Difference between revisions of "Ring Laser Gyroscope"

Revision as of 23:27, 15 May 2019

The Ring Laser Gyroscope is a consumer device version of the Michelson-Gale Pearton Experiment. 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. Like with the Michelson-Gale-Pearson Experiment, some have alleged that Ring Laser Gyroscopes have detected the rotation of the earth.

From a work titled The Sagnac and Michelson-Gale-Pearson Experiments (Archive) by Dr. Paulo N. Correa we read on p.5:

“ 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. As stated above, the inconsistent results were ambiguous in nature and could offer no evidence of the shift in the phase of the light beams.

According to the above, the results of the Michelson-Gale-Pearson experiment was 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.

Importance of Consistency

In attempt of correlating such results with the rotation of the earth the mean is discussed, but what of the average or the median? What of the fact that one of the extremes is near zero? Which is the baseline that is being modified?

Consistency in empirical experimental investigation is of prime importance to science integrity. If one were to conclude from such an experiment that the earth is rotating, but also imagines that a mechanism is modifying the results from their own favored ideal to create the inconsistent results seen, the conclusion is fallacious. That imagined mechanism which modified the results could equally be creating those results. One sees that consistency is required for any valid test of a phenomena. In sciences which are not desperate to prove something, experiments with inconsistent results are often rejected altogether for that very reason.

