vaccum energy" is an important component in modern cosmological models.
2. Can space roll up like a carpet or fold over itself somehow? It's best that you don't think of space as some 2-dimensional rubber sheet that curves in 3-dimensional space, so that whatever image you have of space bending over itself, it probably isn't like that. Black Holes are an example of a region where curvature becomes extremely degenerate as you approach the singularity. You might declare this as a region where space has folded over on itself but you'd need to be working in higher dimensional flat space to "see" that.
String theory sometimes considers the existence of additional dimensions that are described as being tightly rolled up and generally go un-noticed. However, this isn't really a consequence of space doing anything to roll these other dimensions up, they just are tightly curled up for some reason.
Can ' Relativistic mass ' not produce a similar, but not the same, effect such as Gravity?Yes and it essentially does produce a gravitational effect broadly equivalent to having more mass.
1. We don't really use "relativistic mass", it's an old term and discouraged - but we don't need to, we capture the important information about the movement in other ways.
2. In GR various things are sources of gravitation. Sources of gravitation are all the forms of stress-energy that exist and all this information appears in the stress-energy tensor. So, mass is certainly a source of gravitation but so is energy, momentum and pressure. So a moving particle contributes a lot more to gravitation (the curvature of spacetime) then a stationary particle. A moving particle has mass, kinetic energy and momentum. It can also elevate the pressure that exists in a region of space (e.g. a gas has pressure due to the movement of particles in it). Overall, the curvature of spacetime will be more significant when a moving particle is in that region than when a stationary particle is in that region.
If you have Newton's ideas of gravity in the back of your mind then it is broadly equivalent to a moving particle acting as a source of gravity according to its relativistic mass rather than its rest mass. (Why only "broadly equivalent"? At relativistic speeds, where relativistic mass would be significantly different to rest mass, we'd be better off abandoning Newtonian mechanics and Newtonian gravity entirely and using General Relativity. Patching up Newtonian gravity with relativistic mass is only going to be a rough or crude adjustment you could make).
Could the ' Higgs field ' twist, tangle, entangle in on itself?I don't know. The Higgs field isn't an ordinary physical thing and I don't suppose it's very useful to think of it as a thing that can twist and tangle in any ordinary sense. However, such terminology may exist in some very specialised models and areas of Physics that I haven't seen.
Best Wishes.
Post by: Eternal Student on 01/04/2024 17:52:05
About LIGO and gravitational waves:
A lot of physicists thought it would be impossible to detect the effects of gravitational waves. On the face of it, you're talking about finding differences in distance measurements that are smaller than the width of a proton. There were a few physicists writing books at the time just before LIGO was commissioned or when construction had only just started. They wanted to have a chapter on LIGO but many thought "this is never going to work" so they didn't bother. So you're ( @McQueen ) in good company if you think there would be problems like noise dominating any actual meaningful signal.
However, it did seem to work. @Kryptid has already mentioned quite a lot about this. Moreover, I don't think we had any idea about how common black hole or neutron stars mergers actually are. The equipment probably is failing to detect a lot of them but it doesn't seem to matter - there are so many of them every year.
Best Wishes.
Post by: Zer0 on 03/04/2024 19:59:08
I think i get the gist of what you are tryin to say, i might be misunderstanding, but still...
The official " Speed of Light " in a vacuum keeps changing every Century.
Perhaps, a hundred years from now, it won't be what it is today.
Obviously, the ' Speed ' is not changing in Reality, just our instrumentations are getting more precise n accurate n averaging becomes better.
But if all we have are hypothetical models to describe Reality, hence if our Theories change, then so do our Realities!
(gotcha)
ps - @Eternal
Thanks for the replies, always a Treat!
Still, a little shorter, a little less sweet,
Well help me in avoiding DiabeteeZ!
Post by: alancalverd on 03/04/2024 23:41:05
The official " Speed of Light " in a vacuum keeps changing every Century.Since the end of the last century, the speed of light in a vacuum has been defined as constant, and everything else as potentially variable, so distance is "c x time" and so forth.
Perhaps, a hundred years from now, it won't be what it is today.
Post by: McQueen on 04/04/2024 10:58:57
However, it did seem to work. @Kryptid has already mentioned quite a lot about this. Moreover, I don't think we had any idea about how common black hole or neutron stars mergers actually are. The equipment probably is failing to detect a lot of them but it doesn't seem to matter - there are so many of them every year.
