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Far, my understanding is that frame dragging occurs only if an object or particle is spinning. If the Earth had no rotation, an object placed anywhere on a sphere two hundred thousand kilometers from the Earth would experience the some magnitude and direction of acceleration as an object placed anywhere on that sphere.
Elf, Einstein spent the last thirty years of his life trying to unite electromagnetism and gravity. Some materials will block certain frequencies of the EM spectrum but no material, we know of, will block infrared. The best thermos bottle ever made, even with a complete vacuum, will have some infrared EM. There is no place in the Universe, man made or natural, where there is no radiation.
I would ask one question of Phys, can he show us one cubic nanometer of space that does not contain radiation in the Universe? If the answer is no then it could be said that radiation is the aether of space.
I would ask one question of Phys, can he show us one cubic nanometer of space that does not contain radiation in the Universe? If the answer is no then it could be said that radiation is the aether of space
Quote from: Good ElfIt is an interesting point to ponder that aside from the fact that light travels at the speed of light and is simultaneously affected by electrodynamics and also by gravity and "falls" identically like a projectile along the "surface of spacetime" and is a "limiting case of material projectiles" as V -> C. This suggests there really is not action at a distance dependent on the mutual mass between particles since such a theory would mean that if one of the two "attractive" objects was of zero rest mass there would be no "attraction" at all. It is possible to demonstrate very effectively that photons have zero rest mass. So... photons "fall" like a very light stone that is traveling infinitely close to the speed of light.Not quite, Good Elf! Maybe you were keeping it simple, but see that squared-off circle representing a single electron? It's deflected half as much as light: ←↓ ↑ →
It is an interesting point to ponder that aside from the fact that light travels at the speed of light and is simultaneously affected by electrodynamics and also by gravity and "falls" identically like a projectile along the "surface of spacetime" and is a "limiting case of material projectiles" as V -> C. This suggests there really is not action at a distance dependent on the mutual mass between particles since such a theory would mean that if one of the two "attractive" objects was of zero rest mass there would be no "attraction" at all. It is possible to demonstrate very effectively that photons have zero rest mass. So... photons "fall" like a very light stone that is traveling infinitely close to the speed of light.
As described by Wheeler in the early 1960s, geometrodynamics attempts to realize three catchy slogans * mass without mass, * charge without charge, * field without field.
I was keeping it simple...
I note your point though... Clearly the photon does bear "topological charge"... the twisted strip model shows one way in which this "charge" in permanently charged particles may arise. This would go a long way to realizing JA Wheeler's "dream" of geometrodynamics...
The electron in the theory discussed in Williamson and Van der Mark's paper deals with a permanent topological charge in a very energetic optical vortex. These vortices may be created "in the wild" (recent papers have discussed the creation of these entities using simple holograms) and maybe they are stable quantum "resonant" entities with requisite properties of stability. It is possible to explain the charge using this model but it is more difficult to explain mass.
Speculation: Mass appears to be related to the Orbital Angular Momentum of the internal photon exhibiting as an "external" mass which is linked directly to the conservation laws of CPT symmetry.
Your comments noted, PhysBang. But it isn't "my theory". All I've done is researched genuine historical material and bona-fide peer-reviewed papers.
Einstein really did talk of a non-constant guv that causes curvilinear motion along with the aether of general relativity.
The modern interpretation of general relativity genuinely seems to paint a different interpretation to Einstein's, and mathematical exercises just don't assist our discussion.
No, it really is your theory because you are making claims about experiments and observations that contradict what every scientist who uses relativity theory claims. For example, you say that relativity theory, if used "correctly", will produce the right rotation curves for galaxies. However, every scientist working in astronomy and astrophysics says that this doesn't happen.
When you say this, you are obviously ignoring what Einstein said about the aether. You even ignore what the author of the page hosting your favourite link to Einstein's address says about that address. This author writes on the page, "This address has been frequently misunderstood as positing that a return of the ether theory." Anyone who reads the address or the page must see that Einstein is clearly rejecting the standard idea of an aether theory in favour of, at best, an idea that bears only one feature of an aether theory, that of being a medium.
We are not talking about mathematical exercises, we are talking of the actual content of the theory. When you say that relativity theory does away with the need for dark matter, you are making a claim about actual values that are measured and actual values that are calculated. You have shown no way to reconcile these values. If you have a way to reconcile these values, you should share it. If you have no way to reconcile these values, you should retract your claims.
You need to show exactly how "a non-constant guv that causes curvilinear motion along with the aether" produces the calculations for the rotation curve of a galaxy and how this calculation matches up with the observed rotation curve.
An astronomer or an astrophysicist who makes a claim about dark matter backs up her or his claim with the relevant observations and calculations.
I note that you have retracted some of your previous claims. For example, you have removed your two calculations of the size of the universe from your public document version of your theory, two calculations that differed by several orders of magnitude. Many actual scientist retract claims when they have made an error. If your claims about dark matter are in error, it is no shame to retract them.
