# What is Law of reflection: Definition and 19 Discussions

Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface.The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. This behavior was first described by Hero of Alexandria (AD c. 10–70).Specular reflection may be contrasted with diffuse reflection, in which light is scattered away from the surface in a range of directions.

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1. ### Deriving the Law of Reflection from Huygens Principle

Attached is section 33.7 from my book, which introduces Huygen's principle in order to derive the law of reflection. I am more used to the ray model rather than the wave model, so I'm constantly going to try to relate everything back to rays. Making this connection also helps with completeness...
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### Huygen's Principle doesn't necessarily imply the law of reflection

There are many diagrams like the following which demonstrate that if A acts as a point source of wavelets, then we will have constructive interference in the case that ##i=r## as shown, as we can show with a little geometry that the path difference is zero. However, surely this isn't the...
3. ### Derivation of the Optical Law of Reflection

Problem Statement: Derive the optical law of reflection. Hint: Let light go from the point A (x1, y1) to B (x2, y,2) via an arbitrary point P = (x, 0) on a mirror along the x axis. Set dt/dx = (n/c) dD/dx = 0, where D = distance APB, and show that then theta = phi. Relevant Equations: t = nD/c...
4. ### Snell's law and law of reflection derivation -- confusing

I am learning principle of optics written by Born&Wolf and confused with the method to derive Snell's laws and law of reflection. In the textbook,##v_1## is the speed of light in mediator 1 and ##v_2## is the one in mediator 2. ##{\vec s}## is the direction of light and ##{\vec r}## is the...
5. ### Lorentz tranformation of law of reflection

Homework Statement Consider an inertial frame ##S## with coordinates ##x^{\mu}=(t,x,y,z)##, and a frame ##S'## with coordinates ##x^{\mu'}## related to ##S## by a boost with velocity parameter ##v## along the ##y##-axis. Imagine we have a wall at rest in ##S'##, lying along the line...
6. ### Deriving the law of reflection

I'm trying to derive the law of reflection for Electromagnetic Waves and Optics. I'm using some lecture notes that my university provided. I'm confused as to why the two sine functions are changed to cosine functions as you don't do the same when you are deriving Snell's law. Refer to attached...
7. ### The Law of Reflection and Lasers

So I've been looking into the Law of Reflection with Specular and Diffuse Reflection. I understand that electrons have a certain vibrational frequency in objects, and if a light wave matches that, that color wouldn't be observed. My question is, what if I took a red laser pointer and shined it...
8. ### Light rays reflected off vertical mirror (law of reflection)

Homework Statement A vertical mirror is placed at the origin. A ray of light coming from A is reflected by the mirror so that it passes through B. How far from the bottom does the ray hit the mirror? The coordinates are A = (11.4, 15.9) and B = (15.9, 4.7), in centimetres. Homework...
9. ### Question on the Law of Reflection

The law of reflection states that the angle of incidence equals the angle of reflection. In the event of a beam of light reflecting upon a horizontal surface, the incidence angle is 45 degrees (as a variable, 45 degrees will be represented by A). The angle formed by the reflection will...
10. ### Use the law of reflection and index of refraction to find apparent d

Homework Statement See image Homework Equations n1sin(theta1) = n2sin(theta2) 1/s + 1/s' = 1/f The Attempt at a Solution My question is for the second part. I think I've figured out why I got it wrong, but I'm not sure. So since the object distance (s) should be approximately 21 cm, then...
11. ### The second law of reflection

Hi, I am trying to prove the second law of reflection using fermat's principle and I am not entirely sure how to start it. By the way the second law of reflection is: The incident ray, reflect ray and normal ray all lie in a single plane.
12. ### Question about law of reflection

When is the law "the image is formed back in the mirror at a distance equal to that of the object from the mirror applicable? Consider a plane mirror,with a glass slab on it. Let an object be placed in front of it outside the slab, in air. Now due to normal shift the mirror will see the...
13. ### Law of reflection of light

Homework Statement How far behind the mirror is the image of an object that is located in front of a flat (plane) mirror? Why do you think the image produced by a flat (plane) mirror is called a virtual image Homework Equations The Attempt at a Solution
14. ### The law of reflection

What is the law of reflection to the object, when it's perpendicular to the reflective surface. For example, if you face a mirror and stare eye to eye with the reflection- what is the angle?If I have understood correctly, the angle of incidence/reflection is equal, so if for the mirror is...
15. ### Modification of Law of Reflection from a (moving) mirror in Special Relativity

Hi everyone A few weeks ago, I had worked out the relations between the angle of reflection and angle of incidence in case of reflection from a plane mirror, (1) moving toward the incident ray (2) moving normal to the incident ray (PS -- This is not homework.) The way I did it was...
16. ### What is the law of reflection in special relativity?

Hi, I'm working through an Excercise in Sean Carrol's spacetime and geometry book. The question asks you to consider an inertial frame S with coordinates x^\mu=(t,x,y,z) and a frame S' with primed coordinates. Which is related to S by a boost v in the y direction. Imagine a wall( or mirror)...
17. ### Understanding the Law of Reflection in Electromagnetic Waves

Homework Statement An electromagnetic wave is incident upon a planar interface at an oblique angle \theta_i, where it is reflected. For the wave vector components parallel to the interface, we have k_{xi}=k_{xr}. Thus, \theta_i=\theta_r. The wave numbers for the incident and reflected waves...
18. ### Law of reflection problem

Homework Statement In an amusement park maze with all the walls covered with mirrors, Pilar sees Hernando's reflection from a series of three mirrors. If the reflected angle from mirror 3 is 52° for the mirror arrangement shown in the figure, in which = 12°, what is the angle of incidence on...
19. ### Law of reflection and refraction

Hi; I was wondering if someone could please help me with this question: "When you measure the law of reflection and the law of refraction, what is the advantage of making 2 measurements: one clockwise from the normal and one counterclockwise from the normal?" Could an advantage be that this is...