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EARTH DOES NOT CHANGE DIAMETERS. It is a relatively solid planet.
bizerl,So... no comment on realism, top of post 248 or "time" in post 249 or what space is, if anything besides 3-D volume, the void in which things and forces exist and move,i.e., NOT a malleable medium.
You simply assume that reality changes as it is differently observed, including that Earth changes shape as seen from a fast fly-by and that Earth moves closer to Alpha Centauri, as reckoned by a ship with a slowed down clock.
The "ACTUAL" diameter of Earth is nearly 8000 miles... a little shorter through the poles than through the equator. Earth science KNOWS this very precisely from measurements taken at rest with Earth... which is the "preferred frame" for accurate measurements of anything, as we discussed earlier.
Neat trick, moving stars and panets closer to each other and changing their shapes/diameters simply by the magical power of observation/measurement.
So objects have no intrinsic properties of their own, huh? It all depends on how you look at them? No "reality" per se. Each observer creates his own unique reality. Does the falling tree make no sound if it is not heard? Idealists say sound doesn't exist unless it is heard. What do you say?
At this point, you are not responding to what I am posting... not a conversation.
Scientific realism is, at the most general level, the view that the world described by science (perhaps ideal science) is the real world.
The job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference.
OK, so bizerl and the team of length contraction "experts" here insist that an Earth with a 1000 mile diameter is just as valid a description as the well validated nearly 8000 mile diameter. Please correct me if I am wrong.
So I ask the forum (whomever might be still be reading this thread), do you agree with the following, a recent summary statement I made here:QuoteThe job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference. This will be my last attempt to communicate in this thread if no one cares about the above enough to answer.Thanks.
I don't agree with this statement. In my view, the job of science is to understand how the world works through observation and experimentation, and to come up with theories and models that reflect those observations, regardless of how counter-intuitive their implications may seem.
The fact is that all the observational and experimental evidence that has been gathered so far, indirectly supports the fact that if a 20m spaceship flies through a 10m bay at 0.866c, it will (very briefly) fit exactly inside that bay.
So I ask the forum (whomever might be still be reading this thread), do you agree with the following, a recent summary statement I made here:QuoteThe job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference. ... as length contraction theory does.
SR is a very different approach, but it too can accommodate people who want absolute truths about the shapes of things, so you can easily regard the frame in which an object as stationary as being the one which shows its true shape. Many of the adherents to SR appear to believe that veiwing things from different frames of reference does change their shape though, and however surprising that may be to us, it isn't a requirement of SR that you believe what they do.
So far, you've shown us a model of reality in which you can send light faster than the speed of light simply by switching frames, and that's a broken model. There's no point in going on pushing it unless you can find a way to fix that flaw.
"Many of the adherents to SR appear to believe that veiwing things from different frames of reference does change their shape though..."It is to them (and they are many... and they run the show here) that I address my argument.
Regarding your assertions:QuoteSo far, you've shown us a model of reality in which you can send light faster than the speed of light simply by switching frames, and that's a broken model. There's no point in going on pushing it unless you can find a way to fix that flaw.I have answered this false assertion many times.
Realism is not concerned with switching frames of reference, as is the main criterion for "reality" or "the shape of things" or "the distance between things" in SR. See above, yet again, on the natural, intrinsic shape of things and their natual distribution in space, i.e., the naturally occuring distances between them... which does not change with how they are observed, as length contraction insists based on relativity's version of idealism.
The speed of light is constant. Light carries the images of things observed. These images vary as seen from different frames of reference. This does not mean that the physical objects themselves vary. That is where length contraction theory is confused. My intent for this thread has always been and continues to be to correct this confusion of images observed with those objects emitting or reflecting those observed images.
The MM experiment you have been discussing in another thread for instance has two arms of equal length, as the apparatus was built. An observer at rest with the apparatus sees them as they are, equal in length. Another observer, not at rest with it, sees one arm contracted in the direction of relative motion. No argument... He would see one arm as shorter. But that is just the image distorted by his velocity relative to the object.
A rigid object would require a force to squeeze or compact it into a shorter length than it was built. Lenght contraction theorists totlally ignore this fact, as they do not claim that any force is involved. But they also deny that physical objects have the intrinsic property of length, as manufactured or naturally formed, as above.
Here it is again in a nutshell... anyone...:QuoteThe job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference.
The trouble with that is that we have two big theories which both conflict with that. One theory (SR) has as part of its dogma the idea that all frames are equal, and that means that whatever distances are measured in any frame are as true as the distances measured in any other.
