Question
Asked 13th Sep, 2019
• alex-korolev.jimdo.com

# Is the measuring method of Earth rotation speed with an optical gyroscope the same as of local rotation measurement of the gyroscope base?

Optical fiber (or ring laser) gyroscopes with enough sensitivity allow measurements of Earth speed rotation. Let us suppose that the frame of such a gyroscope is located in the plane orthogonal to the rotational axis of the Earth and can be slowly rotated with a motor. Will the signal (proportional to the phase shift or frequency difference) double in the case of artifical rotation speed = Earth rotation speed in comparence with the case when the motor is switched off? Has anyone done a similar experiment, who knows?

## Most recent answer

16th Sep, 2019
Alexander I. Korolev
alex-korolev.jimdo.com
Let's imagine that the light in optical gyroscope propagate in some medium (aether). Then, let's imagine that this medium can rotate together with the gyroscope due to gravity entrainment. This rotation may be weak, but measurable.
Aether wind searching at Earth surface give no result. Thus, Earth orbital movement around the Sun, Milky Way (etc.) should be together with the aether. More likely, the aether does not rotate due to Earth orbiting, yes. Technically, it can be checked. The gyroscope for this should being oriented during a year towards Sun's center by stellar orientation system, for example. The signal of interest can be obtained using low pass filtering.
Aether gravity spinning can explain Mercury perihelion shift, for example. https://www.researchgate.net/post/Can_the_perihelion_shift_of_Mercury_be_caused_by_luminiferous_medium_aether_wind

## All Answers (4)

13th Sep, 2019
Mike Albert
Fibertek
The gyroscope indicates its own rate of rotation regardless as to how that rate of rotation is arrived at. Assuming the gyroscope is oriented so that it is sensitive to earth rate, when your motorized table is off the gyroscope is rotating at the same rate as the earth and will indicate that it is rotating at earth rate. When your motorized table is on, if it is rotating the same direction as the earth then the gyroscope will be rotating twice as fast as the earth and will indicate 2X earth rate. If the table is rotating opposite the earth, the gyroscope won't be rotating at all and will indicate no rate (to its best precision)
13th Sep, 2019
Alexander I. Korolev
alex-korolev.jimdo.com
Dear Mike,
Thank you for explanation. It is clear for me as it should be in theory. But in the experiment there may be some deviation. As I know, for example, the rotation of Earth around Sun is not registered by optical gyroscopes though sensitivity can be quite enough for this.
13th Sep, 2019
Mike Albert
Fibertek
The gyroscope will measure all rates to its level of accuracy and precision. There are no true rotations that for some unexplained reason don't show up in the answer. Orbiting the sun does not intrinsically mean the Earth is rotating, and there doesn't have to be any measurable rotational rate associated with orbiting. However, there is an interesting effect.
We know that the Earth's axis is at a 23 degree tilt to the plane of the ecliptic, but suppose for a second it wasn't tilted at all. The axis of the earth's rotation and the axis of the Earth's orbit would be parallel. You would not be able to distinguish one from the other. Now suppose the Earth didn't rotate, but rather the same side always faced ... NOT THE SUN ... but some distant fixed star. Should you measure a rotation rate? The Earth would not have any angular velocity. It isn't rotating. The rate is zero. That isn't a measurement problem. Zero is the correct answer. Going around an orbit doesn't intrinsically equal a rotation.
Now suppose the Earth kept the same side always facing the Sun (tidally locked). The Earth would rotate once per year, and you would measure that rate. Note that one rotation per year = NO days. Orbiting around the sun means that the rotation rate has to produce one more rotation per year than there are days in the year.
There are 365.249 days per year, so you might expect to measure the earth's rotation rate as 365.249 rotations per 365.249 days = 1 rotation/day. However, Look up the Earth's sidereal rotation period and instead of 24 hours you find 23 hours 56 minutes and 4.1 seconds. The earth rate is actually 366.249 rotations/365.249 days. There is that one extra rotation I mentioned. If you measure Earth rate to better than 1/365 accuracy, this extra rotation will be apparent in the answer.
So orbiting doesn't in itself produce rotation, but since we tend to measure our rotation relative to the sun, orbiting does confuse us as to what the Earth's rotational rate is.
The fact that the Earth's rotation axis is tilted has essentially no effect on this idea.
1 Recommendation
16th Sep, 2019
Alexander I. Korolev
alex-korolev.jimdo.com
Let's imagine that the light in optical gyroscope propagate in some medium (aether). Then, let's imagine that this medium can rotate together with the gyroscope due to gravity entrainment. This rotation may be weak, but measurable.
Aether wind searching at Earth surface give no result. Thus, Earth orbital movement around the Sun, Milky Way (etc.) should be together with the aether. More likely, the aether does not rotate due to Earth orbiting, yes. Technically, it can be checked. The gyroscope for this should being oriented during a year towards Sun's center by stellar orientation system, for example. The signal of interest can be obtained using low pass filtering.
Aether gravity spinning can explain Mercury perihelion shift, for example. https://www.researchgate.net/post/Can_the_perihelion_shift_of_Mercury_be_caused_by_luminiferous_medium_aether_wind

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