Ring Laser Gyroscope

The Ring Laser Gyroscope (RLG) is a consumer device version of the Michelson-Gale-Pearson Experiment (MGP). 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.



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:



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 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 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:

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

G-Ring Post Filtering
Even after filtering, results from the G-ring laser system showing the rotation rate of the earth appear to be questionable. In a 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 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:



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.

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)



Caption:

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

Related

 * Mechanical Gyroscope - In contradiction, the mechanical gyroscopes does not show rotation to the earth