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:P
In two recent issues of Scientific American, Jan-Feb 2004, there are articles discussing Quantum Gravity and Dark Energy/Matter. The articles are very interesting, but the authors leave us with an impression that what we think we understand is somehow incomplete. A much simpler way to understand gravity at a great distance from us would be to postulate that it is not a flat universal constant, as now believed, or as theorized by both Newtonian Classical physics and Einstein's General Relativity, but rather is a 'variable-constant' depending upon where it is measured. This would imply that gravity is not all the same everywhere, and may be weaker near a hot star, as measured in terms of mass inertia, and greater when far away from it, such as on the edge of our solar system or deep in space. One piece of evidence to bear this out is the slowing of the two Pioneer spacecrafts leaving our solar system, which could be understood as greater gravity equals greater inertia. If momentum is constant, then the greater gravity per mass out there would of necessity slow them down. Has anyone seen more on this mysterious development? A possible explanation could be achieved with the photoelectric equation applied to Einstein's famour formula: hc/L(m) = mc^2, where: h = Planck's constant, 6.26e-34 c = lightspeed constant, 3e8 L = deBroglie lambda for proton (m) (m) = 1.67e-27 m = mass = 1 kg This equation, if rewritten as: hc/L(m) = (1-g)c^2, where: 1 = mass g = proton to proton gravitational constant, ~5e-39, gives us an inverse proportion for L and g. The result is that the atom as formed by these equations, proton mass, is an incomplete 'combustion' of electromagnetic energy, so that some force of gravity remains as a very weak force. If the EM energy is greater, this force becomes lesser; conversely, if the EM energy is lower, lower lambda, then the gravitational remainder is greater. None of this has found its way into conventional physics, however, so must be treated with great suspicion until we have some evidence that gravity is not the same everywhere, but is some inverse function of the electromagnetic energy put out by the local star instead. The result would be very great gravity for weak, or cool stars, such as neutron or brown stars. Out in the cold of deep space, this greater gravity may account for the so-called 'dark matter'. Anyway, call it badastronomy, but it may be a possibility that better explains other cosmic phenomena, such as lightredshift from distant quasars, etc. If light redshifts through gravity, then more gravity in the cold of space would redshift it even more? If so, then perhaps the universe is really not expanding, just appears to do so. Cheers. ![]()
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Funny. This thought hadn't even began to speculate about the merest possibility of crossing my mind. :wink: Interesting concept, nonetheless, 'variable-constants'. ![]() Everything should be made as simple as possible, but not simpler. Einstein |
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Lunatik, you might want to look at Toivo Jaakkola's work. He proposed that G changes somewhat in the manner you say. He links it all to a gravitational mechanism which is tied in with various redshift effects. One of his best papers is this one from Apeiron:
http://redshift.vif.com/JournalFiles...F/V03N3JAA.PDF On p. 11 he mentions that the local value for G is one tenth of the value we would find in space well outside the solar system. |
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8) Thanks for the reference to Jaakkola's paper, will look into it. I had doodled on this concept of a 'variable-constant' gravity on other forums, Humancafe: http://www.humancafe.com/discus/messages/70/122.html , and also on the Space-Talk forum: http://www.space-talk.com/ForumE/sho...p;pagenumber=1 (Coppernicus2), where I explored possibilities of gravity being other than as now understood. Got a lot of flack for it, though. Hadn't thought of it as complicating things until now, that a variable-gravity constant, no matter its reason, does make for more difficult calculations in estimating mass of distant bodies, given their orbital behavior. Still, if the Pioneer 10 & 11 distant spacecrafts are slowing for reasons other than space dust of the Kuiper belt, as suggested by: http://www.space-talk.com/ForumE/sho...?threadid=2272 , (see post of 2/23/03), where Paul Marmet's paper is referenced, then "Nasa, we have a problem."
