What is Refraction of light: Definition and 71 Discussions

In physics, refraction is the change in direction of a wave passing from one medium to another or from a gradual change in the medium. Refraction of light is the most commonly observed phenomenon, but other waves such as sound waves and water waves also experience refraction. How much a wave is refracted is determined by the change in wave speed and the initial direction of wave propagation relative to the direction of change in speed.
For light, refraction follows Snell's law, which states that, for a given pair of media, the ratio of the sines of the angle of incidence θ1 and angle of refraction θ2 is equal to the ratio of phase velocities (v1 / v2) in the two media, or equivalently, to the indices of refraction (n2 / n1) of the two media.

















{\displaystyle {\frac {\sin \theta _{1}}{\sin \theta _{2}}}={\frac {v_{1}}{v_{2}}}={\frac {n_{2}}{n_{1}}}}

Optical prisms and lenses use refraction to redirect light, as does the human eye. The refractive index of materials varies with the wavelength of light, and thus the angle of the refraction also varies correspondingly. This is called dispersion and causes prisms and rainbows to divide white light into its constituent spectral colors.

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  1. Marth

    I Optical Effect: curved light source when seen through the bus window

    During the night, I was traveling by local bus. And as I viewed through the window, the light from the street lights and the headlights of other vehicles appeared curved, as shown in the images below: One common answer is: because of refraction Is there any more explanation for this behavior?
  2. L

    Apparent depth of an object underwater

    I would know how to solve this problem if the person had been standing pratically above of the object underwater by using Snell's law and the approximation ##\sin(\theta)\approx\tan(\theta)## fopr ##\theta## small, but in this case I don't see how to find the angles ##\theta_1## and ##\theta_2##...
  3. Paulpaulpa

    I A ray crossing 2 media of different indices and energy conservation

    The ##I_i## are the intensity of the rays, in other words energy per surface units per radians by seconds. The d##\Omega## are the solid angles The equation p75 isis what I don't understand. I suppose that each side represent the energy going and out of the surface dS but I don't understand...
  4. R

    Refraction of light question -- Flintglass submerged in oil

    Hello, hopefully the question made sense, it was hard to translate. i attached a photo about the question. I started with n1=1.4, sinΘ1=37◦ and n2=1.62 1.4(sin(37◦))=1.62sinΘ2 1.4(sin(37◦))/1.62=sinΘ2 arcsin(0.52)=31.34◦ Is it calculated correctly?
  5. A

    EM wave reflected or transmitted?

    As I learn in class, when EM wave goes from medium 1 to medium 2, there are 3 possibilities that can happen Totally transmitted (i.e when the angle of incident is 0 degree) Partially transmitted and reflected (i.e when the angle of incident is between 0 and critical angle) Total internal...
  6. Jaffer2020

    Refraction of Light: Myth or Reality?

    In my latest 10th grade physics lesson, we were learning about the refraction of light. I decided to share what I knew about why light slows down in a vacuum, which is, in short, because the electric field of the electromagnetic wave exerts a force on the charged electrons of a medium, which in...
  7. Make it glow art

    Object magnified inside a cylinder of water

    Would you able to tell me what’s the ideal angle Of a curved glass in order to Magnify an object inside an aquarium to the maximum. Also what would be the ideal distance of the object inside the aquarium. Sorry if I didn’t explain myself properly. I‘m hopeful somebody would be able to explain it...
  8. Adesh

    Putting a slab of some material just after the slits in Young's model

    If I put a slab of some material whose refractive index is \mu and width is D, in front of slits in Young's Double Slit model, then In the figure you can see that I have placed the slab just after the slits. So, when rays going to come out of the slab they will bend away from...
  9. I

    B Do photons bunch up at an interface? Can they lase (laze?)

    If the light slows at an interface, what happens to the photons coming in after the slowed ones? Can these cohere with the leading (slowed) ones and create what amounts to a FEL?
  10. A

    Brewster's angle, dipole radiation and refraction

    So I was wondering how it is possible that there will be no p-pol light reflected when the refracted light is at 90 degrees to the reflected light (so incoming light is at Brewster's angle). The Brewster's angle was explained to me by saying that the electrons in the medium radiate light...
  11. S

    Optimizing Dolphin Tracking: Calculating the Angle for Dart Gun Accuracy

    Homework Statement A scientist investigating the movements of dolphins in the Mediterranean uses a dart gun to shoot small, harmless tracking devices onto the fins of dolphins. When standing on deck, her hand is 1m above the water, and looking along the dart gun she is holding at an angle of...
  12. Akash47

    A cat spots a flower pot through the window

    Homework Statement A cat spots a flowerpot that sails first up and then down past an open window. The pot is in view for a total of 0.50 s, and the top-to-bottom height of the window is 2.00 m. How high above the window top does the flowerpot go? 2. Relevant equation Not sure but the theory of...
  13. K

    How do interference and AR coatings work?

