How does a ring laser detect Earth's rotation?

AI Thread Summary
A ring laser detects Earth's rotation through the Sagnac effect, which measures the phase shift of light traveling in opposite directions around a closed loop. The laser does not need to encircle the Earth; it can detect rotation even when stationary on the surface due to the relative motion of the laser beams caused by Earth's rotation. The Coriolis effect plays a role in this detection, as it influences the behavior of objects in a rotating frame. Understanding the principles of rotating frames helps clarify how the ring laser can measure rotation without needing a complete circuit around the planet. This technology is significant for precise navigation and geophysical studies.
journierman
Messages
2
Reaction score
0
This is my first time posting here so I hope I am in the right place. So I have read about some scientists who have built a ring laser that is sensitive enought to detec the Earth's rotation. I can get how a ring laser can detect the rotation of a missile say if the laser path is perpendicular to the direction of the missile travel. I can not seem to get my head around how a ring laser could detect the rotation of the Earth if its sitting on the surface of the Earth and the beam path is not perpendicular to the Earth rotation. It seems like to me for a ring laser to detect the Earth rotation the laser path would have to go around the whole earth. Can anybody help me understand this?
 
Science news on Phys.org
Why would it have to go around the Earth? If you take a rotating frame and move it off axis, it's still rotating by the same amount.
 
Sorry I am dense. So I understand how it detects rotation when you rotate the ring laser around the center of the area it encloses. I do not understand how it could detect rotation any other way. Does this help?
 
Do you know the Coriolis effect? It's essentially that really.
 

Thread 'Pentaprism with magnification, which surface is curved?'

I would like to use a pentaprism with some amount of magnification. The pentaprism will be used to reflect a real image at 90 degrees angle but I also want the reflected image to appear larger. The distance between the prism and the real image is about 70cm. The pentaprism has two reflecting sides (surfaces) with mirrored coating and two refracting sides. I understand that one of the four sides needs to be curved (spherical curvature) to achieve the magnification effect. But which of the...
View full post »

Similar threads

A Weird pattern for a laser beam spot
Replies
9
Views
3K
A The coherence length is much longer than the manufacturer claims
Replies
10
Views
2K
A Relative efficiency of SHG vs SFG
Replies
6
Views
1K
I Why does laser beam hit the same target when fired?
2
Replies
90
Views
3K
I Does a Fabry Perot cavity charge in discrete steps?
Replies
12
Views
3K
I Quetelet rings on LCD displays?
Replies
3
Views
2K
How does a laser rangefinder work?
Replies
8
Views
3K
Why Is My Nd:YAG Laser Beam Quality Deteriorating?
Replies
6
Views
2K
A How produce twin photons in practice?
Replies
3
Views
1K
Intensity of a Gaussian laser beam
Replies
5
Views
4K

Hot Threads

Recent Insights

Back
Top