At Rest with our Hubble view

LOL, coming from the most incompetent and dishonest person on the internet, John Duffield.

Therein lies the rub, Duffield, you aren't doing physics, you are playing with gifs and jpegs. Because you are unable to do physics.

The gif is not physics Duffield. Physics is being able to do the calculations, something that you are unable to do.

Einstein was wrong on this issue early on. He corrected himself whereas you persist in the same error, Duffield.

 

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Yes. Just like digital clocks. And atomic clocks. And mechanical clocks. And lifetimes of particles. All clocks show the same "tick rates" at the same region of the gravitational field; gravitational time dilation is independent of the clock mechanism.

I have no problem admitting when I am wrong, and have done so on a number of occasions. Now, let physics speak - present us with some experimental evidence that gravitational time dilation is dependent on the type of clock used, and its mechanism. Mainstream science says there is no such dependency, you say otherwise, so the onus is on you to provide the appropriate evidence.

I don't accuse, I am merely stating facts.

Yes, I thought you were going to say something along these very lines. You have played the "censorship" card before, just as you have the "abuse" and "insult" cards. Not very successfully, I might add.

What you said is that "objects fall down" because of "the wave nature of matter". Since GR is a model of gravitational interactions, you are thus implying that GR deals with the "wave nature of matter" in some form or another. If that is not the case, then we are clearly off in the direction of a personal theory of yours. So which one is it ?

No, you are merely and intentionally misrepresenting them.

No, I am thinking that space-time around Earth and on Earth and inside Earth is curved. Hence gravitational attraction. Hence frame dragging. Hence Thomas precession. Hence light deflection. Hence gravitational time dilation. And so on.

What trick ? A simple Google search yields the appropriate translations :

http://en.wikisource.org/wiki/The_Field_Equations_of_Gravitation

Note the use of the term "space-time" throughout, and the complete absence of any mention of variable speeds of light, just as I have told you previously.

This isn't really the point at stake, now is it. What we are discussing is your assertion that GR does not deal with space-time curvature, but instead only with flat spaces and variable speeds of light. Your assertion is that all gravitational interactions, of which GR is a model, can be explained via variable speeds of light in flat space. You are in essence saying that Einstein redefined the meanings of the tensors in his equations to take the "curvature" element out, i.e. he redefined the entire maths of differential geometry. Now try and back that up from Einstein's publications !

 

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I have a very simple scenario for you, which should be quite instructive, and should illuminate things a little.
Imagine a particle travelling along some geodesic which crosses through a given event; this shall be our reference. Now we imagine a second particle, and say that it initially travels parallel to the reference particle with some 4-velocity u through empty space. We assume for simplicity's sake that the particles are uncharged, and don't interact except through gravitation; let's further assume they are massive particles.

Now, so long as they are travelling through empty space their geodesics will remain parallel, no surprises here. If, however, we place a massive body somewhere in the vicinity of our particles ( let's imagine it to be point-like ), that parallelism will be disturbed, and the geodesics will deviate. In standard GR this is an almost trivially simple problem, since the geodesics follow the curvature of space-time; if the separation between the two particles' geodesics is denoted by the 4-vector v, the resulting deviation is

\(\displaystyle{\frac{D^2v}{d\lambda ^2}=-R(u,v,u)}\)

wherein R is the Riemann curvature tensor, and the capital D denotes the covariant derivative as opposed to the ordinary partial derivative. That's it. No assumptions about speeds of light, wave nature of matter etc etc needed. We are in fact not at all interested in any speeds, we only want to look at the separation between their trajectories, and separation ceases to be constant simply because space-time is no longer flat if we place a massive body in it. This is just a very simple model of gravitational attraction.

So now, how would that very simple scenario play out in your little world where space-time is flat, and only the speed of light varies ? What happens to the particles' trajectories, and why ? Remember also that we are not assuming photons here, these could be any type of particle, we place no constraints on it.

And don't even think about bringing out the "hiding behind the maths" argument - this is a simple, perfectly reasonable question about a perfectly simple scenario, to which we can expect an answer from you.

This should be interesting

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Quite right according to everything I have read. Even though GR is portrayed as being unchanging and firmly established by Einstein, BBT is the current cosmological consensus, and it has evolved as I have pointed out throughout this thread.

I stand corrected, but as you can tell, getting the particulars straight is like shooting at a moving target. Time delay can cause a miss, but of course there is no time delay in GR, right, lol.

I agree that the light clocks show the inhomogeneity, and I agree that any path other than perpendicular to the center of gravity will be curved. So I agree, if you plot any such path then the plot is curved.

The "natural geometric cause" was meant to be a reference to the strict mainstream consensus that there is no mechanism, it is "geometry". I agree that the cause is a concentration of energy, whether tied up as the matter of a star, or in the gravitational energy that the so called "mechanism" governs. We share the view that it is not a curvature of an abstract mathematical space that is absolutely static. We agree that space is not spacetime, and I recognize that is an alternative view right now.

That is fine between us, but I was just pointing it out. GR is what it is, although the further away you get from the EFE's and into the greater standard cosmological model of BBT with Inflation, the more room there for disagreement.

As far as it goes, that is perfectly consistent with my evolving view. Now if it was just the two of us talking, the issue between us would not be the inhomogeneity which we agree on, it is the cause of the homogeneity. We both say it is gravity, but the cause of gravity has a mechanism that orchestrates it, while GR and spacetime do not require any mechanism unless you call the geometry of spacetime a mechanism, and they don't. Maybe they don't because they cannot point to any physical nature of it, just math.

