The Direction of Gravity (PDF). Published in Astronomical Review, July 2011, 6(7), 8-14. Points out the gap in our empirical knowledge of gravity with regard to falling bodies inside matter. By appealing to Einstein's equivalence principle and rotation analogy, the paper argues that, due to this gap, we cannot even be certain as to the direction of gravity. Is it downward and refers to falling bodies? Or is it upward and refers to gravitating bodies and their surrounding space? Emphasizes that the gap can be filled in and the direction ascertained by doing the laboratory experiment, which is also briefly described.
Maximum Force Derived from Special Relativity, the Equivalence Principle and the Inverse Square Law. A recent paper by Christoph Schiller expounds on a "maximum force" in Nature, which he derives from General Relativity. Before becoming aware of Schiller's work, I derived a maximum force based on the Space Generation Model (in Strong Field Gravity in the Space Generation Model). The magnitude of the force is exactly the same as that derived by Schiller (c^4/4G). But the SGM derivation is much simpler. This paper presents the alternative derivation and explores the geometrical and physical consequences, which culminate in the experimental proposal featured throughout this website. Schiller's paper was published in the International Journal of Theoretical Physics. So I have submitted this paper to the same journal for publication. (PDF)
Cosmic Everything Charts.The mass, radius, density and acceleration of the whole range of objects in the physical universe plotted on logarithmic scales:
Charts Compared: General Relativity vs. the Space Generation Model. 70-page essay that explains many reasons for questioning standard ideas about gravity. Goes into more depth than previously about the dimensionality of space and the possibility that understanding gravity requires four, instead of three spatial dimensions. Critiques and compares current work on quantum gravity (much of which also appeals to hyper-dimensional space) with the SGM. Cosmological implications are also discussed in detail. 90 references; 19 Figures. (PDF)
Chart 1 represents the standard view, according to which several objects are on the Schwarzschild horizon line (black holes). (PDF)
Chart 2 represents the SGM view, according to which these objects are not black holes and so reside within the horizon. (PDF)
A simplified version of Combined Charts shows the plotted points as linear patterns that are compared side-by-side (GR vs. SGM). (PDF)
Gravity: The Inside Story. Non-mathematical description of the interior solution gravity experiment, reasons why it needs to be conducted, and a discussion of the sociological circumstances that have so far prevented it from being conducted. According to the ideals of science, the experiment should obviously be conducted. But physicists often do not live up to their ideals. (PDF)
Space Generation Model, Cosmic Numbers, & Dark Energy. Updated and augmented version of Space Generation Model and the Large Numbers Coincidences. Helpful detail has been added to the description of the gravity model. Cosmological discussion now includes more background information, especially concerning the connection to the saturation density of nuclear matter. The "cosmological constant (dark energy) problem" is also addressed. As usual, due emphasis is given to the fact that the whole thing hinges on the result of the interior field laboratory test. (PDF)
Strong Field Gravity in the Space Generation Model Most comprehensive exposition of the Space Generation Model. Includes a section called "Beginner's Mind," in which we imagine being members of a civilization who are ignorant of gravity. From our home -- a huge remote rotating "space station" -- we set out on a space journey which takes us to a much huger massive sphere. We ask: "how does the surface of this thing keep accelerating," among other questions. (PDF).
Climbing the Depths of Gravity. A brief look at the influence our cultural heritage has on how we "do physics," among other things. (PDF)
Interior Solution Gravity Experiment. A simple appeal to curiosity and completeness. The Newtonian and General Relativistic predictions that a test object oscillates through the center of a massive sphere has never been tested. This paper points out this fact and refers to prior experiments whose technology could be used to finally test the predictions. Contains no mention of "new physics." (PDF)
The cause of gravity is what I do not pretend to know, and therefore would take more time to consider of it.
--Sir Isaac Newton
Nobody knows whether there is such a thing as gravity. We have no physical understanding of it.
How far into the foundations, when it comes, must the revolution penetrate?
--Thomas E. Phipps, Jr.
