Reflection Definition and 966 Threads

  1. Random Stuffs

    Why does light reflect at exactly 180 degrees?

    I understand the molecular principles behind the reflection itself, however it presents many problems, such as the one above. If you could explain it as easily as you can, I would be grateful. :)
  2. Zoey

    (Snell's Law) How do I find θi and θr?

    Homework Statement [/B]I am supposed to fill out a table with the values of θi and θr with the given information of n1 being 1.00 and n2 being 1.50 for the first row, and I am not quite sure how to do that just knowing the values that were given. I am also supposed to find the sine of θi and...
  3. M

    Reversal of Handedness by Reflection

    Hello everyone, I was just reading on circular polarization on Wikipedia and came across the sentence "The handedness of polarized light is also reversed when it is reflected off of a surface at normal incidence". I can see that the circular polarized wave should propagate in the opposite...
  4. E

    Complex numbers and reflection

    Homework Statement Reflection of the line ##\bar{a}z + a\bar{z} = 0## in the real axis is Homework EquationsThe Attempt at a Solution I know that a line in the complex plane is represented as ##\bar{a}z + a\bar{z} + b= 0## and that its slope ##μ = \dfrac{-a}{\bar{a}}##. I'm not sure how to do...
  5. vetgirl1990

    Thin films: reflection between glass plates

    Homework Statement Two parallel glass plates of index of refraction n are separated by an air film of thickness d. Light of wavelength λ in air, normally incident on the plates, is intensified on reflection when, for some integer m a) 2d=mλ b) 2d=mλ/n c) 2d=mnλ d) 2d=(m+1/2)λ e) 2d=mλ/2...
  6. S

    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...
  7. A

    How to solve for angle of reflection in respect to floor?

    Homework Statement A student stands 2.7 m in front of a floor-to-ceiling mirror. Her eyes are 1.64 m above the floor and she holds a flashlight at a distance 0.85 m above he floor. Calculate the angle θ, in degrees, that the flashlight makes with respect to the floor if the light is reflected...
  8. 1

    B What causes reflection to occur in highly absorptive materials?

    I'm not sure if this belongs here however some of you may know the answer to my question. If I am correct, transparency occurs when light hits an object however the light does not reach the threshold frequency to energize an electron. Thus, the light does not get absorbed and is able to pass...
  9. G

    Total internal reflection, refractive index, optical fibres

    How does the claddibg with lower refractive index reduce the light loss from the core? Thank you.
  10. H

    Orbit invariant under reflection about apsidal vectors

    The book argues that since substituting ##\theta## by ##-\theta## leaves the orbit equation (3.34) unchanged, the orbit is therefore invariant under reflection about the apsidal vectors (Fig 3.12). If substituting ##\theta## by ##-\theta## leaves the orbit equation (3.34) unchanged, then there...
  11. V

    How Does Specular Reflection Support the Particle Theory of Light?

    I think this may have been done before. So people are aware of the geometry of reflection. If I go beyond, I try to say that if light can pump electrons, it is absorbed, if it merely polarizes, it gives rise to an alternating dipole supposed to be polarizing the region around in all directions...
  12. StanEvans

    Photon Reflection: Questions & Answers

    I was wondering while doing some work on the photoelectric effect about how it is that photons interact with their environment. The question that I have is why or how does a massless particle such as a photon reflect of a surface such as a mirror. My first thoughts went to collisions with the...
  13. Jadaav

    Designing a reflection sundial for the southern hemisphere

    Hello, My aim is to build a small reflecting sundial as designed by Sir Isaac Newton. I found from a website that it consists of a ceiling and a small mirror. What I want to know is how it works, the concepts behind it and how to build one. It's for an undergraduate project that I've got...
  14. Danny Boy

    I Why is reflection coefficient defined this way

    In Griffith's "Introduction to Quantum Mechanics, second edition" he states: For the delta-function potential, when considering the scattered states (with E > 0), we have the general solutions for the time-independent Schrodinger equation: $$\psi(x) = Ae^{ikx} + Be^{-ikx}~~~~\text{for }x<0$$ and...
  15. nmsurobert

    Plotting reflection coefficient

    Homework Statement plot the magnitude |r| of the reflection coefficient as a function of incident angle from 0 to 90 degrees with a step size of 1 degree for the following cases: (ill only post one) A transverse electric plane wave in incident from air to glass Homework Equations r = (n1cosθi...
  16. B

    Transmission line and infinite reflection coefficient

    Hello, I am taking some microwave engineering courses and was trying to explain the concept of reflection coefficients to my friend, but he asked me a question I am unable to answer... So we know that given a transmission line with characteristic impedance Z_0 terminated with a load impedance...
  17. D

