Skip to main content

Questions tagged [reflection]

This tag is for questions relating to reflection, the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. A familiar example of reflection comes from water waves; as the waves travel they reflect off objects that are floating in the water, and also reflect off the walls of the container holding the water.

Filter by
Sorted by
Tagged with
0 votes
0 answers
18 views

What is the fundamental difference between Fresnel's reflectivity coeffecient and Bragg's scattering coefficient?

Context: In Chapter 3.1.2, Polarisation properties of surface backscatter, in the book "Polarisation: Applications in Remote Sensing", Dr Cloude explains scattering from a surface using ...
Ashmitha Nihar's user avatar
5 votes
2 answers
1k views

Is there a wavelength shift between sunlight observed from the ISS versus from Earth's surface?

As gasses are not ideal in transmitting sunlight. Are there differences between sunlight observed from beyond the Earth atmosphere and the one observed from the Earth surface? If so, what are they?
Emilija Bradvica's user avatar
-2 votes
0 answers
62 views

Relativity problem about light signals and rockets equipped with mirrors [closed]

I find in a relativity book a problem that states: "A rocket with its own length $L$ moves away from Earth at a constant velocity $v$. A radar signal emitted from a ground station is reflected ...
idefix's user avatar
  • 1
0 votes
3 answers
33 views

Convergence of rays at focal plane after reflection from concave mirror

My teacher taught us that rays parallel to each other(but not necessarily parallel to the principal axis), after reflection from a concave mirror,get converged at a sharp point somewhere on the focal ...
NPC's user avatar
  • 21
5 votes
2 answers
232 views

Huygens' principle and the laws of reflection/refraction

As I understand the Huygens principle, all points on the wavefront are sources of secondary spherical wavelets and the tangent to these wavelets will form new wavefront. This is used to prove the ...
Yevgeniy P's user avatar
0 votes
1 answer
52 views

My explanation of interference contradicts known result (standing waves) - did I add phase wrong?

This is based on question 5d from this A-Level Paper (OCR A 2023 Paper 3): Plane-polarised microwaves are sent out from a transmitter aerial to a parallel receiver aerial. Behind the receiver, along ...
Anis Manuchehri-Ramirez's user avatar
11 votes
2 answers
2k views

What percentage of light gets scattered by a mirror?

Sunlight strikes a mirror at a 45 degree angle. The vast majority of light will be reflected about the normal. Some light will be absorbed by the mirror. Some light will be transmitted through the ...
causative's user avatar
  • 912
8 votes
1 answer
2k views

Is there a name for the number of '9's in numbers such as 0.999 (where it would be 3)?

I am doing an optics simulation involving transmission and reflection coefficients very close to 1, such as 0.999. While I was an undergraduate student, a professor mentioned that, in certain fields, ...
jcuk's user avatar
  • 93
0 votes
0 answers
28 views

$\pi$ phase shift upon reflection in quantum wells

Is there a similar phenomenon to the $\pi$ phase shift experienced by light upon reflection from a medium of lower to higher refracted index for particles in different potentials? For instance, does a ...
TheorVHP's user avatar
0 votes
0 answers
35 views

How is partial reflection of light by two surfaces explained?

I am reading QED by Richard Feynman and he explains how changing the thickness of glass results in a change in the probability of photons reflecting off the glass back to the photomultiplier. However, ...
Jack's user avatar
  • 31
0 votes
1 answer
27 views

Beam displacement at focal point

I'm working on a project that uses galvanometers with mirrors. They're configured to have a focal point of 175mm. The motors rotate at 1 mechanical degree per 500mV, that will be 2 degrees optical per ...
j.valerio's user avatar
1 vote
0 answers
35 views

What happens when a linear polarized EM wave encounters a perpendicular mesh of wires (which are electrically connected)?

Assume a radio wave with wavelength 1 m is traveling in the negative z direction when it encounters a grid of closely spaced wires (say, 10 cm separation) laying in the xy plane, with each wire ...
articpenguin's user avatar
0 votes
1 answer
43 views

Does a mirror have an albedo of 0?

According to the Wikipedia definition of albedo, it measures the fraction of light that is diffusely reflected by a body. Let's consider the visible light wavelenghts; is a mirror an object with an ...
jack_O'Dim's user avatar
1 vote
0 answers
37 views

How to determine if an observer can see an object with multiple mirrors?

How do I determine if an observer can see an object with multiple mirrors? I came across this image online and I am wondering if the observer (point O) see the object (point A) My attempt: I tried ...
Astrovis's user avatar
  • 187
0 votes
4 answers
1k views

How does the mirror know what’s behind the paper?

