Elysium and Interior Solutions

Benish,

Welcome to our little corner of the world. You came here a little over a month ago and asked a number of questions. The central theme of these questions seemed to be “what is, or could be, the physical cause of <some particular> phenomenon?”

This is the right place to be asking such questions. Finding physically plausible explanations (that are also mathematically correct, of course) is one of the highest priorities of Meta Research.

If you have been doing any research here in the last month or so, you will have found the answers to some of your questions. Rather, you will have found our best (so far) attempt at those answers.

If you want to talk about these proposed answers we will be happy to talk to you .

If you want to talk about a comparison between our proposed answers and your proposed answers, or your questions, we will again be happy to talk to you.

If you just want to talk about your proposed answers, you will have more trouble getting us to participate.

I do have a few questions for you.

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You talk about a personal need to be sure that the ‘mass in a tunnel’ experiment actually results in the mass oscillating. If you knew that such an experiment had been performed and produced the predicted results, then you would know that your theory was wrong. And that opens the door (in your case) for gravitons to be considered as a contender for the “correct” explanation.

This suggests that you value the results of experiment over the results of theorizing, a wise attitude to have.

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Your theory says that gravity is caused by motion rather than a force, either pushing or pulling. You presumably also reject GRs curved space description, but do not say so explicitly. I’m familiar with some Expanding Matter Theories, but I’ve not yet seen one that invokes a fourth spatial dimension.

One reason for this is that such theories are automatically non-scientific.

It is easy to envision building a “mass in a tunnel” experiment. Drill a hole through a large (1 meter?) solid ball, release a BB at either mouth of the tunnel, and watch it for a few weeks. It would not work here on the surface, but if it were put into orbit it would work fine. I would like to see it done, but I do not yet have the resources to make it happen. Those with the resources seem less interested. Sigh.

It is not easy to envision building an experiment to detect position, motion or acceleration (or anything else) in a fourth spatial dimension. This does not mean that a fourth spatial dimension cannot possibly exist. It does mean that speculations involving a fourth spatial dimension can’t be tested, hence the status of such speculations as non-scientific.

My first question to you is -

If you insist on experimental proof that Newton is right about the mass in a tunnel thing, why do you not also require experimental proof about the fourth spatial dimension thing?


Based on the impossibility of doing the latter experiment, I would expect you to have little interest in such theories. Perhaps in the future someone will think of a way to measure things in a fourth spatial dimension? Perhaps that someone will be you? What if you re-directed your interest in THAT direction ...

Put speculation about what might be explained by a fourth spatial dimension on your back burner. At this point it is just fantasy, and few with an interest in science care about fantasy (movies excepted, of course). Move speculation about how one would detect anything related to a fourth spatial dimension onto your front burner.

If you succeeded, that would be very cool.

Larry:

Thanks for your thoughtful feedback.

Physics does not advance by sticking to the known; we must venture into the unknown. This often involves imagining processes or entities that are not directly observable, but whose existence is deduced by a process of elimination, mathematical implication or some other logical reasoning. A profound danger in physics is to attach excessive concreteness to such abstract imagined processes or entities when a wiser approach would be to regard them as tentative, heuristic constructs. Examples would be Faraday's lines of force, neutrinos, quarks, gravitons and extra space dimensions. Each of these examples, it seems to me, has the potential to improve (or already has improved) our understanding of nature. None of them, it seems to me, are intrinsically any less scientific than the others. If an idea helps to improve our understanding of Nature, doesn't that by itself make it, in a broad sense, scientific? What is scientific and what is not may not be quite so black and white as you have implied.

If a test object oscillates through the tunneled spherical mass, then I would consider my model to have been falsified and I would bow out of the discussion, unless I thought I could contribute something original about gravitons or any other viable alternative.