I believe there is something basic we are all missing, some wrong assumption we are all making. If this is so, then we need to isolate the wrong assumption and replace it with a new idea....I strongly suspect that the key is time. More and more, I have the feeling that quantum theory and general relativity are both deeply wrong about the nature of time. It is not enough to combine them. There is a deeper problem, perhaps going back to the origin of physics....Motion is frozen, and the whole history of constant motion and change is presented to us as something static and unchanging. If I had to guess (and guessing is what I do for a living), this is the scene of the crime....We have to find a way to unfreeze time. [See graph.]
It is important to realize that in physics today, we have no knowledge of what energy is. We do not understand the conservation of energy.
Some of the assumptions may be wrong, or we may have made a mistake in reasoning, so it is always necessary to check [by experiment].
Things in a force field start to move without anything visible pushing them. Pure magic, but we have talked ourselves into behaving as though such things are perfectly understandable...We think we understand. But, really, we do not. The invisible influences of gravitation and electromagnetic fields remain magic; describable, but nevertheless implacable, non-human, alien, magic. Potential energy is a measure of the strength of this magic.
-- B. K. Ridley
The nagging question remains: Why is it that in frames in which fixed clocks do not keep time at the same rate, free bodies spontaneously accelerate? We have no answers.
R. W. Brehme
After we have described Einstein's Model for gravity...we are still left with a question of the sort 'how is it possible...?' just as with Newton's model.
-- Mook and Vargish
Newton's concept of a 'gravitational force' has always lain as an undigested lump in the stomach of science; and Einstein's surgical operation, though easing the symptoms, has brought no real remedy.
-- A. Koestler
What is gravitation? It would be no exaggeration to say that, although gravitation was the first of the fundamental laws of physics to be discovered, it continues to be the most mysterious one.
-- J. V. Narlikar
I think we are so confused that we should keep an open mind to tinkering with gravity.
-- Michael Turner
It is absolutely necessary that we should learn to doubt the conditions we assume, and acknowledge we are uncertain...In the pursuit of physical science, the imagination should be taught to present the subject investigated in all possible and even in impossible views; to search for analogies of likeness and (if I may say so) of oppositon -- inverse or contrasted analogies; to present the fundamental idea in every form, proportion, and condition; to clothe it with suppositions and probabilities -- that all cases may pass in review, and be touched, if needful by the Ithuriel spear of experiment.
-- Michael Faraday
No experiment is so dumb that it should not be tried.
-- Walter Gerlach
That the physical mechanism of gravity remains a mystery is almost a cliché. But it bears repeating because many physicists either ignore our ignorance or give the impression that the mathematical scheme of General Relativity, for example, suffices to “explain” gravity.
An obscure but important fact concerning our empirical knowledge of gravity is that almost all of it is based on observations of phenomena occurring above the surfaces of large gravitating bodies. Prime examples are the motion of planets with respect to the Sun and the motion of the Moon or more common objects (apples, footballs, etc.) with respect to the Earth.
The primary purpose of my work is to find out what would happen if we could follow the trajectory of a radially falling object below the surface all the way to the center of a gravitating body. For this is something that nobody knows. Of course, the predictions of both Newtonian Gravity and General Relativity (hereafter, NG and GR) are known; every physicist knows what is supposed to happen. But in the cosmic scheme of things that doesn't count. Predictions are extrapolations from the known to the unknown; i.e., guesses. This problem is often found in elementary physics texts, not as a prediction in need of verification, but as a known fact, implicitly requiring nothing more than Newton's theory of gravity to prove it.
In physical science, theories do not prove the correctness of predictions.
Ironically, many millions of dollars have been spent testing for the extremely small observable differences between NG and GR. But the unanswered question as to whether the interior solutions of either of these theories is even roughly correct evidently arouses no curiosity. The half of the observable world below our feet, in effect, remains sadly overlooked.
