<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>No, I attack Lamda-CDM theory as though it's an *untestable* and *unfalsifiable* piece of mainstream dogma. I know darn well it's never been "tested" at all. You can't test for 'dark energy' or 'dark matter' because neither of these things exist in nature. It's a theory based not on testeable physics, but rather unfalsifiable metaphysical constructs. </p><p> <font color="#0000ff">This is utter nonsense. Untested and untestable are not the same at all. There is quite a bit of work ongoing to find a way to verify the hypotheses of the Lamda CDM model, just as there is for other hypotheses. The existence of the Higgs boson is, at this stage just a workable hypothesis. Maybe the CERN experiments will confirm it. Until then a competing theory, consistent with what has been proven, would be objectively evaluated.</font></p><p>I'm keenly aware that it was never "tested" at all."Best available hypothesis" by who's standards? IMO EU theory is a far superior theory because it is based on *testable* aspects of physics. </p><p><font color="#0000ff">Sorry, but you have proved yourself to be completely blind to the overall body of physical theory, EU is indeed testable. It has been tested and found to be invalid. Plasma physics is pretty well known and valid. But extrapolating some small-scale descriptive demonstrations from the laboratory to large-scale astophysical statements that provide no non-trivial predictive capability is not good science. It is in fact shoddy science.</font></p><p>The fact people make *inacurate guesses* with Lambda-CDM theory does not make it a "best" theory. Yep, it's 95% unvalidated, and 95% unfalsifiable too. I can't demonstrate a negative, so emprical science is based on physically demonstrating the existence of something *before* making up a metaphysical mythos based on the idea. Nobody demonstrated that "dark energy" could accelerate plasma before claiming "dark energy" was responsible for the phenomenon of acceleration. You can't even test the idea because you have not idea where "dark energy" comes from, so it is physically impossible to test the idea or falsify the idea. That one metaphysical construct makes up nearly 3/4 of the Lambda-CDM theory. </p><p><font color="#0000ff">You are, as usual, completely and utterly, misrepresenting the issue. The model merely says that IF dark matter and IF dark energy exist then the consequences for predictions using general relativity would be consistent with what is observed. That in and of itself does not guarantee that either exist. There may be alternate explanations that would provide a similar result. We just don't have any alternate explanations available -- and EU is not a valid alternative.</font> </p><p> The rest is mostly made up of "dark matter", which again is completely unflasifiable because it's never been demonstred to exist or have any effect on nature. Yes, I'm well aware of the history here, and this in fact was the "theory" that I was taught in school. The term "dark matter" referred to nothing more than "unidentified mass", more along the lines of MACHO theory. I actually never considered "standard theory' of that time to be the least be "metaphysical' in nature because it was based on known laws of physics, and what we didn't understand (how the thing got started), we just admitted we didn't understand.</p><p><font color="#0000ff">And the hypothesis of the Lamda CDM model is basically only a proposal to fill in what we don't understand. Everyone except possibly you seems to recognize that "we don't understand". Even when you don't understand it is acceptable to make tentative hypotheses and then proceed to determine if they are true or not. The old concept of the aether through which electromagnetic waves were supposed to propagate was such a hypothesis. It seemed reasonable. But it was eventually shown to be false. Similarly the Lamda CDM model may or may not eventually be shown to be correct. But unti that time it provides predictions that can be checked, and if the predictions are found to inaccurate then theory will be discarded or modified substantially. That is how science works. That is how Newtonian mechanics gave way to general relativity. </font> </p><p>Yet "dark energy" has never caused *anything* to "expand" in a controlled experiment, so why stuff that metaphyscial bad boy into an otherwise perfectly good physical theory?</p><p><font color="#0000ff">Because the otherwise perfectly good physical theory seems to be at odds with what is actually observed. So either we need an error in the measurements of the observed phenomena or we need to change the theory. </font> </p><p>Einstein called the instertion of a constant into GR theory his greatest blunder. He "cludged up" an otherwise perfectly good theory about the attraction process of matter with a constant "force" the he never identified, and we not even sure actually related to GR in the first place. He regretted that move his whole life. </p><p><font color="#0000ff">Not quite true. His regret stemmed from the realization that, based on the work of Hubble, the universe is expanding. Einstein had originally believed in a static universe and a static universe requires a cosmological constant in order to exist stably. It was that blind spot that caused Eiinstein to put in the cosmological constant, and thereby miss the opportunity to predict the expansion of the universe. After seeing Hubble's results he saw his mistake and that was the source of his regret. He went so far as to personally visit Hubble to thank him for the insight provided by his observations.</font> </p><p> Never once did he stuff it with "dark energy" however. At least he simply admitted that he had no idea what might cause the universe to say static, and he certainly never tried to explain acceleration with "dark energy". </p><p> <font color="#0000ff">Dark energy is really nothing more than an alternative expression for the cosmological constant. It does not particularly matter what language you use to describe the phenomena, the result is the same. </font></p><p> Lambda-CDM theory is not based on GR theory, rather it is a metaphysically cludged variation of something Einstein called his greatest blunder. Note that he never claimed that C was in any way related to "dark energy". If "dark energy" had ever been shown to cause a "repulsive effect" or an acceleration effect, your statement might be phyiscally meaningful.