What James said. Velocity is a meaningless concept without a reference frame. It is meaningless to talk about the velocity of an object unless you specify relative to what it is considered to be moving. This is the essence in the principle of relativity, no frame of reference is more preferred than another. Yes, the Moon is moving around the Earth with a certain velocity and the Earth is moving around the Sun with another. If I know both I can easily find out how the Moon is moving with respect to the Sun but that does not make it a better or worse description of how the Moon is moving. It just tells me how the Moon is moving in a different reference frame.

Donald,

Relativity, which has survived every test thrown at it, suggests that it is meaningless to speak of anything other than velocity in a given frame of reference and that there is no absolute frame of rest.

Indeed, there are an infinite number of frames of reference (tennis ball, bus, planet, start, etc.) but none are favoured over any other and so one might as well be trying to measure how 'orangey' the worlds oranges are. All are different. Any one orange differs in some way from every other orange, and none are the Platonic ideal orange.

James:

You sound like each velocity measurement is for a different purpose. The question being asked (maybe not as well as could be) is how to understand the velocity of the electron, when all these other velocities are involved in the velocity of that electron.

The electron is not sitting out in space by itself. it is a part of that atom in that macromolecule on that hair of the bouncing tennis ball on the train moving with the earth around the sun and through our galaxy and through our super cluster. Since each of these items has a velocity - what is the 'overall' velocity of the electron.

Where I believe your statement comes in is - which frame of reference to pick in considering the problem. This is part of the problem.

What if the frame of reference is the galaxy super clusters? What is the velocity of the electron relative to this?

I have probably missed the point but how about this,

If an ideal electron is a 'massless' charge, then any mass associated with the particle must be relativistic - associated with its velocity. Couldn't the relative velocity of the electron be determined by the degree that it is (or is not) deflected by a magnetic field?

Normally you determine velocity by measuring position at two different times. So, are you asking "how to measure "positions"? Or "how to measure time"?

Why do you think that the answer should be in a 3-D model of space? That's only our limited frame of understanding, but not the frame of the mathematics of the universe.

What James said. Velocity is a meaningless concept without a reference frame. It is meaningless to talk about the velocity of an object unless you specify relative to what it is considered to be moving. This is the essence in the principle of relativity, no frame of reference is more preferred than another. Yes, the Moon is moving around the Earth with a certain velocity and the Earth is moving around the Sun with another. If I know both I can easily find out how the Moon is moving with respect to the Sun but that does not make it a better or worse description of how the Moon is moving. It just tells me how the Moon is moving in a different reference frame.

@Arkadiusz

What positions could be used to determine these objects moving - and what 'time' would be involved - are good questions.

@W. Westmeier

I do not believe a 3-D model of space is capable of resolving this problem, however it is the 'defacto' model for physical space today. We can move to 'space-time', however this doesn't change the problem of measuring and combining all these velocities. What model is needed to resolve this problem?

@Mattias

So what about the velocity of the electron relative to the super galaxy clusters?

Donald,

Remember how a velocity is defined: as the change of position in time. Position is always relative to the origin of a chosen frame of reference. Therefore, as James already said, it is meaningless to speak of anything other than velocity in a given frame of reference. This is as meaningless as speaking of the absolute position of a galaxy. There is no absolute position of an electron and also no such thing as the 'overall' velocity of an electron.

The question of how velocities, which have been measured in different frames of reference, are added is answered by the theory of special relativity. I suppose this is the precise point of your question.

@James:

The real question I am trying to get at involves velocities and scale.

Can we have relative movement when the objects in question are at vastly different scales? What in special relativity addresses this? Can we have a velocity of a very small object relative to a very large object? Is this, and how is this, addressed by special relativity?

Donald,

I see your question more clearly. If, for some reason Bob (at rest with respect to the Local Group) wishes to measure the speed of an electron in Alice's tennis ball, then he has a problem.

More exactly, he has a problem measuring the speed of *any* electron in any reference frame. Really, it's not easy. One electron? Gee. That's tough.

I would be inclined to use Raman scattering and wave away the engineering problems of preparing one photon and choosing one electron.

This is the experimental approach.

But Mattias hits the nail on the head.

