"The frame in which the CMB is at rest is in no way a preferred frame of reference and nobody but you is claiming that it is. You're free to use any inertial frame in which the CMB is in motion and it changes nothing because all inertial frame are equivalent."
A-wal, just to reinforce just how mistaken this claim is, I will quote the physics factbook website, which says:
"In 1987, a group of seven astronomers uncovered this coordinated motion of the Milky Way and our several million nearest galactic neighbors -- Alan Dressler, Sandra Moore Faber, Donald Lynden-Bell, Roberto Terlevich, Roger Davies, Gary Wegner and David Burstein. Their results were so astounding they acquired the equally astounding nickname of "The Seven Samurai"(the name of a classic Japanese Samurai movie that spawned the classic American Western movie "The Magnificent Seven"). The place towards which we all appear headed was originally called the New Supergalactic Center or the Very Massive Object until one of the discoverers, Alan Dressler, decided they needed a catchier name and came up with "The Great Attractor".
The mass of the Great Attractor truly is great....it's attraction is so strong that we are being sucked into it at the rate of 600 km/s. In comparison, the earth moves around the sun at the relatively pokey rate of 30 km/s and rockets escaping the earth's gravitational pull barely move at 11 km/s."
This has absolutely nothing to do with SR. Seriously, what the hell is wrong with you?
As a point of fact, cosmologists have been using the CMB as a preferred frame from which to calculate absolute motion for decades. This practice is almost universally accepted as is Smoot's claim that the CMB is a valid universal rest frame or purposes of calculating absolute motion. Needless to say, the proposition that absolute motion "can" be detected is also assumed, notwithstanding your denials. You seem to be just a tad bit behind the times as far as theories of motion go, eh?
Yes they prefer to use certain reference frames. Do you think that one of the postulates of SR is that no person or persons shall have a preference when choosing a frame of reference from which to compare motions? Or do you think maybe the term 'preferred' has different meaning when it's used in a scientific context?
Notice that, among other things, the accepted "fact" is that the earth revolves around the sun, not vice versa, and certainly not "both." As a practical matter, nobody accepts the "no preferred frame" premise of SR for everyday useage and ultimate conclusions about absolute motion, no matter how much they may otherwise claim that it is "valid."
Sr doesn't include gravitational acceleration. The valid equivalent here is that moon moves relative to the Earth, the moon moves relative to the sun, the moon moves relative to the centre of the galaxy and the moon moves relative to the greater universe. It moves at an entirely different velocity in each reference frame and all frames are valid, because there is no such thing as absolute motion.
It is assumed that absolute motion can be detected, and this can only be done by positing some frame as preferred. "Every" or just "any" inertial frame will not suffice for this purpose, because every one will give you a different answer. You must posit one which makes sense to treat as a preferred frame, such as the relative motionless solar barycenter for solar system purposes, as I have already pointed out. It would be inappropriate, and lead to inaccurate reults, for example, to use the CMB as a preferred frame for the purposes of calculating relative motion of the planets within the solar system.
Then you should be able to see that motion is an arbitrary choice of whatever object the observer compares themselves to. If you work out a planets motion around the sun then you get a completely different answer to a planets motion relative to the CMB, so there is no such thing as absolute motion through space!
I can almost hear your response now, which will be to call them all "highly stupid" like you did with Smolin because he didn't agree with your naive claims.
Why would I call them highly stupid? Nothing they said even remotely refutes anything in SR. I could however call someone who was under the impression that impression highly stupid.
The accepted resolution to the twin paradox simply adopts the earth's frame of reference as the preferred (as between the two twins) inertial frame of reference.
No it doesn't. The Earth's frame is simply the one the end up in. It makes no difference at all because all frames are equally valid, there is no preferred frame.
The earth twin assumes that he is motionless, and calculates the time dilation experienced by his travelling twin accordingly. As it turns out, his calculations are 100% correct, and his twin's calculations (which are premised on the incorrect supposition that HE is "at rest") are 100% wrong.
Both twins make the correct calculations from their inertial frame. Each twin is time dilated and length contracted from the the perspective of the other, they have to be for the speed of light to be the same for both of them despite they're motion relative to each other. Neither one is wrong, and they get the same results whatever their velocity relative to the Earth when the they start the experiment. The is no contradiction because they're in different frames of reference.
Many people who discuss this issue don't even know what the perceived "paradox" is. Many claim the "paradox" consists of the fact that clocks on moving objects tick at a slower rate than stationary ones. That is not a paradox at all, although the reasons for it might be mystifying.
The apparent paradox (not a genuine paradox) is that twin A ends up younger than twin B from B's perspective and twin B ends up younger than twin A from A's perspective. It's easily resolved simply by using the perspective of whatever frame of reference they end up in. It can be any frame. If the Earth twin accelerates out to meet up with the twin who's in motion relative to Earth then that twin (the one who left Earth last) will be younger.