I found this on social media. Although it was posted for fun, this is a valid question: How does the mirror know what’s behind the paper? Show me how light reflected from the egg reaches the mirror.
Earth is a Spoon's user avatar
0 votes
1 answer
39 views

Pointing flash at LCD television creates a weird diffraction effect

I was looking around my room for something with my phone’s flash on, and noticed a very unique pattern reflecting off of the television. FYI. The flash is white. Any idea why it diffracts like that? ...
RedP's user avatar
  • 390
2 votes
4 answers
133 views

Reflection due to wave nature of light

In my high school, I am studying geometrical optics. I studied why smooth surfaces like mirrors form an image of an object but rough surfaces like a wall don't (due to regular reflection and irregular ...
Himanshu Nirwam's user avatar
0 votes
1 answer
73 views

Electromagnetic reflection without velocity change

The Fresnel equations describe the reflection and transmission of electromagnetic waves between two media. The parameter in the equations is the impedance ratio, where the impedance is $Z=\mu/\epsilon$...
Rd Basha's user avatar
  • 2,141
0 votes
1 answer
47 views

Why are Fresnel coefficients not symmetric?

When talking about reflection, we have the following coefficients for the electric field: $$r_{\perp}=\frac{n_1\cos(i)-n_2\cos(t)}{n_1\cos(i)+n_2\cos(t)} \\ r_{\parallel}=\frac{n_2\cos(i)-n_1\cos(t)}{...
Krum Kutsarov's user avatar
4 votes
1 answer
73 views

Question about amplitude of wave [closed]

Is it always true that: $$\text{Incident Amplitude} = \text{Transmitted Amplitude} - \text{Reflected Amplitude}?$$
Shantanu Binekar's user avatar
0 votes
0 answers
46 views

How can a greater than 1 reflectance coefficient be explained in $\rm SiC$-$\rm SiO_2$ interface?

I ran a simulation using the Transfer Matrix Method to plot the R,T and A curves for a SiC->SiO2 interface. There's a region of incident energies where the |r|^2 I get is higher than 1 and the ...
Daniel's user avatar
  • 11
1 vote
2 answers
45 views

Are reflection and transmission coefficients in 1D problem are independent of the direction in which we choose as incident?

I was watching a lecture series of Quantum mechanics of Professor V. Balakrishnan, There was a problem session, “For an arbitrary potential barrier (any potential function of position and it need not ...
Vivek Panchal 's user avatar
1 vote
0 answers
36 views

Why does scanning a barcode off a mobile phone screen work?

I recently went to a store and showed the loyalty card on a picture taken on my phone. As the cashier moved to scan the barcode, I figured that this won't work. Laser light is presumably coming out of ...
Kotlopou's user avatar
  • 381
1 vote
2 answers
72 views

Why total reflection happens at only 1 angle?

The critical angle can be intuitively understood by Snell's law.If the incident medium has a bigger diffraction index than the refracted medium then according to Snell's law the refracted ray will be ...
Root Groves's user avatar
1 vote
1 answer
57 views

What will be the color of red laser pointer spot on green surface?

I have read this discussion enter link description here , yet I want to make things more clear. In ideal conditions is it true that red laser pointer spot will appear on white sutrface as red while on ...
Igor's user avatar
  • 73
5 votes
4 answers
1k views

How do parallel reflected rays meet to form image at infinity? If they never meet then how is image formed?

In my textbooks it is written that when an object is kept at focus, its image is formed at infinity and is real. But how is this possible because parallel lines never meet and it is necessary for rays ...
Shivam Gogia's user avatar
0 votes
1 answer
29 views

Does white balance in context of direct reflections and glare needs to be treated in another way than it is in diffuse reflections?

Given that I have a few images of a red apple, taken on a yellowish sunset. Given that the goal is to see real apple color without the yellowish light from the evening sun Given that in order to ...
Igor's user avatar
  • 73
0 votes
0 answers
31 views

Property of total internal reflection question

If I create a medium with gradually decreasing refractive index from once face at index 2.0 and other at 1.01, and show a beam of light upon the optically denser side, will there be any losses upon ...
Udaiyan Bhan's user avatar
9 votes
2 answers
1k views

What would your reflection look like if a mirror was going close to the speed of light?

What would your reflection look like if a mirror was going close to the speed of light? Conditions: The mirror is a very long perfect mirror, lets say a light year long, moving close to the speed of ...
Axis Omega's user avatar
1 vote
6 answers
203 views

Real image drawn in case of concave mirror is bit off

About I am trying to draw real image of object in front of concave mirror. Case is when object is lying on the Center of curvature. What I have done so far There are two rays A ray incident on the ...
Pankaj's user avatar
  • 85
1 vote
2 answers
77 views

Deviation suffered by light ray incident on a surface

Problem: Figure shows two spherical surfaces of radii $R$ and $2R$ separating three transparent media of refractive indices $\mu_1=1, \mu_2=2$ and $\mu_3=4$. A ray of light travelling in medium $\...
Haider's user avatar
  • 159
0 votes
2 answers
74 views

Can nuclear material be detonated with light?

In this question https://space.stackexchange.com/questions/65842/nuclear-solar-reflective-plasma-drive I propose a question to use the light from the sun to start a nuclear chain reaction to propel a ...
Justintimeforfun's user avatar
0 votes
2 answers
77 views

Is there a way to calculate the angle between the refracted and reflected rays given the refractive index?

