Constancy of light speed in all inertial systems in SR is somehow hard to understand. Do we have some common explanation ?
My response would be, not sure anyone can answer the "why," any more than anyone can answer why gravity exists. This is simply the natural order of things, as far as we know it at this time.
It appears that the straightforward Newtonian physics becomes increasingly inaccurate as speed increases, and that the singularity occurs at v = c. My "explanation" is that everything else in classical physics becomes distorted, as we approach these relativistic speeds, to accommodate the fact that c remains a constant.
So for example, classical physics implies that applying a constant force to a mass will cause speed to increase linearly, with no limit. What happens instead is that v = c is a singularity, so that something else must be happening to keep speed from increasing. What is being twisted to prevent speed from increasing beyond c? Mass keeps increasing as a function of speed (who knew?), to make sure you'll never have enough energy to allow that mass to reach c. The natural order of things (until we discover that even special relativity is not the general case).
Perhaps something vaguely similar to this is the Cartesian coordinate system. It's nice and predictably straightforward, much like classical physics. But it's not useful in the general case.
My response would be, not sure anyone can answer the "why," any more than anyone can answer why gravity exists. This is simply the natural order of things, as far as we know it at this time.
It appears that the straightforward Newtonian physics becomes increasingly inaccurate as speed increases, and that the singularity occurs at v = c. My "explanation" is that everything else in classical physics becomes distorted, as we approach these relativistic speeds, to accommodate the fact that c remains a constant.
So for example, classical physics implies that applying a constant force to a mass will cause speed to increase linearly, with no limit. What happens instead is that v = c is a singularity, so that something else must be happening to keep speed from increasing. What is being twisted to prevent speed from increasing beyond c? Mass keeps increasing as a function of speed (who knew?), to make sure you'll never have enough energy to allow that mass to reach c. The natural order of things (until we discover that even special relativity is not the general case).
Perhaps something vaguely similar to this is the Cartesian coordinate system. It's nice and predictably straightforward, much like classical physics. But it's not useful in the general case.
Amrit, my best answer is that "this is the natural order of things." As you know, physics observes and codifies, it does not answer "why." The speed of light needs to be a constant (in a vacuum) for other observations to be consistent. This in turn affects what we thought we knew before, such as mass and dimensions are NOT constants, but rather functions of speed. Classical mechanics claims that mass and dimensions are independent of speed.
You might want to read this:
https://van.physics.illinois.edu/qa/listing.php?id=2605
Sir, Sorry for the interruption. I find the comment by Prof. Amirit Sori to be contradicting.
I am no intelligent who has over looked at the equations to answer your question. but have seen some videos and explanations by various authors.
First, from what they observed from the galaxies which are moving away from ours, its certain that the light from those galaxies are shifted to lower frequencies or higher wave length band. i.e. red shifted. however the velocity remains the same.
lets say, a light wave is generated at a particular instant of time and at a particular location. The reason behind the generation of the wave can be of many but that is not our focus now. That light wave travels at the velocity 'c' with respective to that location 'l'. however, at t+dt the particles which were the cause of this wave would have moved by a distance S= c * dt.
Because the source of the wave itself is moving away, the frequency has shifted..
From relativity theory, for time to change with speed, velocity of photons 'differ' such that all the material actions are slowed down. However, the magnitude of velocity we speak are of the order of 'c'.
Hope I add to the understanding of the situation. Thank you.
just a simple answer : c is constant because time cannot move backwards...
all objects on the light cone have "constant speed". This follows from basic properties of Minkowsky space geometry (=metric)
Since c is a dimensionful quantity, not zero and not infinite, we can always choose units for time and length such that c = 299 792 458 m/s. As was done quite some time ago. Whether this was a good choice or not is another matter; so far all evidence is in its favor.
Hello,
The reason is simple: Maxwell's equations. Basically, the speed of light depends only on properties of the medium, not on relative movement of medium, source, and observer.
However, the speed of light is not constant at all -- it is an invariant, The difference is explained in the link below, with more comments.
https://www.researchgate.net/post/What_are_the_worse_yet_enduring_misconceptions_about_mass_and_energy_in_special_relativity
Cheers,
Ed Gerck
Look at the works of Frank Robert Tangherlini... they show you more intuitive roots... ;-)
Reviewing the special relativity postulates, always raises some questions like, “Does the constant speed of light (photon energy), result from a natural accident?” or “what is the difference between the characteristics of mass and energy while the speed rate of energy is fixed; the speed of matter can change and cannot reach the speed of light?”. Meanwhile when the physical and chemical processes occur, some amount of matter is converted into energy; what happens during this process that mass with non-constant speed is converted into energy with the constant speed? For answer see:
https://www.researchgate.net/publication/280491440_Reconsidering_relativistic_Newton%27s_second_law_and_its_results?ev=prf_pub
https://www.researchgate.net/publication/270339919_Interactions_Between_Real_and_Virtual_Spacetimes?ev=prf_pub
Article Reconsidering relativistic Newton's second law and its results
Article Interactions Between Real and Virtual Spacetimes
> the speed rate of energy
Ugh!