Cause of Noise

See: Ring Laser Gyroscope - Seismology

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-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''' is a consumer device version of the Michelson-Gale Pearton Experiment. 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. 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.<sup>[https://wiki.tfes.org/Ring_Laser_Gyroscope#Ring_Laser_Gyroscopes_are_Seismometers]</sup> 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>
+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:
-Researchers have published information pertaining to the detection of microseismic noises and resonances due to the assumed rotation of the earth, and from this some have erroneously misinterpreted these works as a direct observation of 15 degrees per hour beneath the device. Regardless of the popular assumption of directly observed earth rotation, assessing such works in their entirety, directly form the source creators, suggests that no such claim is made at all. Further, we find that Copernican proponents of the earth's rotation ''believe'' how the device operates in detection of the earth's rotation, but seem to have difficulty with ''demonstrating'' that idea using the source research itself.
+{{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 Gyroscopes are Seismometers==
+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. As stated above, the inconsistent results were ambiguous in nature and could offer no evidence of the shift in the phase of the light beams.
-Very sensitive Ring Laser Gyroscopes are often used for research purposes in the study of seismometry. Some research gyroscopes are attached to underground cave walls and cannot be rotated at all to perform their main use in inertial guidance systems of finding orientation. A search of Google Scholar brings up many papers on the matter. From the first three title results of the [https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=%22ring+laser+gyroscope%22%2B%22seismic%22&btnG= search term "ring laser gyroscope"+"seismic"] we see:
+According to the above, the results of the Michelson-Gale-Pearson experiment was 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.
-:"Ring laser gyroscopes as rotation sensors for seismic wave studies"<br>
+''Importance of Consistency''
-:"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 are concluded to be rotational due to appearing near it.<sup>[https://wiki.tfes.org/Ring_Laser_Gyroscope#The_Earth_Line]</sup> The popular misconceptions of the Ring Laser Gyroscope directly observing the rotation of the earth originate from these studies of noise and resonance which sometime speak of seeing the earth's rotation.
+In attempt of correlating such results with the rotation of the earth the mean is discussed, but what of the average or the median? What of the fact that one of the extremes is near zero? Which is the baseline that is being modified?
-==The Earth Line==
+Consistency in empirical experimental investigation is of prime importance to science integrity. If one were to conclude from such an experiment that the earth is rotating, but also imagines that a mechanism is modifying the results from their own favored ideal to create the inconsistent results seen, the conclusion is fallacious. That imagined mechanism which modified the results could equally be creating those results. One sees that consistency is required for any valid test of a phenomena. In sciences which are not desperate to prove something, experiments with inconsistent results are often rejected altogether for that very reason.
-'''Strapdown Inertial Navigation Technology'''<br>
+==Cause of Noise==
-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, which discusses the large laser ring gyroscope at the University of Canterbury, we see that the rotation of the earth is seen with "the Earth line":
+See: [[Ring Laser Gyroscope - Seismology]]
-{{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.}}
-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 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.}}
-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 they are near the earth line that is assumed to be related to the rotation of the earth.
-===Oscillation in the Gain Medium===
-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:
-{{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.'''}}
-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."
-This statement appears to affirm that that the matter is actually a measurement of anthropogenic and microseismic noises, and not a direct measurement of rotation beneath the device as some have alleged. The researchers in such papers do not appear to be asserting that claim themselves.
-==Calculation Agreement==
-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.
-{{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.}}
-"Excellent agreement" with an equation which was likely made to match observation, after the fact, and after the invention of the device.
-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.
-[[File:Siderial day rotation rate.png|600px]]
-The "rotation rate of the earth" is found when one uses a period of 86164 seconds as the Sidereal Day.
-It should be further noted that the 'Sidereal Day' happens to be the general time it takes for the stars to return to their spots above the earth, and which also exists in Flat Earth Theory. It is the Solar Day, that is in regards to the sun, which is supposedly the true rotation of the earth.
-===Applied Optics===
-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.
-[[File:RLG Rotation Rate Input.png|500px]]
-We see that in this equation that the earth's rotation is an input variable into the equation, not an output variable.
-Under the Flat Earth Theory the Sidereal 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 which are used to estimate a frequency are not Round Earth specific and are elements which also exist in FET.
-Although the results of only one location is given, using such elements to create a prediction may indeed be possible.
-==Resonant Frequency==
-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:
-[[File:Earth Line.png|700px]]
-Compare the above to a diagram and units used to depict the resonant frequency of rotating gears:
-'''[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>
-MathWorks example
-''Visualize the Power Spectra for Time-Synchronous Averaged Signals''
-{{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>}}
-[[File:RotatingMachineryv2Example_08.png|600px]]
-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.
-===Frequency Response Function===
-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]):
-{{cite|What is a Frequency Response Function (FRF)?
-A Frequency Response Function (or FRF), in experimental modal analysis:
-:*is a frequency based measurement function
-:*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]]
-{{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.}}
-==Seismic 0.2-1 Hz Region==
-From the paper [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]) we had seen the following quote:
-{{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.}}
-Seismometer devices which are not Ring Laser Gyroscopes also see a prominent peak at the 0.2-1 Hz region. Look at Fig. 5 from a compound pendulum [http://physics.mercer.edu/hpage/compound/compound.html which functions as a horizontal seismometer/tiltmeter] ([https://web.archive.org/web/20160816195618/http://physics.mercer.edu/hpage/compound/compound.html Archive]):
-[[File:Microseism Driven Pendulum 2.gif|600px]]
-The author calls the noise in the background microseisms and earth hum:
-{{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.}}
-Then, from the Wikipedia page on Seismic Noise we find:
-https://en.wikipedia.org/wiki/Seismic_noise ([https://web.archive.org/web/20190227222349/https://en.wikipedia.org/wiki/Seismic_noise Archive])
-''Causes''
-{{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 (i.e. heat from the sun). In the atmosphere seismic waves take the form of sound waves.
-Some information on seismic propagation is provided below.
-===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.''}}
-==Addendum==
-We can see, clearly, that the researchers are speaking of seismic and vibration analysis terms in relation to the rotation of the earth. While it may be that the device is detecting an oscillation in the background, perhaps even an oscillation with a period of a sidereal day, it does not follow that the device is on the element that is oscillating.
-Copernican proponents of Earth's rotation should be able to provide an equal or greater amount of evidence, from the words of the researchers who study the rotation of the earth with it, to ''demonstrate'' their idea of what is occurring, and what they believe is meant by detection of the "earth's rotation" in various papers and articles. Surely this should be possible if it were true and impossible if it were not true. A rebuttal of "That is not how it works!" is insufficient on this matter, yet is the best that has been seen on the topic. In our experience such discussions quickly come to an end with a request of evidence for those Copernican claims made about the Ring Laser Gyroscope.
-==Further References==
-:*[https://www.youtube.com/watch?v=YVvFtTi3RWc Nathan Oakley Discusses the Ring Laser Gyroscope]
 ==See Also==