    Matrix Reflection Homework: Find Orthogonal Matrix in R3 Plane

    Homework Statement Let u1,u2,u3 be an orthonormal basis for R3 and consider M as the plane with equation x1+2x2-2x3=0. Find the matrix of orthogonal reflection in that plane with respect to the given basis. Homework EquationsThe Attempt at a Solution In previous exercises , I had a matrix A...
  18. I

    Potential barrier, reflection coefficient

    Homework Statement Electrons are pushed into a grounded metal tube A by the kinetic energy of 100 eV. After having gone through the tube it passes into another tube, B, at some distance from A. Tube B is kept at a potential of -50V. Calculate how many of the electrons are reflected back into...
  19. T

    Question on laser reflection (pic included)

    Good morning all, I'm currently working in some undergraduate research involving lasers and recently had the opportunity to play around with a few that my research professor has at our disposal. I've included a picture below of a strange phenomenon that has me a little puzzled, but then again I...
  20. D

    Light reflecting off sphere -- Momentum transfer

    Homework Statement Suppose light of momentum -P\hat{\textbf{k}} is shone on a sphere of radius R. What is the momentum transferred onto the sphere? Homework Equations The Attempt at a Solution I think the transferred momentum upon reflection is given by (-2P\hat{\textbf{k}} \cdot...
  21. R

    Interference from reflection off water across a lake

    #89 chapter 35 A microwave transmitter at height a above the water of a wide lake transmits wavelength lambda to a receiver across the lake height x above the water. Reflected wave interferes with waves arriving directly. Assumptions: width of lake D is much greater than a or x, and lambda is...
  22. D

    Fresnel zone and reflection of light on surfaces

    In a Scientific American article from 1968 in which he explains classically how light interacts with matter, Victor Weisskopf states that "the reflection of light on the surface of a solid or liquid involves only the oscillators (electrons) located in a small, pillbox-shaped volume at the...
  23. D

    Reflection and absorption of UV light

    Hi,I have a question when I was reading this website: http://www.webexhibits.org/causesofcolor/7F.html It explains how melanin works to protect us against UV light. From high school physics course we know that black absorbs light while white reflects. I understand when melanin accumulates,more...
  24. M

    Transmission and Reflection Amplitude for Delta Potential SE

    This is not a homework question per se, but it's a simple enough computation question from some notes I'm reading that I think it belongs in this section. I will do my best to keep to you guys' formatThis is not a homework question per se, but it's a simple enough computation question from some...
  25. Vannay

    EM wave reflection: phase shift off of conductor

    I know there is a pi phase shift when going from an area of lower index of refraction to higher. Is this phase shift still pi when going from a non-conducting dielectric with index of refraction n and reflection off a "good" conductor?
  26. Seismic101

    Does reflection accompany refraction in Snell's law?

    If the the angle of incidence of an incident ray is less than (or equal to) the Critical Angle, the ray is refracted, but do we still get some reflection from this same incident ray?
  27. M

    How can I find the minimum index of refraction?

    Homework Statement We look at the center of one face of a solid cube of glass on a line of sight making 55° with the normal to the cube face. What is the minimum refractive index of glass for which you will see through the opposite face of the cube? (Hint: see through will be possible if the...
  28. C

    What Index of Refraction is Needed for a 104nm Coating to Cancel 550nm Light?

    Homework Statement You are designing a thin transparent reflective coating for the front surface of a sheet of glass. The index of refraction of the glass is 1.52 and when it is in use, the coated glass has air on both sides. Because the coating is expensive, you want to use a layer that has...
  29. F

    Reflection of Waves and Formation of Standing Waves

    I have three doubts in regard to waves on a string which I will try to make as clear as possible. For this purpose, I have considered a general wave: $$y_i=y_0\sin(\omega t - kx)$$ (1) If a wave pulse: $$y = y_0 e^{\frac{-1}{T^2} \left(t-\frac xv \right)^2}$$ is incident against a rigid...
  30. RJLiberator

    Do Seismic Reflections Reveal Velocity Information in Layer 3?

    Homework Statement The question is set up by a diagram. It has: Layer 1 velocity = 6km/s Layer 2 = calculated velocity of 7.58 km.s Layer 3 = reflection The angle of the source in layer 1 is 34 degrees, the angle in layer two is then 52.33 degrees The source then reflects off of layer...
  31. J

    Total Internal Reflection explained with Quantum Mechanics

    Is there an easy explanation of total internal reflection of light using Quantum mechanics(or QED)?
  32. Corwin_S

    Calculate the desired incident polarization of a light beam

    Hi I want to calculate the necessary incident polarization of a light beam at a given angle of incidence (theta_i) that reflects off BK7 glass (n = 1.5168) and is linearly polarized (i.e., 45 degrees). I know how to do similar calculations for incident natural unpolarized light, but not in the...
  33. E

    Wave reflection and refraction, relations between angles

    Hello! This post is strictly related to my previous one. Let's consider the same context and the same image. Regarding the oblique incidence of a wave upon an interface between two dielectric, all the texts and all the lectures write an equation like the following: e^{-j k_1 y \sin \theta_i} +...
  34. N

    How reflection and refraction of light are expressed at the particle level?