Thank you Eternal Student for your informative answer. But notwithstanding that, the facts should be stated. The merger of black holes that was first detected by LIGO was 1 billion light years away, since 1 billion light years is approximately 9.46 x 10^15 m , one billion light years would be 9.46 x 10^24 m , since the signal would weaken inversely with the square of the distance, the final signal would be 8.94 x 10^49 times less than whatever the initial signal had been. Surely, a defense of a result involving such numbers would be purely philosophical regardless of how sophisticated the computers that were used were?
Post by: Kryptid on 04/04/2024 17:18:48
Surely, a defense of a result involving such numbers would be purely philosophical regardless of how sophisticated the computers that were used were?
It's a testament to just how much energy was released by the merger (about 3.1 solar masses worth of energy, which is an awful lot when you put it into E=mc2). We already know that radiation can be detected over such immense distances, as we've seen a supernova over 10 billion light-years away.
Post by: alancalverd on 04/04/2024 17:33:22
Post by: McQueen on 05/04/2024 04:00:24
Galileo summed up the argument very neatly: eppur si muove.
But it moves! and also: "In questions of science the authority of a thousand is not worth the humble reasoning of a single individual." - Nelle questioni scientifiche l'autorit? di mille non vale l'umile ragionamento di un solo individuo
Post by: Kryptid on 05/04/2024 05:49:36
"In questions of science the authority of a thousand is not worth the humble reasoning of a single individual."
I hope that wasn't supposed to be an argument in favor of you being right. Your reasoning basically falls into the "argument from incredulity" fallacy. You say how unbelievable you find it that we have detected gravitational waves, thus you conclude that we have not actually detected them. It would do you well to further research how LIGO works and how it manages to get the needed sensitivity to work.
Post by: alancalverd on 05/04/2024 10:04:11
But science is about facts, not belief, and engineering is about making the unbelievable happen.
Post by: hamdani yusuf on 06/04/2024 15:01:22
Of course it is unbelievable. Like the heliocentric universe, and the idea that I can talk to anyone, anywhere in the world, by pushing a few buttons on a piece of plastic.Heliocentric universe is unbelievable if we still use Aristotelian model of natural world, with many unknowns regarding the masses of celestial objects like planets and stars, and mechanisms that govern their motions and interaction.
Post by: hamdani yusuf on 06/04/2024 15:12:38
What makes you think it will never be changed again in the future?The official " Speed of Light " in a vacuum keeps changing every Century.Since the end of the last century, the speed of light in a vacuum has been defined as constant, and everything else as potentially variable, so distance is "c x time" and so forth.
Perhaps, a hundred years from now, it won't be what it is today.
Post by: alancalverd on 07/04/2024 18:59:00
Post by: hamdani yusuf on 08/04/2024 14:41:44
If somebody comes up with a better model than relativity, we might indeed have to base our physics on a new constant. No big deal, as long at it degenerates to the einsteinian or newtonian solution in appropriate circumstances and predicts what happens when those conditions are not met..Under the expanding universe model, speed of light doesn't seem to be a constant, especially over a long distance.
Post by: Kryptid on 08/04/2024 16:34:59
Under the expanding universe model, speed of light doesn't seem to be a constant, especially over a long distance.
Source?
Post by: alancalverd on 09/04/2024 08:44:24
Post by: hamdani yusuf on 14/04/2024 10:55:32
Which doesn't imply a variation in c.If we insist that speed of light in vacuum is constant while also accepting that space is stretching, it implies that we also need to stretch the time by the same amount. So far, I haven't found any source for the latter.
Post by: alancalverd on 14/04/2024 13:43:47
Post by: Kryptid on 14/04/2024 17:38:38
If we insist that speed of light in vacuum is constant while also accepting that space is stretching, it implies that we also need to stretch the time by the same amount. So far, I haven't found any source for the latter.
That doesn't follow. It takes light one second to travel 299,792,458 meters. Of course, over the course of one second, a portion of space of that distance will expand to be ever-so-slightly longer than 299,792,458 meters. As such, it will take ever-so-slightly longer than one second for light to travel that distance because it can only travel 299,792,458 meters in one second.
Post by: Halc on 15/04/2024 00:38:58
If we insist that speed of light in vacuum is constant while also accepting that space is stretchingNobody insists any such thing. Per relativity theory, light moves at c only relative to a flat (Minkowskian) inertial frame, and an expanding metric is not an inertial one, and probably isn't Minkowskian either.
Since spacetime is locally flat anywhere, light moves locally at c.
