At Rest with our Hubble view

[Undefined]

This is false, the invariance of light speed is not "derived", it is postulated. Please stop posting crackpottery while trying to pass t as science.






There is no "difference", constant means invariant. Please stop posting crackpottery while trying to pass t as science.




Nonsense.




No, this is just your cranky contribution to the confusion.





False, c doesn't "vary". Please cease posting crackpottery while trying to pass it as science.





Experiment (and mainstream theory) says that the above is poppy cock.





Experiment says that the above is false. Mainstream SR contradicts your claim. Where do you get all this BS?




False.




Who is "we"? the crackpots that claim the above?



A long series of fallacies. Nonsense from beginning to end.

In the context involved, the postulate is based on the "frame dependent measurements" involving the relative "t" for each frame the measurement is made in to give rise to the "postulated" invariance". Get it?

The rest of your disconnected fixation on isolated remarks is also of equal worth. Hence eminently ignorable as mere opinion lacking in contextual understanding of the points as made in context.

If you could ever rid yourself of the intellectually limiting habit of taking things out of context and ignoring the overall thrust of the aguments made, you would help your own understandings and not be found so wanting as an 'expert' time and time again.

Thanks anyway for your interest if not your bad intellectual habits.

 

[Cheezle]

Brucep, that would be correct assessment..."energy[/physical] cannot be created nor destroyed".....

To best of our knowledge all observations of speed-of-radiation, is a constant, and I got thinking about how, even those radio or near microwave frequencies are shorter or longer relatively speaking, the trees, rock whatever, cause interference but they do not cause invariance, at our medio-macro scale of existence ergo observations.

Loop Quantum Gravity predicted at ultra-short frequencies, radiation would be interfered with by gravitational spacetime--- aka a gravitonic foam ---and that was somehow suppose to be differrent than trees or rocks interfering with EMRadiation i.e. the graviational spacetime foam would intefere only enough to retard the speed-of-radiation, not completely transform it into electronic matter/fermion.

So we still have the mysterious constant c--- that we observe in quantum ---and the mysterious graviational spacetime that we do not observe in quantum--- ergo continous aka smooth ---.

r6

As far as the creation question goes, creation requires a before, during and after. If there was no before then there was no creation. Which makes us ask, then what happened? Well, "to happen" seems to also require the concept of a before. Every process we can talk about seems to require a before, during and after. So people say, that time and space were "created" in the big bang, but that is just a convenient way to talk about a situation that we can't really talk about in normal language. What ever "happened" is beyond our experience to understand.

If you have ever read the Tao Te Ching you will see something similar there. The Tao is a concept that can not be understood. It is said to be a great mystery. You can try and talk about about it in terms we all understand, but you will always fail. The creation of the universe was like that. The closest thing we have to it is a black hole, but he universe did not start as a black hole. It is a mystery. The only possible way we seem to have to talk about the subject is spacetime geometry.

1.1 The Tao that can be expressed is not the eternal Tao; The name that can be defined is not the unchanging name.
1.2 Non-existence is called the antecedent of heaven and earth; Existence is the mother of all things.
1.3 From eternal non-existence, therefore, we serenely observe the mysterious beginning of the Universe; From eternal existence we clearly see the apparent distinctions.
1.4 These two are the same in source and become different when manifested.
1.5 This sameness is called profundity. Infinite profundity is the gate whence comes the beginning of all parts of the Universe.​

The passage above is somewhat circular in its logic. It starts by saying that whatever it is can't be named, and then it sets about naming it. But what else can you do? great mysteries are greatly mysterious.

 

[Tach]

In the context involved, the postulate is based on the "frame dependent measurements" involving the relative "t" for each frame the measurement is made in to give rise to the "postulated" invariance".

False: Postulates are not based, they are given. "Relative t" does not "give rise to the postulated invariance". The rest of your sentence is a re-hash word salad of the nonsense that you posted repeatedly.

Get it?

Yes, I get it, you are posting pure crackpottery trying to pass it as science. You've been doing this for a long time.

If you could ever rid yourself of the intellectually limiting habit of taking things out of context and ignoring the overall thrust of the aguments made, you would help your own understandings and not be found so wanting as an 'expert' time and time again.