One can indeed vectorially sum all of the known velocities - we know the:

1) Temperature of the tennis ball (3/2kT mumble v^2)

2) Latitude and altitude of Alice (geocentric frame)

3) Time and date on her watch (to give solar frame)

4) Approximate location in the galactic plane and galactic 'date'

5) Velocity of the Milky Way with respect to the Local Group

So, Bob could predict moderately well the speed of the electron in advance, and make suitable adjustments for the measured speed with a relativistic correction.

But there's nothing magical about Bob's choice of location. His frame of reference and his time-measuring device are no more special than Alice's.

Perhaps I still do not see your question fully.

Donald,

the point that James made is correct. The velocity is measured in a reference frame, for example the lab on Earth. Than, you can add (following the rules of special relativity) the velocity that the lab has with respect to another reference system, to find the velocity of the electron with respect to this second reference system. In your case, you simply sum the velocity of the electron with respect to the lab, with the velocity of the faraway galaxy with respect to the lab (with the correct signs, and, again, according to the rules of special relativity), and that is it. Although I doubt that it can be of any practical use, apart from discussing examples like here. If you want to kwon how the velocity of an electron can be measured, you can measure the deflection of its trajectory in a magnetic field, and from that, using the strength of the magnetic field, and the mass of the electron (which is not massless, Christopher!) you can calculate the velocity you need. If you wish to know the velocity of an electron bound to the nucleus of an atom, well, here there are problems, because of the quantum mechanical nature of this problem.

Three perspectives: the cosmic, the atomic, and the electron:

Cosmic:

Although it's true there is no a priori absolute frame of reference, there is, none the less, a fairly well-defined a posterior absolute frame of reference: The model of space-time used to model the Big Bang assumes a physically natural frame of reference--essentially, that frame in which the Big Bang is at rest. We can detect this frame by observation of the Cosmic Microwave Background Radiation. That's an eminently reasonable selection for "absolute rest frame".

Atomic:

Velocity as normally considered refers to (solid) objects--not to atoms. Going below the surface of an object to look at the molecules making it up, we see the molecules are, indeed, in motion with respect to the object--that's what we term heat energy. It's not clear that one wants to consider that molecular motion in the same category as motion of the object. Such motion is well-defined, but it just means something very different to our ordinary sense of what velocity is used for.

On the other hand, if you're looking at, say, interstellar dust--basically, isolated hydrogen atoms--then there's no such distinction between heat motion and other motion.

Electrons:

While you can meaningfully talk about the speed of electrons in an electric current in a conductor, once you're looking at, instead, bound electrons in a molecule, things get decidedly unspecifiable. Heisenberg uncertainty implies that the more localized the position of an electron (say, in a molecule or an atom), the less it is even theoretically possible to say about its velocity. In essence, there's no such thing as reasonably definable velocity for a bound electron--the inherent Heisenberg uncertainty swamps out whatever velocity you'd like to attribute to it.

On the last bit, what is the source of all these motions:

Gravity is the source of most the large-scale motions: the galaxy within its cluster, the stars within the galaxy, the planets around the star. There's still the overall motion of the galactic clusters, though: In part that's left over from the Big Bang and the multitudinous interactions--first by strong nuclear force, then by electromagnetic forces--among the elementary particles, then, in later epoch, gravitational interaction.

Within a planet, we have gravity as one of the two main forces, and electromagnetic interaction as the other main one--generally equally balanced (that's why we don't fall to the center of the earth: electromagnetic forces provide surface tension to solid objects, so they don't pass through one another).

If you're interested in heat motion, that's electromagnetic, including absorption of light energy on the surface (not just the sun, but also infra-red radiated by everything), as well as molecule-molecule interaction (electron clouds pushing against one another).

I'm not sure what's meant by "all action derives from the very small". It's true that an individual particle experiences the gravitational force from other individual particles, but it makes a lot of sense to the earth, as a whole, experiences the gravitational force from the sun as a whole and from each of the other planets as a whole--that is to say, the entire earth, as a body, moves as if it were a point mass being acted on by a point mass at the sun's center of gravity, etc. (Not entirely true, though: The earth's body of water, being liquid, moves much more fluidly, with a lobe pointed at the moon, and so on.)

"What positions could be used to determine these objects moving - and what 'time' would be involved - are good questions."

It is all up to you. You can do as yopu will and you will get your velocity. Someone will do it differently and will get his velocity. Velocities always belong to somebody. Much like money.