If it is not low density space dust acting on the Pioneers, then perhaps a new physics is in the offing. The idea that gravity redshifts electromagnetic waves passing through it is not new, and may account for the signal reaching us giving the appearance of slowing down. However, this could be hand in glove with the idea that gravity away from the inner solar region grows stronger, giving mass greater inertia, while at the same time redshifting the light reaching us. In effect, they may be two sides of the same thing. Anderson et al, the LANL team who first calculated the receding spacecrafts lagging acceleration, at present do not have an answer to this enigma, to my knowledge. Possible other clues that gravity ain't all the same everywhere? :P
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Caveat Lector. Experimentum summus judex... |
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I'm skeptical that a decrease in G as you move away from the Sun could be the reason for the Pioneer/Ulysses phenomenon. If mass distribution in the solar system were affecting G, then one would expect G to increase progressively as you get farther away from the Sun. The Pioneer/Ulysses data can be interpreted as a constant acceleration of the spacecraft, which would be consistent with a single step increase in G.
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For an entertaining (well, I think so!) and elementary calculation of a similar experiment, have a look at my "CM's Angels Return" posts in the "Twin Paradox: Definitive Proof That it's SR" thread.
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Microsoft is over if you want it. The bar has been lowered for the promotion of ATM ideas; the bar for the acceptance of ATM ideas must remain high. |
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Glad to hear you're reading up on Jaakkola. That paper is a useful primer to alternative viewpoints in physics and astronomy.
Your description of the Hafele-Keating experiment seems to back up just the point that Jaakkola was making. Suppose we have a non-rotating reference frame centred on the centre of the Earth. In that frame the 'stationary' clock on the Earth's surface is moving slower than the eastbound clock, but faster than the westbound clock. In that frame we would therefore expect to see the eastbound clock lose time relative to the stationary clock, while the westbound clock gains time relative to the other two. But according to SR we could just as easily choose the eastbound plane as our frame of reference, and in that frame it would be the other two clocks which lose time. That is why a Lorentzian interpretation of relativity is to be preferred over SR. In Lorentzian Relativity (LR) the motions of bodies and light take place in a preferred frame, which we would identify with a medium of some kind. LR eliminates the paradox from the twins paradox. Your suggestions relating to GR and the Earth's not being an inertial frame do not change the picture. We could in principle set the stationary clock in a balloon at the same altitude as the planes, and run the experiment for a short time such that the Earth's curvature is not involved. The results would be the same, I think. The same considerations are involved in the GPS. As Tom Van Flandern has emphasized, it is only necessary to make corrections to the clocks at the beginning to adjust for the time dilation effects arising from their different velocities and altitudes. The GPS clocks will then be synchronized from then on. The relative trajectories of the GPS satellites do not enter in. |
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ExpErdMann,
I've read through most of Jaakkola's paper, and found it excellent. Thanks so much for the reference, for it is refreshing to see a clear thinking mind express succinctly what many had attempted to challenge of GR/SR without success. Before I ventured into this arena, I had no ideas physicists could be so vindictive when presented with new ideas. Oh, the knife fights I've seen! I'm also familiar with van Flandern's work, mostly discredited by the physics community, though in my opinion wrongly so. I am not a physicist, so my approach to the discipline is from that of a free thinker, with enough knowledge to be dangerous, but there are such glaring irregularities in modern physics that they beg attention. For example, the atomic clocks' slowing may as much be a function of redshifting while traveling through gravitational fields, same as light does, and vice versa speeding up in the other direction. There should be no mystery there, time is not what is slowing down if a clock slows, merely that the atomic oscillations are slowing. I would think if all my clocks at home suddenly slowed, I would not conclude that time, really a manmade notch on a stick, is slowing either. :P Here is evidence of light redshifting without having to default to a Dopplershift expanding universe: http://www.space.com/scienceastronom...ar_010111.html Light redshifts when it comes through great gravity fields. And if so, then Jaakkola may be right on.
