Is parallax approximation and paraxial approximation same or different? If different then what is actually parallax approximation?
The parallax approximation and the paraxial approximation are two different things.
In geometric optics , the paraxial approximation is a small angle approximation used in Gaussian optics and ray tracing of light through an optical system (such as a lens ).
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight , and is measured by the angle or semi-angle of inclination between those two lines.
Parallax approximation :
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight , and is measured by the angle or semi-angle of inclination between those two lines.The term is derived from the Greek word παράλλαξις (parallaxis), meaning "alternation". Due to foreshortening nearby objects show a larger parallax than farther objects when observed from different positions, so parallax can be used to determine distances.
To measure large distances, such as the distance of a planet or a star from Earth , astronomers use the principle of parallax. Here, the term parallax is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder ", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder.
In geometric optics , the paraxial approximation is a small angle approximation used in Gaussian optics and ray tracing of light through an optical system (such as a lens ).
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight , and is measured by the angle or semi-angle of inclination between those two lines.
Parallax approximation :
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight , and is measured by the angle or semi-angle of inclination between those two lines.The term is derived from the Greek word παράλλαξις (parallaxis), meaning "alternation". Due to foreshortening nearby objects show a larger parallax than farther objects when observed from different positions, so parallax can be used to determine distances.
To measure large distances, such as the distance of a planet or a star from Earth , astronomers use the principle of parallax. Here, the term parallax is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder ", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder.
