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#1660 by Rodal on 16 Sep, 2017 17:21
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For those readers who are struggling how the Mach Principle works here is a quick video on youtube that's easy to understand.
Thank you for the interesting video. Please note:
Shell
1) There is nothing discussed in this video about Mach's principle that is not fully contained in Einstein's General Relativity. So if Mach's principle makes one aware of something that is already present in Einstein's General Relativity, great!. However, there is no "extra-Machian" effect discussed in the video that is not already present in Einstein's General Relativity. Actually all cosmological measurements including Gravity Probe B, that have looked for extra-Machian effects (which were in fashion in the 1960's due to Brans-Dicke theory) have failed to find any Machian effect not present in Einstein's General Relativity
2) The discussion in the video deals with rotation effects: centrifugal-centripetal forces. The MET (PZT stack) experiments feature no such rotation or spin effects and the theory does not analyze any such spin effects either. Instead the MET experiments deal with longitudinal oscillations.
3) It is very difficult to discuss rotational forces in General Relativity for spinning rigid bodies. Actually it is trivial to show that in General Relativity one cannot have anything rigid, as the length of a body in relativity is subject to Lorentzian transformations that are observer-dependent and certainly speed-dependent. It is very problematic in General Relativity to discuss a center of mass for a rotating body. It is this issue that has been recently discussed by an MIT professor to discuss "swimming in space" https://groups.csail.mit.edu/mac/users/wisdom/swimming.pdf .
4) A typo in the captions to the video: where it reads "process" it should read "precess" (referring to the pendulum inside the rotating sphere) as in https://en.wikipedia.org/wiki/Precession as in the precession of a gyroscope
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#1661 by guckyfan on 16 Sep, 2017 17:27
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...In (1) Sakharov disproved Hawking, who previously claimed (before they met in 1987) that maximal entropy alone would reverse the arrow of time. Sakharov showed him he was wrong, as entropy grows with the arrow of time (both are related) and the time arrow can reverse only if entropy reaches a minimal state, i.e. zero value. ...
This is interesting
Thanks for pointing this out.
I am by no means knowledgeable in this area. But I did read Hawkings "A brief history of time". He mentioned the reversal of the time arrow at the end of the book, but as speculation. He later noted that it is not correct. -
#1662 by Monomorphic on 16 Sep, 2017 17:45
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Credit for this goes to Mr. Frank Becker. He and I have exchanged a few emails about his methodology for simulating Unruh radiation. He claims it gives good, "near perfect" agreement with Mr. McCullouch's predictions. His comments regarding my current frustum design are below along with some graphs he shared.:
Actually your design is very much aligned already with the main essence of design strategy in respect to the quantised inertia theory.
Basically the forces which would be established at each side of the cavity (in your case) are not cancelling out much.
That is the main goal to achieve and your selected dimension are doing this quite well.
Please let me share with you some graphs to illustrate your advantageous design.
Please allow me firstly to introduce you the particular dE curves for your design (W/w/L = 0.299/0.178/0.24 & Q=8100(?) & P=25[W]):
Considering the quantised inertia theory each side of the cavity generates a different inertial mass on the bouncing photons.
The force (for each side) is established by the formula F=dE/dx (where dx is a function of the involved Rindler horizon, in this case either W or w).
The opposing cavity plate (towards photon acceleration direction) is damping the Unruh field in front of the (bouncing) photons.
Basically the allowed Unruh radiation (max. wavelength) in front of the photons is reduced by the insertion of the metal plate in front of the travelling path.
There is also a allowed Unruh wavelength behind the travelling photons, therefore we could see Unruh 2 baths (front & back) each repelled photon.
The Unruh radiation in front and at the backside of each bouncing photon has let us call it a different 1 dimensional energy density.
The dE would correspond to the difference in energy density in front and at the back side of each bouncing photon.
So forces would be established at each side of the cavity and by design the dE’s for each side should be as much different as possible.
Now in your case we see, this strategy is actually provided.
Looking now into the established forces, each side of the cavity will have a force “pushing” outwards of the cavity (opposite of travelling path).