Although challenging, it is certainly feasible to arrange experiments in Earthbased laboratories that would begin to fill this lacuna in our empirical knowledge, to replace the guesses with physical facts. It is even possible that the facts discovered by experiment will dramatically conflict with the standard predictions. This is what motivates my secondary purpose: To explore the theoretical consequences of one possible experimental result and to show that perhaps this is what we should expect.
MODIFIED CAVENDISH BALANCE
If the test object depicted above is dropped into the (evacuated) hole and the large mass is uniformly dense, then NG and GR say it will undergo simple harmonic motion from one end of the hole to the other. This is the answer everybody "knows." In communicating with mainstream physicists to generate interest in an experiment to test this prediction my strategy has often been to initially avoid mentioning my unorthodox ulterior motives. For example, I would sometimes refer to my desire to "demonstrate" the Newtonian oscillation. In a pure sense, whether my intent is to demonstrate that Newton is right or to test the viability of a non-standard model makes no difference. If nobody has ever seen the predicted oscillation, that should be sufficient -- or so I thought -- to arouse plenty of interest. Any good scientist would surely be eager to see this gap get filled in.
We'll return to the "ulterior motives" below. Presently, I'll give a brief description of the apparatus that may yet confirm the oscillation prediction, or not.
The figure above is a schematic of a Modified Cavendish balance showing how the large spheres are sculpted so as to allow the arm and bobs to travel all the way through. In a preliminary trial of the balance used by Cavendish in 1798 to measure Newton's constant, the suspension wire was not stiff enough. The gravity of his large masses caused his arm to turn more than he wanted; the bobs bumped into the walls of his narrow enclosure. The pertinent fact for our pupose is that the force of gravity of a pair of ≈150 kg lead spheres is sufficient to cause appreciable motion on a horizontal plane. The problem for our purpose is that even much finer suspension wires or fibers have a torsional restoring force that increases linearly with angle. The reason this is a problem is that, in a test of the interior solution the restoring force would mask the signal. What we need is a suspension system that remains more nearly neutral throughout the entire angular range (≈20°).
I have built such a device using a magnetic suspension system. This is not a servo-controlled "hovering" suspension. The magnets hold up most of the arm's weight; but a small fraction of it is transmitted to a flat sapphire bearing and a spherical ruby pivot. I have demonstrated that the apparatus is sufficiently sensitive. I.e., friction at the pivot is small enough to allow the arm to move even when the horizontal force is significaltly smaller than what would be produced by the gravity of the two 180 kg spheres.
These spheres have not yet been installed into the enclosure because the suspension system still suffers from spurious torques. The problem traces back to the magnets. The magnetic field pole axes are not perfectly aligned with the magnets' cylindrical axes. This asymmetry causes the arm to turn. Much time and money has been spent trying to find better magnets and devising mechanical strategems to compensate for asymmetries in the best ones I could find. I have not yet exhausted all options. More details and progress reports will be entered here later.
Note that my laboratory is very modest and I wear all the hats. Although I may yet succeed, there is no doubt that a laboratory of "institutional caliber" would be much better equipped to solve the various technical challenges posed by this experiment.
ACCELEROMETERS AND CLOCKS
My secondary purpose ("ulterior motive") is to discover to what extent we can trust the readings of two particular motion sensing instruments: accelerometers and clocks. As explained below, if gravity is a force of attraction, this trust is limited by the underlying "relativistic" stipulation that everyone (and their co-moving accelerometers) is supposed to regard themselves as being in a state of rest. This point of view requires us to deny that non-zero accelerometer readings, for example, indicate absolute acceleration. Whereas, I propose that it may be fruitful to rescind that limit and adopt the interpretation that non-zero readings mean the accelerometers are indeed really, actually, absolutely accelerating. Similarly, if we find that seemingly non-moving clocks tick at different rates, we do not attribute this to a static gravitational potential. Rather we interpret this to mean that such clocks are in a state of absolute velocity. The most important consequence of interpreting our motion sensing devices this way is that, if correct, the test object in the above experiment will not oscillate through the sphere. Other consequences are discussed in papers 1, 2, 3, and 4 (near the top of the left column).
