A Can a Ring Laser Interferometer Measure Earth's Spin and Determine Latitude?

AI Thread Summary
The discussion focuses on measuring Earth's rotation and deriving latitude without celestial references, emphasizing the challenges of using gyroscopes due to alignment issues and internal friction. A sextant is suggested for measuring the elevation of Polaris, while a pendulum is mentioned as a potential tool for determining rotation rates. Participants note that distinguishing between gravitational and rotational forces is complex, particularly since these forces overlap. The effectiveness of gyroscopes is questioned, with alternatives like a ring laser interferometer proposed for more reliable measurements. Overall, the conversation highlights the difficulty of accurately measuring Earth's spin and related forces with stationary devices.
aladinlamp
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Hi

is there any device or experiment, which could measure Earth spin vector and magnitude, centrifugal/centripetal forces, so i could derive from it, where is west and east , what's the vector of Earth rotation and what's my lattitude.

Im assuming these forces and effects has to be measurable with todays technology.

the device will be stationary, non moving( car, aeroplane), without external referencing, celestial objects,etc...

spin.jpg
 
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Gyroscope.
 
Tom.G said:
Gyroscope.
Trouble with a gyroscope is it needs to be set up and aligned, so i don't think it can measure the eart's rotation axis.

My choice would be a sextant, measuring the elevation of Polaris (and with more complex calcs, you can get closer than a half degree).

For the period...a clock is all you need, and a view of the horizon.

For forces, that is a lot tougher since gravity and the rotational forces overlap. I'm not sure there is a way to distinguish them in measurements(unless you own a satellite); only in calculations.
 
Pendulum?
 
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Tom.G said:
Gyroscope.
i tried with precision gyroscope, did not work,did not move, i guess too much internal friction in joints
 
russ_watters said:
Trouble with a gyroscope is it needs to be set up and aligned, so i don't think it can measure the eart's rotation axis.

My choice would be a sextant, measuring the elevation of Polaris (and with more complex calcs, you can get closer than a half degree).

For the period...a clock is all you need, and a view of the horizon.

For forces, that is a lot tougher since gravity and the rotational forces overlap. I'm not sure there is a way to distinguish them in measurements(unless you own a satellite); only in calculations.

I meant device without referencing celestial objects, just blindly measuring forces and vectors ( inside the box)

gravity and the rotational forces overlap, that's true but on poles rotational forces should be zero and at equator should be max, so has to be measurable difference there, from which lattitude could be derived
 
aladinlamp said:
i tried with precision gyroscope, did not work,did not move, i guess too much internal friction in joints
A gyroscope measures what happens when you move.
I meantdevice without referencing celestial objects, just blindly measuring forces and vectors ( inside the box)
Other than a pendulum to measure the rotation rate, I don't think what you are after can be done.
gravity and the rotational forces overlap, that's true but on poles rotational forces should be zero and at equator should be max, so has to be measurable difference there, from which lattitude could be derived
That would only be true if the gravitational component of the force were constant, which it isn't.
 
russ_watters said:
A gyroscope measures what happens when you move.
.

yes groscope disk should change angle relative to base, since gyroscope base is moving with earth, but no angle change for me

gyr.gif
 
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aladinlamp said:
yes groscope disk should change angle relative to base, since gyroscope base is moving with earth, but no angle change for me

View attachment 104490
How far did you move?
 
  • #10
russ_watters said:
How far did you move?

once spun to max revolutions, it took 27 minutes for the disk to stop, i know it needs high rpm all the time, but should move at least few degrees

7.5 degress in 30 minutes, if all was by the book
 
  • #11
aladinlamp said:
once spun to max revolutions, it took 27 minutes for the disk to stop, i know it needs high rpm all the time, but should move at least few degrees

7.5 degress in 30 minutes, if all was by the book
What direction was the axis pointed?
 
  • #12
russ_watters said:
What direction was the axis pointed?
of course i tried all possible angles and orientations, nothing happend
 
  • #13
You can use a Foucault pendulum to measure your latitude.

A ring laser interferometer will be more reliable than a gyroscope, particularly since it sounds like your gimbal has sticky bearings.
 
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