</p><p><font color="#0000ff">Sorry, but you could not be more wrong. the Lamda CDM model is an attempt to reconcile observation with general relativity. Nothing more, nothing less. I have no idea what you have in mind wiht the the statement regarding the relationship between C and dark energy. I assume that by C you mean c, the speed of light in a vacuum in local coordinates. If so I agree, it has nothing to do with dark energy, nor has there been any claim to the contrary by any responsible physicist of which I am aware. Dark energy is a repulsive effect with regard to space-time. That is the whole point. We see a repulsive effect, we do not have an explanation for it, so it is given a name -- dark energy. If you would prefer to call it Oscar, that would be OK too. The problem is then to find a more fundamental description of Oscar.</font></p><p> </p><p> As it stands, from a skeptics perspective, it's like handwaving in the effect of invisible elves on matter because we all know that elves have a repulsive effect on matter. How do I go about testing or falsifying that inviisble elves or dark energy exists in nature?Then why not just say so instead of tellling students about the repulsive effects of "dark energy". You can't demonstrate that "dark energy" has a repulsive effect on anything. Claiming that "I don't know what drives acceleration" is totally different that claiming "dark energy has a repulsive effect on matter". The first statement if physicallly true. The second statement is false, unfalsifiable, untestable, and outside the realm of real physics. "I don't know" is an acceptable part of science. "Dark energy has a repulsive effect on matter" is not.Throwing statements like "dark energy causes repulsive effects in matter" is not the same as claiming "I don't know". "We don't know" is fine by me. "Dark energy did it" is not. Dark energy is a figment of your imagination as far as I can tell. I have not idea why you would even state that "dark energy causes repulsion". It doesn't. It doesn't do anything because it doesn't exist.</p><p><font color="#0000ff">You are getting all humg up on semantics. This has been pointed out to you on numerous occasions. Best advice -- get over it.</font> </p><p> Well then, why do Lambda-CDM proponents want EU theorists to make up some sort of creation event before they'll take the idea seriously? You don't see that as a gross double standard? </p><p><font color="#0000ff">There is no double standard involved. Electromagnetism is well understood. If there is some large current flow through space then there should be a motive force generating it and directing it. If it were to exist it would be easily detectable using standard methods. The necessary and logical results of the existence of such a current are not detected, and would be is the current existed. Therefore one concludes that it does not exist. Perioid. </font></p><p> </p><p> You can stuff metaphysics into LAMBDA-CDM theory, but I can't just stuff metpahysical forces into EU theory. </p><p><font color="#0000ff">EU theory is rampant with non-existent methaphysical forces. For at least the third time I point out to you that if the Sun really was a giant neon light bulb powered by a current flowing through it from some source outside the solar system then there would be an enormous magnetic field at the surface of the Earth. That magnetic field does not exist.</font></p><p> When I say "I don't know" about some big picture issue, Lambda-CDM theorists claim their theory is "better" because it "predicts' these kinds of behaviors. Of course it's "predictions" are *always* wrong. For years the mainstream has been gloating about how inflation's "key prediction" has been verified. Last year we found out that the physical universe is not homogenously distributed, rather it has gaping giant holes in it. What then is the usefulness of inflation in the first place? It is another of those metaphyiscal terms that ultimately is "I don't know". Stuffing math related to "repulsive elves" into GR theory, may in fact "show acceleration and expansion", but how in the heck might I verify that repulsive elves had anything to do with that observed phenomenon? </p><p><font color="#0000ff">Your inability to handle mathematics is no reason for science to jettison a theory.</font> </p><p> That math might be perfect, but what about the emprical testing? So what makes it "better" than EU theory if you can't physically confirm that "dark energy"" even exists in nature? </p><p><font color="#0000ff">Because EU theory has been demonstrated to be inconsistent with what is observed. You might want to look at the papers to which links were provided by doubletruncation in another thread. </font> </p><p> What makes "dark matter" better than 'missing mass"?</p><p><font color="#0000ff">Same thing. You seem to be really hung up on semantics. </font> </p><p>I know why. You grossly understimated the mass in a galaxy by at *least* a factor of 2. The galaxies are twice a bright as you tought, and they contain at least twice as many ordinary stars and standar mass as you thought. I know one thing for sure. </p><p> <font color="#0000ff">And what might that really be? The problem is that you seem to know only one thing for sure -- there is a mystical and enormous current flowing through the universe. </font></p><p><span class="body"><font size="2" color="#0000ff">It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so. -- Mark Twain</font></span></p><p> "Dark matter" has absolutely nothing to do with your "missing mass", because it has never been shown to exist in nature. </p><p> <font color="#0000ff">Rather by definition, it is the missing mass. If and when we find it, it won't be dark matter any more.</font></p><p>It's not real.And my reaction to this metaphysical variation of GR theory is about the same reaction you'd have If I stuck "repulsive elves" and "fat invisible gnomes" into the same formula. I might be able to get my formulas to come into agreement with observation, but my Lambda-fat gnomes theory would not be "better than" EU theory only because i got it to agree wtih observation.It doesn't exist! Thats the whole point. You can't stuff metaphysics into GR and then claim that such a theory is in any way superior to any other theory. Any theory that begins with "I don't know" is equally acceptable isnt' it?</p><p> <font color="#0000ff">No, absolutely not. To be acceptable an alternative theory either must be consistent with currently accepted theories, such as general relativity, or offer a plausible alternative. It must be consistent with everything that is observed. It must not invalidate accepted theories in circumstances in which they are known to provide very accurate predictions.</font></p><p>If I came to you and stuffed my invisible repulsive elves and fat invisisible gnomes into a GR theory, you would not claim it is equal to Lambda-CDM theory, or would you? </p><p><font color="#0000ff">Certainly not. But I would take it as equal to EU theory.</font> </p><p><br />Posted by michaelmozina</DIV><br /></p> <div class="Discussion_UserSignature"> </div>