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Caveat Lector. Experimentum summus judex... |
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redshifts don't happen when light goes through big gravity fields; even theoretically. The gravitational redshift occurs theoretically when light goes from a high gravity field to a low one, not when passing through. If it passes through, it blue shifts on the way in and then red shifts on the way out resulting in no red shift.
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I said the following once, it's worth saying it again:
I have one main problem with "pushing gravity": it is about the wrong geometry. Pushing gravity is ultimately about particle cross-sections. In contrast, general relativity is about geodesics in curved spacetime. Pushing gravity holds that space is filled with as yet undetected particles that are transmitting their momentum to ordinary matter. We are not pulled towards the surface of the Earth but pushed there because the Earth shields us from the momentum flux moving in our local "up" direction. We do not become weightless when we go indoors; the roof over our heads is not strong enough to pull us up (Newtonian gravity) or shield us from the downward momentum flux (pushing gravity). Another observation is that naively we expect that the Sun and Moon should be equally effective at shielding us from gravity since their apparent sizes are the same and thus that the pull of the Sun and Moon on the Earth should be equal. Celestial mechanics shows us that this is not so. Instead the force is proportional to the product of the masses, as measured in countless Cavendish-type experiments. In fact, pushing gravity just cannot account for the fact that the gravity of a nucleus is proportional to the mass of the nucleus within one part in 10^12 or so. If A is the number of nucleons in a nucleus, the radius is known to be proportional to the cube root of A and the cross-sectional area is proportional to A^(2/3), while the mass is roughly proportional to A. In brief, pushing gravity cannot account for the equivalence principle which has been observed to be true to a high degree of precision.
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Microsoft is over if you want it. The bar has been lowered for the promotion of ATM ideas; the bar for the acceptance of ATM ideas must remain high. |
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Another problem that I have with Jaakola's paper is this: in section 5i of the paper he derives the force law by taking the change in momentum of body 1, S_1, to be eta_2 * m_1 * A_2 / (2*pi) and the change in momentum of body 2 to be the same with subscripts 1 and 2 interchanged. Here eta_i denotes a measure of absorption, m_i the mass, and A_i/(2*pi) the fraction of the sky subtended at the other body by the i-th body. Jaakola then makes the leap of setting eta_i equal to G * m_1 / R_1^2, that is, equal to the surface gravity. The problem is that Jaakola is assuming the result from Newtonian gravity, not arguing from a consistent application of first principles of pushing gravity. In other words, he arrives at the Newtonian result for the force between two bodies by assuming the Newtonian result for surface gravity of a body.
If pushing gravity were really valid the surface gravity would be the same whether I'm standing on Earth, the Moon, or Phobos. Half of the sky is blocked off by the body below my feet. If you argue that I should be considering each nucleus in the body to be blocking some area and subtract the resulting sum of blocked momentum flux, you are still not going to get a result proportional to the mass divided by the radius squared. The cross-sections of the individual nuclei are proportional to the 2/3 power of the number of nucleons while the mass is proportional to the number of nucleons. Pushing gravity is a geometric theory of gravity, a seductively simple idea, simple enough for the mathematically-challenged to understand it. Unfortunately it is the wrong geometry. Sorry, there is no royal road.
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Microsoft is over if you want it. The bar has been lowered for the promotion of ATM ideas; the bar for the acceptance of ATM ideas must remain high. |
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Hmm... I must admit that the redshift of light through gravity is still something of a mystery to me. It appears that light can redshift in a strong gravitational field, whether blue and red redshifting alternately as mentioned above, or simply a function of what happens to electromagnetic wavelengths in that environment.