Why would one be interested in measuring the velocity of a tennis ball (e.g)

at the reference frame of the galactic center? What is the physics scope of this?

Anyway, I guess that we can add vectorially all the velocities with respect to the galactic centre and find the result in question.

The cross section of a high energy process is inversely proportional to the relative speed of the two colliding particles. Therefore the physics lies there.

@Emmanuel

How might we determine the position of the different vectors - so that we could add them? The position measurement of a galaxy is going to be on a very large scale. Removing the electron and stopping at the atom or macromolecule for velocities - how can we compare positions when the objects we are measuring vary so much in size?

The 'positions' needed for a velocity determination of our super cluster and of our galaxy are large orders of magnitude different - to say nothing of this compared with the positions of even the hair on the tennis ball.

If we consider two position measurements for any of the objects above, along with the error term for them, we can think of this situation as a line between the positions with a 'width' as the +/- error term. The width of this line for super clusters, even with 12 significant digits for the measurement, will dwarf any position measurement of the tennis ball.

Are the different positions (and hence velocities) even comparable so that they could be added?

Two notes:

1) The problem is pure mathematical one and has nothing to do with physics.

2) None of the frame of reference is inertial.

@Mikhail

I disagree. I believe the problem is that our theories are too tied to a presumed 3-D geometric model of space - where scale does not come into play.

In a 3-D model of space, the problems of position and velocity at very different scales should not occur (as scale is not a consideration when position only consists of Length Width and Depth).

The concept of 'simply adding vectors' is a purely geometric answer to the problem, that presumes infinitesimal points are allowed in physical space. The answer does not acknowledge the realities of scale in the universe.

So 'simply adding vectors' is the pure mathematical part and accounting for scale is the physical reality part.

I observe the greater part of answers are in concordance with Special Relativity. Nobody wonders if that theory is able to give correct answers. I see many write about velocity and addition of velocities. One of main contradictions of SR is just this: SR eliminated the vector characteristic of velocities and replaced it with the theorem of scalar addition of velocities.

The concept of total velocity is equivalent to the concept of absolute velocity. Both concepts are meaningless because the absolute reference frame doesn' exist and we cannot think to replace it with CMBR, that is emitted from billions of moving stars.

The fact that the absolute reference frame doesn' exist it doesn' exclude the existence of a preferred reference frame.

In the Theory of Reference Frames (TR) I have demonstrated the preferred reference frame coincides with the reference frame where physical phenomenon happens and where the primary observer is placed.

The same thing is valid for inertial reference frames, it is true that the absolute inertial reference frame doesn' exist but relative inertial reference frames exist.

The question of measurement scales exists everywhere, also in the reference frame of the earth. For instance when I want to compare 1 micrometre with 1 kilometre. From mathematical viewpoint this question is solved through mathematical techniques (powers, logarithms, etc.). From physical viewpoint that question can be solved also through techniques of approximation and errors.

I don't think questions of scale can be solved increasing in affected way space dimensions.

@Donald

"So 'simply adding vectors' is the pure mathematical part and accounting for scale is the physical reality part" - that is what I mean in p.1. Thank you for clarification.

Velocity is only a mental project connected with reference. In classical mechanics we assume that exist velocity itself and we try to measure with errors. With Einstein the meaning of velocity is connected with transformation and geometry. Physical masses change the space time curvature and also the velocity and the Kinetic Energy with the hypothesis that the physical reality ( velocity ) must be independent from observer. Now in quantum mechanics the relativity constrain collapse and the physical reality change with the action of the measure of the observers. In quantum mechanics Fisher information space include the form of the uncertainty and introduce a new Kinetic Energy connected with the information form. In synthetic Physics a novel entropic space based on the model of Maxwell Equations introduce the geometry of the intrinsic uncertainty due to the information form of quantum noise. So In quantum mechanics we can have velocity and Kinetic Energy with information ( measure ). So for the dependence of velocity with information we cannot really discuss of velocity but we can only see the dependence between velocity an information as field or space.

Consider the cycles. In 60 000 years or so, our relative velocity vector in our galaxy will be inversed. This kind of inversion occurs at each cycle, very short in atoms, very long in galaxy. So, adding the vectors is meaningless outside a specific cycle and scale.