There is nothing I can do, you make so many mistakes per sentence, I have to cut up your cranky text into pieces in order to point out your mistakes and falsities.

Thanks anyway for your interest, if nor your bad intellectual habits.

You are welcome, please refrain from polluting the thread with more of your crackpottery.

 

[Undefined]

False: Postulates are not based, they are given. "Relative t" does not "give rise to the postulated invariance". The rest of your sentence is a re-hash word salad of the nonsense that you posted repeatedly.



There is nothing I can do, you make so many mistakes per sentence, I have to cut up your cranky text into pieces in order to point out your mistakes and falsities.



You are welcome, please refrain from polluting the thread with more of your crackpottery.

Given? By whom, and from where do they arise in the mind of man who postulates it? It is from observtions from nature around us and logical mathematical indications that 'postulates' are prompted/derived for someone to 'put' in the first place.

Look, Tach, it is well known you argue rashly out of some compulsive need to prove 'superiority' or whatever, but sometimes without full cognizance of that which you speak. That is what has landed you into trouble more than once. For a moment there you seemed to be improving your intellectual capacity for actually understanding rather than twisting what is being said and why. Your choice. But if you persist, all I can do (as advised by management) when you are behaving thus is to simply thank you politely and ignore your games. Hence, thanks and bye.

 

[Tach]

Given? By whom, and from where do they arise in the mind of man who postulates it?

By Einstein, since 1905. Try taking a class, beats posting BS and trying to pass it as science.

 

[Undefined]

By Einstein, since 1905. Try taking a class, beats posting BS and trying to pass it as science.

Read the rest properly (I edited while you were hurrying to reply).

Ie, where did Einstein come up with said postulate, etc? Get it now? Thanks anyway for your interest.

 

[Tach]

Read the rest properly (I edited while you were hurrying to reply).

You replace one hilarious error with another hilarious error in an attempt to conceal your ignorance on the subject.

Ie, where did Einstein come up with said postulate, etc? Get it now? Thanks anyway for your interest.

Why do you persist in trying to cover your ignorance and crackpottery? Einstein came up with the postulate of light speed constancy in his 1905 paper " The Electrodynamics of Moving Bodies". Take a class, stop wasting your time posting BS.

 

[Undefined]

Why do you persist in trying to cover your ignorance and crackpottery? Einstein came up with the postulate of light speed constancy in his 1905 paper " The Electrodynamics of Moving Bodies". Take a class, stop wasting your time posting BS.

The "who?" and "By whom" was rhetorical. Can't you see that in the context?

I knew full well who postulated what. I pointed out that the postulation was prompted by something, and that something was the necessity of trying to reconcile the observations of the times and make mathematical/geometrical relationships which would be consistent with these observations. Hence the 'derivation' of the postulate from the observation of light over space distance during a "relative t" applying in the frames where the observations and the calculated "measurements" were made.

Do you ever stop to think about the full context of a discussion/point? Apparently not.

Good luck and thanks for your pedantic and trivial argumentations while you continue to miss the original point I was making about the subtle but crucially important difference between 'invariant' and 'constant' in this context which makes these two not equivalent as you and certain other 'experts' seem to believe even though it has been explained to you where your confusions derive from (ie, from you treating the term 'invariant c' and the term 'constant c' as effectively/logically one and the same things/concepts...which they are not in this context, as I explained already and as you would understand if you will only read properly for a change).

Bye.

 

[quantum_wave]

Sometimes I wake up and am amazed at the developments on my threads over night. My posting and threads over the years have become a hobby of mine for the purpose of discussing thoughts and ideas about the nature of the universe. I have developed what I call my "so called model" of the universe so I have talking points, and it evolves over time as a result of my own reading, surfing, and conducting discussion threads. Often my threads become a "meeting place" for all kinds of chat and discussion, on and off topic, and I have started hundreds of threads in various forums over twenty or so years.

By doing so, sometimes people make more of that than can be made if you go by what I say about it myself, but go figure. Its the Internet, and it has become a part of our subculture to present, and to mine what has been presented in open forums for things we think will be of interest to someone. Sometimes people are interested and sometimes not, and my view is that my threads and posts are generally not interesting to more that a tiny few.