We concluded a pre-condition that those forces are “uneven” (as much different to provide a high net-force in one direction) is a high difference in dE’s.
Looking into the next graph, we see that in your case (by the selected dimension) this works out pretty fine:
You will notice checking the 2 graphs also, that the “operational points” are basically your ratios of “cavity length divided by cavity end plate size”.
The main contributor for your effect is the number of photon, basically your power input and the Q-factor (force multiplier).
Therefore you will (as planned) measure your anticipated boost in the effect (prediction).
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#1663 by Mulletron on 16 Sep, 2017 18:30
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Sorry folks. I'm not seeing the EM drive in all this loose, just a hijacked topic.
Which can be easily addressed by you (or someone else) posting something on EM Drive - related to space flight applications. Posting is the best way to bring the thread back on focus
The above discussions are peripherally related to the subject as follows: there have been posts conjecturing whether the EM Drive can be explained by gravitational waves, or by General Relativity or by super-Machian effects not present in General Relativity.
Many people are still wondering: how can something like the EM Drive accelerate the center of mass?
The thread naturally gyrated to some fundamental issues, because these fundamental issues are not resolved -as excellently documented by flux_capacitor-
Yeah, in a weird way, I'm interested in all this black hole entropy stuff, and similar research I'm doing on the side, because I think I convinced myself the other day that an EMdrive must be allowed a way to have an exhaust, as in only a portion of the energy in the system can be converted to thrust, and the rest must be able to escape. -
#1664 by tchernik on 16 Sep, 2017 18:51
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Sorry folks. I'm not seeing the EM drive in all this loose, just a hijacked topic.
Which can be easily addressed by you (or someone else) posting something on EM Drive - related to space flight applications. Posting is the best way to bring the thread back on focus
The above discussions are peripherally related to the subject as follows: there have been posts conjecturing whether the EM Drive can be explained by gravitational waves, or by General Relativity or by super-Machian effects not present in General Relativity.
Many people are still wondering: how can something like the EM Drive accelerate the center of mass?
The thread naturally gyrated to some fundamental issues, because these fundamental issues are not resolved -as excellently documented by flux_capacitor-
Yeah, in a weird way, I'm interested in all this black hole entropy stuff, and similar research I'm doing on the side, because I think I convinced myself the other day that an EMdrive must be allowed a way to have an exhaust, as in only a portion of the energy in the system can be converted to thrust, and the rest must be able to escape.
I find it curious that Mike McCullough's theory has a strong bias towards conservation of information (or lack thereof) at "horizons" (those of the universe or those in a tin can) as an explanation for the Emdrive and other mysterious phenomena.
And that so much ink and bytes have been poured over the same topic concerning black holes. Seems to me like the kind of small missing detail or fracture in the mainstream theoretical edifice, that end up bringing it down, to be replaced by another one.
By the way, thanks Jamie for a very interesting update! This is what makes me come back for more again and again.
Keep up the good stuff y'all(and avoid unnecessary repetition).
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#1665 by Rodal on 16 Sep, 2017 19:47
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...I find it curious that Mike McCullough's theory has a strong bias towards conservation of information (or lack thereof) at "horizons" (those of the universe or those in a tin can) as an explanation for the Emdrive and other mysterious phenomena.
And that so much ink and bytes have been poured over the same topic concerning black holes. Seems to me like the kind of small missing detail or fracture in the mainstream theoretical edifice, that end up bringing it down, to be replaced by another one. ...
according to McCulloch's controversial theory, inertial mass is related to Unruh radiation
See the connection to Hawking radiation and black holes here, for example:
https://en.wikipedia.org/wiki/Unruh_effectQuoteThe Unruh temperature has the same form as the Hawking temperature of a black hole, which was derived (by Stephen Hawking) independently around the same time. It is, therefore, sometimes called the Hawking–Unruh temperature
Therefore if discussion of McCulloch' theory for the EM Drive is on topic for this thread, so it is reasonably arguable that discussion of Hawking's radiation and black holes is peripherally on topic as well.