Contra Daniele Sasso, the Cosmic Microwave Background Radiation does not come from stars. It comes from the background, from all over: it is the echo of the Big Bang, still ringing throughout the universe. Hence, it provides a very reasonable "ground-state" reference frame: Basically, choose a velocity in which the CMBR shows no red-shift or blue-shift in any direction; then you're at rest with respect to the Big Bang, and that's as much basic-at-rest-ness as one can reliably speak of in the universe.

But it's true that we aren't in an empty, flat spacetime; there is a significant amount of geometry (curviness) in the universe, and that makes special relativity not applicable in contexts that take the large scale structure of the universe into account: Not only can we not add velocity vectors, as if this were a Newtonian universe, we cannot even do the Special Relativity addition of 4-velocities. In a general spacetime, it simply makes no sense whatsoever to say "object X is moving with velocity v with respect to object Y" unless X and Y are overlapping one another--there is *no* measurement of velocity at a distance: not only no absolute velocity, but not even any relative velocity except for things (momentarily) touching.

But the inaccuracies are very small if the context is confined to, say, our galactic cluster. It's only when you're looking at cosmic dimensions that this really comes into play. So it does make good sense to ask, what is the relative velocity between (say) me and the rest-frame of the CMBR (as measured by me right here)?

I think the most important is what really affecting the measured physical quantity and the accuracy of the measuring devices. As an example if you are measuring frequencies emitted from distant galaxies the most important is the receding away speed which is related to expansion of the universe. so we don't have to consider the other movements (like spinning) if they are not important in the research proposed and if the accuracy is not enough because it's simply can be neglected.

Dear Dr. Steven Harris,

I disagree with your ideas, but I respect them.Your reasoning on the Big Bang, on Cosmic Microwave Background Radiation and on the origin of the universe is based on a wrong assumption: "choose a velocity in which the CMBR shows no red-shift or blue-shift in any direction: then you're at rest with respect to the Big Bang".

That choise is altogether arbitrary because it supposes a zero relative velocity between the earth and your reference frame at rest and consequently the arbitrary knowledge of a sample frequency as source in the microwave band. Firstly I observe that earth has numerous movements (unless you subscribe the Aristotelian universe that is antecedent to the Newtonian universe) and therefore if the relative velocity is zero also the reference frame you associate to the Big Bang has necessarily movements. Secondly we can neither know if the source sample frequency of CMBR belongs to the microwave band. Microwaves don't have atomistic physical nature and their frequencies are smaller than infrared frequencies. Those ideas represent only a vague hypothesis to which we cannot assign value of scientific theory.

On rest-frame of Cosmic Microwave Background Radiation

It is simplicity to find a velocity vector here which represents rest with respect to the CMBR: Just look at the CMBR as we see it now: It shows red-shift in one portion of the sky, blue-shift in the opposite portion. That defines both a unique direction (running from the point of max red-shift to its diametrically opposite point of max blue-shift) and also a unique speed (that which is necessary to generate that particular red-shift and blue-shift). That's all there is to it.

(It's an experimental fact that it is possible to detect red-shift and blue-shift in the CMBR--intervening monomolecular hydrogen clouds absorb frequencies selectively, allowing precise measurement of shifted frequencies--that the points of max red-shift and max blue-shift are diametrically opposed in the sky, and that the max red-shift is equal to the max blue-shift. In other words, what we observe coincides with what one expects to see if there is a body of microwave radiation in the universe, and we are moving at specific velocity--direction and speed--with respect to that body. There ain't nothing vague about this; it's very elementary radio-frequency astronomy that we've been doing for decades, just applied with especial care for this signal, using the COBE satellite and others. No assumptions being made; pure data-driven deduction.)

Whether one likes to think of the CMBR rest-frame as legitimate absolute frame of reference for the universe is a matter of aesthetics, as there is no actual physical content--theoretical or practical--to the phrase "absolute frame of reference of the universe". Best just to say, "So-and-so is our velocity with respect to the CMBR," and leave it at that.

On Lorentz invariance of combining astronomical velocities:

If I recall correctly, our CMBR-relative speed isn't a very significant fraction of the speed of light (though i'm not certain)--and our speeds with respect to sun, galactic center, and center of mass of our galactic cluster are clearly way below light-speed--which means that we don't have to worry about Lorentz invariance on adding up velocities, unless we're aiming for higher precision than our data actually allows us.

