Latest revision as of 04:14, 21 June 2023

The Ring Laser Gyroscope (RLG) is a consumer device version of the Michelson-Gale-Pearson Experiment (MGP)^[1]. The principle of operation of these devices is based on the Sagnac Effect, which was famed for showing that light changes velocity on a rotating platform. In the RLG and MGP experiment the Earth is used as the 'rotating platform'. Like with the Michelson-Gale-Pearson Experiment, some have alleged that Ring Laser Gyroscopes have detected the rotation of the earth.

In a University of Canterbury paper A Study of Ring Laser Gyroscopes (Archive) we read that the Michelson Gale Pearson experiment was an early Ring Laser Gyroscope which is alleged to have detected the rotation of the Earth.

“ 1.1 Historical Overview and Summary of the Present Ring Laser Systems

As early as 1925, Michelson, Gale and Pearson demonstrated that it was possible to measure the rotation of the Earth using a Sagnac interferometer. Their device had a rectangular form of dimensions 2000×1100 feet and was made from evacuated sewer pipes near Clearing [37]. This remarkable technological achievement (for the time) yielded a detectable 1/4 fringe phase difference due to earth rotation thereby demonstrating a measurement of an absolute rotation rate from within a rotating reference frame. ”

From a work titled The Sagnac and Michelson-Gale-Pearson Experiments(Archive) by Dr. Paulo N. Correa we read on p.5 that the results from the MGP experiment were inconsistent and the conclusion was based on statistics:

“ The outcome of the MGP experiment was ambiguous, though maybe no more ambiguous than the small persistent positive shift observed in MM experiments. Composed of 269 separate tests with readings that varied from -0.04 to +0.55 of a fringe, and a mean at +0.26 fringes, the MGP experiment could be interpreted to yield a positive result of ≈ 0.3 km/s - therefore near the speed of the earth's rotation, but the result was of borderline significance. It could be said that the experiment was inconclusive because it adduced neither proof that there was a shift in the phase of the light beams, nor that there wasn't one. ”

Essentially the tests saw wild results. There was almost no change to light's velocity in one test, and then a lot of change in another test. It is perplexing that the rotation of the earth would start and stop when tested at different times. Only through the statistics was it claimed that the experiment saw the rotation of the earth. The inconsistent results were ambiguous in nature and could offer no evidence of the shift in the phase of the light beams. As stated above, the results of the Michelson-Gale-Pearson experiment were inconsistent and an algorithm was applied to get the desired result. If we are to say that the Ring Laser Gyroscope is the same device, then the same criticism would apply.

It is further seen that, like the original MGP experiment, the raw results of the gyroscopes are inconsistent^[2] and dwarf the results from rotation. The device is affected by effects which are not the rotation of the Earth. If there are effects from unknown sources in the experiment and the desired effect must be pulled out with statistics, then one may suggest that it is not possible to indicate which effect comes from what phenomena. It could be an oscillation from another diurnal phenomena which is affecting the device.

Additionally, the Mechanical Gyroscope offers a proof by contradiction. The rotation of the Earth is unable to be detected, despite the device detecting an artificial situation when it is placed on a rotating platform with a rotational period of 24 hours.

Ring Interferometer

Micheson-Gale was a ring interferometer and the basis for all ring interferometers to come after this experiment. Its Wikipedia article says:

“ The Michelson-Gale experiment was a very large ring interferometer, (a perimeter of 1.9 kilometer) ”

The second slide in a presentation titled "Ring Laser Gyroscope Measurement of Absolute Earth Rotation" introduces the Michelson-Gale experiment as basis for the Ring Laser Gyroscope:

Ring Laser Gyroscope Measurement of Absolute Earth Rotation
3rd International Workshop on Rotational Seismology

https://slideplayer.com/slide/10532529/ (Archive .ppt)

Further Reference

Ring Lasers - a brief history (Archive) - Describes that the Ring Laser Gyroscope is a Sagnac/MGP device.

Raw Data

G-Ring Laser Gyroscope

In a 2020 paper A Multi-Component Ring Laser for Geodesy and Geophysics (Archive) the text implies with the Ring Laser Gyroscope that the earth's rotation is pulled out of noise:

“ An extremely sensitive ring laser system (G-ring) was installed in 2002 at the Geodetic Observatory Wettzell (Schreiber et al., 2009c) measuring the local component of rotation around the vertical axis. The G-ring was specifically designed for geodesy, built on a monolithic Zerodur structure, buried underground, thus providing sufficient long-term stability to be able to resolve tidal effects and polar motion (e.g., Schreiber et al., 2003, 2011). As with many observation systems one person’s noise is another person’s signal. The G-ring observations of Earth’s rotation are superimposed by local rotational ground motions from a variety of sources. The unprecedented high-resolution (single-component) ground rotational observations of the G31 ring of local, regional, and teleseismic earthquakes (Igel et al., 2005; Cochard et al., 2006; Igel et al., 2007) triggered research into the potential of using additional rotation components for seismological research questions. ”

According to Marriam-Webster the definition of superimposed is "to place or lay over or above something".

