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ExpErdMann
2004-Aug-05, 04:53 PM
In other threads it has been discussed whether the gravitational constant G could be diminishing over time, as Dirac had proposed. Dirac's idea was premised on the Big Bang-type cosmology. In a static model we would not imagine that G was decreasing on a universal basis. Yet some lines of evidence suggest that the gravitational force is indeed getting weaker over time. What could be causing this?

What if the gravitational potential energy of a body or a system of bodies were in the form of electromagnetic energy? Then this energy might be subject to a cosmic redshift effect identical to the redshift causing 'tired light' in static models. We could liken the attractive force between two masses to elastic bands attaching them together, which weaken and break over time.

A question though. The gravitational potential energy, U, is ordinarily considered to be negative. When two bodies are separated by infinite distance it is said to be zero. What is happening to U in my system above? When two bodies like the Moon and the Earth become more separated over time, is U decreasing, increasing or staying the same?

gritmonger
2004-Aug-05, 05:04 PM
If your model were correct, I should be able to eliminate or counteract gravity or bend light with a powerful enough magnet - and considering I didn't notice any lightening of my body or light-warping effects during my MRI, I doubt the relatively puny effect by comparison of the earth's magnetic field would be enough to keep me pinned to the table to the point I got a lower backache from laying for half an hour.

Add to that that diamagnetics (materials made to specifically exclude magnetic fields) should be comparatively weightless, yet still appear to have weight, and perhaps a new line of inquiry is suggested.

[edited for spelling]

ExpErdMann
2004-Aug-05, 05:13 PM
When I say the gravitational energy is electromagnetic, I include within that the notion that it may not be a form of em radiation that we are familiar with. It might for instance be linked to the quantum mechanical matter waves of bodies. Also, think of the SED model of Putfoff et al, where all the forces are in the end em forces.

gritmonger
2004-Aug-05, 05:21 PM
When I say the gravitational energy is electromagnetic, I include within that the notion that it may not be a form of em radiation that we are familiar with. It might for instance be linked to the quantum mechanical matter waves of bodies. Also, think of the SED model of Putfoff et al, where all the forces are in the end em forces.

EM radiation, of whatever stripe, shares the trait of "Electro" and "Magnetic." Electric and magnetic fields are generated at "right angles" to one another in the case of changing fields, and I'd assumed that you were postulating a field theory, at which point diamagnetics can exclude magnetic field lines, and the gravitational potential of objects depends more upon their reaction to magnetic and electric fields, meaning either we can do something special with conducting plates or make maglevs from bismuth.

EM radiation of what type? All EM radiation is essentially propagating E and B fields (electric and magnetic) and we generally have a description of how they behave, what energy they transfer (which generally tends to be a "pushing" rather than a "pulling" force) and at what energies they are generated.

I'm curious to hear you elaborate on your model.

ExpErdMann
2004-Aug-05, 05:52 PM
Without wanting to detract too much from the generality of my suggestion, I at least can offer a brief overview of my mechanism (or at least one variant of it).

In stochastic electrodynamics (SED) it is postulated that space is filled with em radiation with a broad range of wavelengths and phases. de la Pena and Cetto suggested that this random radiation, when it interacts with an atom or particle, is converted to a coherent form, which they considered to be the matter wave of the particle. I suggest that the latter waves form the 'shadow' of gravity and the former waves the 'push'. I am in favour of Le Sage's mechanism of gravity. So, in my model, if the matter waves degrade over time, the specific gravitational interaction between two bodies declines likewise.

Your specific points neglect the difference in energy levels. The SED fields dwarf the em forces in the lab, in most situations.

gritmonger
2004-Aug-05, 07:35 PM
I'm not sure what you meant by "energy levels." At the local level, and in laboratories, what makes gravity so prevalent, and not so powerful, is that nothing really impedes it; compared to electromagnetic forces, it is very weak. It can't pull salt ions apart - and water can. Yet we can shield electronics from outside interference from long wavelength EM waves with a conducting cage, or a simple box in the case of light, or lead in the case of X-rays.

The power of gravity is that it works through just about any medium. And so we have a problem with pushing gravity. If it pushes, and produces a force, it must be capable of being "stopped" by matter- but to work underground, matter has to be transparent to pushing gravity, at least somewhat.

If I enclosed you in a sphere, would you suddenly be weightless? Would you if the sphere was of the right material? If this shadow exists, then shouldn't we be able to create one by simply going indoors, in that our weight should decrease commensurately, if only by a small amount?

Wouldn't the planets have slowed down and spiraled into the sun by this point? Or would the universe have to be only a few hundred years old?

Glom
2004-Aug-05, 07:48 PM
Since I've only just returned to the fold last night, I am not familiar with the intricacies of the prior discussions.

