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.
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Phong diffuse reflection: Plotting the BRDF [closed]
I want to plot the Phong BRDF dependent on the input direction. I found some pictures for this and there it is clearly shown that the maximum intensity of the reflected light is where theta_out equals ...
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Rainbow formation [duplicate]
Please help me with my query regarding rainbow formation.
Many Books gave formation of only red and violet colour whereas middlemost colours are rising doubt.please check the following picture .My ...
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Can a point source be focused to a point by a mirror?
Does a shape exist such that light from a point source at f1 will be focused by a mirror of that shape to another point f2? What is the name or equation for such a surface? And what happens to the ...
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Adjectives regarding interfaces
I'm studying X-Ray reflectivity at interfaces and the book I'm reading reads:
... The ideally flat, but graded interface, and the ideally sharp, but roughened interface, will be considered...
I'm ...
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Can mirrors reflect destructive lasers or do they absorb the energy and would get destroyed themselves?
There is much talk of using lasers to bring down drones. That talk is followed by talk of protecting the drones by surfacing them with mirrors.
Would that work or does light falling on a mirror ...
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What are natural retro-reflectors?
Recently I was on an airplane on a sunny day. The sun was shining on the other side of the plane and noticed a bright patch on the ground following beside us. Eventually I noticed a dark centre to ...
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Specular and diffused reflections
reflectivity of a mirror is very high but on a microscopic level no mirror is perfectly smooth so all the reflections must be diffused and we should not see any perfect reflection so how do we see ...
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Can you laterally invert a virtual image?
Could you possibly make a mirror that would show how you look to a person in front of you instead of laterally inverting the image?
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Why do the 'colors' of liquids in differently sized glass cylinders appear similar despite varying absorption rates?
For some liquids, such as cooking oil, I have observed that when filling two glass cylinders (with lids) of different diameters (e.g., one with a 5 cm diameter and another with a 10 cm diameter) with ...
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Why does the inner wall of a smooth glass have seemingly rings when viewed from above?
I was looking at my glass and I found these rings. Are they reflection of the upper circle of the glass?
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Are there any material coatings that would currently be effective to counter the rise of directed energy weapons?
I've been reading into directed energy weapons recently, and they seem like they're going to be a gamechanger. I'm just curious as to material countermeasures. I've learnt that some dielectric mirrors ...
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Predict color of dye under a certain wavelength of light?
I am picking fluorescent dyes to be put under a UV of known wavelength and would like to be able to predict approximately what color the dyes will appear under the light. I can request ...
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Modeling an Acoustic Reflection from a Wall
I am trying to simulate the reflection of a sound ray, that goes from a sound source, bounces off a wall, and is received by a microphone.
The wall has a an absorption coefficient, and a specular ...
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Problem measuring local reflectance through objective lens
Measuring the reflectance of copper substrates using only reflection probes gives an expected reflectance (orange plot). But when an objective lens is used to focus the incident light, I can see the ...
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Apparent violation of laws of reflection for an inertial observer [duplicate]
I am actually having an introductory course in Special Relativity in which I was looking at the Michelson Morley experiment. And I have this silly confusion.
The setup for the Michelson Morley ...
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Phase change in a light wave
Is there a phase change of pi when light is reflected of off a simple plane mirror?
Do we take into account the presence of glass underneath
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Why rainbow colors are as they are? [duplicate]
There are handful of questions related to rainbow formation here already, but after looking into them, I feel that I must ask yet another one.
I did a little research on the subject, and most of the ...
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Where can I find tabulated data for reflectance per wavelength (for Cu, Ag, Fe etc)?
I'm looking for a tabulated data for reflectance per wavelength for various materials for the visible light range. I found only images so far. Are there any spreadsheets with the raw numbers?
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Number of images formed by combination of more than 2 plane mirrors
It is very widely know that the number of images of an object formed by placing two plane mirrors at an angle $\theta$ can be described by certain formulae.
It is also of my knowledge that the images ...
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Phase shift of a light wave due to reflection at the interface of a higher refractive index medium
If a light wave is traveling from a medium of a refractive index $n_1$ to another medium of a refractive index $n_2$, why does it undergo a phase shift of a $180^○$ when the reflection takes place at ...
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Reflect visible light transmit infrared light
I have a color camera and PIR sensor inside a commercial security camera which records when motion is detected.
I want to hide the security camera behind a 1/2 inch polycarbonate window which reflects ...
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If photons are massless, how are they reflected and blocked by something that has mass? Shouldn't they pass right through any object?
If photons are massless, how do they get reflected, blocked when something comes in its way? Shouldn't the particle just pass right through any object?
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How do we calculate the probability of each path a photon would take to reach from point A to B?
I was reading about how reflection and refraction work at a quantum scale. What I understood was that the photon "can" take multiple paths to reach the end point and when we consider all ...
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A Rainbow Paradox
I was studying the phenomena of the formation of a rainbow. In my book, the following diagram is given:
So, the rays at the red end of the spectrum make a larger angle with the incident ray than the ...
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what is the difference between reflectivity and reflectance?
This question is in the context of solar reflections in buildings that cause glare. The two terms are similar but they have differences.
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What causes an object to be more reflective than refractive?
This is a question that a high school student asked me and I couldn't give him a satisfactory answer. He started by saying that
An object appears red because the energy corresponding to a "red&...