G-Ring Post-Filtering

Even after noise filtering, results from the G-ring laser system showing the rotation rate of the earth appears to be questionable. In another paper on the G laser in Geodetic Observatory in Wettzell (Bavaria, Germany), the rotation rate of the earth appears to shift between and positive values above zero and negative values and below zero over time. Units in Modified Julian Date and pico-radians per second. A radian is an angular unit of measurement, like degrees.

https://ia600702.us.archive.org/22/items/arxiv-1007.1861/1007.1861.pdf

From p.6:

“ FIG. 4: The rotation rate of the Earth measured with the G ring laser as a function of time. Averaging over 2 hours was applied to a corrected dataset, where all known geophysical signals have been removed. ”

MEMS Gyroscope

Similarly, raw data from Section 4.1 of a paper titled Measuring the Earth’s Rotation Rate Using a Low-Cost MEMS Gyroscope (Archive), which uses another kind of gyroscope to detect the Earth's rotation, shows that the raw data is inconsistent and noisy. The Earth's rotation is pulled out of noise.

“ During the measurements the gyroscope was stationary on the floor. Its positive sensitive axis was parallel to the local horizontal plane. Total data collection time of the experiment spans to approximately 61 hours. The raw data collected directly from the sensor is shown in Figure 2 as a function of time. ”

If one were to directly conclude that the movement is due to the rotation of the earth, one would also have to conclude that much of the data involves the earth 'spinning' backwards from its supposed direction. In truth, the noise seen is caused by other effects which are not the earth's rotation, subverting the results. Only through noise analysis is the the Earth's rotation interpreted and pulled out with an algorithm. It is through the interpretation of noise that the Earth's rotation is found.

Microresonator Brillouin Laser Gyroscope

Another type of gyroscope which claims to detect the Earth's rotation, with increased precision over MEMS Gyroscopes, is the Microresinator Brillouin Laser Gyroscope. Assessing the inset graphic of the raw data in (a) and the variations in (b) appears as if this device is also pulling data out of noise:

Microresonator Brillouin Laser Gyroscope with Earth-Rotation-Rate Sensitivity (Archive)

“ Optical gyroscopes are widely used for precision navigation and there has been growing interest in the possibility of integrated optical gyroscopes. In this talk, we report a chipbased Brillouin laser gyroscope with Earth-rotation-rate sensitivity.

...The enhanced performance is orders of magnitude better than that of micro-electro-mechanical-systems (MEMS) rotation sensors which are widely used in consumer electronics. ”

Caption:

“ Fig. 2. Performance of Brillouin Gyroscope (a) Allan deviation of measured dual-SBL beatnote before and after drift compensation. Inset shows raw data used in these measurements. (b) Sagnac shift frequency versus time while the axis of the gyroscope is switched between North and South (N-S, upper panel) and East and West (E-W, lower panel) with ∆νs < 0 (∆νp = -500kHz). The resulting angular-rate change for N-S is close to twice the Earth’s rotation rate (2×15◦/h), while the E-W measurement shows near zero change (histograms at the right panel). Both measurements show similar residual long-term drift from the environment. ”

According to this caption when switching the East-West axis to North-South it creates a phenomenon where twice the rate of the Earth's rotation rate is detected (2×15◦/h) with this method of detection. Consider whether for a physical mechanical gyroscope the Earth should ever be measured to be spinning twice as fast as the earth's angular rate of rotation in any orientation.

Addendum

According to the RE interpretation the earth is rotating and giving consistent results. There are other secondary mechanisms modifying and dominating those results. Due to the range seen, these secondary mechanisms are also somehow related to the speed of the Earth's rotation. It is from these mysterious mechanisms that the rotation of the earth is indirectly pulled out of the noise with an algorithm.

Alternatively, we may interpret this as one mechanism which is creating that range of results, and which is related to the diurnal period of the sun, tides, or celestial bodies which move over the earth. Should it be unreasonable that a very sensitive device can detect a background oscillation of the world in the noise it detects? Whether the responsible mechanism is seismic, pressure, or 'aether' related, we know by the direct evidence of inconsistency that the results are modifiable by a mechanism present in the experiment which is not the rotation of the earth. If it is modifiable then it is also entirely createable.

We should ponder whether an inconsistent experiment has ever been a proof of anything in science. As the experiment is tainted by uncontrolled and unmitigated effects which affects the device, one can only conclude that it is unclear as to what is being measured, what effects are involved, and whether there is even a constant baseline beneath it all; negating any statistical conclusions and thus demonstrating that the device is not decisive evidence for the rotation of the Earth.