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#1666 by Mezzenile on 16 Sep, 2017 22:20
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You may hold your own individual opinions on this and many other things, but regardless of your opinions, there is an objective reality out there: the existence of black holes is widely accepted by mainstream science, because cosmological observations accurately agrees with mathematical predictions. Furthermore, the first observation of gravitational waves, on 11 February 2016; is widely understood by mainstream science to be due to waves generated from the merger of binary black holes. The measurements are in excellent agreement with General Relativity's model for the waves that will originate from the merger of a binary black hole...
I have absolutely no problem to accept all the physical phenomenas you have listed (gravitational waves ...) . They most find a theoretical justification in the frame of General Relativity. I just want to pin point the fact that what you call Black Hole in these phenomenas cannot be, according General Relativity itself, a place where the matter for its mass is hiden behind a no possible return frontier. Actually General Relativity equations predict that it would take an infinite time (according any fixed outside observer) to see a first atom crossing this one way frontier. All these phenomenas can be properly analysed as resulting from the properties of massive accretion disks free falling towards an horizon at a speed more and more close to the speed of light but with no chance to reach it before an infinite amount of time.
I dont really know why some mainstream physicists want to present contemporary black holes with all their mass already behind their one way frontier. May be they think it is easier for the great public to understand it this way or it makes some computations easier or it is more sexy
. But it is clearly an abuse which plays at odds with what should be the language of the simple mathematical thruth.
And I am quite sure that the mathematician Von Neumann would agree with me as I know does Mr Jean-Pierre Luminet (astrophysicist - Specialist of General Relativity and of the overalll shape of the universe). -
#1667 by RotoSequence on 16 Sep, 2017 22:31
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The evidence for the existence of Black Holes is nearly iron-clad. The Black Hole Information Paradox truly means we have an inadequate understanding of Gravitation and/or Quantum Information Theory.
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#1668 by Rodal on 16 Sep, 2017 22:52
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Some of the popular science descriptions of black holes are bad.
I have absolutely no problem to accept all the physical phenomenas you have listed (gravitational waves ...) . They most find a theoretical justification in the frame of General Relativity. I just want to pin point the fact that what you call Black Hole in these phenomenas cannot be...
One not very fortunate description is of black holes as "giant vacuum cleaners in space"
A good model/description:
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#1669 by Mulletron on 17 Sep, 2017 01:51
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#1670 by RotoSequence on 17 Sep, 2017 02:00
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This is cool. Look at equation 5.
http://gsjournal.net/Science-Journals/Research%20Papers/View/6775
Kind of a poor fit on a few of those data points, no?
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#1671 by Mulletron on 17 Sep, 2017 02:02
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This is cool. Look at equation 5.
http://gsjournal.net/Science-Journals/Research%20Papers/View/6775
Kind of a poor fit on a few of those data points, no?
True. -
#1672 by Mulletron on 17 Sep, 2017 02:40
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Just had an idea for an experiment. It's a Cavendish experiment. It consists of two masses off the balance, and two identical EMdrives, one on each end of the balance. It's not necessarily a thrust experiment. It's to see if G is any different and whether or not it's dependent on orientation of the drives.
Actually there's no reason to have the drives on the balance. The static masses can be on the balance and the drives off balance. That'll make things easier. I know from experience that it's very scary and a nightmare to balance all that gear on an extruded aluminum screed hanging from fishing line.
Edit: And I really only need just one drive, instead of two. -
#1673 by Propylox on 17 Sep, 2017 04:30
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How can this (emphasis mine):
According to current theories, gravity is instantaneous - if the Sun blinked out of existence we'd fly off our orbit immediately while light continued shining for ~8min.
be compatible with:But a sudden change in localized mass, and the distortion of spacetime it creates, would propagate at a defined rate.
as the (almost) circular motion of planets around the Sun is due to spacetime being bent by the presence of our star? In this thought experiment, if spacetime is still deformed locally around the Earth for several minutes after the disparition of the Sun, why would the Earth "immediately fly off its orbit" despite the gravitational potential making its motion circular has not gone yet?