    How reflection and refraction of light expressed at the particles level ? Thanks in advance
  35. D

    Magnification at a Different Distance from Mirror?

    Homework Statement The focal length between a person and his mirror that produces a magnification of 1.50 when his face is 12.0 cm away is 0.36 m. He then moves to a distance of 3.7 times the focal length away from her mirror. What is the magnification now? Homework Equations di/do=m...
  36. L

    Reflected Light at 3D Angle: Shift in Polarization

    I've searched high and low for answers to this, and a friend of mine finally pointed me in the right direction. I decided to write a post about it so hopefully others who have the same question will find the answer more easily. When linearly polarized light is reflected at a 3D angle, the...
  37. A

    Reflection and refraction: the same thing at the atomic level?

    I got cornered in a discussion on the internet... I am not sure if I am right or not (I thought I was when I started). If you guys here tell me I am wrong, I have no problem admitting if I am indeed wrong first... person 2 said "Refraction =/= reflection. The atmosphere is colorless because...
  38. J

    Reflection of wave at open end (boundary condition)

    Hello! I need to understand one seemingly simple thing in wave mechanics, so any help is much appreciated! When a pulse travels to the right toward an open end(like a massless ring that is free to oscillate only in the vertical direction), then when the wave reaches the end it gets reflected and...
  39. merlyn

    Reflection Coefficient: Steps 4 to 5 Explained by Drforbin

    Hi all, Great forum. I really don't know if this is the proper place for this, so if it is not please forgive me. I have been researching reflective coefficients in transmission lines. I understand everything except steps 4 -> 5. Perhaps it is a lacking in my math skills but could someone show...
  40. M

    Progressive harmonic wave & reflection / transmission

    Homework Statement An incident wave frequency f =500Hz , power Wi = 50 W and amplitude Ai= 5 mm spreads to the positive x in a linear density rope u1 unknown. When the wave encounters another rope ( attached to the first at a point P) density linear u2= 64 g/m (such as u2>u1 ) , The...
  41. A

    Window reflection when dark out side act like mirror

    Why is it that when a light is on in a room with a window made out of glass, and it being dark out side the window. That you cannot see through the window and instead see light being reflected form the room around you. And vice versa when it is darker inside the room and brighter out side you...
  42. cainko

    MC (multiple choice) question about total internal reflection

    Homework Statement There is an optical fiber.A light ray enter it at i°.Total internal reflection occur at X. What are the necessary conditions for the light ray to travel along the core of the fiber? (I have canceled B and D already.) A.n1>n2 and angle i should be greater than a certain value...
  43. S

    How Does Light Reflect in an Ellipse to Connect Its Foci?

    I needed the proof of this:if a ray of light passes from one focus of an elipse after reflection it will pass the other focus.please i need the one only using the fact that i=r ( not the fermat rule)
  44. lilknaap

    Reflection coefficient S11 vs Resonator animation

    Hello, I'm trying to do an animation of a photon being absorbed by a resonator vs. the corresponding S11 plot being plotted against frequency. Can anyone give suggestions on how to go about this. As the photon goes through Vin, at other frequencies it will be reflected and probed at Vout. This...
  45. B

    Finding the distance of reflection in a mirror

    Homework Statement A student wants to find the position of an image in a plane mirror. She sets up the plane mirror with a pin placed vertically a few centimetres in front of it. To find the image the student looks into the mirror at an angle a little further along the mirror. She can see the...
  46. kelvin490

    Question about intensity of EM waves

    For electromagnetic wave if it's reflected from a perfect conductor standing wave can be form. I wonder why Poynting vector can be used to describe the intensity of standing EM wave. (see p.19 of http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide13.pdf ). From some textbooks...
  47. C

    Reflection of particle between Inertial frames in SR

    Homework Statement Suppose a frame S' is related to S by a boost in the y direction by v. Imagine a wall is at rest in the S' frame along the line y'=-x'. Consider a particle moving in the x'y' plane that strikes the surface and is reflected by the usual law of reflection θ'i=θ'r. Find the...
  48. KaseyKC

    Why Are Sine Functions Changed to Cosine in 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...
  49. X

    Polarization change upon Reflection

    Hello, I am trying to determine how an electromagnetic wave changes polarization upon reflection off of an arbitrary object. Here are my confusions in particular. 1. My assumption is that the change in polarization is very much dependent on the geometry of the object, but I don't know the...
  50. H

    Transmission and Reflection amplitude

    To calculate Transmission and Reflection amplitudes (t and r), say in the figure below which is composed of three regions, first we have the solution of Schrodinger equation in each region as: \psi _i=A_i |i> +B_i |-i> ; i=I,II,III. It seems that by matching the three wave functions and their...
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