Here is an example of light redshift taking place in the vicinity of neutron stars and black holes (as posted earlier above): http://www.space.com/scienceastronom...ar_010111.html What intrigues me in these X-ray images is that light redshifts as it enters the very great gravity region, with no evidence of blueshift. Since I am still reading Jaakkola's paper, still do not understand this completely yet. Also, I too am not comfortable with "push gravity" conceptually. In my mind's eye, gravity is what is left over, a kind of remainder force, from how the atom is modified by electromagnetic energy, so where there is much energy, such as near a hot star, gravity would tend to be very low per mass; vice versa, where there is a dearth of energy, such as far out in space far from any galaxy, gravity per mass should be much greater, giving mass out there tremendous inertia. (This was the thrust of my original post above. ) Not knowing more, these remain merely conjectural, but there may be some evidence that the postulated (and unobserved) Dark Matter is no more than this deep space gravity effect, where all atoms and molecules there experience a much greater gravity per mass. I too regret Jaakkola's passing, since he seemed to be closing in on something of value. If gravity is indeed a 'variable-constant', then there is much future work to be done in physics, especially astrophysics, I would think. Regarding how lightshift goes from high gravity to low gravity may account for why light 'bends' around massive bodies, especially solar bodies and galaxies, which are energy rich. Note that the resulting images from gravity lensing do not give us an inverted image, as would happen if gravity was truly a lens, but give us dual images, or halo images, as would happen if light blue and redshifts as had been described. I only bring this up as a point worth considering, though do not have a definitive answer on how this gravity lensing works. :-?
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Pushing gravity can generate Newton's law at least, as has been shown countless times. So far no one has been able to add the GR 'correction' to the models, such that GR is regenerated. However, one can easily conceptualize a PG frame of reference analogous to an accelerating frame by considering frames of reference in which the flux of particles or waves is the same from all directions. Such frames would be seen to be moving ('falling') towards gravitating bodies. From this consideration I suppose that a GR variant for pushing gravity can be constructed, but so far it hasn't been done. That could be because GR makes just minor corrections to Newtonian gravity, and so is rarely used in ordinary physics. It will be sort of the 'icing on the cake' when PG is shown to be fully compatible with GR. And remember, Einstein was not opposed to the existence of a gravitational medium. Quote:
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Some try to tell me, thoughts they cannot defend,... - Moody Blues. Neptune- The original Dark Matter. The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth |
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Mapp = M (1- h d l ) , where h is the absorption coefficient, d is the density and l is the radius. From this one finds for instance that the Jupiter's apparent mass is only about 95 % of its true mass. Now as a star moves through different stages it should show different apparent masses, as you suggest. But it is important to remember that at a certain size, bodies will absorb almost the whole flux, and at this point the gravitational force is related to their cross-sectional area only. One could object, as the astronomer H.N. Russell did, that the solar system would become chaotic if the gravitational masses of the planets deviated from their inertial ones. However, it can be posited that the inertial masses change in tandem with the gravitational masses. Incidentally, this topic is covered well in the recent book "Pushing Gravity", in papers by Radzievskii and Kagalnikova and by Roberto Martins. |
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ExpErdMann, and all,
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I had gone back through Jaakkola's paper, specifically item 5.1 "The 2-body Problem", and see how the 'impulse' space description of gravity is understood as a kind of 'screening' shadow created by massive bodies, so that the force from space 'pushes' on these bodies together. He is also quick to point out that this force acts in a Newton described inverse square law, 1/R^2, because we know this from experience. So a kind of 'shielding' takes place by matter, where the exhibited gravitational attraction is a function of the gravitons pushing on it. I cannot help but think of this as a euphomism for the attractive force of gravity, another point of view, but not necessarily correct. In the same way nature abhors a vacuum, it also seems to abhor a void of mass, so that when two material bodies are in proximity, they will exhibit an attraction to fill that void. This is a subtle epistemological point, but it shifts