As everyone knows since kindergarten, invariance under translation in time and space leads to conservation of energy and momentum. And invariance under rotations leads to conservation of angular momentum.
What does invariance under Lorentz boosts lead to? It turns out that it leads to conservation of the velocity of the center of energy.
By the way... the cardinal point for an intuitive understanding is a clear comprehension of the concept of clocks synchronization. All the experiments deal with a "two ways" speed of light, i.e. a "back and forth" trip of the light beans. The local, "one way" speed can be assumed as more or less than "c", thus permitting the concept of an aether with its proper index, without breaking the relativistic transforms.
Einstein himself, in 1906 paper that elucidated his Special Relativity had commented that his Light Postulate was a consequence of Maxwell's equations
The constant velocity c is not a speed limit for motion in space but a constant connecting time with space in the four-dimensional geometries of General and Special Relativity (GR and SR). We know already from SR that time goes slower in motion and that therefore the effective velocity in terms of distance travelled per second is greater than the velocity v appearing in SR. Again, c is a constant of nature that has nothing to do with how fast things move.
Light speed is a property of space, such that anything with no rest mass moves at light speed. More technically light speed is governed by the interaction of electricity and magnetism. Special Relativity has flat space, meaning the properties of space are not changing from one place to another. With curved space, meaning acceleration or gravity, the properties are changing with distance. Einstein treated light speed in gravity as a variable in his technical book of GR, including 5th edition late in life. Many scientists following lead of Peter Bergmann believe light changes direction but not speed. They are not in agreement with Einstein's math. Most notable supporter of Einstein's point of view is Max Born and to some lesser extent Richard Tolman as written in their books.
In periodic relativity, basic unit of time is the period of the wave and basic unit of length is the wavelength of the wave. The following answer could be understood only in this context.
Nothing can travel faster than speed of light. If a massive body is accelerated to reach the speed of light, it may become more massive for some time, only to disintegrate and shade its mass before reaching the speed of light. Only a particle with zero rest mass can attain speed of light in vacuum. With this basic information we define the following law of nature:
The ratio of the wavelength and period of any particle wave with zero rest mass will always be a constant and equal to the speed of light c regardless of the inertial frame from which it is observed.
This is also reflected in the currently accepted value of the velocity of light in vacuum which is exactly 299 792 458 m/s. There is no uncertainty. See the following NIST site.http://physics.nist.gov/cgi-bin/cuu/Value?c|search_for=abbr_in!
NIST experiment simultaneously defines the length of meter and the speed of light as given in the link below.
http://nvlpubs.nist.gov/nistpubs/sp958-lide/191-193.pdf
Article Periodic relativity: Basic framework of the theory
Christian> It is wrong to believe that we have space-time first and then we place objects into it. It is the other way around
According to GR this is a symbiosis. Matter tells spacetime how to curve, spacetime tell matter how to move. Nevertheless, Minkowski space is a solution of the matter-free Einstein equation. I don't know for certain if it is a stable solution; but someone has surely checked, and it would have been commonly known if it wasn't. This is anyway an irrelevant question; in quantum physics even emptiness (the lowest quantum state) has material properties.
Constancy of speed of light is one of the postulates of special relativity. So, it has to be assumed to be true and with that deduce other things. Question is, whether it agrees with nature. So far, there are no physical phenomena which question this postulate. It is indeed hard to understand because it is contrary to what one observes in day to day life. But experiments show that speed of life is indeed independent of inertial frames of reference.
“… ”Empty" space-time does not exist. It's a chimera.”
- that seems as rather strange, however. It is impossible to define the notions “space”, “time”, and “spacetime” “by a theory of interaction” and at that to avoid the vicious circle of reasoning.
(as well as to obtain at that a number of other things, for example – what are coordinate systems, coordinate transformations between different systems, etc...)
Cheers
“…So far, there are no physical phenomena which question this postulate….”
- Shashikant, that isn’t of course so; even Einstein in his 1905 paper considered speeds (c+v) and (c-v), as well as such consideration is, as a rule, used when the Doppler effect is considered; and that are real speeds in these cases. So in the reality the speed of light isn’t a constant, it is invariant; and, besides, it is invariant only in a subjective product - in the inertial reference frames where clocks are concretely synchronized in accordance with two procedures - by light pulses (when the constency appears by definition) or by slow motion of initially synchronized in the same spatial point clocks.