Next: RLG Seismology

While inconsistent experiments are typically questionable as demonstration of any particular cause, one potential contributor of the noise in these very sensitive devices is the seismic disturbance inherent in the background environment. Unlike earth rotation, seismic disturbance is not a constant phenomenon. This page continues onto: Ring Laser Gyroscope - Seismology

@@ Line 1: / Line 1: @@
-The '''Ring Laser Gyroscope''' is a type of gyroscope that is based on laser beams which move around a cavity. The principle of operation of a RLG is based on the Sagnac Effect, which was famed for showing that light changes velocity on a rotating platform. The changing velocity of light as seen in the Ring Laser Gyroscope and Sagnac Experiments is said to be contrary to the consistency of light as proposed by Special Relativity (See the [[Michelson-Morley Experiment]] and [[Sagnac Experiment]]).
+The '''Ring Laser Gyroscope (RLG)''' is a consumer device version of the [[Michelson-Gale-Pearson Experiment]] (MGP)<sup>[https://wiki.tfes.org/Ring_Laser_Gyroscope#Ring_Interferometer]</sup>. The principle of operation of these devices is based on the [[Sagnac Experiment|Sagnac Effect]], which was famed for showing that light changes velocity on a rotating platform. In the RLG and MGP experiment the Earth is used as the 'rotating platform'. Like with the Michelson-Gale-Pearson Experiment, some have alleged that Ring Laser Gyroscopes have detected the rotation of the earth.
-Some have alleged that Ring Laser Gyroscopes have detected the rotation of the earth. When assessing these claims, it is found that modern Ring Laser Gyroscopes are very sensitive devices which are often double-purposed as seismometers. Researchers have used these sensitive devices to detect patterns in the background microseismic noise, where certain features are interpreted to be caused by the earth's rotation. The feature of the background noise assumed to be an effect of the earth's rotation is called the "Earth line," and is admitted to be of unknown origin and cause.<sup>[https://wiki.tfes.org/Ring_Laser_Gyroscope#Oscillation_in_the_Gain_Medium]</sup>
+In a University of Canterbury paper ''[https://core.ac.uk/download/pdf/35460022.pdf A Study of Ring Laser Gyroscopes]'' ([https://web.archive.org/web/20230322163520/https://core.ac.uk/download/pdf/35460022.pdf Archive]) we read that the Michelson Gale Pearson experiment was an early Ring Laser Gyroscope which is alleged to have detected the rotation of the Earth.
-One description of an equation involved in the noise analysis states "With the sidreal day taken as 86164s the Earth's rotation rate is found."<sup>[https://wiki.tfes.org/Ring_Laser_Gyroscope#Calculation_Agreement]</sup> The claim that these methods are directly measuring the rotation of the earth is thus in dispute. These researchers do not appear to be claiming this. The researchers have released information pertaining to the detection of microseismic noises and resonances due to the assumed rotation of the earth and others have misinterpreted these works as direct observation of 15 degrees per hour beneath the device. Regardless of the popular assumption, assessing such works shows that no such claim is made at all.
+:{{cite|1.1 Historical Overview and Summary of the Present Ring Laser Systems
-==Ring Laser Gyroscopes are Seismometers==
+:As early as 1925, Michelson, Gale and Pearson demonstrated that it was possible to measure the rotation of the Earth using a Sagnac interferometer. Their device had a rectangular form of dimensions 2000×1100 feet and was made from evacuated sewer pipes near Clearing [37]. This remarkable technological achievement (for the time) yielded a detectable 1/4 fringe phase difference due to earth rotation thereby demonstrating a measurement of an absolute rotation rate from within a rotating reference frame.}}
-Very sensitive Ring Laser Gyroscopes are often used for research purposes in the study of seismometry. A [https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=%22ring+laser+gyroscope%22+%22seismic%22 search of Google Scholar] brings up many papers on the matter. From the first three title results of the search term "ring laser gyroscope"+"seismic" we see:
+From a work titled ''[http://www.aetherometry.com/publications/direct/AToS/AS3-I.2.pdf The Sagnac and Michelson-Gale-Pearson Experiments]''([https://web.archive.org/web/20170702190257/http://www.aetherometry.com/publications/direct/AToS/AS3-I.2.pdf Archive]) by Dr. Paulo N. Correa we read on p.5 that the results from the MGP experiment were inconsistent and the conclusion was based on statistics:
-:Ring laser gyroscopes as rotation sensors for seismic wave studies<br>
+:{{cite|The outcome of the MGP experiment was ambiguous, though maybe no more ambiguous than the small persistent positive shift observed in MM experiments. Composed of 269 separate tests with readings that '''varied from -0.04 to +0.55 of a fringe''', and a mean at +0.26 fringes, the MGP experiment could be interpreted to yield a positive result of ≈ 0.3 km/s - therefore near the speed of the earth's rotation, but the result was of borderline significance. It could be said that the experiment was inconclusive because it adduced neither proof that there was a shift in the phase of the light beams, nor that there wasn't one.}}