Just like it is fun for me keep my views widening and evolving, it is fun for others to dispute those ideas, and the Internet is well known for good and bad ways to do that. My threads historically are full of discussion of ideas and flaming of ideas and people, but we all come together to state our opinions, and/or respond to, or ignore the opinions of others. The result is a growing "thing" we call the Internet. It remembers even if no one in particular pays attention. It is a history out there for people to spend their time with, or waste their time with, and how we individually do that can become a way judge each other if that is something we are in to.

Have fun and enjoy it, but don't take it too seriously on its surface. Meaningful things will find their own depth over time.

(29255)

P.s. Is there a secret agenda hidden in the unsaid things on my threads?????????? Is Cheezle on to something with that??????????? Stay tuned ...

 

[Farsight]

The speed of light in a vacuum is measured to be the same in all frames and FROM all frames. If a spacecraft passes an observer at relativistic speed with a beacon flashing inside his cabin that can also be seen by the observer, both the observer and the passenger would measure the speed of the light from that beacon the same. The observer would see the flashes coming faster or slower(time dilation due to speed)and the light would be shifted(toward blue while approaching, then the correct color as it went by and red as it receded. The Doppler effect). The passenger would see no such shift in frequency. In all cases all parties would measure the speed of light in a vacuum to be the same. Period. This is one of the most tested LAWS of our Universe, nobody will be making a dent in that fact.

You always measure the local speed of light to be 299,792,458 metres per second. But you know that gravitational time dilation means the seconds at one location are not the same as the seconds at another. That's a fact. So you know that one 299,792,458 m/s is not the same as another. You also know that the coordinate speed of light varies in a gravitational field.

Farsight

Your "bouncing ball" diagrams are demonstrating frequency change, not speed change. In your diagrams motion is vertical and does not vary, while the frequency is horizontal, slowing with gravity, varying with Doppler as well.

Not so. Motion is horizontal, frequency is irrelevant. In both cases the motion is at 299,792,458 metres per second, but the seconds at one location are not the same as the other, so the two speeds are not the same.

I see Aqueous is rather railing instead of addressing the physics. Note the following Einstein quotes:

1911: If we call the velocity of light at the origin of co-ordinates cₒ, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = cₒ(1 + Φ/c²).
1912: On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.
1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light).

Einstein overturned his SR postulate, which was the constancy of the speed of light.

 

[przyk]

I see Aqueous is rather railing instead of addressing the physics. Note the following Einstein quotes:

1911: If we call the velocity of light at the origin of co-ordinates cₒ, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = cₒ(1 + Φ/c²).
1912: On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.
1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light).

You rely on the same argument from authority that you always do. Those are words. Not physics.

Einstein overturned his SR postulate, which was the constancy of the speed of light.

Hardly, since the postulate you are referring to only says that the speed of light is invariant for inertial reference frames. This is just as true in GR as it is in SR: if you have a family of (globally) inertial reference frames then they all share the same constant speed of light. Period. The only thing that is overturned is that GR denies that globally inertial reference frames can always be defined.

I would also like to remind you that the main reason behind gravitational time dilation is simply the fact that if we're standing at a fixed altitude above the Earth's surface we are actually -- as far as GR is concerned -- accelerating. Everything you see if you play with two atomic clocks at different altitudes on Earth you would also see, to first order at least, if you did the same experiment with clocks placed in different locations in an accelerating rocket. This can be derived entirely from SR.

 

[Farsight]

przyk: those are Einstein's words, don't dismiss them. And don't dismiss the physics either. The principle of equivalence was instrumental to Einstein in developing GR, but when we're standing on the surface of the Earth in front of two NIST optical clocks, we are not truly accelerating. However the lower clock truly goes slower than the upper clock. The same applies to the parallel-mirror light clocks.

 

[Cheezle]

1911: If we call the velocity of light at the origin of co-ordinates cₒ, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = cₒ(1 + Φ/c²).
1912: On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.
1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light).

Einstein overturned his SR postulate, which was the constancy of the speed of light.