Similar stories for other kinds of non-inertial metrics like a rotating frame or an accelerating one, either of which can also be mapped onto flat Minkowskian spacetime.
As such, it will take ever-so-slightly longer than one second for light to travel that distance because it can only travel 299,792,458 meters in one second.A more pointed example illustrating the non-constant speed of non-local light in an expanding metric:
Light emitted from the creation of the hydrogen in your body was emitted near 'here' at the recombination event 13.8 billion years ago and is currently ~45 GLR away, meaning it has averaged a velocity of over 3c. Meanwhile, the CMB light that we detect here today was emitted 13.8 billion years ago from material that was at a proper distance that was much closer then than where Andromeda is now. which is an average velocity of around 0.0001c
An example closer to home which doesn't involve expanding space: If you put a reflector on the surface of Mars and Mercury, light shone to Mercury will make the round trip at a speed a bit less that c, and the round trip to Mars at a speed a bit above c.Both are as measured by an Earth observer, and both are examples of light speed being dependent on gravitational potential.
Post by: Eternal Student on 15/04/2024 01:08:00
It takes light one second to travel 299,792,458 meters. Of course, over the course of one second, a portion of space of that distance will expand to be ever-so-slightly longer than 299,792,458 meters. As such, it will take ever-so-slightly longer than one second for light to travel that distance because it can only travel 299,792,458 meters in one second.I'm not sure if you meant to do it but this is actually a perfect way of suggesting that light will change its speed.
Let's keep it simple and have light travel at 3 x 108 m/s precisely. Let's assume a constant rate of expansion for space set at 10% per second.
Let's have some light emitted out to space by a man with a flashlight on a planet. We'll assume the planet is co-moving with the expansion of space. We also ought to make it clear whose time we're using, we'll use co-moving time, so that will be the time recorded by a stopwatch that stays with the man on the planet.
Now, you ( @Kryptid ) claim light will travel 3 x 108 m after 1 second, that's the distance you can measure between the planet and the light after 1 second. The problem is, the space which it has covered will now also start to expand. So after 2 seconds, the light has travelled on a bit further. However the total distance between the planet and the light will be a bit more than 6 x 108 m/s (2 lots of c). Specifically, it will now be this far away from the planet:
3 x 108 + (1.1 x 3 x108) = 6.3 x 108 m
[Distance moved t=1 to t=2] + [110% of the distance travelled t=0 and t=1]
Between t=1 and t=2, which is just 1 second for the man on the planet, the light became 3.3 x 108 m further away from the planet, so it's average speed over that second was 110% of c.
A similar calculation shows that the average speed of the light would be 3.63 x 108 m/s between t=2 and t=3. In general the speed of light seems to be increasing by 10% every second.
Anyway, it can be some fun to think about it for a while. It's fixable but usually leaves us forced to talk about the movement of light through that bit of space which is local to it. Specifically we cannot consider the rate of change of physical distance from any point that is even just slightly remote from the particle - which can take a page to fully explain and develop the idea. [ Sean Carroll in "Spacetime and geometry" takes most of a chapter].
When we say light has the speed 3 x 108 m/s we don't really mean that it will be 3x108 metres away from where it was emitted after 1 second. We wouldn't be able to say anything about the physical distance between the light and the place of emission unless we also knew something about the curvature and especially the evolution of the scale factor in this region of space and over this time.
So, that can be used as an alternative way to mitigate the earlier comment from @hamdani yusuf
If we insist that speed of light in vacuum is constant while also accepting that space is stretching, it implies that we also need to stretch the time by the same amount. So far, I haven't found any source for the latter.No, we don't. Mostly because the speed of light isn't as restrictive as you might imagine. It's a description of the movement of the light through space that is absolutely local to it (which is a different bit of space at every instant of time). It certainly isn't enough on its own to tell us about the physical distance between the light and any place that is remote from that light. If space is expanding rapidly with time, this distance (from the light to the place of emission) can grow much faster than 3 x 108 m/s, that isn't a problem and that does happen. We do not need to scale time in any way because we are under no obligation to keep that rate of change at 3 x 108 m/s, the speed of light never meant that, it only meant that light has a local speed of 3 x 108 m/s.
Best Wishes.
[Overlap with @Halc who posted just before I did. At a glance, we have said similar things, just in different ways and it won't hurt to have two different styles of explanation].
Post by: alancalverd on 15/04/2024 09:58:57
That doesn't follow. It takes light one second to travel 299,792,458 meters. Of course, over the course of one second, a portion of space of that distance will expand to be ever-so-slightly longer than 299,792,458 meters. As such, it will take ever-so-slightly longer than one second for light to travel that distance because it can only travel 299,792,458 meters in one second.