As I have stressed, a literal interpretation of the readings of accelerometers and the rates of stationary clocks leads to the idea that a gravitating body and its surrounding "field" are in a state of perpetual outward motion. If this is true, then the test object will not oscillate. After reaching a maximum apparent downward speed, it will asymptotically approach the center. A possible alternative to the idea of extra space dimensions comes to mind when considering test objects dropped from different heights inside the tunnel. The initial apparent downward acceleration is always the negative of the upward acceleration measured by a stationary accelerometer at each given height. Objects dropped "now" from near the center would appear to be accelerating (with a small apparent velocity) as objects dropped earlier from higher up (having now a large apparent velocity) would appear to be decelerating. This could perhaps be interpreted as being due to a velocity (and distance) dependent repulsive force, as though the test objects were moving through a fluid medium.

I don't really like this interpretation because the force is not reflected by accelerometer readings. The readings on all the falling objects, whether appearing to accelerate or decelerate, would be zero. Nor does the idea help to conceive of motion in an external field, where the apparent gravitational force is not velocity-dependent (in the Newtonian approximation).

There are many discussions in the literature about hyper-dimensional space as a mathematical idea without reference to physical reality, as though it makes sense to conceive of space being independent of matter. A common point is that a fourth space dimension would involve motion in a direction that is not directly visualizable. Lots of fanciful possibilities have been described. I suggest that it may be enlightening to imagine these possibilities as being constrained by physics, for I think the dimensionality of space is utterly dependent on the properties of matter.

If the test object oscillates in the tunnel, then the simplest mathematical description involves only three space dimensions. I would see no reason to invoke a fourth.

What would be the simplest mathematical description if the object does not oscillate? If instead the motion agreed with my model? I'm not certain, I'll admit, but my hunch – based on all I've read about geometry, physics, the rotation analogy for gravitational fields and discussion with mathematicians – is that this would involve a fourth space dimension.

A Euclidean space of three dimensions is mathematically simple and seemingly sufficient to accommodate all physical reality. If certain physical phenomena prove difficult to describe using only three Euclidean space dimensions, but are more "naturally" accommodated by a scheme of four space dimensions (possibly, even curved space dimensions) then one may still continue conceiving of the world as "flat" and three dimensional. But there would be reason to speculate that the curvature and extra dimension(s) in the math reflect some deeper physical reality, which some thinkers might take to mean that physical reality's spatial dimensions were actually curved and/or numbered greater than three. People obviously have different standards of "proof" for such things.

Accepting the possibility that the test object might not oscillate may itself be difficult. But if this is empirically proven to be what happens, I'd guess many people, myself included, would regard it as strong evidence for the existence of a fourth space dimension.

Perhaps I've focused too much on my own model here, in violation of the rules, as you have kindly explained them. I am grateful for the common ground we share in challenging the status quo and in seeking the truth.


RBenish

RBenish:

The higher mandate that LB was describing can be stated succinctly as "Keep it real and relevant." Just as we do not accept political or religious conversations here, we try to keep all participants focused on "reality" in the areas of interest we cover.

To be scientific, a hypothesis must indeed be testable, not just "helpful" because the latter is like beauty and tends to exist only in the eye of the beholder. However, one way to test hypotheses is by gedanken (thought) experiments using the rules of logic. For example, it you had evidence for the existence of a phenomenon that could not be described or understood using only the five known dimensions (3-space + time + scale), and seemed to demand an addition to that list, that would be at least tentative grounds for proposing a new dimension. But if that dimension produces one phenomenon, it surely produces others. So the scientific method mandates making predictions of new phenomena that distinguish the new dimension hypothesis from other possibilities, one of which might be "none of the above".

By contrast, if one proposes a new dimension because it seems phychologically attractive to his/her mind to do so, in the absence of any observational, experimental, or logical imperative, such a proposal has its appeal in philosophy, art, science fiction, and many other field. But it is specifically excluded from "deep reality physics", which is the superset of physical thinking that our Message Board is limited to. In other words, although making comparisons to mainstream models and to our Meta Model are things anyone interested in pursuing new ideas ought to do, the core essence of what we do here is talk about things that are possible in physical reality. So if an idea doesn't conform to our basic principles for reality as described at metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp , then it is the province of another field of investigation, but not ours.

