Frame Dragging

[KALSTER]

To quote Wiki:

Albert Einstein's theory of general relativity predicts that rotating bodies drag spacetime around themselves in a phenomenon referred to as frame-dragging. The rotational frame-dragging effect was first derived from the theory of general relativity in 1918 by the Austrian physicists Joseph Lense and Hans Thirring, and is also known as the Lense-Thirring effect.[1][2][3] Lense and Thirring predicted that the rotation of an object would alter space and time, dragging a nearby object out of position compared to the predictions of Newtonian physics. The predicted effect is incredibly small — about one part in a few trillion. In order to detect it, it is necessary to look at a very massive object, or build an instrument that is incredibly sensitive. More generally, the subject of field effects caused by moving matter is known as gravitomagnetism.

 

Different forms of:

Rotational frame-dragging (the Lense-Thirring effect) appears in the general principle of relativity and similar theories in the vicinity of rotating massive objects. Under the Lense-Thirring effect, the frame of reference in which a clock ticks the fastest is one which is rotating around the object as viewed by a distant observer. This also means that light traveling in the direction of rotation of the object will move around the object faster than light moving against the rotation as seen by a distant observer. It is now the best-known effect, partly thanks to the Gravity Probe B experiment.

 

Linear frame dragging is the similarly inevitable result of the general principle of relativity, applied to linear momentum. Although it arguably has equal theoretical legitimacy to the "rotational" effect, the difficulty of obtaining an experimental verification of the effect means that it receives much less discussion and is often omitted from articles on frame-dragging (but see Einstein, 1921).[4]

 

Static mass increase is a third effect noted by Einstein in the same paper.[5] The effect is an increase in inertia of a body when other masses are placed nearby. While not strictly a frame dragging effect (the term frame dragging is not used by Einstein), it is demonstrated by Einstein to derive from the same equation of general relativity. Again, a tiny effect difficult to confirm experimentally.

 

Ok, so my question is whether this effect occurs on a planetary surface as well? What about underground? There is a Gravity Probe experiment underway which involves the launching of satellites into orbit in order to measure the tiny effect with the use of gyroscopes, but this will only measure the effect in near space and not on the surface or underground.

[Tormod]

As is stated above, it happens with all objects and thus also on a planetary surface, but the effect is so small that it's almost impossible to detect.

[KALSTER]

As is stated above, it happens with all objects and thus also on a planetary surface, but the effect is so small that it's almost impossible to detect.

Thanks, but what I was wondering was how the effect changes in strength as you move through the atmospheer and onto the surface? You see, I always thought that the measured effect would lessen as you come closer to the surface, because you would be entering the frame of the earth. But then if that were the case, that would mean that the frame of the earth is isolated from the surrounding space to some degree, no?

[KALSTER]

No takers?

[sanctus]

Why should it lessen? It is the frame of earth which is draggened along no?

[KALSTER]

Why should it lessen? It is the frame of earth which is draggened along no?

Yes, I am asking about the measured effect lessening. As you move further out into space the measured effect would become larger. In other words whether the frames of the earth on the surface and an arbitrarily chosen second frame would become more isolated from each other as the second frame moves away from the earth.

[modest]

Yes, I am asking about the measured effect lessening. As you move further out into space the measured effect would become larger. In other words whether the frames of the earth on the surface and an arbitrarily chosen second frame would become more isolated from each other as the second frame moves away from the earth.

 

The closer you are to the angular momentum of the mass dragging the frame the greater the effect. In other words, the effect diminishes with distance from earth's surface. Also, yes - frame dragging persists in a rigid mass. A neutrino (or some other particle) that passes through the earth would do so faster (by a ridiculously small amount) if it passes through the side with positive velocity relative to the neutrino's movement. This would be a very hard thing to calculate - beyond my ability.

 

-modest

[KALSTER]

Thanks. I was just wondering, supposing an ether in some form did exist, if the frame-dragging effect might influence Michelson–Morley type experiments in such a way as to give results that would appear to confirm the absence of it. Some modern ether theories do not think of the hypothetical ether as being comprised of some type of conventional particle anyway. Does the presence of an ether in all its proposed varieties necessarily contradict relativity?

 

I have always in my mind sort of linked the geometric nature of the space-time fabric to some form of aether. I mean what exactly is bent in the presence of matter to have the phenomenon of gravity as a result? And when carrying the 2D idea of bent space (you know, the stretched cloth with a marble in the centre) over to a 3D scenario has in my mind led to an analogy of stretched rubber with the varying degrees of local tension (and maybe even a form of density) corresponding to the strength and direction of the local force of gravity.

 

I am trying to think at what exactly space-time is. When you start from a point, you can go in three main directions (3D) with any direction possible as a combination of these three. Time is nothing other than a way to measure relative movement. So if I am not mistaken, the 4D space-time geometric equation () incorporates time to be able to provide a convenient and accurate mathematical basis from which to work when describing movement in space-time. So from this utilitarian perspective on space-time as more of an accurate mathematical model, at least in my mind, no paradox need result from some kind of aether theory. So while it might make predictions, I think of relativity theory more in terms of a mathematical model that describes phenomena, observed and experimentally verified, but that it does not neccesarily describe the precise nature of the space-time fabric. The same goes for QM in my mind. It does (maybe by accident) quantifiably describe the sub-atomic world, but that it does not neccesarily mean that it exactly describes the exact nature space-time. Am I way off-base here?