    How does AR coating works on cameras? How do they decrease reflection? And how does it improve the quality?
  14. D

    I What properties allow me to see past Earth's curvature?

    I recently was able to view a 193 foot building from 24 miles away. The base of the building is approximately 15 feet above sea level and my eye level was approximately 9 feet above sea level. I was viewing the building across a Lake. I could see a substantial amount of the building, which...
  15. H

    Find the formula for refraction angle?

    Homework Statement Homework Equations Snell's Law sin tetha1/v1 = sin tetha2/v2 n1 = c/v1 n1 . sin tetha 1 = n2 . sin tetha 2 The Attempt at a Solution I try to make triangle out of line PO, so that it will have correlation to tetha, since o = center, then let's say there's point C at...
  16. R

    What is the Optical Table Simulator and how can it be used?

    Hi All, My name is Radek Strugalski and I am creator of an Optical Table Simulator, a 2D precise ray tracing engine written in Silverlight 5. It can be used for educational purposes, experimentation or jus fun. It's completely free and so far no plans to spoil it with ads. :) I saw that some...
  17. H

    What is the refraction of light and its relevance in Bsc physics?

    I am studying Bsc physics. Edit by mod: removed spam Please give me the details about the above question.
  18. F

    Intuitive reasoning for frequency remaining constant during refraction

    What is the intuition for why the frequency of light does not change as it passes from a less dense medium to a denser one (or vice versa)? Classically, if we treat light in terms of waves, then intuitively, is the reason why the frequency does not change because it is determined by the...
  19. Lakshman Chaudhari

    Direction observed by fish when man flying air to water?

    what is the direction of velocity observed by fish when man flying from air to water?
  20. Martin Hanna

    Finding angle of refraction given angle of incidence?

    Can someone help me in solving this question ? my attemp is sin42/sin 90 to get the refractive index then n =sin i/sin r to get c and for b n=1/sinc
  21. J

    Angle of Refraction through a Prism

    Hello everyone, I am trying to figure out how to explain an aspect of this question to my students, but cannot seem to recall the geometry that explains the textbook's approach. In the figure below, for part (b) of the question, we are using the angles of refraction at the left boundary to...
  22. 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
  23. I

    Refraction of Light question assistance needed

    As revision for my upcoming physics exam, I'm doing an old exam paper from a previous year of the course, for which the answers aren't published. However, I'm stuck on a basic angle of refraction question: "A light ray makes an angle of 35degrees to the surface of an oil layer. [A diagram is...
  24. M

    Understanding Refraction of Light: Exploring Index of Refraction and Reflection

    Why is the index of refraction of one color of light different than the index of refraction for that same medium? Also why is some light reflected and some refracted when it comes in contact with a new medium?
  25. A

    Refraction of Light: Is There No Refraction?

    I understand that when light goes between air and water, refraction occurs (either towards or away from the normal). If the light going between air and water is already going in the same direction as the normal, is there no refraction (or a refraction angle of 0 degrees)? Thank you.
  26. oreo

    Does a Light Pulse Undergo Phase Shift in a Denser Medium?

    When a pulse of light enters a denser medium(slow medium) then is there phase shift or rather it passes unshifted?
  27. aditya ver.2.0

    Refraction of light in denser medium

    Why does light bend in a denser medium?
  28. W

    Refraction of Light: Does Color Change?

    So I have this very primitive doubt- When light travels through a medium its wavelength changes,so does the colour even change, as it is also associated with it? I mean that if we had a photographic plate as a detector to detect the colour change in the medium. Like if I send blue light through...
  29. Manraj singh

    Why Does Light Change Its Path When Speed Alters in Different Media?

    Yeah sure, change in speed of light as it travels from one medium to another. But why does it affect the path? I mean, shouldn't the light ray just go in the same direction with a different speed? Why does it have to change its path?
  30. S

    Reflection and refraction of light

    Homework Statement One of the contests at the school carnival is to throw a spear at an underwater target lying flat on the bottom of a pool. The water is 0.900 m deep. You're standing on a small stool that places your eyes 3.20 m above the bottom of the pool. As you look at the target, your...
  31. S

    Problem regarding refraction of light question

    I have a problem in this question ... and i can't get an answer . Also please mention for which class is this question meant for if you know :) . I tried solving it but can't apply trygnometery to the angle A for the prism . P.S: I couldn't find the homework forum so i asked here :) .
  32. C

    How does refraction of light in water affect the perceived location of objects?

    Hi, I was trying the following question; 'A child of height 90 cm is standing at the edge of a 1.2m deep swimming pool. She looks into the water and sees a brick lying on the bottom of the pool. From the child's perspective, the brick appears to be 2.0m horizontally away from the side of...
  33. R

    How Does Refraction Influence Measurement Accuracy in Ripple Tank Experiments?