If that dogma was removed (which could be done without destroying the important core of SR), then the solution becomes the same as the one in LET where there is a correct, hidden truth about any distance, but you can't tell what it is. Your intrinsic distances don't take into account the contractions that may actually be applied to them, unless you take the trouble to declare clearly that they are subject to contractions which can't be determined.
What is much more important now is for you to find a position for yourself where the model you're pushing holds together properly, but that's either going to need length-contraction incorporated into it or some fiendishly clever alternative which no one's thought of yet.
The job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference. ... as length contraction theory does.
David Cooper:QuoteThe trouble with that is that we have two big theories which both conflict with that. One theory (SR) has as part of its dogma the idea that all frames are equal, and that means that whatever distances are measured in any frame are as true as the distances measured in any other."The trouble with that is"... That we have a "scientific theory", length contraction, claiming that, either science doesn't know (for instance) the true diameter of Earth, or that it varies from about 1000 miles, as measured from the old near 'c' fly-by, to nearly 8000 miles, as measured at rest with Earth.Earth does not change diameters. Therefore the theory that its diameter contracts is false.
Any rigid physical object requires a force to compact it into a shorter length (or diameter.) No force is applied in any case of length contraction. Therefore any observed contraction is due to the image being distorted by observation from extreme velocities. Different observations do not make physical objects change shapes or lengths. Claiming that that do is false.
QuoteIf that dogma was removed (which could be done without destroying the important core of SR), then the solution becomes the same as the one in LET where there is a correct, hidden truth about any distance, but you can't tell what it is. Your intrinsic distances don't take into account the contractions that may actually be applied to them, unless you take the trouble to declare clearly that they are subject to contractions which can't be determined.The truth about Earth's diameter (and the distance between Earth and Sun) is not "hidden." They are well and precisely known by legitimate Earth science and astronomy, yet denied by length contraction theory. The theory that objects and distances have no intrinsic properties but instead depend on the frame of reference from which they are observed and measured is false.
Realism says that the world exists and has intrinsic properties independent of how it is observed. (Best observed from at rest with the object.) Idealism says that there is no reality independent of observation, so that as observations vary, the objects/distances observed vary. Length contraction is based on idealism. It is wrong.
QuoteWhat is much more important now is for you to find a position for yourself where the model you're pushing holds together properly, but that's either going to need length-contraction incorporated into it or some fiendishly clever alternative which no one's thought of yet.My above replies state yet again "my position." So does the summary statement I've repeated several time now... which you still don't seem to understand:QuoteThe job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference.... as length contraction theory does.
The job of science is to study and accurately describe things as they are, not to re-create them as subjective versions of an infinite number of "realities" depending on who is looking at what from whatever different frame of reference.... as length contraction theory does.
You still don't get it, and I am again done with this "conversation" with you.
Mods,I need help (again) to shake this guy and his personal agenda "off my case."
And no: you are not a realist. Realism requires you to take length contraction on board in order to account for the results of actual experiments which show your "realism" to be wrong, but you refuse to do that.
David Cooper:QuoteAnd no: you are not a realist. Realism requires you to take length contraction on board in order to account for the results of actual experiments which show your "realism" to be wrong, but you refuse to do that.Yet again... Wiki:"Realism... the belief that reality exists independent of observers."
"Observers" include frames of reference as used in the context of lenght contraction.In other words, realism denies that different observations of the same object or distance (from different frames of reference) reflect real differences in those objects and distances.
(Force is required to actually change the shape or length of a physical object, and length contraction posits no such applied force.)
This is quite obvious in the case of Earth's diameter and distance to the sun, neither of which actually contract, even if they could be observed to contract from extreme relativistic frames.
The same principle holds for other supposedly "contracted" objects like my "probe"* or arms of the MM apparatus, or your train.
* It was measured from Earth to be 10 meters, approaching at .866c, but at as the shuttle pulls alongside to capture it, it is seen as it is... 20 meters long, twice as long as the shuttle bay. You never did get that one, an expose of... a reality check on... the length contraction fallacy.
The operative phrase in length contraction is always some version of "for observer A vs for observer B... the length is measured to be different."Realism insists that the objects themselves do not change even if observed/measured to change. Observers seeing an object differently does not mean that the same object actually changes.
Yet we have length contraction "theory" insisting that an Earth with a 1000 mile diameter is equally accurate ("no preferred frame") with the "real animal" which is nearly spherical with a nearly 8000 mile diameter.
The same principle holds for "length contracted trains" and the MM apparatus arms.
No, David, different observations do not create different lengths for the same object.