Meaning of Gravitaional Shear?

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In summary, gravitational shear refers to the focusing of light beams and can be calculated by finding the difference in velocity between Earth's closest and farthest sides from the sun. This difference is typically very small, around 1 meter/second. Gravitational shear is often mentioned in relation to gravitational lensing, specifically weak lensing, which causes background galaxies to become elongated and curved towards the center of a foreground cluster.
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beech
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Is there more than one meaning for "gravitational shear". It seems to refer to focusing of light beams.

When I calculate the difference in velocity, of Earth's side closest and farthest from the sun: the difference is about one meter/second. Is that gravitational shear?

Calculation

Orbital velocity is 2 times pi times the distance to the sun, divided by time, in this case the number of seconds in a year.

Velocity of Earth
v1 =2 * pi * 1.5 * 10^8 / ( 365.25 * 24 * 60 * 60 )
= 29.8653 km/sec.

v2 =(2 * pi * 1.5 * 10^8 - radiusEarth) / ( 365.25 * 24 * 60 * 60 )


Subrtact v1 - v2

The Radius of Earth is 6378 km.
The orbit is inclined to have a different velocity, at the sides nearest and farthest from the sun. This difference is, 1.27 meters/sec.
 
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Usually, gravitational shear is mentioned in relation to gravitational lensing, mainly weak lensing. The shear causes background galaxies in relation to a foreground cluster to become elongated, and also curved towards the center of the cluster. Look up "weak gravitational lensing". . .
 

1. What is gravitational shear?

Gravitational shear is a term used in physics to describe the distortion of an object's shape due to the influence of gravity. It is caused by the difference in gravitational forces acting on different parts of an object, resulting in a stretching or squeezing effect.

2. How is gravitational shear measured?

Gravitational shear is typically measured using a quantity called shear strain, which is defined as the change in length of an object divided by its original length. This measurement can be taken using specialized instruments such as strain gauges or by analyzing images of an object before and after being subjected to gravitational shear.

3. What causes gravitational shear?

Gravitational shear is caused by the distribution of mass in the universe. The gravitational pull of massive objects, such as galaxies and clusters of galaxies, can cause the space around them to warp and stretch, resulting in gravitational shear.

4. How does gravitational shear affect light?

Gravitational shear can affect the path that light takes as it travels through space. As light passes near massive objects, such as galaxies, it can be bent and distorted by the gravitational shear, resulting in effects such as gravitational lensing.

5. What is the significance of gravitational shear?

Gravitational shear is an important concept in the study of gravity and cosmology. It can provide insights into the distribution of mass in the universe and help us understand the large-scale structure of the universe. It is also a crucial factor in phenomena such as gravitational lensing, which can help us observe and study distant objects in the universe.

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