-:Ring laser detection of rotations from teleseismic waves<br>
-:Sideband analysis and seismic detection in a large ring laser
-It is seen that Ring Laser Gyroscopes are used in seismic studies. It is from such studies that the rotation of the earth appears, manifested as the "Earth line," as well as the seismic components near the Earth line which is concluded to be rotational due to appearing near the Earth line.
+Essentially the tests saw wild results. There was almost no change to light's velocity in one test, and then a lot of change in another test. It is perplexing that the rotation of the earth would start and stop when tested at different times. Only through the statistics was it claimed that the experiment saw the rotation of the earth. The inconsistent results were ambiguous in nature and could offer no evidence of the shift in the phase of the light beams. As stated above, the results of the Michelson-Gale-Pearson experiment were inconsistent and an algorithm was applied to get the desired result. If we are to say that the Ring Laser Gyroscope is the same device, then the same criticism would apply.
-==The Earth Line==
+It is further seen that, like the original MGP experiment, the raw results of the gyroscopes are inconsistent<sup>[https://wiki.tfes.org/Ring_Laser_Gyroscope#Raw_Data]</sup> and dwarf the results from rotation. The device is affected by effects which are not the rotation of the Earth. If there are effects from unknown sources in the experiment and the desired effect must be pulled out with statistics, then one may suggest that it is not possible to indicate which effect comes from what phenomena. It could be an oscillation from another diurnal phenomena which is affecting the device.
-'''Strapdown Inertial Navigation Technology'''<br>
+Additionally, the '''[[Mechanical Gyroscope]]''' offers a proof by contradiction. The rotation of the Earth is unable to be detected, despite the device detecting an artificial situation when it is placed on a rotating platform with a rotational period of 24 hours.
-By David Titterton, John L. Weston, John Weston
-From [http://read.pudn.com/downloads165/ebook/756655/Strapdown%20Inertial%20Navigation%20Technology/13587_15c.pdf Chapter 15.6] ([https://web.archive.org/web/20190221065130/http://read.pudn.com/downloads165/ebook/756655/Strapdown%20Inertial%20Navigation%20Technology/13587_15c.pdf Archive]) on p.497 we see that the rotation of the earth is seen with "the Earth line":
+==Ring Interferometer==
-{{cite|The Fourier transform of the output from the laser cavity gives a spectral line associated with the rotation of the Earth often termed 'the Earth line'. Analysis of this spectral line is used to monitor the impact of seismic waves and other events. This ability to make high-precision measurements of rotation rates has led to applications in geodesy.}}
+Micheson-Gale was a ring interferometer and the basis for all ring interferometers to come after this experiment. Its [https://en.wikipedia.org/wiki/Michelson%E2%80%93Gale%E2%80%93Pearson_experiment Wikipedia article says:]
-Analysis of the Earth line is used to monitor seismic events. On p.498 we read that the Earth line is around the 0.2-1Hz region:
+{{cite|The Michelson-Gale experiment was a very large ring interferometer, (a perimeter of 1.9 kilometer)}}
-{{cite|The effect of seismic events is to induce frequency-modulated side bands, in the 0.2-1 Hz region, around the 'Earth line', which indicate the presence of rotational components associated with seismic events.}}
+The second slide in a presentation titled "Ring Laser Gyroscope Measurement of Absolute Earth Rotation" introduces the Michelson-Gale experiment as basis for the Ring Laser Gyroscope:
-We also read that seismic events around that region is assumed to indicate the presence of rotational components associated with seismic events. The researcher and others are making the conclusion that seismic events near the line must be rotational components because it is near the earth line that is assumed to be related to the rotation of the earth.
+'''Ring Laser Gyroscope Measurement of Absolute Earth Rotation'''<br>
+rd International Workshop on Rotational Seismology
-===Oscillation in the Gain Medium===
+https://slideplayer.com/slide/10532529/ ([https://web.archive.org/web/20200616180741/http://player.slideplayer.com/download/36/10532529/Obqm-n4MgUsxkealMUoEVg/1592334243/10532529.ppt Archive .ppt])
-In [https://ir.canterbury.ac.nz/bitstream/handle/10092/12898/King_1999_thesis.pdf Ring Laser Dynamics] ([https://web.archive.org/web/20190221065001/https://ir.canterbury.ac.nz/bitstream/handle/10092/12898/King_1999_thesis.pdf Archive]) by B Tom King it is admitted that the nature of the 'Earth line' is unknown and unverified. From p.152 we read:
+[[File:Michelson-Gale.png|700px]]