At that the coordinate transformations between relatively moving IRF are Lorentz transformations. But these transformation are correct only if in the IRFs material bodies (including IRF's clocks and sticks/rules) constitute some rigid systems, for free bodies the transformations aren’t correct; for example – if a pair clocks with light sources, having a speed V, were synchronized in a point and further one clock was slowly moved along the speed V on a distance A12, then measured by the clocks the speed of light will not be equal to c, it will be (c+V) – for light that moves from front clock and source to back, and (c-V) – for light that moves from back to front.
More -see https://www.researchgate.net/publication/273777630_The_Informational_Conception_and_Basic_Physics
Cheers
Article The Informational Conception and Basic Physics
Dear Colleagues, I focus to the original question, why does light propagate at the same velocity in different IFsR, according to SR? The most adequate answer - in my view – is; Because, it was so postulated in that theory. SR also postulates the behavior of length and timescale in IFsR. These three postulates together predict physical phenomena which range with the experience. On that reason we find SR to be a good theory.
Henry Poincare stated in his famous book Science and Hypothesis in 1904 that the world does not have any own geometry. Describing physical phenomena we are allowed to use any geometry we like, but physical laws look different in different geometries. A complete theory defines the geometry or metric and formulates the physical laws. So does SR.
The question titled to him: “Why did he use Minkowski metric and curved spacetime in relativity theory?” Einstein answered; because physical laws look the simplest in that geometry. Some physicists doubted this assertion.
As a conclusion I think the law of light propagation in IFsR in only valid together with Minkowski metric.
Christian> At the same time, QM tells us that local realism is an illusion
Yeah. But I only think about that when nobody looks. There is the Ghirardi–Rimini–Weber theory of spontaneous collapse, which may hint towards a possible solution of this conundrum (but GRW is not relativistic invariant). It is a good working hypothesis that there is a solution that make the use of a classical paradigm very reasonable.
Jerry> ...curved space, meaning acceleration or...
A laboratory under acceleration in Minkowski spacetime would not measure any curvature (it is still flat space, although perhaps described in curvilinear coordinates).
It's the other way around: light is an electromagnetic wave, it turns out that these are described by electric and magnetic fields that are solutions of Maxwell's equations, these equations are invariant under Lorentz transforrmations, that leave the speed of light invariant and from this fact everything else follows. And inertial frames can be consistently defined as those that are related by Lorentz transformations. From this one deduces that spacetime, as probed by electromagnetic waves, can be described by a Minkowski metric and so on.
Kåre, Christian and all,
The universe is expanding, but expanding into what? Into what is not space-time. Otherwise, it would not be an expansion. Therefore, space-time exists because of objects and their interaction. Where those things do not exist, there is no space-time. One could call it the "formless void" or something else, and we have no physical laws for it -- although it must (in a way) exist.
Comments?
Cheers,
Ed Gerck
The light-velocity in vacuum is
(1) c = 1/sqrt(ε0μ0),
where the subscript 0 means the value in vacuum. Are ε0and μ0frame dependent?
But, the constant c appears also in the field equations of Einstein,
Gμν+ gμνΛ = 8πGTμν /c4.
If the value of c in (1) is equal to the constant c in (2), then the light-velocity is frame independent because of (2), where obviously it is a frame-independent constant.
But why are these two values equal? The equation (2) is essentially an equation of mechanics, and (1) of electro-magnetism. What have to do the space curvature, the metric and the stress–energy tensor, the cosmological constant and Newton's gravitational constant, with the electromagnetic constants ε0 and μ0 ?
Here is a way of looking at it that doesn't depend on singling out electromagnetism. Suppose an observer always measured time spatially (e.g. hands on a clock, diurnal movement of the heavens, a burning candle). Then time must transform as space and if you insist on a linear transform then you get a constant maximum speed. Light just happens to be it.
General coordinate invariance of general relativity and its extensions implies that, at any given point in spacetime, it's possible to eliminate curvature effects and define a Minkowski frame, where Lorentz invariance holds-which implies that electromagnetic effects are well defined. This isn't possible globally, if the spacetime is curved. This, also, implies that the speed of light that appears in Einstein's equations is the speed of light that appears in Maxwell's equations, and in the transformation laws of energy and momentum, since, otherwise, it wouldn't have been possible, in general, to define a Minkowski frame at any given point.
