Not sure what you mean. There is a big, big difference between a hole in our knowledge (a prediction that didn't quite pan out) and something that contradicts already theories that already have experimental data backing them up that covers the situation in question. There is a reason anti-gravity and perpetual motion often share the same website. Just ask our friend aviator...Ivan Seeking said:Russ, why do you and others keep talking about this violating the laws of physics when we think that dark energy may dominate at large distances?
russ_watters said:Not sure what you mean. There is a big, big difference between a hole in our knowledge (a prediction that didn't quite pan out) and something that contradicts already theories that already have experimental data backing them up that covers the situation in question. There is a reason anti-gravity and perpetual motion often share the same website. Just ask our friend aviator...
Right, dark energy is not a fringe topic: anti-gravity, wrt this thread (ie, relating to perpetual motion, gravitational field generators, etc), is. You seemed to be trying to compare the two: they are not the same thing.Ivan Seeking said:Dark energy is not a fringe topic. I don't get your point.
All the matter that produces this repulsive force has already done so. Once in a while a guy will be digging a hole and an anti-gravity rock will fly out of it past his face, but good luck to him trying to prove it.Ivan Seeking said:Also, let's get real folks. When we say anti-gravity we mean a new force in nature that works oppositely to gravity - that produces a repulsive force in proportion to the mass of the object.
El Hombre Invisible said:Vis a vis the whole accelerating expansion of the universe malarky... the expansion is equal everywhere, isn't it. I mean, if you have a mile of empty space in one place and another mile in another, they will expand to equal sizes in equal amounts of time?
If there was some form of energy (dark energy) pushing galaxies away from us, would the rate at which a given galaxy was moved not depend on the mass of the galaxy, not the distance it is from us? I mean, if galaxy A weighs 1, galaxy B weighs 2 and galaxy C weighs 3 and they were equidistance on a straight line, if some force were pushing galaxies A and C away from B, you would expect C to recede more slowly, no? I'm sure the brains have got it covered, but I wonder what their thinking is.
Since the ToE must be compatible with GR, I still can't see why you have an issue with it.Ivan Seeking said:But I still take issue with citing violations of the laws of physics since we don't have a quantum theory of gravity. For all that we know, a complete theory may demand that anti-gravity exists; or even that this missing variable is partly why the famed TOE is so elusive.
russ_watters said:Since the ToE must be compatible with GR, I still can't see why you have an issue with it.
...Antigravity and the impossibility arguments
Proposed by Morrison [7] in a celebrated paper, antigravity is known to violate the sacrosanct CPT symmetry, contradict the results of the Eötvös-Dicke-Panov experiments [10], exclude the existence of the long-lived component in the neutral kaon system in the presence of the Earth gravitational field [8], violate energy conservation and imply vacuum instability [7,11]. The arguments against antigravity then appear to be so compelling that it may seem presomptuous or even foolish to reconsider them
[12]. However, Nieto and Goldman have recently reviewed critically these arguments [13] and we refer the reader to their recent review for a thorough discussion and an historical perspective on these impossibility arguments (see also Ref. 14). Here, we will only insist on the points necessary to the following discussion and on those parts of Nieto and Goldman's review with which we disagree. Concerning the first two impossibility arguments, let it suffice to say that the CPT theorem has not generally been demonstrated on curved spacetime and that the ineluctability of a past singularity imposed by the theorems of Penrose and Hawking [15] make it doubtful that the CPT
theorem can ever be demonstrated without modification for gravitation 16,17].
Similarly, Goldman and Nieto have repeatedly stressed [18] that Schiff's argument on the Eötvös-Dicke-Panov experiments [10] is invalid because of his incorrect renormalization procedure. Attempts have been made to consider some adjustable vector interaction which, added to the tensor (and therefore always attractive) interaction dictated by general relativity, would lead to a violation of the equivalence principle applied to matter and antimatter. This arbitrariness is aesthetically objectionable, but Morrison's original antigravity [7] appears even worse : Goldman 3 and Nieto themselves reject the possibility of such a gross violation of the equivalence principle where antimatter would “fall up”, the total force on a static e+ e– pair, e.g.,being zero, since it would lead to a violation of energy conservation. We will come back later to the argument of energy non-conservation and first turn to Good's argument which appears to impose the most stringent constraint on antigravity.
Have you ever read about the Dean Drive? It got big press in the 1960s, and then suddenly dissappeared.Chronos said:Having been intimately involved in the design, development and deployment of vibratory mechanical equipment, I can assure you there is no free energy [i.e., anti- gravity] lurking between oscillations. I made numerous trips to customer facilities to fix the dang thing when it broke. I would not volunteer for a deep space mission that employed such a device for propulsion. Aside from being hugely inefficient, the spare parts payload would be prohibitively expensive.
sd01g said:The probability of an antigravity particles is about the same an antiphoton particle--almost zero. How do I know? Just check for any real evidence. There is none.