But there's no particular need to add velocity vectors, except for the fun of parcelling out the different physical contributions (general universal expansion vector, vector of motion of our galaxy with respect to the cluster, vector of motion of our sun with respect to the galaxy, earth's vector of motion with respect to the sun). From a practical standpoint, we just look at the microwave sky and say, "Behold! Here's our total motion vector with respect to CMBR."

From my viewpoint the Cerenkov effect is very interesting because it proves in suitable physical conditions the velocity of a particle in a medium can be greater than the velocity of light in the same medium. Certainly this effect raises a big problem for the Lorentz factor, but it is fully compatible with the Theory of Reference Frames.

There is nothing at all significant (for relativity effects) about the speed of light in a medium. The speed of light in the interior of the sun is orders of magnitudes below that of light in vacuum (because photons generated at one atom are absorbed and readmitted at another, at the speed of quantum-level changes in excited atoms); but this doesn't mean that the sun is subject to weird relativistic effects.

"The speed of light" in relativistic formulations refers to what happens in vacuo, not what happens in a medium. The reason is that what counts for the basic structure of the universe is the speed of a photon in the interstices between atoms, not how quickly the excitation levels of an atom react to being energized and then falling back down to a lower level.

Dear Mrs Harris,

I would want to ask a few explanations on issues regarding astronomical measurements.

Generally when we consider the Doppler effect it is usual to describe a redshift and a blueshift relative to frequencies of visible band, where the redshift shows a decrease of frequency and the blueshift instead an increase of frequency. Now I observe you make use of these words also for the microwave band. But here those words have no reference to red and to blue. Is it like this?

With regard to relativistic effects Einstein in his formulae used the speed of light in a vacuum because he supposed to perform his thought experiments in a vacuum.

If we want to perform the synchronization of two remote clocks in the atmosphere of the earth through rays of light, it is manifest in that case we have to make use of the speed of light in air. All equations, including the Maxwell equations and relativistic formulae, have to be considered always with respect to the real medium (not only vacuum) where the physical phenomenon happens. Besides the Cerenkov effect proves a real fact unless it is refuted through experiments.

Some interesting discussions going on.

The main purpose of this 'thought experiment' is to bring out the differences we find in the universe at different scales. How we measure 'velocity' differs when we measure objects at different scales. The physics we employ for these measurements is not the same - we do not measure the positions of a galaxy at t = 1 and t = 2 and calculate |p(2) - p(1)| / t. For the tennis ball, measuring these positions could be the method, but not the red-shift of the tennis ball.

Scale matters - and it matters a lot. It is something I believe has been passed over when considering how the universe works. I'm not (simply) referring to GR and QM, I am referring to actions across the entire spectrum of scale.

Are there objects or events which move across scale (eg a nuclear bomb)? Heat and certain forms of energy seem to cross levels of scale. Does (and how does) physics account for this?

I would disagree with @Daniele, as I think that:

1) We have explored scale as a continuum of reality and of space

2) We have found reality to be composed of very different objects at different scales and we use different tools to operate on objects at different scales (why would a 3-D non-scale dependent model need these different methods?)

3) We can use tools that operate at one scale to measure objects at another very different scale - meaning the levels of scale are connected (eg. use of spectra in astronomy)

4) A 3-D object at one level (say our body) can be composed of different objects filling the same 3-D volume at different scales (eg. organs, cells, proteins) - how is this possible using only a 3-D model of space?

5) We can take the 3-D volume of our body and 'slide' it down in scale, generating a 4-D hypervolume of our body that can incorporate these other objects in (not) the same 3-D volume. Scale can fit the definition of a 4th dimension of physical space.

I also believe this is the next direction for physics to address - as we are already attempting to connect nano-technology with our macro scale. Scale matters in nearly everything we do and we need to account for it in our physical models of space.

Redshift and blueshift refer to the Doppler effect of perceiving, respectively, a decrease or increase in frequency, due to relative motion between emitter and receiver. The color-names are chosen to represent, roughly, the shift in frequency within the visible light spectrum (the lower end of the visible frequency range is red, the upper end is blue shading into violet); but the terms apply whether we're talking about decrease/increase in visible light, radio waves, or any other portion of the spectrum.