Sofia @
The two dimensionful quantities ε0 and μ0 depend on the units we use to measure electric and magnetic fields in vacuum, relative to other units. They cannot be defined independently, since a committee has decided the value of their product. What about the value of their ratio? It turns out that sqrt(μ0/ε0) = 376.73031... ohms. The numerical value is the first digits of an exact (irrational) number, defined by the committee already referred to. It is related to the definition of Ampere, and hence indirectly to the definition of Coulomb. [There additional interesting aspects of this story, if we start to consider the fact that the fine structure constant in principle depends on temperature and other physical conditions of the universe.]
The occurrence of 1/c4 on the right hand side of your equation (2), can be viewed as a definition. It is done in order to make the coefficient G equal to Newton's constant, as used in Newtonian gravity (and mechanics). This definition depends on the requirement that the units for energy E and mass m are related such that E = mc2 for a particle of mass m at rest. It would have saved ResearchGate Q&A for many meaningless discussions if the above committee had defined their units such that c=1.
Hi, Kåre!
What I tried to say is that explanations of the invariance of the light velocity in base of the Maxwell's equations are not sufficient, this invariance has a more profound root.
If I understand correctly what you say, the constant c won't appear in the Einstein's field-equations if the basic units were chosen in a particular way. So be it! But what has to do this constant in the formula of invariance of the relativistic interval?
r2 - (ct)2 = const.
Take for instance two events which have nothing to do with electromagnetism (e.m.), E1 = an explosion on a distant star, E2 = I yawn. What is doing the light-velocity in the relationship between their space-distance r, and time-distance t?
So, the light velocity happens to be a universal constant, frame-independent, that appears in the transformation relations of every relativistic 4-vector, be it of e.m. nature, or not.
Relationship to Special Relativity
Light speed seems to be strain rate in flat space (not curved space) for me.
Since the flat space is homogeneous and isotropic, the strain rate is constancy as the property of flat space.
Conceptual description is as follows.
Given a priori assumption that space as a vacuum has a physical fine structure like continuum, it enables us to apply a continuum mechanics to the so-called “vacuum” of space.
Assuming that space as vacuum is an infinite continuum, space can be considered as a kind of transparent elastic field. That is, space as a vacuum performs the motions of deformation such as expansion, contraction, elongation, torsion and bending.
a) When the infinitesimal distance regulating the distance between the two points changes by a certain physical action, the change is continuous, and the space maintains a continuum even after its change.
b) The spatial strain is defined as a localized geometrical structural change of space. It implies a change from flat space involved in zero curvature components to curved Riemann space involved in non-zero curvature components.
c) Space has the only strain-free natural state, and space always returns to the strain-free natural state, i.e., flat space, when an external physical action causing spatial strain is removed. Spatial strain means some kinds of structural deformation of space.
Based upon above notion, now let us suppose the following fundamental axiom, i.e., “The nature of flat space is identical independent of stationary system and moving system uniformly and rectilinearly”.
Since the metric tensor of flat space is Minkowski metric, we get the following two conditions from strain equation of space-time:
The square of the infinitesimal distance “ds” between two infinitely proximate points is identical and strain tensor eij=0.
Based on two conditions, for both coordinate systems, the wave velocity of both coordinate systems becomes identical, that is, c’=c and this wave motion requires the transversal wave. The wave velocity cannot exceed the strain rate of continuum as space-time.
Thus, we can get the principle of constancy of light velocity. As a result, the principle of constancy of light velocity is embedded in the space-time as a physical nature from the outset.
Concerning the detail explanation, please refer to the following article:
Space Strain Propulsion System (16th ISTS 1988) ; page 13/14,14/14.
ARTICLE · MAY 1988
Or
Book: Advances in General Relativity Research ISBN: 978-1-63483-120-8
Editor: Cameron Williams
Chapter 3 General Relativity from the Aspect of Continuum Mechanics of Space-Time .
Dear Amrit: I would not say that the Shapiro delay gives a slower intrinsic velocity of light. The retardation is due to the angle that it makes due to the double bending of light, compared with the straight line without bending. Both issues (double bending and Shapiro delay) are identical, but the angle is one measurement and the delay is another.
However, if this interests you, it is obvious that the speed of light and the equation E=mc² are two related issues in terms of mechanics, as shown in the annexed article. In fact, E=mc² is the transcription of the very, mechanical definition of the speed of light.
This allows us to suppose that the speed of light, which is a dimensional "constant", is dependent from the physics in which it bathes.
Indeed, every "constant" that has dimensions is dependent from the physics in which it bathes.
See annexed article.