In our everyday experience, acceleration arises for three distinct reasons: 1) forces directed linearly, such as from a motorized vehicle or bodily muscles; 2) rotation; and 3) gravitation. The case of rotation is of particular interest because it is curiously analogous to the case of gravitation. It is well-known that Einstein used this analogy in the course of building his General Theory of Relativity (GR). [1, 2] Imagine a body such as a large, wheel-like space station uniformly rotating in outer space. Accelerometers and clocks are fixed to various locations throughout the body. Upon inspecting their readings and comparing their rates (in the case of the clocks) we would find, 1) negative (centripetal) accelerations varying directly as the distance r, from the rotation axis, and 2) clock rates varying as
where w is the angular velocity, c is the speed of light and f_0 is the rate of a clock at rest with respect to the rotation axis. Since the accelerations and velocities of a uniformly rotating body are constant in time, such systems are often referred to as being stationary (as distinct from being totally "static," i.e., not moving at all) [3 , 4 , 5 ]. To an inhabitant of the space station observations of accelerometers and clocks and the sensation of motion are quite similar to what is found on a large gravitating body such as planet Earth.
On a planet the range of acceleration and time dilation would become more evident by having numerous accelerometers and clocks fixed to extremely tall rigid poles firmly planted on the body. We’d then find that the acceleration varies as 1/r^2 and that clock rates vary as
where G is Newton’s constant and M is the mass of the body.
Having the idea that such a body and its field are utterly static things, the similarity of these two cases was taken by Einstein to mean that rotating observers should regard themselves as being at rest -- at rest in a "gravitational field." This approach is tantamount to a denial that accelerometer readings and clock rates are reliable indicators of motion. This seems to have happened somewhat subconsciously, even prior to Einstein.
The Newtonian concept of force and its relation to acceleration is unambiguous if it is applied to rotation or to non-gravitational forces. In these cases the direction of the acceleration indicated by an accelerometer is the same as the direction of the force. But in the case of gravity, thought of as a “body force,” a positive accelerometer reading is now interpreted as the negative of the acceleration a body would experience if it were allowed to fall. And a zero reading means a falling body is accelerating with the local value of the force (divided by the body’s mass).
The potential for confusion only increases when GR is brought into the picture. For here a positive accelerometer reading is thought of as indicating an acceleration with respect to a nearby geodesic (free-fall trajectory). Hence, in standard texts one sometimes finds expressions as “acceleration of a particle at rest” [6, 7]. Of course this expression has a degree of consistency within GR’s mathematical scheme; but with regard to the common meaning of the word, acceleration, it is contradictory. This becomes especially evident when we note that the “resting” particle is referred to as such because it is at rest with respect to a static Schwarzschild field. According to GR everything “at rest” in a static gravitational field is also accelerating. According to Newton, when gravity is not involved a positive accelerometer reading means acceleration with respect to absolute space; when gravity is involved, a positive accelerometer reading means “trying” (but failing) to accelerate in the negative direction. Is this the best we can do?
As I've implied above, one of my core motivations is to explore the consequences of eliminating this confused state of affairs by maintaining a simple and consistent interpretation of the meaning of motion sensing devices. Accordingly, let us now assume that accelerometer readings and clock rates are utterly reliable indicators of motion. It follows that, since a body undergoing uniform rotation is a manifestation of absolute stationary motion, so too is a gravitating body. In the case of gravitation both the velocity and the acceleration are positive, being directed radially outward. Although the rotation analogy is a poignant clue, there is at least one significant difference between rotational stationary motion and gravitational stationary motion. As with uniform linear (i.e., inertial) motion, rotational motion can also be characterized as being motion through space. Whereas the present conception of gravity is that it is a manifestion of the motion of space. This difference is profoundly important (as discussed in paper 4) and will be a recurring theme in what follows.
With regard to the first of our motion sensing instruments the basis of our new model may thus be simply stated:
Believe the Accelerometers.