You are making a mistake here that we are all warned about in introductory physics courses. There is a difference between velocity and speed and many a student has made that mistake. If in the quotes above you replace "velocity of light" with "speed of light" then the statements would no longer be true. Einstein was specifically referencing the fact that light curves in gravitational fields. That curvature implies a change in direction, and so a change in velocity. This quote is NOT about the speed of light. It is quite obvious. All that Einstein is saying is that light rays curve in a gravitational field. A little later in the theory he talks about an experiment to verify the curvature of light due to gravity.

It is quite true that the velocity of light changes with position, in a gravitational field. It is kind of a no brainer now, but in 1916 it was kind of a big deal.

Other people have told you this before, But I just thought I would emphasis it. These quotes of Einstein's do nothing for your argument. IF you still think that Einstein thought the SPEED of light changes, then you will have to find that in his theory. I think that if he had said such a thing, then he would have given it a section all to its own and emphasized it repeatedly. It should be easy to find if it exists.

 

[Grumpy]

Farsight

You always measure the local speed of light to be 299,792,458 metres per second

Yes.

But you know that gravitational time dilation means the seconds at one location are not the same as the seconds at another.

Yes. Motion gives similar TIME dilation.

So you know that one 299,792,458 m/s is not the same as another.

Actually, lightspeed remains the same, it is frequency, wavelength, time and distance which change in the direction and to the extent necessary to insure that the actual and measured lightspeed remains constant, it is an intrinsic property of spacetime, as I explained in my last post. ALL light travelling in a vacuum throughout out Universe moves at exactly the same velocity, you will find no measurement of the speed of any photon, anywhere in vacuum, that moves at any other speed, period. That is a fact, no matter what frame you are in or what frame you are observing. Invariant means just that, it does not vary in speed. It is the linchpin around which all other properties pivot.

Not so. Motion is horizontal, frequency is irrelevant. In both cases the motion is at 299,792,458 metres per second, but the seconds at one location are not the same as the other, so the two speeds are not the same.

Horse poo, for your images to accurately portray light, motion must be vertical, the slowing is a slowing of the frequency, not the speed of light in a vacuum(which does not vary). You obviously know nothing about Relativity, it would behoove you to seek an education, stop assuming you already know, it's obvious you don't.

Grumpy

 

[rr6]

Time 2-fol---- Fading past)( dawing future--)2D time eternal NOW(

Cheezle .."As far as the creation question goes, creation requires a before, during and after."

Aka time/frequency/motion/scenario of events.

If there was no before then there was no creation.

Cheezle, I don't follow that logic. If there was no-- [physical/enerygy existence before ] ---then there IS a "creation" event.

Which makes us ask, then what happened? Well, "to happen" seems to also require the concept of a before.

Thats correct assessment, because physical/energy exists eternally in some form or another, and at minimum only as gravitational spacetime.

Every process-- ergo vectorial events and time --- we can talk about seems to require a before, during and after. So people say, that time and space were "created" in the big bang, but that is just a convenient way to talk about a situation that we can't really talk about in normal language. What ever "happened" is beyond our experience to understand.

I can talk about it in normal way. There exists infinite non-occupied space that embraces within, a finite occupied space of quasi-physical-- because ultra-micro ---gravitational spacetime and physical/energy

If you have ever read the Tao Te Ching you will see something similar there. The Tao is a concept that can not be understood.
It is said to be a great mystery.

Yeah the invariance of speed-of-radiation( c ) and spooky-action-at-a-distance.

You can try and talk about about it in terms we all understand, but you will always fail. The creation of the universe was like that.

Physical/energy cannot be created nor destroyed and at minimum can only exists as a finite gravitational spacetime.

The closest thing we have to it is a black hole, but he universe did not start as a black hole. It is a mystery.

Black holes appear to us being macro-finite. As for them being micro-infinite well that is presumed by some perhaps. However, if I recall, some or all black holes are said to eventually evaporate. If this latter 'evaporation' is the case then black holes are not micro-infinite.

I think the easy way to visualize a black hole is in the following link to a scenario of a tetrahedron going to zero-volume and therein defining a cubo-octahedron, that, if all were in spherical form, the four internal bisecting planes that define a cubo-octahedron are exactly equal to its surface--- think event horizon ---.