Dear Ed Gerck:
It is well established in SR that (relativistic) mass does change with change in speed. Relativistic mass simply means kinetic energy and nothing else. Rest mass does not change. Many scientists including yourself have their own ideas about relativistic mass to which I do not subscribe.
Regards,
Vikram
Hello Vikram and Ed,
Rest mass may not change, but what is its origin? Please see https://www.academia.edu/19652036/The_Origin_of_the_Electrons_Inertia . Also, does not relativistic mass gamma m include rest mass m ?
Richard
Hello Amrit,
I think it is simpler than this. Kinetic energy is simply the difference between total energy gamma mc^2 of a moving object and its rest energy mc^2. This is standard special relativity. Rest mass m is an abstraction since no particle is at rest, rather m=Eo/c^2 for an electron where Eo = 0.511 MeV. An electron can be composed of a circulating spin 1/2 charged photon with energy hf = gamma mc^2 = gamma Eo for a moving electron. Please see https://www.academia.edu/15686831/Electrons_are_spin_1_2_charged_photons_generating_the_de_Broglie_wavelength for more details. Also, I found in my approach to the inertia of an electron that mi = gamma m, that is, mi increases with the speed of the mass just like relativistic mass gamma m.
Richard
Richard> Please see...
If you decide to hide your work somewhere unaccessible, why the hell should I care about it?
I don't want to read hundreds of pages of legal agreements, and report on every aspect of my life, before downloading a paper which in the end may turn out to be uninteresting.
Note added: What you have shown in your paper is that the "transverse inertial mass" of point particles is |p|/|v|. Nothing wrong with that, but I prefer to think about it, and denote it, as |p|/|v|. It is more useful to note that v = pc2/E, where E = sqrt[(mc2)2 + (pc)2] is the particles energy (excluding its possible potential energy). Also note that the "longitudinal inertial mass" is a different expression. Which is why I in several threads have recommended that the concept of inertial mass is placed in a museum, to display its former glory and historical importance.
Kååååre !
Since when do you express yourself so highly academically (==>"why the hell") ??!!!!!!!!!
(Though, I have to say that I agree with you.)
The speed ol light is c as long its measured through the flat spacetime. For distant objects the spacetime does not remain flat, as well as the velocity of the distant objects exceed the the speed of light c.(speed of light🔛c🔛flat spacetime🔛locality🔛special relativity🔛causality). 🔛 means equivalent.
Gist of the question is related to “Constancy of light speed in all inertial systems in SR is somehow hard to understand.”, because not related to the photon itself, is simply stated my thoughts. I thought Good question from Amrit.
Further I agree with the statement “A scientist must always ask why things are the way they are.”
Concerning "c" as your infinity, there can be no any speed including strain rate is also an infinite.
Sofia> so highly academically...
Yes indeed :-D. I was more than a little bit frustrated. Towards Google, not so much towards Richard (but it is inconsiderate to place the work you want to promote in a difficult-to-reach place). But, as you could see from my Note added, I in the end went through all the necessary motions to download the paper. Which Richard should take as a compliment.
Remi> not just excepting the just-so stories
In my opinion this is exactly what Amrit does, by not accepting anything of the "just-so" written by the "mainstream" :-)
Or, have I misunderstood the english language completely?
Dear Amrit,
What you reached is same what I reached in my paper Reinterpretation of Lorentz transformation according to Copenhagen School and The Quantization of Gravity http://vixra.org/pdf/1509.0059v2.pdf
In fact by this principle quantum and relativity unified. Locally the speed of light is constant, by globally it is vacuum energy dependent. In this case the phase velocity, group velocity and the uncertainty principle play the rule. I reached to a new transformation which expresses about the transformation of group
x=R^2(x'-vt'), t=R^2(t'-vx'/c^2), y=Ry' and z=Rz'
R is Lorentz factor.
Here space is invariant. My transformation explains to you the CMB anisotropy. and according to my transformation all the paradoxes of SRT disappeared by refusing the reciprocity principle. It is expresses about the wave-particle duality and the uncertainty principle and vacuum energy dependent.
Dear All,
According to my transformation Sagnac effect and H&K experiment explained completely,
Sagnac effect is given according to my transformation as the difference in the time term t-=R^2(t'-vx'/c^2), and t+= R^2(t'+vx'/c^2) where by considering x'=L where space is invariant in this case delta (t)=R^2(2vL/c^2) which is agree with Galilean transformation. Review this paper Classical and Relativistic Derivation of the Sagnac Effect W. Engelhardt
http://arxiv.org/pdf/1404.4075v1.pdf
Hello Kåre,
You are absolutely right about links. The link to my charged photon modeling the electron article is on researchgate at https://www.researchgate.net/publication/281322081_Electrons_are_spin_12_charged_photons_generating_the_de_Broglie_wavelength . The link to my short electron inertia article is at https://www.researchgate.net/publication/292215155_The_Origin_of_the_Electron%27s_Inertia . This is a work in progress. So suggestions are particularly welcome.