You and I differ there. Einstein lived a long and controversial life during a period in history where science as advancing in leaps and bounds. He said a lot of things, but he left us the EFE's. Anything beyond the EFEs can certainly be an honest portrayal of what Einstein said or thought at any time, so disputing GR on the basis of "but he said this or that" is a no win situation, IMHO.

 

You couldn't be any more right

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Petty Farsight doesn't get this.

 

A lot of what you say doesn't resonate with me but I'm not saying you shouldn't go off on tangents. Often it results in a learning experience. I'm not going to take on the role of teacher, but the thread has established a way to determine "who is moving", as opposed to when you said:

Motion can be observed relative to the background. Throughout the thread we have discussed the possibility of a fixed location in space relative to the generalized redshift and the CMB.

If that is the case, then any twin rocket thought experiment taking place anywhere in space should allow a determination of which twin is in motion and/or if both are in motion relative to the background.

 

Farsight has several balls up in the air and is trying to connect those things in a consistent way to keep them up there. We sometimes get to a point that we would prefer to fight the prevailing wind instead of letting one or another ball drop.

We, Farsight, you and I, agree on one thing:

Originally Posted by Farsight *
"The NIST optical clock runs faster when it's 30cm higher."

On a different topic, when you said something like "GR is deterministic", a question came to mind. Are you refering to the philosophical meaning of determinism? Can you elaborate on the difference between a static determined cosmology and a philosophical determinism?

 

Well there you go. You have actually exactly described the problem here.

In Farsight's GIF if you consider the higher light clock from the lower light clock, the photon has to have a velocity faster than the local (lower) speed of light (as viewed from the lower clock reference). This is clearly impossible. So the only way to come to terms with the situation is to consider that the relative wavelength of the two light clocks is different. Due to time dilation and length contraction, the wavelength can change while the velocity of the photons stays the same. Wavelength relates to energy and energy has to be conserved. Because energy contains units of space (length) and time, as the local space and time change, so do the local measurement of energy. It is relative. E=T+U. The T and U change but the E does not.

 

You may get some argument on that here, but I wouldn't go down that rabbit hole unless you link to this post on my latest "Alternative Theories" thread. Maybe it will give us something to talk about during Friday fun night

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Your alternate theory thread is dead. I don't plan to help you reactivate it. Maybe if you told me which point I mentioned that was in error I might be able to rebut.

 

I don't think it needs you to reactivate it. I'm capable of doing it, and plan to in my own sweet time

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Why would we link to your crackpot theories? Let them rot in the cesspool of "Alternative Theories".
To put Cheezle's words in a mathematical form:

Start with the Schwarzschild solution:

\((c d \tau)^2=(1-r_s/r)(cdt)^2-dr^2/(1-r_s/r)-(rd\theta)^2\)

For a clock that doesn't move radially \(dr=0\) so:

\((c d \tau)^2=(1-r_s/r)(cdt)^2-(rd\theta)^2\)

The above can be rewritten as:

\(d \tau=dt \sqrt{(1-r_s/r)-( r \frac{d\theta}{dt})^2}=dt \sqrt{(1-r_s/r)-r^2 \omega^2}\)

where:

\(r_s\) is the Schwarzschild radius
\(r\) is the radial coordinate of the clock
\(\omega\) is the angular speed of rotation
\(d \tau\) is the proper period of the clock

For two clocks situated at radial distances \(r_1\) and \(r_2\) on the geoid:

\(\frac{\lambda_1}{\lambda_2}=\frac{cd \tau_1}{cd\tau_2}=\frac{\sqrt{1-r_s/r_1-r_1^2 \omega^2}}{\sqrt{1-r_s/r_2-r_2^2 \omega^2}}\)

where \(\lambda_{1,2}\) are the wavelengths of the two (light) clocks. The same would happen with atomic clocks or any other wave-based type of clock.

 

People can argue with Cheezle all they want though I doubt that many would agree with him much of the time when he trys to "teach" us. Me, I've dealt with his attempts to miseducate people for a couple of years now, and I don't plan to here. And it is good that some of the least civil members stay clear of my "alternative crap" though, lol.

 

Yeah, what is the point of wasting your time learning when you can spend the time manufacturing your own alternative "stuff", as you have been doing for years?

 

Have you quit learning?

 

We are always discovering new fabrications, but that's not generally what we mean by learning

 

That is splitting hairs. Aside from discovering new fabrications, have you quit learning?

 

I think manufacturing new stuff is called discovery. Most learning is done after discovery, after it has been sanitized. Some people try to bring you in at the ground floor of discovery, but most people can't work well there but need it laid out for them.

Picture if you were hanging with Einstein, when he was just beginning to ponder relativity, but before it was thought of as science. He was the quack of his day, based on the consensus thinking of his time; learned thinkers. He work as a clerk, where the learned would not annoy him, and others would let him be, until he could dumb it down enough for the learned. Now anyone can memorize and if you are good at math can follow the derivations. Beyond that is where discovery begins again and learned are too smart to learn.

Discovery requires you put it out on the line. While learned allows a group defense of a linear thing. Until discovery becomes linear enough so all the learned can huddle together and no one learned person has to feel insecure.

 

What you, quantum-wave, OnlyMe, Farsight are doing is not "discovery".

 

This post is meaningless and without merit. It seems to be intended to provoke.