Er, no. A second is defined by the frequency of an atomic (currently cesium) clock, and a meter is defined as the distance that light travels in one somethingth of a second, so if c were to vary, our measure of distance would change by the same amount and we wouldn't know about it.
Except that if c were to increase, the number associated with the length of the stick in your hand would decrease.
So the abandonment of material standards means that we no longer have the ability to determine whether c is constant!
Post by: Eternal Student on 15/04/2024 19:45:24
First of all, I think 3 people in succession have now said something slightly opposing @Kryptid . So, just to be clear, we don't dislike you @Kryptid . Quite the contrary, people probably wouldn't have bothered making comments if they didn't think you and your ideas were sensible and could be amenable to discussion.
So, let's challenge the comment made by @alancalverd slightly instead. It's not his fault, it's mainly just the "SI council" of people who make changes to the measurement system are often about 10 years behind the state of the art in science. (I don't know if they are called the 'SI council' but that's what I will refer to them as). I suppose they have their reasons, for example why change a system that works well enough until there's a good reason for it, especially if it could be expensive for all instititutions to re-callibrate all their equipment etc. They may also feel that certain things are simply beyond their jurisdiction and control. For example they probably concentrate on providing a system that works here on Earh and over a few years that we can call "now" rather than suggesting all precise callibrations and definitions refer only to a region of outer space that is well behaved.
Anyway, this is how it is: The SI council changed the definition of a metre much as described by @alancalverd . That happened in 1983 and was extremely useful and sensible because it puts things on a footing that agrees nicely with the theory of special relativity. Sadly, it did NOT pay a lot of attention to the later theory of General Relativity and has left a lot of "mud in the water".
So that's a fairly bold claim and I'd better have some evidence for this instead of just walking away.
1. It's not just me who thinks the current SI definition of the metre fails to recognise the impact or role of General Relativity. The CIPM (International committee for weights and measures) are aware of these limitations.
The CIPM issued a clarification in 2002:
Its (..the speed of light..) definition, therefore, applies only within a spatial extent sufficiently small that the effects of the non-uniformity of the gravitational field can be ignored (note that, at the surface of the Earth, this effect in the vertical direction is about 1 part in 1016 per metre). In this case, the effects to be taken into account are those of special relativity only.
(The CIPM) ....Considers the metre to be a unit of proper length and thus recommends this definition be restricted to "lengths ℓ which are sufficiently short for the effects predicted by general relativity to be negligible with respect to the uncertainties of realisation"....
Various extracts from https://en.wikipedia.org/wiki/Metre#Speed_of_light_definition
2. Credible physicists have also written about this:
This is an article by various contributors and held on the University of California website:
https://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html
We'll only need a few sentences from it:
.....in the presence of more complicated frames and/or gravity, relativity generally relinquishes the whole concept of a distant object having a well-defined speed. As a result, it's often said in relativity that light always has speed c, because only when light is right next to an observer can he measure its speed? which will then be c. When light is far away, its speed becomes ill-defined. But it's not a great idea to say that in this situation "light everywhere has speed c", because that phrase can give the impression that we can always make measurements of distant speeds, with those measurements yielding a value of c. But no, we generally can't make those measurements. And the stronger gravity is, the more ill-defined a continuum of observers becomes, and so the more ill-defined it becomes to have any good definition of speed.
I'll need to elaborate on this a bit: If we are considering a solution to the EFE with a scale factor that changes significantly every second, then even 1 light second, is still too far away to be able to treat this as the local vicinity of the light now. We can't just measure the physical distance between the light and the point of emission and divide by 1 second. Where we seek precision over the definition of the speed of light, or the metre, then even 1/300 000 000 th of a second is too long and has allowed the light to move too far away. Specifically, the SI definition of the metre works here on Earth and right now only because the scale factor won't have changed very much over 1/300 000 000 of a second in this region of space.
3. Let's just see how the physical distance from the point of emission and the particle of light evolves from first principles.