-{{cite|While lasing in single longitudinal mode and unlocked under the Earth's rotation a Lissajous figure is generated on an oscilloscope with the Sagnac signal from G0 on the x-axis and a sinusoid (from a signal generator) on the y-axis. The figure can be made stationary by varying the frequency of the generated signal. Once achieved this becomes an extremely sensitive detector of phase shifts in the G0 output. A variety of tests can then be performed. Artificial seismic events are easily detected as a jitter in the Lissajous figure. Also the introduction of a magnetic field near the gain medium has the effect of shifting the beat frequency and hence causes the Lissajous figure to rotate at a constant rate. '''However, the question remains as to whether or not this signal is necessarily the Earth induced line. It is difficult to impose a rotation on the laser as it is rigidly mounted to a solid concrete wall which in turn is moulded around the solid volcanic rock that forms the interior cavern wall. It is conceivable that the signal can be traced back to some oscillation in the gain medium. This problem is yet to be clarified.'''}}
+==Further Reference==
-We are told that the nature of the Earth line is unknown and that the signal may be traced back to some oscillation in the gain medium. The reader should ponder how it could be possible for an observed rotation rate of 15 degrees per hour beneath a device to really be an "oscillation in the gain medium."
+:*[https://www.europhysicsnews.org/articles/epn/pdf/2017/04/epn2017484p25.pdf Ring Lasers - a brief history] ([https://web.archive.org/web/20190611180957/https://www.europhysicsnews.org/articles/epn/pdf/2017/04/epn2017484p25.pdf Archive]) - Describes that the Ring Laser Gyroscope is a Sagnac/MGP device.
-This confirms that that the matter is actually a measurement of anthropogenic and microseismic noises and resonance frequencies, and not a direct and undeniable measurement of rotation beneath the device as some have alleged. The researchers in such papers do not appear to be asserting that claim themselves.
+=Raw Data=
-==Calculation Agreement==
+==G-Ring Laser Gyroscope==
-The author of the above paper goes on to deduce that because the earth induced line agrees with an equation, it is assumed that the rate is indeed from the earth.
+In a 2020 paper '''[https://eartharxiv.org/repository/object/1723/download/3715/ A Multi-Component Ring Laser for Geodesy and Geophysics]''' ([https://web.archive.org/web/20210428031545/https://eartharxiv.org/repository/object/1723/download/3715/ Archive]) the text implies with the Ring Laser Gyroscope that the earth's rotation is pulled out of noise:
-{{cite|However, it is assumed that the signal is indeed the Earth induced rate mostly because of the excellent agreement between the measured output frequency (see Figs. 6. 7 and 6.8) and the expected frequency of 287. 75 ± 0.46 Hz.}}
+{{cite|An extremely sensitive ring laser system (G-ring) was installed in 2002 at the Geodetic Observatory Wettzell (Schreiber et al., 2009c) measuring the local component of rotation around the vertical axis. The G-ring was specifically designed for geodesy, built on a monolithic Zerodur structure, buried underground, thus providing sufficient long-term stability to be able to resolve tidal effects and polar motion (e.g., Schreiber et al., 2003, 2011). '''As with many observation systems one person’s noise is another person’s signal. The G-ring observations of Earth’s rotation are superimposed by local rotational ground motions from a variety of sources.''' The unprecedented high-resolution (single-component) ground rotational observations of the G31 ring of local, regional, and teleseismic earthquakes (Igel et al., 2005; Cochard et al., 2006; Igel et al., 2007) triggered research into the potential of using additional rotation components for seismological research questions.}}
-"Excellent agreement" with an equation which was likely made to match observation, after the fact, and after the invention of the device.
+According to Marriam-Webster the [https://www.merriam-webster.com/dictionary/superimpose definition of ''superimposed''] is "to place or lay over or above something".
-On p.152, where the paper discusses the theory of the equations, it is shown that the rotation rate of the earth involves the length of day, a period of 86164s, is applied as an input into the interpretation. The process is using a predefined period to assess a daily variation or feature of the noise to get a "rotation rate". This would be opposed to a process of finding the rotation rate from the raw data.
+===G-Ring Post-Filtering===
-[[File:Siderial day rotation rate.png|600px]]
+Even after noise filtering, results from the G-ring laser system showing the rotation rate of the earth appears to be questionable. In another paper on the G laser in Geodetic Observatory in Wettzell (Bavaria, Germany), the rotation rate of the earth appears to shift between and positive values above zero and negative values and below zero over time. Units in Modified Julian Date and pico-radians per second. A radian is an angular unit of measurement, like degrees.
-The "rotation rate of the earth" is found when one used a period of 86164 seconds as the Sidreal Day.
+https://ia600702.us.archive.org/22/items/arxiv-1007.1861/1007.1861.pdf
-It should be further noted that the 'Sidreal Day' happens to be the general time it takes for the stars to return to their spots above the earth. It is the Solar Day, that is in regards to the sun, which is supposedly the true rotation of the earth.