The only possible way we seem to have to talk about the subject is spacetime geometry.

I would restate that as eternally existent, geodesic, gravitational spacetime. At the Universe's entropic heat death end--- superficial ending ---it is said that all physical/energy will become one very large and very flat least energy ergo longest wave/frequency photon.

If this is to occur, I believe there will exist on both sides of this finite, flat--- seemingly 2D --photon, two geodesic sets of 31 or more great/equlatorial circles of gravitational spacetime and that these geodesic are the fundamental/primary patterns for all bosons. Here is my simple texticon to express this simple concept O!O

The Tao that can be expressed is not the eternal Tao;

2D---)'NOW'(----

The name that can be defined is not the unchanging name.

Metphysical-1 mind-intelligence concepts as eternal cosmic truths aka finite set of absolute cosmic/generalized laws/principles.

1.2 Non-existence is called the antecedent of heaven and earth;

This is 2-fold set of existence;

1) metaphysical-1---absolute and relative truths as mind/intelligence,

2) metaphysical-2---non-occupied space( macro-micro infinite )

Existence is the mother of all things.

1)Finite set of Gravitational spacetime---5/phi-fold icosahedral set of 62 left and right skew great/equaltorial circle/tori/rings as the embracing and restraining womb of,

2) Finite set of physical/energy--- see fermions and bosons ---

The nucleated--- 12-around-one ---cubo-octahedron/vector equlibrium is the pregnant "mother", once the one is born-out--- pop-out to outside surface, then the 12 contract to the more stable icosahedral formation of 12-around-none. This is geometric fact.

1.3 From eternal non-existence, therefore, we serenely observe the mysterious beginning of the Universe; From eternal existence we clearly see the apparent distinctions.

See my texticon above--- O!O ---is ending and beginning of eternal set of cyclings of our finite existence called teh occupied space of existence.

1.4 These two are the same in source and become different when manifested.

Cheezle, there is no cosmic "source" for the existence of our finite Universe of gravitational spacetime and physical/energy.

The closes we can come to placing a "source" attribute to Universe is why is it the only perpetual motion machine? I've laid out in this thread previously how the oddity of 2-1 ratio of triangle--- see 3 quark stable proton analogy --- can provide that answer for Universe eternally chasing its own tail.

1.5 This sameness is called profundity. Infinite profundity is the gate whence comes the beginning of all parts of the Universe.[/I][/INDENT]

Finite gravitational spacetime is said to be smooth--- not gravitonically grainy --and I believe that is incorrect. Rather it is occurring at ultra-micro scales ergo it appears to me-- if not us ---as being of hyper-spatial dimension.

Our finite Universe can never exist in equlibrium state/phase i.e. Universe abhors eqilibrious sameness. Or at best Universe can briefly pass through such a state/phase on its way between left or right skew existence on at minimum for differrent possible cosmic axi.

The passage above is somewhat circular in its logic. It starts by saying that whatever it is can't be named, and then it sets about naming it. But what else can you do? great mysteries are greatly mysterious.

A circle chases its own tail because the minimal circle is a triangle with a 2-1 ratio occurrence. imho. A simple, 2D understanding of ultra-macro complexity of interrelationships far beyond the accounting abilities of humans or any of its computers. imho.

r6

 

[quantum_wave]

Some advice I have heard and like: Trust people who are seeking the truth, and not people who say they have found it.

From the perspective of GR, gravity is the curvature of space time ... how? My answer is that the concept of space time works and the math is the best we have to describe gravity. But there is no "how". My ideas about gravitational waves, wave energy density of space, quantum action at a foundational level, and arena action on a grand scale work together to provide an explanation of the "how" that satisfies me so far, but it is far from complete. However, it doesn't change reality, it is just one set of hypotheses that work better for me because they contain the mechanics of "how" gravity works, what caused the big bang, and what causes the presence of particles. Why would I care what others think about it who haven't listened, asked questions, challenged some content? And you don't do that by telling me your favorite model and saying you have the truth.