We'll have a simple FRW metric for a universe with 0 spatial curvature (which is what we think we do have in our universe).
dS2 = a(t)2 ( dr2 + r2 dΩ2 ) - c2dt2
[Reference: https://en.wikipedia.org/wiki/Friedmann%E2%80%93Lema%C3%AEtre%E2%80%93Robertson%E2%80%93Walker_metric#General_metric ]
a(t) = scale factor; r = reduced circumference co-ordinate ---> it's a co-moving co-ordinate based on a radius as used in spherical polar co-ordinates upto some constants or choice of units; dΩ2 is based on the polar and azimuthal angles for the co-moving co-ordinate system, dΩ2 = dθ2 + Sin2 θ dφ2.We'll centre the co-moving spherical co-ordinate system at the place of emission of the light at t=0 and will only be considering light that progresses along the radial direction, so dθ = dφ = 0 and the metric simplifies to:
dS2 = a(t)2 dr2 - c2dt2
Light is a null ray, dS2 = 0, so a(t)2 dr2 = c2dt2. taking the positive square root is appropriate for an outward travelling ray which is what we will be considering (the light was emitted at r=0 and t=0 and travels outward). So we have,
dr = c dt / a(t)
That's the relationship between a differential change in time, dt, and a differential change in radial co-ordinate, dr. This holds at all times and at any place along the path taken by the light. Note that this t and r are the co-moving times and r co-ordinate.
So from time t=0 to t = an arbitary t, the total change in the co-moving r co-ordinate for the particle of light is given by a simple integration.....
(... LaTeX mathematics support is still not working....so it's not so simple.... I'll just insert an image....)
Delta r.jpg (8.76 kB . 438x126 - viewed 59 times)The initial radial co-ordinate of the light r(at t=0) = 0, the radial co-ordinate of the light at time = t is r(t) = RH (I've got to call it that, that's the image I could find - they were calculating a cosmological horizon so a letter H made sense for them).
Recall that this, r(t) is a co-moving co-ordinate, we multiply by a(t) = the scale factor at time t, to obtain the physical distance RH(t) between the particle of light and the place of emission at time=t.
Delta R.png (14.25 kB . 528x139 - viewed 55 times)In the situation where a(t) is strictly increasing with time, i.e. we say the universe is expanding, then the integrand above is strictly greater than dT / a(t) while T<t. ( I can't get the tilda above the t and have used a capital T, just evaluate the integral knowing that a(T) < a(t) while T varies between 0 and t in the integral ).
We have (omitting limits on the integral because LaTeX isn't avalaible), a(t) . (1/a(t)) . c . ∫ dT = c ∫dT = ct .
So we have RH = the physical distance from the point of emission to the particle of light > ct. Hence the speed of the light (if we define it as physical distance between point of emission and the particle of light after 1 second) > c.
We get equality if the scale factor a(T) in the aforementioned integrals remained effectively constant throughout the whole time between t=0 and t. If the universe expanded during this time interval, then we don't. Hence, the SI definition of the metre doesn't actually work when you consider General Relativity and an expanding universe. I mean it is what it is - that's how they defined it and what we have to use - but it just doesn't quite define what we would really want it to define. It gives a satisfactory definition of a metre and an appropriate speed of light follows from this ONLY in a region of spacetime (which means over a small time and over a small region of space) where the scale factor can be assumed to hold constant.
It turns out that having an expanding universe is only one way in which GR challenges the SI definition of a metre. Other spatial curvatures (which are often described as gravitational fields) can also present problems.
The safest way to talk about "the speed of light" is to refer only to what someone could measure as a differential rate of change while they are right at the same location as the light. The SI definition of the metre is just some "mud in the water". We shouldn't measure the distance from an initial position to a final position, not even over a tiny time interval like 1/300 000 000 th of a second because GR suggests that various things about the metric or gravity can still mess up that distance.
Maybe the SI council will adapt the way a metre or the speed of light is defined in the future but provided the Universe doesn't suddenly return to expansion rates like the epoch of inflation or become very close to an extreme source like a gravitation like a black hole, then what we have as the definition of the metre will, I suppose, just have to do.
Anyway, that's why it might seem like there are at least two slightly different sorts of replies that may seem slightly contradictory:
The General Relativists (e.g. @Halc ) suggesting the speed of light is only a local thing. Also me who will stand by the statement that in 1/300 000 000 of a second light may not have travelled 1m of physical distance from where it was, we need to know about gravity or the evolution of the metric before we could determine that physical distance (e.g. assume the scale factor ≈ constant).
The Practical-ists (e.g. @alancalverd ) suggesting that the metre is the metre as set by the SI council and that's the deal. The speed of light follows. So, regardless of where you are, how fast the universe is expanding, or the existence of unsual gravitational fields in the region, light will have travelled 1 m after 1/300 000 000 of a second.
Best Wishes.