+From p.6:
-===Applied Optics===
+[[File:G-ring-earth-rotation-rate.PNG|450px]]
-On p.2520 of paper titled [https://www.researchgate.net/publication/5532091_Design_and_Operation_of_a_Very_Large_Ring_Laser_Gyroscope Design and Operation of a Very Large Ring Laser Gyroscope] from Vol.38, No.12 of Applied Optics we find another equation which predicts the frequency of 287. 75 ± 0.46 Hz.
+{{cite|FIG. 4: The rotation rate of the Earth measured with the G ring laser as a function of time. Averaging over 2 hours was applied
+to a corrected dataset, where all known geophysical signals have been removed.}}
-[[File:RLG Rotation Rate Input.png|500px]]
+==MEMS Gyroscope==
+Similarly, raw data from Section 4.1 of a paper titled '''''[https://web.archive.org/web/20191024195012/http://www.tkt.cs.tut.fi/research/nappo_files/Symposium_Gyro_Technology_2010_web.pdf Measuring the Earth’s Rotation Rate Using a Low-Cost MEMS Gyroscope]''''' ([https://web.archive.org/web/20191024195012/http://www.tkt.cs.tut.fi/research/nappo_files/Symposium_Gyro_Technology_2010_web.pdf Archive]), which uses another kind of gyroscope to detect the Earth's rotation, shows that the raw data is inconsistent and noisy. The Earth's rotation is pulled out of noise.
-We see that in this equation that the earth's rotation is an input variable into the equation, not an output variable.
+{{cite|During the measurements the gyroscope was stationary on the floor. Its positive sensitive axis was parallel to the local horizontal plane. Total data collection time of the experiment spans to approximately 61 hours. The raw data collected directly from the sensor is shown in Figure 2 as a function of time.}}
-Under the Flat Earth Theory the Sidreal Day is the general time it takes for celestial bodies to return to their positions over the earth. The Latitude is the distance from the poles or from the equator. These input values used to estimate a frequency are not Round Earth specific.
+[[File:MEMS Gyro Raw.png|500px]]
+If one were to directly conclude that the movement is due to the rotation of the earth, one would also have to conclude that much of the data involves the earth 'spinning' backwards from its supposed direction. In truth, the noise seen is caused by other effects which are not the earth's rotation, subverting the results. Only through noise analysis is the the Earth's rotation interpreted and pulled out with an algorithm. It is through the ''interpretation of noise'' that the Earth's rotation is found.
-==Resonance Frequency==
+==Microresonator Brillouin Laser Gyroscope==
-From the [https://ir.canterbury.ac.nz/bitstream/handle/10092/12898/King_1999_thesis.pdf Ring Laser Dynamics] ([https://web.archive.org/web/20190221065001/https://ir.canterbury.ac.nz/bitstream/handle/10092/12898/King_1999_thesis.pdf Archive]) paper we find an illustration of the Earth Line on p.153:
+Another type of gyroscope which claims to detect the Earth's rotation, with increased precision over MEMS Gyroscopes, is the Microresinator Brillouin Laser Gyroscope. Assessing the inset graphic of the raw data in (a) and the variations in (b) appears as if this device is also pulling data out of noise:
-[[File:Earth Line.png|600px]]
+[https://authors.library.caltech.edu/111757/1/Microresonator_Brillouin_Laser_Gyroscope_with_Earth-Rotation-Rate_Sensitivity.pdf Microresonator Brillouin Laser Gyroscope with Earth-Rotation-Rate Sensitivity] ([https://web.archive.org/web/20230323212823/https://authors.library.caltech.edu/111757/1/Microresonator_Brillouin_Laser_Gyroscope_with_Earth-Rotation-Rate_Sensitivity.pdf Archive])
-Compare the above to the diagram and units used to depict the resonance frequency of a rotating gear:
+{{cite|Optical gyroscopes are widely used for precision navigation and there has been growing interest in the possibility of integrated optical gyroscopes. In this talk, we report a chipbased Brillouin laser gyroscope with Earth-rotation-rate sensitivity.
-'''[https://www.mathworks.com/help/signal/examples/vibration-analysis-of-rotating-machinery.html Vibration Analysis of Rotating Machinery]''' ([https://web.archive.org/web/20190227182411/https://www.mathworks.com/help/signal/examples/vibration-analysis-of-rotating-machinery.html Archive])<br>
+...The enhanced performance is orders of magnitude better than that of micro-electro-mechanical-systems (MEMS) rotation sensors which are widely used in consumer electronics.}}
-MathWorks example
-''Visualize the Power Spectra for Time-Synchronous Averaged Signals''
+[[File:Microresonator-brillouin-laser-gyro.PNG]]
-{{cite|Calculate the power spectrum of the time-synchronous averaged gear signal. Specify a frequency range that covers 15 gear sidebands on either side of the gear mesh frequency of 292.5 Hz. Notice the peaks at ''f''<sub>sideband,Gear</sub>}}
+Caption:
-[[File:RotatingMachineryv2Example_08.png|500px]]
+{{cite|'''Fig. 2. Performance of Brillouin Gyroscope''' (a) Allan deviation of measured dual-SBL beatnote before and after drift compensation. Inset shows raw data used in these measurements. (b) Sagnac shift frequency versus time while the axis of the gyroscope is switched between North and South (N-S, upper panel) and East and West (E-W, lower panel) with ∆νs < 0 (∆νp &#61; -500kHz). The resulting angular-rate change for N-S is close to twice the Earth’s rotation rate (2×15◦/h), while the E-W measurement shows near zero change (histograms at the right panel). Both measurements show similar residual long-term drift from the environment.}}
