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5
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1answer
202 views

How is it possible for an Ultrasound device to correctly interpret a negative density change in tissue?

I understand the principles of Ultrasound Imaging, and the mathematics behind sonar velocity, impedance, and reflection. I also understand that an Ultrasound device recieves an echo produced by ...
0
votes
2answers
412 views

Colors in the secondary rainbow reverse of that in the primary rainbow

Why the colors of Secondary rainbow is reverse of that in the color in the Primary rainbow? What can be the possible reason among the following options Because it is formed by one internal ...
1
vote
0answers
80 views

How does a lens affect the field of view in a mirror?

If one looks into a mirror, he can see a certain field of view. If he places a convex lens that magnifies (or a concave lens that does the opposite) in front of the mirror, but so that he can still ...
17
votes
1answer
691 views

Why does the spotlight reflected off of a rectangular mirror tend to become circular?

Background and setup When I was 12 I used to like a girl, we were almost neighbors and it was essential that our parents don't find out. So whenever one of us wanted to call the other they'd signal ...
2
votes
1answer
156 views

Can small clouds reflect enough light to hurt your eyes/blind you?

I looked out my window a minute ago and immediately noticed a very bright spot where a cloud and a jet/plane trail met. The spot was so bright that I thought the sun was behind it because it left that ...
0
votes
1answer
404 views

Refraction and Reflection Seismology

So I am wondering if I got the difference right. Both methods use explosives to send waves into the earth's surface. Now reflection seismology tries to get information from the reflected waves; the ...
5
votes
1answer
358 views

Special Relativity & Mirror Reflection

If you move at $5$ $ms^-$$^1$ towards a plane mirror, your reflection moves $10$ $ms^-$$^1$ towards you. But what happens if you're moving much faster, say $0.8c$? Would your reflection move at ...
3
votes
4answers
27k views

Why do diamonds shine?

I have always wondered why diamonds shine. Can anyone tell me why?
-1
votes
2answers
313 views

A light and magnetic mirror paradox?

If light is an electromagnetic wave and lightspeed is constant (we ignore spacetime or gravity for this question) why can't we slow down light with a few dozen wellplaced magnets and electricly ...
1
vote
1answer
62 views

Rays in Symmetric Resonator

I'm having some trouble figuring out how to get started on this question: If I have a symmetric resonator with two concave mirrors of radii $R$ separated by a certain distance, after how many round ...
0
votes
0answers
38 views

Reflection of light [duplicate]

Possible Duplicate: What is the difference between a white object and a mirror? When I look at a red object under white light, I see it as red because it absorbs the other colours and ...
3
votes
1answer
405 views

Bragg condition for transmission: Why is the full diffracted angle Two times Theta? Or isn't it?

On a Bragg reflection with incomming angle Theta the total diffraction angle of the incomming wave is 2*Theta, of course. But I have Bragg transmission with electrons on a graphite crystal ...
3
votes
5answers
10k views

Free Optics Simulation Programs

I'm having an extremely difficult time finding an optics program that is easy to use and offers accurate physics simulations. I'm not asking for much, I just want to be able to simulate a laser going ...
3
votes
2answers
287 views

Redirecting light beams from beam splitters

I'm doing a project where I am taking a laser beam and sending it through a beam splitter. As I understand, approximately 50% of the light will go pass through and 50% will be reflected. So this means ...
0
votes
2answers
5k views

Refraction, reflection, and what is total reflection?

So if light travels from one media to another with a different refraction index, what may happen happen? Refraction, reflection or total reflection? I am quite confused as to the differences between ...
6
votes
3answers
9k views

What is the color of a mirror?

A mirror couldn't be white, as then you wouldn't be able to see your reflection so clearly. It wouldn't be transparent, as that then won't reflect. So what color is it?
8
votes
3answers
3k views

Why does your reflection stay the same size when you move further away from the mirror?

This was an experiment I saw in my son's workbook. It said to mark out the top of your forehead and the bottom of your chin on a mirror using a whiteboard marker. Then slowly move backwards, and ...
1
vote
1answer
4k views

Why does your reflection suddenly turn upside down while slowly walking away from a curved mirror?

Many people should have realised, when looking into a concave curved mirror (or even a rather reflective spoon in that fact) at a close distance, you will see a slightly distorted reflection. But as ...
2
votes
2answers
212 views

How can one prove that the number of images formed by the reflecting surfaces of two plane mirrors at right angles to each other is 3?