These principles are very different from those in the world of mathematics, as noted in this sarcastic yet insightful quote from Michael Kroyter: "Physics is about everything one can see, hear or think about in the whole world. Mathematics is about everything!" All our fundamental principles in deep reality physics could be encapsulated into one dictum: no miracles allowed.

Then when we start talking about curving or altering dimensions, we have left the playing field. Dimensions were originally set us as concepts used for measurement, and as such are not material, tangible entities that can interact with substance. If we want "space" to curve, we should call it something else like "subspace", a sci-fi term just begging for a definition. If we allow space to curve, that would leave us without an uncurved dimension against which we can measure curvature in particular and reality in general. So it is counterproductive to preempt the words for our dimensions to have some new meaning when we still need a word for the old meaning.

Therefore, masses don't curve space. At best, they alter a material, tangible medium in space in such a way as to alter the trajectory of larger bodies. Calling that medium "space" just because we haven't discovered it yet is changing the definitions we require for clear thinking, the concepts we need so we are not talking gibberish to one another. String theory may have produced some extraordinary art, but no "science" (as herein defined) that I have noticed.

It may take some of the fun and some of the mathematical appeal out of your ideas, but I recommend you try to reformulate them in ways that do not require a new space dimension because such a thing can be invoked only because it is so ill-defined, and we really have no idea what it means, much less how to test it. OTOH, if you called it "benishium" and assigned some physical properties to it, testability would soon follow. And it would then be worthy science instead of just laudable imagination. -|Tom|-

Tom and Larry,

I fully appreciate the spirit of keeping things real. That's why I put so much emphasis on the readings of accelerometers, the rates of stationary clocks, observations of star clusters and the importance of testing my model in a laboratory with a modified Cavendish balance: [url] www.gravitationlab.com/Grav%20Lab%20Link...-Experiment-2007.pdf [/url]

Gedanken experiments and the rules of logic are all well and good. But they are not absolutely conclusive; they are no substitute for brute physical facts.

RBenish

I guess I have some problems with somebody not being able to postulate an additional spacial dimension on the grounds that it's undetectable, but allowing such things as gravitons. Gravitons are detectable only by effect, as presumably is RBenish's "fourth dimension".

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by nemesis</i>
<br />I guess I have some problems with somebody not being able to postulate an additional spacial dimension on the grounds that it's undetectable, but allowing such things as gravitons. Gravitons are detectable only by effect, as presumably is RBenish's "fourth dimension".<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">There is no problem with something undetectable with present-day technology. We know technology will improve, and we do not expect that we can observe things whose properties are beyond the limits of our existing instruments. (For example, observational constraints tell us that Le Sage "gravitons" are about a million times smaller than a proton.) So "undetectable now" leads to predictions for testing the hypothesis as soon as detectibility becomes possible. And that is good science.

But a fourth spacial dimension is undetectable in a different sense: it has no physical properties. It is undefined. It is a pure math concept on a par with the infamous "square circle", even if not self contradictory. No test of its reality can be conceived of. So it is outside the realm of consideration by deep reality physics.

Mathematics, by contrast, often indulges in multiple dimensions. They can easily be described by equations even in the absence of physical or observable properties. They invoke the finite becoming infinite, singularities, uncaused effects, time reversal, and many other concepts that are ruled out of physics using logic alone by the "no miracles allowed" general principle.

So as I said before, unless an observational, experimental, or logical imperative is discovered that mandates a new dimension, we are obliged IN PHYSICS to explain all physical phenomena with the five known dimensions. Those wishing to explore other dimensions, singularities, infinities, time reversals, and such are contributing to other fields, but not to physics.

If it were not for the public demand for "relevance", mathematicians and philosophers would be content to keep their ideas "pure" because physics and reality are messy and filled with constraints. The problem only arose when funding agencies started demanding practical applications. So now these other fields feel the need to force-fit their pure-math ideas onto the physical world -- to the detriment of clear thinking in both worlds. -|Tom|-