-The detector device in the above example is not spinning around on the outer edges of the gears, but is ''listening to the vibrations''. It is listening to something oscillate.
+According to this caption when switching the East-West axis to North-South it creates a phenomenon where twice the rate of the Earth's rotation rate is detected (2×15◦/h) with this method of detection. Consider whether for a physical mechanical gyroscope the Earth should ever be measured to be spinning twice as fast as the earth's angular rate of rotation in any orientation.
-===Frequency Response Function===
+=Addendum=
-See also the [https://community.plm.automation.siemens.com/t5/Testing-Knowledge-Base/What-is-a-Frequency-Response-Function-FRF/ta-p/354778 Frequency Response Function] ([https://web.archive.org/web/20190227183318/https://community.plm.automation.siemens.com/t5/Testing-Knowledge-Base/What-is-a-Frequency-Response-Function-FRF/ta-p/354778 Archive]):
+According to the RE interpretation the earth is rotating and giving consistent results. There are other secondary mechanisms modifying and dominating those results. Due to the range seen, these secondary mechanisms are ''also'' somehow related to the speed of the Earth's rotation. It is from these mysterious mechanisms that the rotation of the earth is ''indirectly'' pulled out of the noise with an algorithm.
-{{cite|What is a Frequency Response Function (FRF)?
+Alternatively, we may interpret this as ''one'' mechanism which is creating that range of results, and which is related to the diurnal period of the sun, tides, or celestial bodies which move over the earth. Should it be unreasonable that a very sensitive device can detect a background oscillation of the world in the noise it detects? Whether the responsible mechanism is seismic, pressure, or 'aether' related, we know by the direct evidence of inconsistency that the results are modifiable by a mechanism present in the experiment which is not the rotation of the earth. If it is modifiable then it is also entirely createable.
-A Frequency Response Function (or FRF), in experimental modal analysis:
+We should ponder whether an inconsistent experiment has ever been a proof of anything in science. As the experiment is tainted by uncontrolled and unmitigated effects which affects the device, one can only conclude that it is unclear as to what is being measured, what effects are involved, and whether there is even a constant baseline beneath it all; negating any statistical conclusions and thus demonstrating that the device is not decisive evidence for the rotation of the Earth.
-:*is a frequency based measurement function
+==Next: RLG Seismology==
-:*used to identify the resonant frequencies, damping and mode shapes of a physical structure
-:*sometimes referred to a “transfer function” between the input and output
-:*expresses the frequency domain relationship between an input (x) and output (y) of a linear, time-invariant system}}
-[[File:Frequency Response Function.png|500px]]
+While inconsistent experiments are typically questionable as demonstration of any particular cause, one potential contributor of the noise in these very sensitive devices is the seismic disturbance inherent in the background environment. Unlike earth rotation, seismic disturbance is not a constant phenomenon. This page continues onto: '''[[Ring Laser Gyroscope - Seismology]]'''
-{{cite|Bode Plot of Amplitude and Phase of a FRF function. Amplitude has peaks corresponding to natural frequencies/resonances of test object. Phase has shift at resonant frequency.}}
+==Related==
-==Seismic 0.2-1 Hz Region==
+:*'''[[Mechanical Gyroscope]]''' - In contradiction, the mechanical gyroscope does not show rotation to the earth
-From the paper Ring Laser Dynamics we had read the following quote:
+==See Also==
-{{cite|The effect of seismic events is to induce frequency-modulated side bands, in the 0.2-1 Hz region, around the 'Earth line', which indicate the presence of rotational components associated with seismic events.}}
+''Flat Earth Topics on Rotation and Revolution''
-Seismometer devices which are not Ring Laser Gyroscopes also see a prominent peak at the 0.2-1 Hz region. Look at the following compound pendulum [http://physics.mercer.edu/hpage/compound/compound.html which functions as a horizontal seismomemeter/tiltmeter]:
+:*'''[[Michelson-Morley Experiment]]''' - Light velocity experiment which suggests a lack of Earth's motion around the Sun
+:*'''[[Sagnac Experiment]]''' - Experiments which show that light's velocity is indeed affected by detector motion
+:*'''[[Airy's Failure]]''' - An experiment which suggests that the stars are in motion, rather than the Earth
+:*'''[[Time Dilation by Latitude]]''' - The predicted time dilation caused by Earth's rotation does not occur
+:*'''[[Aviation]]''' - Mechanical air flight assumes a flat, non-rotating Earth
-[[File:Microseism Driven Pendulum 2.gif|600px]]
+''Round Earth Topics on Rotation''