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Influence of absorption, reflectance and light source on interference in thin films
I am not a physicist, but reading up on interference in thin films.
I understood how the relation of two interfering light waves intensities $I_1$ and $I_2$ of a thin film (the first reflected at the ...
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One-way mirror with both sides lit
is there already a technology that provides one-way viewing glass with no regard to whether the back side is lit or not?
the case is:
two rooms (A and B) side by side, people in room A want to see ...
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How do we see the picture of an object as a whole thing in spherical mirrors?
When we see an object in a spherical mirror, the different parts of the object has different pictures which are also at different locations compared to each other.
The lights that go from the tip of ...
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Why didn't I reach $\frac{1}{p}+\frac{1}{q}=\frac{1}{f}$?
In optics for convex and concave mirrors there is the following formula: $$\frac{1}{p}+\frac{1}{q}=\frac{1}{f}$$ where $p$ is the distance between the object and the mirror, $q$ is the distance ...
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Changing the size of the lamp reflected from the water surface
Have you noticed that the image reflected from the water surface with ripples differs in size from the initial one?
From the image you can see that it’s reflect some times.
Moreover from basic optical ...
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Can mirrors on the inside of a container reflect infrared radiation thereby keeping the contents inside warmer for longer?
So I was wondering if it was possible to prolong the "entropy" of the bottle by making sure the heat of the contents of the inside of the bottle doesn't escape by first having a secondary ...
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Diamond Dust - Reflection and Shimmering
Diamond dust is a natural phenomenon that occurs when ice crystals form closer to Earth and interact with sunlight. Now diamond dust shimmers because of the reflection and refraction of sunlight. I ...
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What happens if 2 rays of light coming from an extended object intersect before hitting a reflecting surface? [duplicate]
Why don't we see any images in our daily lives if this can happen?
This question is asked in context of formation of images.
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Why does gold only glow red after flame is removed?
I was at a jewelry workshop today and saw somebody place a gold ring under an intense flame. Weirdly, the ring looked normal when underneath the flame, but glowed "red-hot" as soon as the ...
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Lambertian surface and radiant intensity
I am sure this question has been answered a gazillion times but I still struggle to find an answer that clears out all my doubt.
Assuming a Lambertian surface $A$ is illuminated by a light source $S$. ...
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Why are things reflective, absorbent, transparent etc? [duplicate]
What determines whether a material reflects, absorbs or transmits a certain wavelength of light? Just a layman's question.
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Can the terms "Lambertian albedo" and "white-sky albedo" be used interchangeably?
To my knowledge the "white-sky albedo" is the surface albedo corresponding to diffuse illumination while "black-sky albedo" corresponds to the direct illumination. I am confused ...
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Fresnel coefficients with permanent magnetism
I am familiar with the standard derivation of the Fresnel coefficients for linear magneto-dielectrics (for instance https://en.wikipedia.org/wiki/Fresnel_equations#Derivation). However, I was ...
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Diffuse reflection of a laser beam
I'm trying to calculate how much power is detected from a laser beam after it reflects off a diffuse material. The setup is the following (image source: https://pe2bz.philpem.me.uk/Lights/-%20Laser/...
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Is it possible to raise an object's temperature by reflecting or absorbing and re-radiating its own radiation back on it?
I am a layman with a little beginners knowledge.
This question is an effort to prove or disprove the Greenhouse Effect (GHE) theory as this is the basis of "back radiation" as described by ...
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Davisson-Germer experiment
Davisson and Germer's experiment confirmed the wave-particle duality of matter.
In this experiment a slowed down electron beam is reflected by the surface of a nickel crystal, which is able to split ...
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Calculating non-dielectric reflectance without using complex numbers [closed]
I need a to calculate the fresnel reflection ratio of a non dielectric material given the incident angle, the refractive indexes of the incident and interfacing materials and the extinction ...
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Why white body cannot emit photons (quantum level)?
As far as I've found white body by definition reflects 100% of electromagnetic radiation (EMR). According to thermal equilibrium as I've read it (but not been able to fully agree with the proof - so ...
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Combined reflection and refraction [closed]
Suppose a plane mirror is half-submerged in another medium (say water) and light rays are incident obliquely on mirror at the interface separating two media.
My questions -
(a)- Will reflected rays ...
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Roughness reflectance relationship
i am confused about a result in paper related to reflectivity from etched hole in silicon. The reflectance oscillation varies with surface roughness but i am not getting similar oscillation while ...
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Mathematical relation between wavelength of wave and area of surface for reflection
I was reading about the reflection of sound waves, and the condition provided is that the reflecting surface's area should be greater than the wave's wavelength. But there isn't a single mention of ...
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Deviation from law of reflection in (non-perfect) inelastic collisions
Does the law of reflection hold for balls bouncing inelastically on inclined planes?
In the above question, an answer included the following paragraph:
The law of reflection only holds if the ...
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How does diffuse reflectance brightness varies with the line of sight?
Wikipedia asserts that
The rays represent luminous intensity, which varies according to Lambert's cosine law for an ideal diffuse reflector.
Describing this figure:
I understand this is a ...
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Is it really just the electrons which decide the reflection from metals?
uh I'm curious again regarding the theories of reflection.
This is known that
Metals contain free electrons that absorb energy and vibrate when they
come in contact with light. Later, they release ...
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