As for "every scientist", you should read Mordehai Milgrom's New Physics at Low Accelerations (MOND): an Alternative to Dark Matter at http://arxiv.org/abs/0912.2678. Note page 4 where he says:"We see that the modification of GR entailed by MOND does not enter here by modifying the ‘elasticity’ of spacetime(except perhaps its strength), as is done in f(R) theories and the like."
I've merely stated the obvious. Einstein told us that a gravitational field is a region of inhomogeneous space, and we all know of the raisins-in-the-cake analogy for the expanding universe. Space expands between the galaxies but not within, giving rise to another source of inhomogeneous space. According to Einstein, that's a gravitational field, with no causative matter. I really can't see why you have such a problem with this.
I'm not obviously ignoring anything, I'm reporting what Einstein said. He talked about a non-constant guv that causes curvilinear motion, and he talked about the aether of general relativity. See http://www.zionism-israel.com/Albert_Einstein/Albert_Einstein_Ether_Relativity.htm. What more can I say? There it is, in black and white.
Quote from: PhysBang on 28/01/2010 02:17:57We are not talking about mathematical exercises, we are talking of the actual content of the theory. When you say that relativity theory does away with the need for dark matter, you are making a claim about actual values that are measured and actual values that are calculated. You have shown no way to reconcile these values. If you have a way to reconcile these values, you should share it. If you have no way to reconcile these values, you should retract your claims.No I shouldn't. We have free speech in science, and observations and comments are permitted.
Quote from: PhysBang on 28/01/2010 02:17:57An astronomer or an astrophysicist who makes a claim about dark matter backs up her or his claim with the relevant observations and calculations.But even to this day, no astronomer or astrophysicist can provide conclusive proof for the existence of dark matter. It remains the subject of debate. And since it was first proposed by Zwicky seventy three years ago, we are surely free to discuss alternatives. People are discussing them more, and proposing experiments, see for example Testing MOND/TEVES with LISA Pathfinder by Christian Trenkel, Steve Kemble, Neil Bevis, and Joao Magueijo at http://arxiv.org/abs/1001.1303.
The widely examined and accepted cosmological models are not relevant here. I have a problem with your claims because you are denying the facts. The facts are that the rotation curves of galaxies do not work out unless we include dark matter. Please show us, and the entire scientific community including Milgrom, how standard GR can produce the rotation curves of galaxies without the need for dark matter.
Perhaps you failed to notice that this proposes a modification of GR. Do you propose a modification of GR...
I report Einstein's statements: a gravitational field is a region of inhomogeneous space caused by a concentration of energy tied up the matter of a planet, which in turn causes the curvilinear motion that is described as curved space-time.
I don't deny the facts of general relativity, I report them.
Physbang: see http://www.zionism-israel.com/Albert_Einstein/Albert_Einstein_Ether_Relativity.htm"According to this theory the metrical qualities of the continuum of space-time differ in the environment of different points of space-time, and are partly conditioned by the matter existing outside of the territory under consideration. This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that “empty space” in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials gμν).."Einstein said this in 1920, and he talked about curvilinear motion in The Foundation of the General Theory of Relativity in 1916. The theory I offer is Einstein's relativity. I'm not denying the facts.
PhysBang, let's keep ad hominems out of the forum. Such as accusations of dishonesty and promoting ignorance.
Talk to the facts, and only the facts, such as those on public record. Offer your interpretation, if you wish, be specific, then let the readers decide for themselves if there is any distortion going on.
Physbang: I'm afraid it isn't a small subset of the available literature. In 1911 Einstein wrote a paper "On the Influence of Gravitation on the Propagation of Light" where he said "If we call the velocity of light at the origin of co-ordinates c0, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = c0 (1 + Φ/c²).". See http://www.relativitybook.com/resources/Einstein_gravity.html for an online version.
All you have to do is look at the original material to understand that the modern interpretation of relativity is different to Einstein’s, and appreciate that this then causes misunderstanding.
Hence the article says Einstein’s variable speed of light makes sense, and doesn’t make sense.
Why, if you want to defend a point about general relativity, are you looking at things Einstein wrote before general relativity?
Since you seem to want to use the 1911 theory as representative of Einstein's theory, please show us using this theory where Einstein uses an aether.
OK, so please demonstrate how, using the 1911 theory or the later theory, the rotation curve of a galaxy doesn't produce a measurement of dark matter.
...As the authors note, the constant speed of light is fundamental to the way that general relativity determines causal structure.
Thus it is conceptually more fundamental than the time it takes for light to cross a certain distance in a certain time in a certain particular system of coordinates. This is particularly true since the correct description of any physical system in any well-formed set of coordinates in general relativity must maintain this causal structure.
The most well known system of coordinates in general relativity with what one might call a variable speed of light is that associated with the Friedmann equations. These equations provide a solution to the Einstein field equation and the form the basis of a family of cosmological models preferred by Einstein after 1929 and survive in a modified version in contemporary cosmology.
In these solutions, light can travel faster than light, because over time the distance between where the light left and where the light is received can get larger. However, one should recognize that this is not a way to measure speed that is representative of the causal structure of the universe...
..and when one takes that into account properly, one finds the speed of light as constant.
Despite working with, and accepting as approximately correct, the Friedmann models, cosmologists do not run around saying that the speed of light is variable.