Working on the idea of the expanding universe, it could simply be a case that as the universe expands, the energy becomes more diffuse.

The suggestion of cavarite gives way to a free energy machine. The ability to shield against electromagnetic fields is made possible because the interaction can be both attractive and repulsive.

ExpErdMann
2004-Aug-05, 08:45 PM
If I enclosed you in a sphere, would you suddenly be weightless? Would you if the sphere was of the right material? If this shadow exists, then shouldn't we be able to create one by simply going indoors, in that our weight should decrease commensurately, if only by a small amount?

The attenuation of the gravitational flux in passing through matter is very small, according to Le Sage's theory. Inside a sphere your weight would indeed become less by a tiny amount.


Wouldn't the planets have slowed down and spiraled into the sun by this point? Or would the universe have to be only a few hundred years old?

That is a criticism of Le Sage's theory that has often been made. Using the em Le Sage model that I am supposing, one can get around that problem. (You're taking me outside the zone I was wanting to discuss here, but you asked!) Looking at the matter wave aspect again, we see for instance that the waves emanating from the Sun and the Earth form an interference pattern. Let's take that interference pattern to be the 'shadow', in the sense that atoms located at certain points within that pattern will not feel the em flux. From aberration, the Earth 'receiver' must tilt ahead a little bit to receive the em ray from the Sun. But the ray emitted by the Earth which interferes with that ray has to be directed against the direction of the Earth's motion, if that ray is to hit the Sun. (Marmet has used the analogy how a running duckhunter must point his rifle rearwards to describe this). So the recoils of the absorbed photon and the emitted one cancel out, and the orbit remains stable.

I wonder if I could get your opinion on the question I posed at the top, about whether U is increasing or decreasing in my model.

gritmonger
2004-Aug-05, 08:56 PM
With regard to an emittive gravity model and redshift attenuation, this would (on the surface) have the effect of "pushing" less from outside a galaxy, and eventually would lead to a gradual dispersion of matter. The galaxy would be the first to go, as its stars spiraled off into extragalactic space, then the sun would expand as earth's orbit spiraled outward, and the atmosphere of the earth would escape into space. If this were the model for the universe, one would also expect "gravity" to have been stronger closer to the Big Bang, or stronger in the past in Steady State if you accept expansion and not BB. One would expect more hot stars in "younger" galaxies: more blue giants, and smaller galactic radii, more black holes (again, if you accept GR) and pulsars, and for current galaxies to be more full of supernovae remnants, heavier elements, and pulsars and neutron stars.

ExpErdMann
2004-Aug-06, 01:36 AM
With regard to an emittive gravity model and redshift attenuation, this would (on the surface) have the effect of "pushing" less from outside a galaxy, and eventually would lead to a gradual dispersion of matter.

Well no, not exactly. Let's say we have two types of radiation, the 'pushing' kind (which could be random ZPF or something similar) and a 'shadow' kind (which could be like the matter wave radiation mentioned above). It is really the shadow radiation which is being redshifted, since it is going back to the pushing kind. So inside a galaxy the shadow radiation is getting weaker over time, and so the galaxy will be expanding, like you say. Maybe we're saying the same thing here.


The galaxy would be the first to go, as its stars spiraled off into extragalactic space, then the sun would expand as earth's orbit spiraled outward, and the atmosphere of the earth would escape into space.

This seems right.


If this were the model for the universe, one would also expect "gravity" to have been stronger closer to the Big Bang, or stronger in the past in Steady State if you accept expansion and not BB. One would expect more hot stars in "younger" galaxies: more blue giants, and smaller galactic radii, more black holes (again, if you accept GR) and pulsars, and for current galaxies to be more full of supernovae remnants, heavier elements, and pulsars and neutron stars.

I would mostly agree with this, providing we are talking about a static model. Quasars/AGNs are the young galaxies with the hot stars, spirals are intermediate, and ellipticals are the oldest, with mostly old, red stars. Eventually, the ellipticals will evaporate their stars off into space and the those stars will eventually also shed their hydrogen back into the space to allow new star formation to occur.

ExpErdMann
2004-Aug-06, 03:05 PM
Wouldn't the planets have slowed down and spiraled into the sun by this point? Or would the universe have to be only a few hundred years old?

Maybe I didn't answer the right question here. Suppose momentum is transferred to an atom during the time interval in which a gravitational ray is passing through the atom. When the atom is moving in the opposite direction as the ray, the time interval is reduced and so less momentum is transferred. When the atom and the ray are moving in the same direction, the time interval is greater and so more momentum is transferred. But the effects due to time interval are exactly balanced by the Doppler shifts in each case. So the total momentum transferred by a ray to an atom is the same regardless of the atom's motion.