The true paradox, which has never been resolved (by SR, anyway), lies in the inconsistencies generated by SR itself. If, as SR claims, all inertial frames are "equally valid," then why is the earth's frame preferred in this case? That inconsistency is what creates the paradox.
Earth's frame isn't in any way preferred, it's simply the frame they end up in. It works the exact same way if they start from a frame that's in motion relative to the Earth.
Put another way, how is it possible to get an absolute answer from a theory which posits that all motion is strictly relative? An absolute answer should be impossible to arrive at if the premises are correct.
It's easy to get an absolute answer once you actually understand the model. It's very straight forward and gives definite and absolute results but definite and absolute results that use relative rather than absolute motion and a constant speed of light in all inertial reference frames. This is the only way to get the correct answer.
The term "paradox" has been defined and explained as follows:
"a statement or proposition that, despite sound (or apparently sound) reasoning from acceptable premises, leads to a conclusion that seems senseless, logically unacceptable, or self-contradictory."
Nothing in SR is senseless, logically unacceptable, or self-contradictory. It's counter-intuitive if you're not used to it and some people simply don't have the intelligence required to grasp it. Unfortunately some of those people would rather live in denial and insist that the model must be wrong because they find that easier to swallow.
The way to resolve a paradox is NOT to accept mutually exclusive claims as both being true. That is what creates the paradox, not what resolves it. The solution is to determine what aspect of a claim is, despite being "apparently sound," actually unsound, and then reject, rather than accept, that aspect.
Yes, but there is no paradox in SR.
The twin paradox is easily resolved by rejecting the self-contradictory claim that "all inertial frames of reference are equally valid." Once that's done, all of the numerous "paradoxes" generated by SR disappear.
No, that actually creates a paradox where none exists because we know that the speed of light is the same in all inertial frames of reference and the only way that can be true is described by SR.
An apologist for SR is prone to say that the stay at home twin and the travelling twin are "both correct" in their calculations. But this is logically impossible, and so, not surprisingly, the accepted resolution denies that they are "both correct." The resolution says that only one (the earth twin) is correct in his calculations and that the other (the travelling twin) is incorrect in his calculations.
So then, SR "resolves" the paradox it creates in the only way it can--it denies the soundness of its own premises. In order to resolve the paradox, it must abandon the claim that all inertial frames are equally valid and that therefore absolute motion cannot be detected.
Utter BS! The Earth's frame is in no way a preferred frame in the twin paradox, it's simply the one they end up in when they compare their age at the end.
SR apologists are also prone to point out that the situations of the two twins are "not symmetrical." This is absolutely true, of course, but does nothing to answer the question posed. Of course they are not symmetrical--one is moving (relative to the other) and one is not. What the SR apologist does not, and cannot, explain or reconcile, is the concomitant claim that absolute motion cannot be detected.
One is moving and one isn't? Moving relative to what? They are moving relative to each other. There's nothing to reconcile, that's the only type of motion that can be determined and that makes any sense.
Feynman said that the answer to the twin paradox is simple: The one which has accelerated is the one who experiences time dilation, he says. He's undeniably correct, because it is the one who has accelerated that is moving (relative to the one who has not). And in SR (and every other theory which adopts the LT, for that matter) it is the moving clock which slows down. Acceleration is universally admitted (even by SR) to be absolute motion, not relative motion.
It is the one who accelerates that experiences less proper time in the twin paradox but acceleration itself isn't the cause. If they repeat the test again and the twin who leaves Earth accelerates to the same velocity relative to Earth as before but waits twice as long before turning round and coming back then the difference in proper time that elapses for the two will be double what it was the first time, but the acceleration was the same.
To elaborate somewhat, the proposition that "all inertial frames are equally valid" is, in certain respects, true, (the laws of physics are the same, for example). But one of the conclusions drawn from this "equality" by SR is unwarranted and fallacious.
The unwarranted conclusion is this: Therefore you can never say which of two objects is moving relative to the other. That by no means follows. There are a great number of ways to determine which (of two) clocks is moving relative to the other. SR itself (the LT, actually) provides the means to determine that, because it holds that the "moving" clock will run slow.
Empirical experiments, such the one performed by Hafele and Keating, show that clocks do tick at different rates due to varying speeds. So, when the experiment is complete, you only need see which clock(s) have slowed down. Those are the ones that were "moving."
Needless to say, notwithstanding the incoherent claims of SR to the contrary, the H-K experiments empirically prove that each of two clocks do NOT record elapsed time which is less than is recorded by the other. Time dilation is simply not "reciprocal," as SR claims.
More complete BS. Objects that are in motion relative to the frame of reference of the observer will be length contracted and time dilated. This is true in all inertial frames, if object B is time dilated and length contracted in the reference frame of object A than object A is time dilated and length contracted in the reference frame of object B. This is the only way that the speed of light can be constant in all inertial frames. The one clock that shows less elapsed time is the one that was in motion relative to the frame of reference that they end up in.