Post by: Halc on 15/04/2024 20:41:25
and a meter is defined as the distance that light travels in one somethingth of a secondI think I can compress ES's post to a short line.
A meter is what light travels in one somethingth of a second relative to an inertial frame.
The original official definition might have omitted that presumption since one can get light to move pretty much any distance you want in a second if the right kind of non-inertial frame is chosen.
because only when light is right next to an observer can he measure its speed? which will then be c.Technically, even then the speed cannot be measured, and is only presumed. A meter is best measured by light reflected from one end to the other and back, in two somethingths of a second. Since an inertial frame is required for this, obviously you can't have both ends of the meter stick be comoving at once.
Your quote refers to non-inertial frames as "more complicated frames", and any expanding frame would be one of those.
Post by: paul cotter on 15/04/2024 22:28:50
Post by: Eternal Student on 16/04/2024 01:38:50
I think I can compress ES's post to a short line.I do like it and it is a bit shorter than my post. I did have to read the line twice, make inertial frame a bit more obvious and I wouldn't have had to.
Best Wishes.
Post by: hamdani yusuf on 20/04/2024 07:07:47
We don't insist, we define c to be a constant. Then we can measure everything else.What is the difference?
Post by: hamdani yusuf on 20/04/2024 07:28:51
Light emitted from the creation of the hydrogen in your body was emitted near 'here' at the recombination event 13.8 billion years ago and is currently ~45 GLR away, meaning it has averaged a velocity of over 3c. Meanwhile, the CMB light that we detect here today was emitted 13.8 billion years ago from material that was at a proper distance that was much closer then than where Andromeda is now. which is an average velocity of around 0.0001cWhat causes the asymmetrical difference? It speeds up in one case, while slows down in the other case?
Post by: alancalverd on 20/04/2024 10:13:54
You need to ask the UK House of Lords.We don't insist, we define c to be a constant. Then we can measure everything else.What is the difference?
Our corrupt, incompetent government wants to spend taxpayers' money shipping invaders to Rwanda, but this would be illegal as several legitimate Rwandan refugees have been granted asylum here and you cannot deport anyone to an known unsafe country.
So instead of insisting that Rwanda is safe, a procedure that could be tested in court or overturned by Parliament by the evidence, His Majesty's so-called Government has attempted to bypass civilised procedure by defining Rwanda as a safe place.
Anticipated developments on this theme include "black = white" and "2 + 2 = 5", by definition. You could base optics and mathematics on these axioms but not everyone is a politician, economist, or totally stupid. Problem here is that the only intelligent life in Parliament resides in the Lords, not the Commons.
However when it comes to physics, we have to start somewhere, and if we define c as constant we can derive the equations that seem to predict pretty much everything that happens in the universe, to an acceptable degree of precision.
Post by: Eternal Student on 20/04/2024 14:54:17
What causes the asymmetrical difference? It speeds up in one case, while slows down in the other case?The light was trying to travel towards the place you measure distance from, or away from that place. For an expanding space, this matters.
The terms "speed" or "velocity" were used informally. Ratios of change in physical distance with time were being described. In a flat Euclidean or Minkowskian space this is exactly what we can call a speed or velocity.
Best Wishes.
Post by: hamdani yusuf on 22/04/2024 13:31:11
However when it comes to physics, we have to start somewhere, and if we define c as constant we can derive the equations that seem to predict pretty much everything that happens in the universe, to an acceptable degree of precision.If the word "define" is replaced by "insist", would the statement become false?
Post by: hamdani yusuf on 22/04/2024 13:44:31
The light was trying to travel towards the place you measure distance from, or away from that place. For an expanding space, this matters.In an expanding space, everything that's stationary in the space-time continuum always moves away from one another over time.
IMO, the observer is always on the receiving end.
Post by: alancalverd on 22/04/2024 15:24:45
If the word "define" is replaced by "insist", would the statement become false?
It becomes different. This was actually the reason for the foundation of the National Physical Laboratory and international standards ever since.
I can define a meter as the length of a particular stick (indeed we did just that for many years) and if everyone signs up to the same standard, we can make things that fit together. A problem arose during the First World War when artillery shells made in Coventry didn't fit the cartridges made in London. Each factory insisted that their machines were calibrated to trading standards but it turned out that the Coventry Municipal Inch, good enough for dressmaking and housebuilding, was significantly different from the Woolwich Arsenal Inch, so the Imperial Statute Inch was defined as the one held in a London laboratory.
Subtle, but it saved lives.