I'll start with the second, "the sudden change in localized mass". If a mass is headed your way the distortion in spacetime propagates at its defined closure rate. If two masses orbit each other, the observed spacetime distortion is defined by their orbiting rate.
The center of spacetime distortions are at the instantaneous center of mass, not trailing that center with moving or orbiting bodies. The effects of spacetime distortion does not trail movement due to c, nor are moving bodies' velocity constantly retarded by a center of mass preceding their own center of spacetime distortion.
If the distortion in spacetime due to matter was limited to c, and not instantaneous, all moving masses in the Universe would eventually drag to a halt, all orbits would degrade and orbital capture would be impossible, including coalescing matter into larger masses. As such, if matter was to hypothetically blink into or out of existence (as the Sun in my analogy), the spacetime distortion of that matter would appear or disappear just as instantaneously.
Einstein considered anything faster than his speed limit of c as unacceptable. But regardless, the effects of "gravity" and the observation of "gravity waves" remains instantaneous - which is to say we can observe the orbits of binary stars or blackholes on the other side of the Universe in real time via "gravitational waves".
Considering the many and occasionally contradictory views and theories of "gravity" - does it or its fundamental particle really exist, or is it just an observation of mass and its fundamental particle? - could you two elaborate on your posts listed below?In GR gravitational effects only propagate at the speed of light. This was one of the original reasons it was obvious that a new theory of gravity (GR) was needed after special relativity was developed.
That's why I thought, thanks. Maybe Propylox mistaken the propagation speed of gravitational waves and "spacetime distortion ripples" limited to c vs inertial reaction forces, which are instantaneous (a difference Dr Woodward insists on). -
#1674 by OnlyMe on 17 Sep, 2017 06:11
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How can this (emphasis mine):
According to current theories, gravity is instantaneous - if the Sun blinked out of existence we'd fly off our orbit immediately while light continued shining for ~8min.
be compatible with:But a sudden change in localized mass, and the distortion of spacetime it creates, would propagate at a defined rate.
as the (almost) circular motion of planets around the Sun is due to spacetime being bent by the presence of our star? In this thought experiment, if spacetime is still deformed locally around the Earth for several minutes after the disparition of the Sun, why would the Earth "immediately fly off its orbit" despite the gravitational potential making its motion circular has not gone yet?
I'll start with the second, "the sudden change in localized mass". If a mass is headed your way the distortion in spacetime propagates at its defined closure rate. If two masses orbit each other, the observed spacetime distortion is defined by their orbiting rate.
The center of spacetime distortions are at the instantaneous center of mass, not trailing that center with moving or orbiting bodies. The effects of spacetime distortion does not trail movement due to c, nor are moving bodies' velocity constantly retarded by a center of mass preceding their own center of spacetime distortion.
If the distortion in spacetime due to matter was limited to c, and not instantaneous, all moving masses in the Universe would eventually drag to a halt, all orbits would degrade and orbital capture would be impossible, including coalescing matter into larger masses. As such, if matter was to hypothetically blink into or out of existence (as the Sun in my analogy), the spacetime distortion of that matter would appear or disappear just as instantaneously.
Einstein considered anything faster than his speed limit of c as unacceptable. But regardless, the effects of "gravity" and the observation of "gravity waves" remains instantaneous - which is to say we can observe the orbits of binary stars or blackholes on the other side of the Universe in real time via "gravitational waves".
Considering the many and occasionally contradictory views and theories of "gravity" - does it or its fundamental particle really exist, or is it just an observation of mass and its fundamental particle? - could you two elaborate on your posts listed below?In GR gravitational effects only propagate at the speed of light. This was one of the original reasons it was obvious that a new theory of gravity (GR) was needed after special relativity was developed.
That's why I thought, thanks. Maybe Propylox mistaken the propagation speed of gravitational waves and "spacetime distortion ripples" limited to c vs inertial reaction forces, which are instantaneous (a difference Dr Woodward insists on).
The affect of gravitation between two massive objects propagates at the speed of light. It is not instantaneous. The earth and sun are attracted toward one another based on their time of light delayed positions.