You're right that I am calculating the transverse electron inertial mass for a moving electron when I get gamma m using the inertial mass calculation method in my electron inertia article. But a circling photon as in my charged photon model of the electron would only have a transverse inertial mass since a photon cannot accelerate in its longitudinal direction anyway as this speed remains c. So the inertial mass of a circling photon composing a resting electron remains hf/c^2. And since this result is independent of the radius of the circle, this circular radius can approach infinity without changing the photon's transverse inertial mass hf/c^2, and therefore this result would apply to a linearly moving photon also, while the invariant mass of a photon is zero.
As far as term "relativistic mass" equaling gamma m for an electron being a museum piece I think you are correct, since it can lead to confusion, and electron energy and momentum can be calculated without this concept. But I think my main result that the resting electron's inertial mass can be derived from the momentum of a circulating photon (modeling an electron) of momentum mc = hf/c = Eo/c still stands.
Richard
Research Electrons are spin 1/2 charged photons generating the de Bro...
@ Christian Baumgarten:
You are right. Relativistic mass simply means kinetic energy in case of photon and nothing else.
@ Richard Gauthier:
Yes, relativistic mass does include rest mass for massive particles but not for photon.
The origin of rest mass in my theory is due to condensation of kinetic energy along the line of Bose Einstein Condensate theory. When the kinetic energy of the particle condense into the rest mass, its velocity drop and the inertia sets in. The process is reversible. Now from this point of view, if the rest mass is also made up of kinetic energy then what is the harm in saying that relativistic mass is simply the kinetic energy? But I do not wish to alter the conventions.
Relativistic objects aren't, necessarily, quantum objects: the speed of light, that sets the scale for relativistic effects, is independent of Planck's constant, that sets the scale for quantum effects. The kinetic energy of a relativistic object is just the difference between the total energy and its energy in the rest frame. The mass is independent of the frame, the value of the energy-and of the kinetic energy-depends on the frame.
@Amrit Sorli :"is energy of quantum vacuum" you repeat this constantly without ANY argument for that: this "vacuum energy" exists only in your fantasy.
1) "matter and energy cannot exist in an empty space deprived of physical properties."
this is your private believe, actually medieval philosophy!
2) Even if such a vacuum energy would exist, there is absolutely no argument for being this is your "Planck energy"
Sofia> If I understand correctly what you say, the constant c won't appear in the Einstein's field-equations if the basic units were chosen in a particular way.
First, the concept of a light cone is also built into GR. This defines a maximum speed which ought to be the same as the speed of light in vacuum. In the limit of geometric optics the spacetime path of light, and all massless particles, should be null geodesics. My remark about the normalization of G was only meant to illustrate that we do not have to insert the factors of c, as is done. It is just a convenience to make the connection to Newton gravity more direct.
If one writes the Einsteins equations in its most beautiful form, one would use units such that c=1 and G=1/(8 pi).
For the example you mention: I think the only invariant question is whether you register photons (or neutrinos) from the explosion before you yawn, exactly when you yawn, or after. There is this star Betelgeuse, which is about to explode. Perhaps it has already exploded, in someones coordinate system (not very likely though), but light from the explosion has not reached us yet. The last part of the previous sentence is an invariant statement, the first is coordinate dependent (hence metaphysical).
Dear Kåre,
You say
"the concept of a light cone is also built into GR. This defines a maximum speed which ought to be the same as the speed of light in vacuum. In the limit of geometric optics the spacetime path of light, and all massless particles, should be null geodesics."
Hmmm! Yes! In the GR, the light-cone is a basic concept and your statement above is taken there as an axiom, a basic property of our universe. Next, the light-cone can be replaced by the cone of whatever massless particle.
I see here an interconnection between three concepts belonging to three different fields: light-velocity (electromagnetism), null mass (standard model, particle physics), and geodesics (GR).
But what for God's sake ( :-D ) has to do GR with electromagnetism?
Anyway, the above basic axiom can be reformulated as: null mass particles possess a velocity that cannot be surpassed, and which is invariant at a change of frame (defining null geodesics).
By the way, it seems strange to me that only the carriers of the long and medium-range fields, i.e. the gravitational and the electromagnetic, have null mass, while the carriers of the weak and strong interaction have rest mass. Why the boson of Higgs doesn't visit the photon and the graviton, to give them some rest-mass?