Is there a way to calculate the refracted and reflected rays? I know we use Snell's law to calculate the refracted rays, but is there a formula to calculate the angle of the reflected rays, or does it ...
Astrovis's user avatar
  • 187
0 votes
1 answer
57 views

If a silver screen works for a movie projector then why not a mirror?

I have a projector and use a white sheet, thumb tacked, and stretched over a wall. It works fine. I went to the movie theater and looked at their screen closely. It was a fine silvery white glitter-...
user avatar
0 votes
0 answers
32 views

What is the speed of light during reflection? [duplicate]

What is the speed of light in a vacuum when the light reflects off of a mirror?
Christina Daniel's user avatar
2 votes
2 answers
83 views

Is reflected photon the same? [duplicate]

When a single photon is reflected is the same one, or is it a new photon (emitted) while the 'original' photon has been absorbed? I'm not sure how to imagine a refleced photon - it's not a ball ...
matej's user avatar
  • 209
6 votes
4 answers
985 views

Treatment of infinite reflections in thin-film interference

Why do we only consider interference of the first two reflected waves when studying thin-film interference (see attached diagram)? Is there a rigorous treatment that considers the infinite number of ...
antoine's user avatar
  • 411
0 votes
3 answers
79 views

Why no image is formed when an incident and reflected ray intersect?

When two light rays intersect after reflecting from a concave mirror they form a real image. but what happens if, say, a ray from the head of the object A collide with the reflected ray DA'? It might ...
Ansh Dwivedi's user avatar
1 vote
0 answers
36 views

Isn't Reflection just absorption and emission? [duplicate]

How do mirrors work? How do the atoms in a mirror reflect photons. Does it absorb and reflect? As I understand it, after an atom absorbs a photon it is bound to release that same photon of the same ...
user15755358's user avatar
-1 votes
1 answer
31 views

Why does reflected light not cancel out depending on color?

I have been learning about light reflection and refraction and was thinking about objects reflecting only certain wave-lengths. Why doesn't a red object with a green light shone on it appear black? I ...
Silas Brock's user avatar
0 votes
0 answers
11 views

Can a real object also be considered as a real image if the direction of rays were to be reversed?

I came across the concept in a book wherein a real object is classified as a body that emits diverging beams of light; whereas the virtual objects are a point or a collection of point where the light ...
Atul Kashyap's user avatar
0 votes
0 answers
68 views

Finding the limiting refractive index of a rainbow

Give the limiting refractive index of a rainbow. The raindrops are modelled as spherical droplets, with refractive index $n$, with parallel rays from the Sun incident on it. I have a very limited ...
Developer's user avatar
0 votes
1 answer
72 views

Object and Image Distance from Image height, Object height, and focal length [closed]

Is there a way to find the object and image distances from the object height, image height, and focal length? I understand that the magnification is equal to $-\frac{d_i}{d_o}$ or $\frac{h_i}{h_o}$, ...
Astrovis's user avatar
  • 187
0 votes
1 answer
38 views

Would a hypothetical perfect reflector emit thermal radiation?

The question says it all. I believe a hypothetical perfect reflector is what's referred to as a "white body", but I might be wrong. From what I understand such a hypothetical perfect ...
Outis Nemo's user avatar
0 votes
0 answers
29 views

Minimum Radius of Curvature an Optical Fiber can be bent

Using the thickness and refractive index of an optical fiber, is it possible to know the maximum radius of curvature it can be bent before there are losses due to refraction? In my research, I came ...
Astrovis's user avatar
  • 187
0 votes
2 answers
142 views

Height of Mirror Required [duplicate]

I was curious about the minimum height of a mirror required to see your full body, and I found out that it was half of your height, in other words the minimum height to view the image = your height / ...
Astrovis's user avatar
  • 187
4 votes
4 answers
179 views

Trapping light by total internal reflection

Consider the attached image. Light is passed through a circular prism in the form of a disc (by refraction) in a way so that the the angle made by the refracted ray with the normal is 45 degrees....
Nightwing's user avatar
  • 489
1 vote
1 answer
34 views

Total flux is bigger than radiation flux, error?

The topic of this question is the collection of radiation from the sun. (renewable energy course) The total radiation flux is $$I_\text{total} = I_\text{direct}+I_\text{diffracted}+I_\text{reflected} ....
Root Groves's user avatar
0 votes
2 answers
69 views

Reflection of electromagnetic waves from dielectric

I have several questions regarding EMW reflection. If it will be helpful, I am thinking about the reflection of powerful EMW and problems like heating associated with it. Does EMW reflect from ...
AlexGenesis's user avatar
9 votes
3 answers
8k views

Does the fingernail test for detecting two-way mirrors really work?

I was looking for the working of a two way mirror when I came across this video. The person says that if you place your finger on the mirror and there's no gap between the image and the finger, then ...
Stuti's user avatar
  • 702

1
2 3 4 5
36