(Correction to what I said before about method of detecting redshift and blueshift in CMBR: I think it's pretty much a single pure frequency, not a spread across an octave or so like what comes from a star; so we don't need to analyze absorption bands by dust clouds, we just need to see what frequency it is in this part of the sky, and what frequency it is in that part. Observation shows it's highest in one direction, lowest in the diametrically opposite direction.)

Einstein's thought-experiments are, indeed, done in vacuum. To be precise about it, special relativity is applicable only to vacuum--and also only with an absence of gravity and of electromagnetic fields. General relativity is necessary for interaction with matter, as well as for the effects of gravity and EM fields. But the main point remains: The interior of the sun has no weird relativistic effects due to the fact that the speed of light in the sun is orders of magnitude slower than in vacuum; that's totally irrelevant to anything except things like calculations of heat-transfer within the sun. The physics of the sun is governed by things like plasma physics and nuclear reactions--not so much by relativity. Relativity becomes important when looking at more extreme densities, as with what happens when a star goes supernova.

Now your explanation is very clear. The observation in one direction gives higher frequencies than in the diametrically opposite direction.

It nevertheless doesn't prove there is a resting reference frame, but only the relative speed between observer and source of radiation is a relative speed of approach in one direction and a relative speed of deviation in the diametrically opposite direction. Thanks for your explanation.

Yes, that's accurate. "At rest with respect to the Big Bang" is close as I know how to come to choosing a "natural" rest frame at all points: It has the advantage of being readily observable and definable at all points, and it refers to something truly cosmic in the universe--evidently in the present epoch (the sea of radiation) and, by inference, in the past (the Big Bang). But it's only a choice to be made.

The models that serve to explain how the Big Bang gave rise to what we see today (Friedmann-Lemaitre-Robinson-Walker models, upon which Inflation is based) make use of what might be called a resting reference frame spanning the universe (more precisely: these models presume a homogeneous spatial model for the universe, unchanging in time save for uniform contraction or expansion; and that homogeneous spatial model is what I'm calling "a resting reference frame spanning the universe"). This is obtained by assuming a "smoothing out" procedure can average all the galactic clusters and voids together. Whether this smoothing out actually yields a good way of modeling the universe is not yet clear; that requires a good deal more mathematical analysis.

The entire relativity discussion since Einstein has been misguided by a false assumption. The false assumption is that space is inert, rigid, and absolute. The concept of Aether posits that space is fluid and constantly in motion, it is not absolute.

Fluid Aether is evident all around us. It manifests as frame dragging, dynamic magnetic fields, vacuum fluctuations, and space-time curvature tensor in GR to name a few examples. The Michelson Morley experiment DID measure an Aether drift of ten kilometers per second. It was not the magnitude expected for an absolute and rigid Aether, but it was of a magnitude appropriate for a fluid Aether.

When there are over 100,000 data points measuring a fluid Aether, and there are numerous examples in the real world of a fluid Aether, then the science should be interpreted as proof in favor of a fluid Aether. But no, for whatever ignorant reason, modern science keeps saying that because there is no rigid Aether then the Aether is proved to not exist.

Each scale of physical existence, from galaxies to subatomic particles, has its own influence on the fluid Aether by virtue of its magnetic and electric properties.

The Aether does not behave within a Cartesian coordinate system. The Cartesian coordinate system is a close approximation when the system being observed is near rest. However, when one region of space is moving into another region of space, then we observe what has come to be known as relativity. Now the space of one system has to be quantified relative to the space of another system, which is what General Relativity does with its space-curvature (Aether) tensor and mass-energy (matter) tensor.

Albert Einstein, himself, repeatedly commented that there has to be an Aether, although it could not be the rigid Aether proposed for the Michelson Morley experiment. My work lays a solid foundation for understanding the physics of Aether and its relationship to matter. As a result of my work, I achieved what Albert Einstein could not. I successfully and mathematically, using simple Newtonian force laws, unified all the forces.

The foundations of physics are far simpler than expressed by the Standard Model with its several incorrect assumptions. As a result of my work, when it is fully accepted by the scientific community, we will be able to engineer the manipulation of space in the same way we manipulate matter. We will be able to build higher resolution telescopes that not only see across space, but time as well. Most importantly, the science of physics will be brought into the realm of common sense and be understood by far more people.