-The author calls the noise in the background the earth hum:
+:*'''[[Foucault Pendulum]]''' - Pendulum device which is alleged to detect the rotation of Earth
+:*'''[[Coriolis Effect]]''' - Eastwards deflection of bodies caused by Earth's rotation
+:*'''[[Coriolis Effect (Weather)]]''' - Hurricanes and other effects due to Earth's rotation
+:*'''[[Ring Laser Gyroscope]]''' - Ring laser experiment alleged to observe the rotation of Earth
-{{cite|Shown in Fig. 5 is a record that was collected for an interval approaching 24 h. The spectrum has been scaled relative to the maximum component observed during this time (microseisms), and plotted on a linear rather than logarithmic scale. The linear scale shows more clearly the mHz structure associated with the pendulum's response to persistent eigenmode oscillations '''(earth hum)'''. Based on data collected with other of the author's different instruments during hurricanes, the spectrum below 10 mHz is expected to become distinctly different and highly variable during powerful storms.}}
+''Related''
-Then from the Wikipedia page on Seismic Noise:
+:*'''[[Michelson-Gale-Pearson Experiment]]'''
-https://en.wikipedia.org/wiki/Seismic_noise
+[[Category:General Physics]]
+[[Category:Rotation and Revolution]]
-''Causes''
+[[Category:Relativity]]
-{{cite|'''Research on the origin of seismic noise[1] indicates that the low frequency part of the spectrum (below 1 Hz) is due to natural causes, chiefly ocean waves. In particular the peak between 0.1 and 0.3 Hz is clearly associated with the interaction of water waves of nearly equal frequencies but opposite directions.[2][3][4][5]''' At high frequency (above 1 Hz), seismic noise is mainly produced by human activities such as road traffic and industrial work; but there are also natural sources, like rivers. Around 1 Hz, wind and other atmospheric phenomena are also a major source of ground vibrations.[6]}}
-This page seems to say that the peak in seismometers between 0.1 and 0.3 Hz is caused by the ocean.
-==Seismic Wave Propagation==
-'''Q:''' If the Ring Laser Gyroscope is assessing seismic noise and others have misinterpreted the claims, how is it that Ring Laser Gyroscopes on airplanes can see the rotation of the earth? How can Seismic activity reach the airplane?<br>
-'''A.''' Not all types and sizes of Ring Laser Gyros claim to be capable of observing the "rotation of the earth," which we have read above is indirect. It is unclear whether those types of RLGs in airplane guidance systems claim to be able to detect the earth's rotation.
-However, seismic and anthropomorphic noise can indeed propagate through the air, and does not necessarily only originate from within the earth. Other possible sources for the noise are the daily changes or activity of the atmosphere or influence from the celestial bodies upon the atmosphere (ie. heat from the sun). In the atmosphere seismic waves take the form of sound waves.
-===Background Seismic Noise===
-From http://microglacoste.com/gPhoneNoise/gPhoneSeismicNoise.pdf ([https://web.archive.org/web/20190121230624/http://microglacoste.com/gPhoneNoise/gPhoneSeismicNoise.pdf Archive]) we read:
-{{cite|It is interesting to speculate on the precise origin of the background seismic noise. Haubrich et al ii for example, open their article with the following description of the seismic noise background and the large interest it has generated over the years as well as the intractability of its investigation:
-The low‐level background unrest of the earth, called microseisms or earth noise, has puzzled seismologists and other scientists for nearly a century. The problem of its nature and causes has proved particularly unyielding, not, however, for lack of investigation. A bibliography covering work up to 1955 [Gutenberg and Andrews, 1956] iii lists over 600 articles on the subject; one covering the years from 1955 to 1964 [Hjortenberg, 1967] iv lists 566. Unfortunately, much of this work has advanced the subject but slightly.}}
-===Airborne Transmission===
-https://en.wikipedia.org/wiki/Seismic_wave ([https://web.archive.org/web/20190208041916/https://en.wikipedia.org/wiki/Seismic_wave Archive])
-{{cite|Primary waves (P-waves) are compressional waves that are longitudinal in nature. P waves are pressure waves that travel faster than other waves through the earth to arrive at seismograph stations first, hence the name "Primary". These waves can travel through any type of material, including fluids, and can travel nearly 1.7 times faster than the S waves. In air, they take the form of sound waves, hence they travel at the speed of sound. Typical speeds are 330 m/s in air, 1450 m/s in water and about 5000 m/s in granite.}}
-https://amp.livescience.com/24209-earthquakes-infrasound.html ([https://web.archive.org/web/20190217200748/https://amp.livescience.com/24209-earthquakes-infrasound.html Archive])
-{{cite|As earthquake waves ripple through the Earth, the crust buckles, rumbles and roars — both audibly and at infrasonic frequencies, below the range of human hearing. '''A new study finds the Earth's surface acts like a speaker for low-frequency vibrations, transmitting an earthquake's infrasonic tumult into the air.'''}}

Difference between revisions of "Ring Laser Gyroscope"