[KALSTER]

Sorry:doh:

[modest]

Thanks. I was just wondering, supposing an ether in some form did exist, if the frame-dragging effect might influence Michelson–Morley type experiments in such a way as to give results that would appear to confirm the absence of it.

 

No, the effect is too small by many orders of magnitude.

 

Some modern ether theories do not think of the hypothetical ether as being comprised of some type of conventional particle anyway. Does the presence of an ether in all its proposed varieties necessarily contradict relativity?

 

Relativity does not exactly make æther an impossibility. What it does is take the property of motion (or time) from it. If æther is going to have any interaction that is measurable then it cannot be bound to a particular reference frame. Which means the historical quality æther had (that of being a mechanical medium for light propagation) it cannot have.

 

So while it might make predictions, I think of relativity theory more in terms of a mathematical model that describes phenomena, observed and experimentally verified, but that it does not neccesarily describe the precise nature of the space-time fabric. The same goes for QM in my mind. It does (maybe by accident) quantifiably describe the sub-atomic world, but that it does not neccesarily mean that it exactly describes the exact nature space-time. Am I way off-base here?

 

I think it would be a mistake to think the fields in general relativity or quantum mechanics need a luminiferous-like æther to exist. The geometry of spactime is not what is normally though of as an æther.

 

That said, Einstein himself did not rule out the possibility:

Ether and the Theory of Relativity

 

-modest

[KALSTER]

What I am trying to do is basically start from scratch and see if I might be able to explain observable phenomena and experimental results in a way that could at least potentially allow for it to be quantifiably described and verified by both Einsteinian Relativity and QM. Now I know all too well that every second schmuck thinks he can come up with his own little "theory" and more often than not professes him/herself to be the author of THE TOE/GUT. This is also almost always accompanied with wild claims, unsubstantiated assumptions and shoddy or no math. I am trying to do nothing of the sort. I first want to run with this hypothetical to see if it could at least qualitatively provide a logically consistent framework for current physics theory to exist in. If some insurmountable problem arises, I’ll abandon it as I am not interested in nonsense half baked “theories”. I am genuinely interested in the truth.

 

I did post my initial thoughts on a forum HERE if you’d care to read it. If not I’d be happy to expand if you are interested (morbidly amused would also do :eek: ).

Some of the ideas has evolved somewhat while still keeping with the initial premise, which is the possibility that all of the universe (matter and forces) are geometric distortions of an infinite medium. I am thinking that if a qualitative framework could be erected, that some testable predictions might be possible with the addition of the appropriate math and that it could ultimately bridge the gap between QM and Relativity. Of course, it has to WORK first and that is where you guys come in.

 

 

If nothing else, this is an interesting and stimulating mind experiment (at least for me) and I highly appreciate any input you can provide, whether it be suggestions, criticism or suggested further reading. You might deem this thread suitable for the pseudoscience section, by I don't think it is as I am not making claims as such, only "whatif's".

 

So there you have it.:eek:

[KALSTER]

Wow, thanks for the link you provided. Good reading! It has made me think a bit further on the nature of the proposed aether. Einstein says that for the aether to be consistent with Relativity it can not be thought of as existing of individual particles in relation to which motion can be measured. But then how can it have the needed properties for electromagnetic radiation and gravity to exist? Logic dictates that everything is infinitely devisable, for when you choose to stop dividing after any number of divisions you could still in principle divide to yet another level. So if you take it to the limit (pun intended) mathematically, you will be left with a particle with dimensions that tend toward zero. An infinite number of these particles together? And you have a possible aether!

 

The seperation between these particles would also tend towards zero, but slight variations in these seperations would allow for any kind of 3D dynamics on the makro scale.

 

The question is: How would the fluid dynamics of these particles (strings maybe :?: ) be affected when the particles and seperations are on a sub Planck length scale?

[Jose50]

To quote Wiki:

 

 

Different forms of:

 

 

Ok, so my question is whether this effect occurs on a planetary surface as well? What about underground? There is a Gravity Probe experiment underway which involves the launching of satellites into orbit in order to measure the tiny effect with the use of gyroscopes, but this will only measure the effect in near space and not on the surface or underground.

I believe there is no frame-dragging effect of gravity on mass, only on electromagnetic energy!

Curiously, the Lense-Thirring effect in Gravity Probe B has the same value than the geodetic effect of the Earth around the Sun.

NASA error?

An interesting experiment!

Understanding Gravity Probe-B experiment without math 

http://www.molwick.com/en/gravitation/082-gravity-probe-b.html 

http://www.molwick.com/en/gravitation/r-lense-thirring-frame-dragging.jpg