Einstein's logic, which was to always regard yourself as being at rest no matter what your accelerometers say, is thus regarded as being blindingly backwards. Believing the accelerometers also "inverts," in a sense, the Newtonian conception of gravity, and the consequences of doing so are starkly evident. For example, this inverted scheme treats gravitation as a process of outward motion instead of as a force of attraction. If accelerometers are to be believed, there is no "pull" of gravity; it would be more accurate to say that the mechanism of gravity involves the perpetual outward motion of matter and space.
The effects indicated by our other motion sensing instruments, clocks, are generally less pronounced. In Newton's day they could not have been revealed, but with modern technology (e.g., the Global Positioning System) they are a fact of everyday life on Earth. Since we regard Einstein as having made a wrong turn with regard to acceleration, it follows that the relativistic conception of velocity is similarly suspect. This is not to revive the old aether theory, nor to deny the validity of experiments proving how difficult it is to find evidence of absolute velocity. Rather, it is to reassess the meaning of these experiments and of experiments that actually imply the existence of absolute velocity in the case of rotation. I propose that the most logical interpretation of the gravitation-rotation analogy indicates not the negation of absolute motion (as per Einstein) but the prevalence of absolute motion. Empirical evidence thus suggests that, in general:
An arrray of stationary clocks whose rates differ from one another indicates the existence of a range of absolute stationary velocities.
Note that the rate of one clock does not inform us in the manner of the reading of one accelerometer; we need at least two. Hence, our statement involving velocity (clocks) is wordier than our statement involving acceleration (accelerometers).
Another key difference between rotational and gravitational stationary motion should be pointed out. In the case of rotation the stationary inward accelerations and stationary tangential velocities are perpendicular to each other. In the case of gravitation the motions are co-directional: stationary outward acceleration and stationary outward velocity. (More details and testable consequences of this scheme are discussed in Paper 3.)
This implies that both matter and space are involved in a perpetual process of self-projection and regeneration. Space generation proceeds according to an inverse-square law; but due to the resulting local inhomogeneities, it is impossible to consistently model or visualize in three-dimensional space. If this interpretation is correct, it would thus require another space dimension to accommodate and to maintain the integrity of the inhomogeneous expansive motion. (For a graphic representation of this idea, see link.) A natural consequence of regarding gravitation as a perpetual manifestation of motion instead of as a static cause of motion, is the apparent spacetime curvature of our seemingly three-dimensional world.
However radical this Space Generation Model (SGM) may seem to be, it is simply based on the assumption that the readings of accelerometers and the rates of clocks are telling the truth about their state of acceleration and velocity. In principle, as discussed above, the model can be easily tested. Another way of looking at the most important (testable) consequence is in terms of clocks rates. According to our new hypothesis, a clock located at the center of a large gravitating body will have the same maximum rate as a clock “at infinity.” Unlike GR’s interior and exterior Schwarzschild solutions, clock rates in the SGM do not indicate the potential for motion, they indicate the existence of motion. According to GR, the centrally located clock has the slowest rate because it is at the bottom of a "potential well." Whereas, in the SGM, this clock has a maximum rate because, just as the acceleration diminishes “by symmetry” and goes to zero at the body’s center, so too, does the velocity. It follows that inside a gravitating body a radially falling test object would not pass the center and oscillate through it. Rather, after reaching a maximum apparent downward speed, the object would only asymptotically approach the center.
The huge difference between this prediction and the prediction based on NG or GR is the reason I am so eager to find out the results of the interior solution experiment (primary purpose). Novel predictions also arise in the SGM for the behavior of light and clocks near and beyond the surfaces of large gravitating bodies. (See Paper 3.) These predictions deviate strongly from those of GR for one-way light signals and for rates compared between ascending and descending clocks. Due to the two-way nature of experiments designed to detect these effects, the SGM actually agrees with their results. This is demonstrated for the Shapiro-Reasenberg time delay test and the Vessot-Levine falling clock experiment. Cosmological implications of the model are discussed in Paper 2.
