- #1
Alche
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Why do we measure the angle of incidence or reflection (or say refraction even) w.r.t normal to the surface and why not w.r.t the horizontal surface?
Why do we measure the angle of incidence or reflection
- Thread starter Alche
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In summary, the angle of incidence or reflection (and refraction) is measured with respect to the normal to the surface because it is easier to define and can better explain the phenomenon of reflection and refraction of light in nature. Measuring the angle horizontally may not provide as clear of an explanation, especially in the case of curved objects. Therefore, measuring with respect to the normal is preferred for simplicity and clarity.
- #2
tiny-tim
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Hi Alche! 
I think it's because defining the angle a ray makes with a line (the normal) is easier than defining the angle it makes with a plane (the tangent plane, to a surface that may be curved).
I think it's because defining the angle a ray makes with a line (the normal) is easier than defining the angle it makes with a plane (the tangent plane, to a surface that may be curved).
- #3
Alche
- 21
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Even I think the same.
I think we measure the angle with respect to the normal because by doing so we can explain many phenomenon that happens in the nature due to reflection and refraction of light.May be by measuring the angle horizontally we won't be able to explain those phenomenon so neatly. Or may be we'll be but only in the case of flat objects.
And in the case of reflection and refraction on spherical surface where surface is not horizontal we won't be able to explain all the things without having lots of assumptions.
So for keeping the things easy and clear we measure the angle w.r.t to normal.
1. Why do we measure the angle of incidence or reflection?
The measurement of the angle of incidence or reflection is important in understanding the behavior of light and other waves. It helps us determine how light will interact with different surfaces and materials, allowing us to predict and control the direction and intensity of reflected light. This is essential in fields such as optics and photography.
2. How is the angle of incidence or reflection measured?
The angle of incidence or reflection is typically measured using a protractor or other angle measuring tool. It is measured in degrees, with 0 degrees representing a ray of light that is perpendicular to the surface, and 90 degrees representing a ray of light that is parallel to the surface.
3. What is the relationship between the angle of incidence and reflection?
The angle of incidence and reflection are always equal, as stated in the law of reflection. This means that the angle at which a ray of light strikes a surface will be the same as the angle at which it is reflected off the surface.
4. Why is the angle of incidence or reflection important in the study of optics?
The study of optics is focused on how light behaves and interacts with different materials and surfaces. The angle of incidence and reflection is a key factor in understanding this behavior, as it allows us to predict and manipulate the direction and intensity of light. This is crucial in fields such as lens design, telescope construction, and laser technology.
5. Can the angle of incidence or reflection change?
Yes, the angle of incidence or reflection can change depending on the properties of the surface or material it is interacting with. For example, a smooth and flat surface will reflect light at the same angle as it was incident, while a rough or curved surface may cause the light to be scattered, resulting in a different angle of reflection. Additionally, the angle of incidence may change if the light passes through a medium with a different refractive index, such as air to water.