the focus from push to pull, as I think it should. The reason I like pull better is because of the inertia factor, which tends to resist acceleration when force is applied, including gravitational force. In the Haisch-Rueda paper, "Nature of Mass", at CalPhysics: http://calphysics.org/mass.html , there is a discussion of mass and ZPF, where they also invoke the deBroglie wavelength equation combined with Einstein's famous equation for energy: hc/L = mc^2. It is theorized that gravity and inertia have an equivalence. In my view, if in the deep cold of space gravity is great, inertia should likewise be great. This would mean we would need more acceleration to move mass there, or so it would seem, certainly more than our rocket ships can provide... not an alien conspiracy theory! As a curiosity, taking the equations I listed at the very beginning of this thread, where m = 1, is replaced with m = (1-g), something interesting happens at a very low frequency of light, where L = 3.97e-7 meters. So that: hc/L(m) = mc^2 = (1-g)c^2, where h = Planck's, L= lambda, (m)= proton mass, 1.67e-27 kg. multiplier (to make equation balance out on both sides in kilograms), and g = proton gravitational constant (dimensionless times mass), where m is always m = 1, we get: (6.626e-34)(3e8) / (3.97e-7)(1.67e-27) = (1-g)c^2 = E. This is a curiosity, because the denominator cancells Planck's constant h, and thus we are left with: 3e8 Joules = (1-g)c^2, for which result we find that (1-g) = 1/c (approx.), since the resulting E = ~c Joules, or pc = E, where p =1, or momentum is at its lowerst level. Below that, it falls into fractions approaching zero, or a black hole. This 'cut-off' frequency, where p =1, and L = 3.97e-7 meters, may in fact be the gravity level of dark instellar space far from galaxies, or a kind of background space... only a thought. This would also mean that if a star, or galaxy, was unable to generate electromagnetic energy above this 'cut off' energy, it would be extremely gravity dense, if this is so. Anyway, so much for 'Dark Matter', which is unobservable if it consists of merely deep space great gravity. These are merely 'doodles' or thinking aloud, but they pose interesting possibilities. I like them better than the gravitational flux being absorbed by the sun and planets, or stars and galaxies idea, though it too bears watching for clues. Too bad Jaakkola is not around to explore these some more... RE Quote:
One possible test for all this would be to find out if comets de-precess as they exit the solar system, something no one thinks they do at present. If it's all relative, where the inertial mass increases as it enters greater gravity, then all elliptic orbital motions would remain the same, except for velocity, where it should slow... I would think. 8) Ps: We know there is a precessional acceleration for Mercury when it is at its perihelion, same as we know the Pioneer distant space craft appear to be slowing as they exit the solar system. This may be a clue that at their aphelion, the comets which have very large elliptical orbits may likewise slowdown, while speeding up at their perihelion. I think this could be an important clue.
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Celestial Mechanic, very much enjoyed your reference above to "CM Angels Return", http://www.badastronomy.com/phpBB/vi...=199050#199050
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The math seems to bear this out... but is it proof positive that "Time" actually is changing? Or is it merely a calculation illustrating why the atomic oscillations will red/blue shift? I can't claim to understand this GR/SR stuff completely, though I know it somewhat. But I also like to cut to the quick and find what's real. Though math may be elegant, it can sometimes be true only in terms of itself, and not necessarily express what is happening. Chaotic results can flow from very small discrepancies in how numbers work, especially at very small micro values, since we are using digital to express analog, and the two don't always match up. Not to disparage your very fine example, but do you see where I'm coming from? Gravity is known to red/blue shift light, so this must be taken into consideration, I would think. [-X
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Contrast this with GR which says that spacetime curvature (in the form of the Einstein tensor) is proportional to the stress-energy tensor. That means that gravity couples to everything, masses of components and binding energy alike, resulting in the equivalence principle automatically. (Of course Einstein argued this in the opposite direction!)
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Microsoft is over if you want it. The bar has been lowered for the promotion of ATM ideas; the bar for the acceptance of ATM ideas must remain high. |
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You've just transferred the problem from one realm to another. I'm pointing out that your criticism of GR above, also applies to the theory that you are advocating. |
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