This is not obviously apparent when dealing with slow moving orbital systems because the classical velocities are small relative to the speed of light propagation time and generally one assumes one of the massive objects as the frame of reference for comparison.
We do not observe gravity waves from the other side of the universe in real time. We don't even observe the sun in real time. Or the position of planets in the night sky. We are always looking into the past. How far depends on the time of light delay.., just how far away in light minutes or years we are looking.
Newton imagined gravity as acting instantaneously. The problems that led to as our ability to observe solar mechanics in greater detail is one of the reasons that lead Einstein to develope the theories of special and general relatively.
From the perspective of a Machian model, inertia is local instantaneous resistance to acceleration, based on a time of light delay in the influence that the distributed mass of the universe has in this instant locally.... being redundant about it... Inertia is an instantaneous reaction to the time of light delayed affect that mass throughout the universe has locally, right now.
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#1675 by meberbs on 17 Sep, 2017 07:41
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If the distortion in spacetime due to matter was limited to c, and not instantaneous, all moving masses in the Universe would eventually drag to a halt, all orbits would degrade and orbital capture would be impossible, including coalescing matter into larger masses. As such, if matter was to hypothetically blink into or out of existence (as the Sun in my analogy), the spacetime distortion of that matter would appear or disappear just as instantaneously.
This is simply untrue see here for an explanation. In short, gravitational fields depend on the motion of the mass, and it does so in a way that may happen to point to the current position of the mass, but this is an illusion and based only upon the state of the mass at a previous time. An acceleration, or magic disappearance, would only have the new state of the mass updated at the speed of light.Einstein considered anything faster than his speed limit of c as unacceptable. But regardless, the effects of "gravity" and the observation of "gravity waves" remains instantaneous - which is to say we can observe the orbits of binary stars or blackholes on the other side of the Universe in real time via "gravitational waves".
Completely untrue, and it seems as if you are trying to claim that you are smarter than Einstein. It is not just Einstein, but everyone physicist who understands relativity realizes that any kind of information including gravity travelling faster than light results in time travel paradoxes.Considering the many and occasionally contradictory views and theories of "gravity" - does it or its fundamental particle really exist, or is it just an observation of mass and its fundamental particle? - could you two elaborate on your posts listed below?
What do you mean by "many theories of gravity"? There is one theory of gravity known as general relativity, which has been quite thoroughly tested. The only different theories that are taken seriously are just attempts that have not been verified by experiment. As a basic condition of these theories, they have to match all of the tested predictions of general relativity. The only differences arise in the realm that merges quantum and gravity, things like hawking radiation from a black hole, or other super high energy physics that we have no experimental data on.In GR gravitational effects only propagate at the speed of light. This was one of the original reasons it was obvious that a new theory of gravity (GR) was needed after special relativity was developed.
That's why I thought, thanks. Maybe Propylox mistaken the propagation speed of gravitational waves and "spacetime distortion ripples" limited to c vs inertial reaction forces, which are instantaneous (a difference Dr Woodward insists on).
Edit: removed reference to "only quantum gravity" since Rodal pointed out other theories exist like Brans-Dicke's gravitation that allows variable G, but has been highly constrained by experiment. -
#1676 by Mulletron on 17 Sep, 2017 12:15
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Last I checked, in 2017, it's been ironed out already that gravity does not violate causality. Different story ~300 years ago. We want to progress, not regress.
Here's proof. The delay time between the two sites.
http://www.sciencemag.org/news/2016/02/gravitational-waves-einsteins-ripples-spacetime-spotted-first-time
http://forum.nasaspaceflight.com/index.php?topic=39297.msg1490624#msg1490624 -
#1677 by Mulletron on 17 Sep, 2017 13:00
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This very old idea, that G is a constant, also needs to be challenged.
http://www.scirp.org/journal/PaperInformation.aspx?paperID=65063 -
#1678 by Rodal on 17 Sep, 2017 14:15
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This very old idea, that G is a constant, also needs to be challenged.