Best regards!
Dear Dr. Amrit,
First of all, it's not necessary to address me with "Dr.". We are all friends here. Therefore, Sofia is enough.
Now, the mass-energy equivalence E = mc2 is well-known. What seems mysterious is this strange connection between electromagnetism and gravitation, two different fields, with forces of different ranges.
I just downloaded your article and read it - it seems interesting and easily readable.
Best regards,
Sofia
Hello Vikram,
You refer to the kinetic energy of a photon in relationship to relativistic mass. Photons have energy E=hf and no rest mass, but kinetic energy is reserved for particles or object with rest mass, isn't it?
The convention about kinetic energy is that it is the excess of the total energy E of a particle with rest mass, over its rest energy Eo. So KE = E - Eo = mc^2 (gamma -1). When v^2/c^2 is small, this excess become nearly equal to KE = 1/2 mv^2 , otherwise the object's KE is more than this.
Richard
Dear Amrit,
Lorentz and Einstein simply took the constance of light's speed as a matter of fact. No explanation. Moreover Einstein could write the SR exactly thanks to the constance of light's speed (i.e. thanks to Lorentz factor).
I am sure that the reason why light behaves this way is found in the properties of quantum space.
1) if light moves through vacuum it actually moves through quantum vacuum = quantum space. Let's consider it as a superfluid.
2) Why then light couldn't be considered as a "sound" through this fluid? That is, why a photon couldn't be a phonon through superfluid quantum space? A pulse of space's quanta? All equations seem to confirm that this hypothesis is correct (see section 1.2 of the attached paper).
If this is true, we know after all, that also the speed of sound is constant independently from the source's speed (only frequency changes, exactly as for light > redshift).
In the paper (§1.2) you can really see how all equation confirm that photon is a phonon (discrete pulse) of space's quanta, also from a quantum point of view and as far as the dual nature wave/particle of photon is concerned.
Now, only a thing would remain unexplained. Supersonic airplanes can overcome the speed of sound but we can't overcome that of light. Why? The answer is that air (or water) is a newtonian fluid while superfluid quantum space wouldn't be.
By supposing that it acts as a superfluid until shear stress remains at subrelativistic velocities and it shows a dilatant behavior for shear stress (something moving through it) at relativistic velocities all SR is easily explained from a quantum point of view. Only a fluid reformulation of the equivalence principle is made. Coming back to the speed of light, if quantum space acts as a dilatant fluid is clear that acceleration has an upper limit and that the speed of sound (of light) through it is the maximum possible speed. Of course when I speak of sound I don't mean mechanical waves of atoms or molecules as in the air, but of space's quanta. I attach the paper. Greetings.
Article A superfluid Theory of Everything? [outdated version]
Dear Amrit,
In fact your ideas is same my idea in my paper Reinterpretation of Lorentz Transformation According to Copenhagen School and the Quantization of Gravity http://vixra.org/abs/1509.0059
And also in my other papers
1- AlMosallami, A. (2014). The Quantization of General Relativity: Photon Mediates Gravitation. IJSER, 5(10), 451–468. doi:10.14299/ijser.2014.10.002
2- AlMosallami, A. (2014). Time Contraction: The Possibility of Faster Than Light without Violation of Lorentz Transformation or Causality and the Vacuum Energy Dependent. IJSER, 5(4), 128–142. doi:10.14299/ijser.2014.04.001
Time Contraction: the Possibility of Faster Than Light Without Violation of Lorentz Transformation or Causality and the Vacuum Energy Dependent
http://vixra.org/abs/1401.0043
3- A Modified Special Relativity Theory in the Light of Breaking the Speed of Light http://vixra.org/abs/1111.0001
4- Quantum and Relativistic Theories Unified in Concepts Principles and Laws http://gsjournal.net/Science-Journals/%7B$cat_name%7D/View/2311
5- The Relativistic Quantized Force: Newton's Second Law-Inertial and Gravitational
http://gsjournal.net/Science-Journals/%7B$cat_name%7D/View/2310
6. Time Contraction: The Possibility of Faster Than Light without
Violation of Lorentz Transformation or Causality and the
Vacuum Energy Dependent http://www.modernscientificpress.com/Journals/ViewArticle.aspx?SfWnMobAtcwdxlLwAbWx2sGaHtaamxzv1MpVqJcbV022s2JCYyHy7HdpBwUNekcqmZmGpIYIRVPBYJG8jdVfqg==
@Richard Gauthier:
In your equation KE = E - Eo, when you put Eo = 0, you get KE = E = hf =mc^2. Here m is the kinetic energy equivalent of the relativistic mass of photon. So E = hf, is just the kinetic energy of photon.