ExpErdMann
2004-Aug-06, 03:12 PM
The suggestion of cavarite gives way to a free energy machine. The ability to shield against electromagnetic fields is made possible because the interaction can be both attractive and repulsive.

Shielding is also related to the frequency of the radiation. A familiar example is that of radio waves, which can easily penetrate a building while shorter waves cannot. A variation of the electromagnetic Le Sage model in fact uses very long wavelength radiation. This idea was first put forward by Charles Brush and more recently by John Kierein. I find this model just as good as the SED one (or at least I should say I have not seen anything yet which excludes either model).

Glom
2004-Aug-06, 06:43 PM
So gravitational waves are ultra long frequency?

ExpErdMann
2004-Aug-06, 07:25 PM
Perhaps you are thinking of gravitational waves of the type that are generally thought to be caused by gravitons, the hypothetical spin-2 entities. But those waves are not the same as the waves we are talking about here, which are actual carriers for the gravitational force. The em waves causing gravity could be very long wavelength, as John Kierein supposes, or very short wavelength, as one might have in SED.

Glom
2004-Aug-07, 09:43 AM
Isn't John Kierein extremely ATM? I am not aware of the gravitational interaction being carried by photons. Theory says they are carried by gravitons.

ExpErdMann
2004-Aug-07, 03:08 PM
You could say John K and I are working from the same page. Yes, we're ATM now, but 10 years from now maybe we're totally TM! :)

Celestial Mechanic
2004-Aug-08, 04:09 AM
My principal argument against LeSagean "pushing" gravity remains the fact that pushing gravity is concerned with cross-sections instead of volumes. I have yet to see any realistic derivation of a gravitational force proportional to the volume of a nucleus instead of its cross-sectional area. That, I think, speaks volumes.

If you perform a google search on +"eclipse"+"Foucault pendulum" you will see hundreds of web pages about experiments that were going to be performed during the solar eclipse of 1999 August 11. Almost all of these pages are dated from 1999. There are no results, which, I think, speaks volumes. There don't seem to be any experiments at any of the eclipses in the five years since then and I think that too speaks volumes.

Finally, why wait for eclipses? The Sun and Moon rise and set every day. Perform the experiment around these times. Perform it inside a cave so that meteorological effects can be ruled out. No one has done even this simple experiment, which I think speaks volumes.

ExpErdMann
2004-Aug-08, 03:15 PM
My principal argument against LeSagean "pushing" gravity remains the fact that pushing gravity is concerned with cross-sections instead of volumes. I have yet to see any realistic derivation of a gravitational force proportional to the volume of a nucleus instead of its cross-sectional area. That, I think, speaks volumes.

No, the cross-sectional area alone can do it. What you have is an effective collisional cross-sectional area per nucleon. This value can be very small.

But volume can be involved in the electromagnetic Le Sage model. I explained above why a body in motion does not experience a drag force due to more and stronger impacts from the front. Say it takes a certain time t for a gravitational 'photon' to pass through a nucleon. During this time a small fraction of the photon's momentum is transferred to the nucleon, this fraction being proportional to t. Now if the nucleon is moving at v relative to the Le Sage frame, then for photons hitting the nucleon from the front, the interaction time is reduced to t/(1+v/c). But the Doppler frequency is increased by a factor (1+v/c). So the two effects cancel and there is no drag. The volume is important in this case.


If you perform a google search on +"eclipse"+"Foucault pendulum" you will see hundreds of web pages about experiments that were going to be performed during the solar eclipse of 1999 August 11. Almost all of these pages are dated from 1999. There are no results, which, I think, speaks volumes. There don't seem to be any experiments at any of the eclipses in the five years since then and I think that too speaks volumes.

There weren't many pages published because the lead investigator Noever left NASA and took the combined data with him. There were a few published accounts of positive results though, but these were in smaller journals. There were later experiments done, including by Wang et al (who did the well-known 1997 experiment in China, which had a definite positive result), but I haven't seen numbers yet.


Finally, why wait for eclipses? The Sun and Moon rise and set every day. Perform the experiment around these times. Perform it inside a cave so that meteorological effects can be ruled out. No one has done even this simple experiment, which I think speaks volumes.

This is not such a simple experiment. There are tidal effects here too.

CM, could you comment on the problem in my OP? Say gravitation is an electromagnetic phenomenon. Suppose that the gravitational potential energy U weakens over time, as in a 'tired light' cosmological model. But then you have that U is a maximum when it is 0. So if we have (dU/dt)=UH, then we have also (dU/dt)=0 when U is at a maximum. This doesn't work obviously.