This very old idea, that G may be a variable with respect to time, has been tested and refuted for several decades. The time variation of G has been tested particularly motivated by Brans-Dicke's theory of gravitation in the 1960's that allowed such a variation (in contrast with Einstein's theory, where G is a constant). However astonomical observations have bounded the rate of change of G to very tight bounds. One such powerful bound is based on observations of the variable white dwarf G117-B15A, a ZZ Ceti pulsator in the constellation Leo Minor that has been studied with astroseismological techniques for several decades. This white dwarf is one of the most stable optical clocks ever found (https://en.wikipedia.org/wiki/G_117-B15A) . Biesiada and Malec (http://adsabs.harvard.edu/full/2004MNRAS.350..644B) recently derived the bound (based on these observations) of (dG/dt)/G < 1.3x10-17 1/s.
http://www.scirp.org/journal/PaperInformation.aspx?paperID=65063
Yes, that is 1 part in 10 to the 17 power, an order of magnitude less than a quintillion ("Exa") or 100 quadrillions ("Peta") s.
Four decades ago, Shapiro's team at MIT had given the same upper limit on this bound. (https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.13.789) -
#1679 by SeeShells on 17 Sep, 2017 15:17
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Dr. Rodal,
Thanks for your comments, always love them. Yes, you're quite correct a few things were missed in this video, although a critical point was made how mass is all connected in the universe. Some readers of this blog are not as gifted as you are with the depth of knowalage you or others here possess.
The point was even if the Mach or MEGA drive is totally enclosed in a box (or a skating rink ) it will still show acceleration if done correctly and not violate CoM or CoE.QuoteIf we produce a fluctuating mass in an object, we can, at least in principle, use it to produce a stationary force on the object, thereby producing a propulsive force thereon without having to expel propellant from the object. We simply push on the object when it is more massive, and pull back when it is less massive. The reaction forces during the two parts of the cycle will not be the same due to the mass fluctuation, so a time-averaged net force will be produced. This may seem to be a violation of momentum conservation. But the Lorentz invariance of the theory guarantees that no conservation law is broken. (*added bold) Local momentum conservation is preserved by the flux of momentum in the gravity field that is chiefly exchanged with the distant matter in the universe.
https://en.wikipedia.org/wiki/Woodward_effect
I've been saying since posting here the EMDrive (or variants of it) has to interact with gravity, the QV or generate particles that penetrate the cavity walls to obey the Conservation laws. That hasn't changed and it's one reason I've not been a huge supporter of Shawyer's theory, as he doesn't.
My Very Best,
ShellFor those readers who are struggling how the Mach Principle works here is a quick video on youtube that's easy to understand.
Thank you for the interesting video. Please note:
Shell
1) There is nothing discussed in this video about Mach's principle that is not fully contained in Einstein's General Relativity. So if Mach's principle makes one aware of something that is already present in Einstein's General Relativity, great!. However, there is no "extra-Machian" effect discussed in the video that is not already present in Einstein's General Relativity. Actually all cosmological measurements including Gravity Probe B, that have looked for extra-Machian effects (which were in fashion in the 1960's due to Brans-Dicke theory) have failed to find any Machian effect not present in Einstein's General Relativity
2) The discussion in the video deals with rotation effects: centrifugal-centripetal forces. The MET (PZT stack) experiments feature no such rotation or spin effects and the theory does not analyze any such spin effects either. Instead the MET experiments deal with longitudinal oscillations.
3) It is very difficult to discuss rotational forces in General Relativity for spinning rigid bodies. Actually it is trivial to show that in General Relativity one cannot have anything rigid, as the length of a body in relativity is subject to Lorentzian transformations that are observer-dependent and certainly speed-dependent. It is very problematic in General Relativity to discuss a center of mass for a rotating body. It is this issue that has been recently discussed by an MIT professor to discuss "swimming in space" https://groups.csail.mit.edu/mac/users/wisdom/swimming.pdf .
4) A typo in the captions to the video: where it reads "process" it should read "precess" (referring to the pendulum inside the rotating sphere) as in https://en.wikipedia.org/wiki/Precession as in the precession of a gyroscope
Thanks for pointing this out.