Dear Amrit
How can we accept that a photon with speed c reash the earth from the sun in 8 min. while a particle with speed .99c cross the same distance in less than 2 min.. If the distance equals velocity * time, and if the velocity is the constant speed c while the time is variable(changing), could the distance (lHS of the equation) still keep constant?!
Dear Amrit,
Your papers are very great, and they are completely right. Do not let any one to change your mind and let you think contrary of that. Your reached to the reality. Congratulations!!!
Physicists understands well the reality, and thus relativity must be unified according to quantum theory since long time, since Einstein. But physicists close their eyes. They do not want to see the reality for many reasons.
Dear Salah A. Mabkhout,
The answer of your question is related to how quantum theory is dealing with time, since quantum theory separates between space and time, and thus according to the modified relativity space must be invariant. In classical mechanics, a special status is assigned to time in the sense that it is treated as a classical background parameter, external to the system itself. This special role is seen in the standard formulation of quantum mechanics. It is regarded as part of an a priori given classical background with a well defined value. In fact, the classical treatment of time is deeply intertwined with the Copenhagen interpretation of quantum mechanics, and, thus, with the conceptual foundations of quantum theory: all measurements of observables are made at certain instants of time and probabilities are only assigned to such measurements.
@Amrit,
I totally agree with your paper, where you state:
"time is a numerical order of material changes, i.e. motion which runs in quantum vacuum"
Time exists because of motion. A clock is consequently slowed down if their components get heavier and this is what happens when a clock moves through quantum space, due to an additional gravitational force opposite to motion due to quantum space's minimal viscosity, which gets however important when shear stress is pushed to relativistic velocities.
In short, time is movement, it is measured through movements which are produced by forces and clocks can be slowed down by forces (in fact they're slowed by gravity, which is a force). Moreover they're slowed down by speed since it implies a greater interaction with space's quanta (fluid equivalence principle, chapter 1 of the attachment), i.e. "gravity" also in this case. For this reason we will overcome a theory of SR without gravity... I show how SR can mathematically be included in GR. There are not two different causes of time dilation (velocity and gravity) but only one, gravity.
I'm sure we will soon stop considering time as a fundamental quantity.
Article A superfluid Theory of Everything? [outdated version]
Valentin,
At least as far as my studies are concerned, it is at rest, yes, BUT matter absorbs it (I see a particle as a superfluid vortex of space quanta, as a topological defect of quantum space) and this provokes flows of space quanta (what we call gravitational field). So, as soon as a gravitational flow occurs, quantum space (in that region) is not at rest. Where gravity tends to zero, it is. Therefore, my best answer could be:
it is at absolute rest until it's not perturbed by the presence of masses.
QS is a scalar field, like Higgs field, but probably the elementary one.
Vikram,
The equation KE=E-Eo = m(gamma-1)c^2 is meant to apply to a particle with mass (rest mass), which the photon doesn't have. Eo is the rest energy mc^2 of the particle. So you can't set Eo equal to zero for a photon as you did. Rather, set m=0 for a photon, and the relativity equation E^2 = p^2 c^2 + m^2 c^4 gives E^2 = p^2 c^2 + 0 , or E= pc for a photon which is correct. E is the total energy of the photon hf. You can call this the photon's kinetic energy if you want since the photon is moving at c. But it's not 1/2 mv^2 or 1/2 mc^2 since m=0 for the photon.
Richard
Sahleh> How can we accept that a photon with speed c reash the earth from the sun in 8 min. while a particle with speed .99c cross the same distance in less than 2 min..
Who are the we you are talking about, who don't think the particle needs (8/0.99) minutes?
We have said the same thing, which can be seen from eq.(4.1) and (4.2) of the following article. We are in agreement.
Research Alternative explanation for orbital period decay of a pulsar
Ales> ...also presumed speed of gravity...
I think it would be best to define it as the maximum speed of anything.
Why? Because it is not obvious to me that real photons will always move on null geodesics (even in the absence of anything material). Because the photon (and graviton) has spin, and the equations of motion for spinning particles are in general not exactly equal to the geodesic equations, due to a coupling between spin and curvature. It is not clear whether this effect remains for massless particles; I have not to wanted check. Because it is so amusing to think that photons may not move with the speed of light :-).
There is a similar analysis to be performed for the Maxwell equations in curved space. On top of that, there are small nonlinear corrections to the equations of electrodynamics, due to vacuum fluctuation effects (Euler-Heisenberg terms). So, in realty, it must be due to some deep symmetry if light travels exactly on the light cone in curved spacetime...!
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