―Fresnel further assumed that, when a body is in motion, part of the Aether within it is carried along-namely, that part which constitutes the excess of its density over the density of Aether in vacuo; while the rest of the Aether within the space occupied by the body is stationary.‖ Sir Edmund Whittaker A History of the Theories of Aether and Electricity; The Classical Theories (London; New York, American Institute of Physics,

1987) 110

―The outcome of the Michelson - Morley experiment would, therefore, suggest that the ether is dragged along with the earth, as far as the immediate neighborhood of the earth is concerned. Introduction to the Theory of Relativity Peter Gabriel Bergmann (New York, Prentice Hall Inc., 1947) 27

― Dayton C. Miller, Science, New Series, Vol. 63, No. 1635 (Apr. 30, 1926), 433-443 It is also noted in an article by Robert S. Shankland, Science, New Series, Vol. 176, No. 4035 (May 12, 1972), 652-653 that at the strong encouragement of Albert Einstein, the Miller data was re-examined posthumously and judged to be questionable due to the claim that Miller’s results correlated with the temperature gradient across the interferometer table. For all of Miller’s extensive experience, it seems highly suspect that Miller did not notice what should have been an obvious flaw in the results, were it true.

There is a basic confusion.

Velocity (or speed) in any geometry (galilean or relativist) has a precise meaning for a material point, without extension. When one considers velocity of a larger body, it is implicit, from our common experience, that this is a solid, for which there is a global relation between the velocities of its different material points, represented by another quantity which its rotation. But the velocity of a fluid has no meaning (more precisely one usually defines a vector field corresponding to the velocity of material points of the fluid) individual velocities do not add up..

In galilean geometry the motion (translational and rotational) of a solid can be represented by two 3 dimensional vectors (one for the speed and one for the instantaneous rotation). But in relativist geometry this is more complicated : there is no solid (the lengths are not cnstant), and the rotation in space-time actually encompasses a part of the translation. So the usual definition by the Poincaré group (whic requieres 10 parameters) is not physical. Some considerations lead to define the motion by spinors (2 three dimensional vectors) which are actually what is used in particles physics. In some way we have the same kindof representations (by spinors) whatever the scale, but that does not imply that the spinors add up in a composite body (the velocities of material points do not add up in a body, even a solid).

Donald, there is no such thing as "absolute space." That is what the Michelson-Morley experiment actually proved. Absolute space as a concept is a faulty assumption of the Standard Model. Space is fluid and moves with matter. Hence, the expected Aether wind that would be expected from a rigid Aether was falsified.

"Frame dragging" is just one of several measurable examples of a dragged Aether.

Also, Morley never rejected his findings. He and Dayton Miller insisted until their deaths that 100,000 data points conclusively proved an Aether drift. It was Albert Einstein, who placed undue pressure on Robert Shankland, who nullified the Morley-Miller results posthumously.

I take issue with the concept of mass-energy equivalence. Mass is just a dimension; it is not an objective thing. Energy is just a unit of work. Energy is not a "thing" of any kind. Electrons, photons, and protons possess the non-material qualities of mass and energy, but they are not made from mass and energy. Similarly, a car is not made from velocity even though its primary function is to provide motion.

Energy is equal to mass times velocity squared. By definition, the unit of energy always possesses the dimension of mass. One cannot convert or equate energy with mass anymore than they can equate a brick house with bricks; a brick house is more than just bricks, which is why it is called a house and not bricks. Energy is more than just mass, and energy has nothing at all to do with the structure of material objects. Similarly, the unit of resistance also contains the dimension of mass, and yet nobody speaks of "resistance-mass equivalence."

Furthermore, velocity squared is dimensionally equal to the unit of temperature. In the relativistic paradigm, velocity squared is related to the speed of light even though it has nothing to do with speed in a linear sense. Instead of saying energy is equal to mass times velocity squared, we should be saying energy is equal to temperature times mass.

Donald - What seems to be absolute space is a fluid space that is distorted in the presence of matter; hence, orbital precession near massive objects, gravitational lensing, frame dragging, black holes, magnetic and electric fields, and other space-distorting phenomena. Space may seem absolute to our normal day to day experience of the world, but the exceptions do exist.