Certainly I don't expect anyone to follow the thought patterns that have lead me to my so called model as I seek the truth, and if they don't know the thinking step by step but say it can't be so because they have found the truth, I don't trust them any more than they trust me. But we are having fun, right.

(29394)

 

[Tach]

The "who?" and "By whom" was rhetorical. Can't you see that in the context?

What I can see (from all your posts) is that you are clearly ignorant on all subjects. Despite you pretending. Give the trolling a rest, stop trying to pass crackpot BS as science, take a class.

 

[Grumpy]

Farsight

Einstein overturned his SR postulate, which was the constancy of the speed of light.

No, he modified it with General Relativity.

1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position.

One of the things Einstein had to modify, it is not the differential in velocity, it is a curvature of the straight lines through spacetime that light always follows. LIGHTSPEED IS ALWAYS THE SAME, it never varies, everything else varies in the direction and to the extent necessary so that light always has the same velocity, it is like the floor upon which all other events occur, no matter what everything else does, that floor is still there, the same for all observers. And the point is that ALL frames see light moving at the same speed both within their own frame and from ALL other frames, no matter what. The light coming from some Neutron star teetering on the edge of collapse into a Black Hole will certainly be shifted in frequency/wavelength, but every photon is measured to be travelling at exactly the same speed as every other photon ever measured anywhere in the Universe. There is no such thing as slow light in a vacuum, from any source, in any frame. It's not intuitive, it doesn't match our experience, it requires an effort to understand, but it's true.

Until you understand that the speed of light is a fundamental, physical constraint/requirement for our Universe you will never understand our Universe at all. For some reason it is the one thing that everything else is regulated by, Mass is equivalent to energy by the ratio of lightspeed squared, time and lightspeed are inversely proportional for anything with mass, though it is impossible for anything with mass to even reach lightspeed, as it gets near lightspeed it's energy level causes increased mass(mass=energy=mass), requiring more energy to go ever smaller increments of additional speed in an infinite spiral where the mass nears that of the entire Universe and the energy nears infinity, it's all tied together with the value we measure for the speed of photons in vacuum. This was the stupendous insight that Einstein had that led to SR and GR. He didn't get everything right(CC, "dice"), but he sure hit that one right out of the park. That understanding led to our current Cosmological understanding, yet you want to deny it. Good luck with that.

Grumpy

 

[Tach]

Einstein overturned his SR postulate, which was the constancy of the speed of light.

Duffield, I see you go away for a while after being thoroughly embarrassed , you wait for the embarrassment to be forgotten and you come back with the same crank ideas. Einstein did not "overturn his SR postulate", you, like Undefined , do NOT understand relativity. Light speed is an invariant. Live with it.

 

[Farsight]

You are making a mistake here that we are all warned about in introductory physics courses. There is a difference between velocity and speed and many a student has made that mistake.

It isn't a mistake Cheezle. Really.

If in the quotes above you replace "velocity of light" with "speed of light" then the statements would no longer be true. Einstein was specifically referencing the fact that light curves in gravitational fields. That curvature implies a change in direction, and so a change in velocity. This quote is NOT about the speed of light. It is quite obvious. All that Einstein is saying is that light rays curve in a gravitational field. A little later in the theory he talks about an experiment to verify the curvature of light due to gravity.

Look at the quote again. Einstein is saying one of two things:

A curvature of light occurs because the speed varies with position.
A curvature of light occurs because the direction changes with position.

The second one is tautological. It's as much use as "light curves because it curves" and makes no sense whatsoever. And Einstein referred to the SR postulate. That was the constant speed of light.

It is quite true that the velocity of light changes with position, in a gravitational field. It is kind of a no brainer now, but in 1916 it was kind of a big deal.

The big deal is that what you've been taught is wrong.

Other people have told you this before, But I just thought I would emphasis it. These quotes of Einstein's do nothing for your argument. IF you still think that Einstein thought the SPEED of light changes, then you will have to find that in his theory. I think that if he had said such a thing, then he would have given it a section all to its own and emphasized it repeatedly. It should be easy to find if it exists.

He said it repeatedly in papers between 1911 and 1916. I gave the quotes. And yet people dismiss them along with the parallel-mirror gif.