1. J. Stachel, “The Rigidly Rotating Disk as the ‘Missing Link’ in the History of General Relativity,” Einstein and the History of General Relativity, Birkhäuser (1989) 48–62.
2. A. Einstein, Relativity, Crown. (1961) 79–82.
3. C. Möller, Theory of Relativity (Clarendon Press, Oxford, 1972) p. 284.
4. W. Rindler, Essential Relativity (Van Nostrand Reinhold, New York, 1969) p. 152.
5. L. D. Landau and E. M. Lifschitz, Classical Theory of Fields (Addison-Wesley, Reading, Massachusetts, 1971) p. 247.
6. W. Rindler, op. cit., p. 182.
7. C. Möller, op. cit., pp. 279, 374.
Graphics Library & Brief Commentaries
|Cosmic Everything Chart: Mass vs Density|
|2||Holey Sphere Falling Trajectory with Graph; Asymmetry of Time's Arrow|
|3||Star Cluster Distance-Velocity Chart|
|5||Extreme Case Velocity Dispersion Graphs|
Accelerometer Photo Gallery (Yes, it really works! Zero when falling; 9.8 at Earth's surface.)
|Dimension Hierarchy & Stationary Motion|
More Written Works by Richard Benish
|1||Includes discussion of supporting evidence in astrophysics: Laboratory Test of a Class of Gravity Models (PDF)|
|2||Cosmological implications: Space Generation Model of Gravitation and the Large Numbers Coincidences (PDF)|
|3||Comparison with Schwarzshild solution: Light and Clock Behavior in the Space Generation Model of Gravitation (PDF)|
Published Works by Richard Benish
(Same content as papers in "Written Works" above. Format of above papers is more reader-friendly.)
Laboratory Test of a Class of Gravity Models (Apeiron Paper 1)
|2||Space Generation Model of Gravitation and the Large Numbers Coincidences (Apeiron Paper 2)|
|3||Light and Clock Behavior in the Space Generation Model of Gravitation (Apeiron Paper 3)|
...the General Theory of Relativity, whose basic points of view physicists will surely always maintain...
-- Albert Einstein
Gravity is not really mysterious.
-- P. C. W. Davies
And the point of this experiment would be...? Gravity is one of the best understood of nature's phenomena and there is really no need to verify each cute little example which has been dreamed up.
-- F. Todd Baker, "The Physicist" of askthephysicist.com (See whole Q&A)
General relativity specifies the detailed mechanism by which gravity works.
-- Brian Greene
'Gravity is a great mystery. Drop a stone. See it fall. Hear it hit. No one understands why.' What a misleading statement! Mystery about fall? What else should the stone do except fall? To fall is normal. ...Fall is.
Misner, Thorne and Wheeler
We already know the laws that govern the behavior of matter under all but the most extreme conditions.
-- Stephen Hawking
The experiment you mention has never been done. It would be doable on an asteroid, but the money would be better spent on other things.
-- Bryce deWitt, 1996 personal communication
[Responding to Brehme's question in left column]: For the most general considerations on this matter, Landau and Lifshitz are the last word, so there is nothing further to say.
-- K. J. Epstein
Gravity is more understandable than any other force of nature... Spacetime grips mass, telling it how to move... Mass grips spacetime, telling it how to curve.
J. A. Wheeler
("Beware ye, all those bold of spirit who want to suggest new ideas." -- Brian Josephson)
So how do the string theorists -- or for that matter, the loop theorists -- respond to the insistent warnings of these accomplished physicists that perhaps we are all making a wrong assumption? We ignore them. Yes, really, flat out. To tell the truth, we laugh at them behind their backs, and sometimes as soon as they have left the room. Having done Nobel Prize-level physics -- or even having won the prize itself -- apparently doesn't protect you when you question universally held assumptions such as the special and general theories of relativity.
-- Lee Smolin
PHYSICISTS are not IMMUNE
...Human beings are perfectly capable of messing things up, big time, just because they entertain funny ideas divorced from reality.
-- Juan Cole, July 28 2011