    Homework Statement I've preformed an experiment where in a ripple tank I had to count the number of waves and length of as long a train of waves as possible, so that I can calculate the wavelength. A stroboscopic light was used and I had to count the number of bright patches/shadows of the...
  34. A

    What is reflection and refraction of light at the microscopic scale?

    I'm not asking for what reflection and refraction are or the usual law governing it, but I would like to understand what they represent at the quantum atomic, molecular level? In a mirror is it about photons absorbed and emitted with the same wavelength and same direction through atomic electron...
  35. L

    Refraction of light through a prism

    Homework Statement Revered members, Please see my attachment which deals with refraction of light through a prism. PQ is incident ray, QR is refracted ray and RS is emergent ray. i1,i2 are angles of incidence. i1 is angle of incidence, but how i2 qualifies to angle of incidence. Similarly how...
  36. S

    Physics Photo Contest: Refraction of Light

    Hello! so this is for a physics photo contest. i have to do a little write up and i'd really like for my information to be accurate. http://i165.photobucket.com/albums/u43/ninjanamine/115-5.jpg?t=1304830133 the physics part is the orange tree in the water droplet (refraction of light)...
  37. P

    How does refraction of light work

    I've looked into refraction of light, and I understand the basic principles thoroughly, but there are a few things that I don't understand, if you know any of the answers to these questions, please help me: 1.) Why does light bend when it slows down instead of just continuing on in the same...
  38. S

    Refraction of light and wavelength

    Light of wavelength 680 nm in air enters water making an angle of 40 degrees with the normal. Find the angle of refraction and the wavelength of light in water. I found the angle of refraction, but I don't know how to calculate the wavelength with this information.
  39. S

    Refraction of Light: Why Frequency Stays Unchanged

    Why does the frequency of light wave doesn't change during refraction ?
  40. H

    Refraction of Light: Isosceles Prism of 120°, Refractive Index 1.44

    An isosceles prism of angle 120* has a refractive index 1.44.Two parallel monochromatic rays enter the prism parallel to each other as shown in figure.the ray emerge from the opposite faces- (A)Are parallel to each other (B)are diverging (C) make an angle 2[sin^ -1(0.72)-30*] with each other...
  41. P

    How does refraction of light take place?

    how does refraction of light take place?And why does it always shift towards the normal while traveling from rarer to denser medium,why not away from normal?
  42. H

    Why Does Water Refract Light and Improve Visibility?

    Homework Statement If you dive without goggles, you can't see very clearly. Why? Homework Equations The Attempt at a Solution I guess the reason is water around the eyes refracts the ray so that the image produced in the eye is blur. Right? But why when using goggle we can see...
  43. K

    Angle of refraction of light in water

    Homework Statement A ray of pure yellow light reaches the surface of a pond at an angle of incidence of 60°. What angle does it make with the normal inside the water? Speed of light in air = 300,000,000 m/s Speed of light in water = 225,000,000 m/s So the Refractive index μ = 1.33...
  44. K

    Question about refraction of light

    Homework Statement A pair of students measure the refraction of light in passing from acetone into air for several angles. When the angle of incidence is 30, the angle of refraction is 42. (a) What is the index of refraction n of the acetone? Homework Equations n=c/v The...
  45. N

    Porro prism and Refraction of Light

    Homework Statement Ligh is incident normally upon one face of a prism of glass with an index of refraction, n. The light totally reflected as shown in the picture*. What is the minimum value n can have? *Picture shows a Porro prism (45-45-90 prism) Homework Equations n sin(a) = n2 sin...
  46. T

    What Angle Does Light Refract in Ice?

    Homework Statement A beam of sunlight with a wavelength of 500 nm strikes an ice floe at an angle of 66.5 If ice has an index of refraction n=1.31, at what angle is the beam refracted? Homework Equations Law of Refraction- n(i) sin 0(i)=n (r) 0 (r') The Attempt at a Solution I'm...
  47. B

    Reflection and refraction of light problem

    Homework Statement 3. Assume the slab is perfectly rectangular and has width W. (a) Calculate the distance (L) the light travels INSIDE the block as a function of W and the angle t1. (b) From the right-angled triangle with vertices IPE calculate the lateral displacement x in terms of...
  48. cepheid

    Rainbows and refraction of light

    Hi, I have always wondered this about the standard explanation for a rainbow. Okay, so individual water droplets refract light entering them, dispersing it, as well as changing its direction. Fine. Here's my question: why don't we see millions of little discrete spectra, one for each droplet...
  49. A

    Refraction of light in three mediums

    1. 2 cases: there are three mediums first case: light travels from first medium to second, then to third. n1 = 1.1; n2 =1.6; n3 =1.9 angle of incidence before first = theta 1 angle of refraction after first = theta 2 angle of refraction after second = theta 3 second case: light travels...