How can one prove that the number of images formed by two plane mirrors at right angles to each other is 3? Is there a mathematical proof for the same ?
10
votes
4answers
3k views

What happens when a photon hits a mirror?

When a photon of light hits a mirror does the exact same photon of light bounce back or is it absorbed then one with the same properties emitted? If the same one is bounced back does it's velocity ...
2
votes
3answers
2k views

Reflection of Electromagnetic Waves

Visible light - Being an Electromagnetic wave is reflected by glass (take mirror). Would all other waves in the electromagnetic spectrum be reflected in the same way by our simple mirror... For highly ...
5
votes
1answer
1k views

What IS reflection?

How does quantum electrodynamics actually explain HOW reflection occurs on a microscopic scale? Note that Feynman's QED lecture series/book is not sufficient, as he only assumes that light DOES ...
2
votes
1answer
959 views

What are the properties of the partially polarized light on refraction?

When a ray of ordinary light is passed on the surface of the water the reflected light will be completely polarized( vibrations in one plane). My question is what will be plane of vibration in the ...
2
votes
2answers
992 views

Rotating mirror - Foucault's measurement of light speed

Some time ago I came across a secondary web source on measurement of light speed in water made by Foucault around 1850. I append its redrawn scheme below (light is reflected from the rotating mirror ...
5
votes
2answers
2k views

How do mirrors work?

Apparently, light is just a certain wavelength, or "the visible spectrum" of electromagnetic waves. If I recall correctly, my physics teacher explained to me that electromagnetic waves are basically ...
0
votes
2answers
394 views

How much of himself a person can see in the mirror? [closed]

A man who is $6$ ft tall is standing in front of a plane mirror that is $2$ ft in length. The mirror is placed lengthwise with its bottom edge $4$ ft above the floor on a wall that is $5$ ft ...
14
votes
4answers
11k views

Phase shift of 180 degrees on reflection from optically denser medium

Can anyone please provide an intuitive explanation of why phase shift of 180 degrees occurs in the Electric Field of a EM wave,when reflected from an optically denser medium? I tried searching for it ...
6
votes
2answers
4k views

Reflection of transverse and longitudinal waves

Why is it that when a transverse wave is reflected from a 'rigid' surface, it undergoes a phase change of $\pi$ radians, whereas when a longitudinal wave is reflected from a rigid surface, it does not ...
2
votes
1answer
259 views

Can Mirror box simulate long light travel?

Imagine that there is a cube box that has mirrors all 6 faces in . If we use a strong laser and enter in the box from a small hole on the box. The laser light travels in the box long time that we can ...
3
votes
2answers
439 views

At what angle does a single atom “reflect” a single photon?

Does this question make sense in the quantum world? Imagining a single photon (wave packet?) interacting with a single atom (its electrons etc) how do we currently describe/define the emitted photon ...
1
vote
0answers
188 views

How to derive a multi-reflection echo from a given single-reflection “trace”

Consider a one-dimensional semi-bounded "ray" (or thin "cylinder") of stratum (or just any homogeneous substance) which has several "features" along it's length (say, thin films). Consider a wave that ...
0
votes
2answers
932 views

Eliminating IR light reflection perceived by a steep viewing angle

I am having a problem with reflection on an acrylic surface, in the IR part of the spectrum. This reflection is interfering with an algorithm that looks at objects, as it makes two show up when only ...
1
vote
1answer
118 views

size and distance of mirror used in projected “smart” whiteboard

Apologies in advance for complete ignorance of optics (beyond conic sections) How is the size, distance, and angle of the mirror used here calculated? The mirror is I believe the open flap in front ...
13
votes
5answers
603 views

What longest time ever was achieved at holding light in a closed volume?

For what longest possible time it was possible to hold light in a closed volume with mirrored walls? I would be most interested for results with empty volume but results with solid-state volume may ...
44
votes
1answer
7k views

Why does a window become a mirror at night?

In day, when you look in the room through the window out, you can clearly see what happens outside. At night when it's dark outside but there's light inside you can look in the window but it becomes a ...
2
votes
3answers
667 views

Electromagnetic wave reflection vs. light reflection

Related: x-ray interaction with atmosphere I know that electromagnetic waves of particular frequencies reflect from the ionosphere. And the light (which from one perspective is an electromagnetic ...
0
votes
1answer
200 views

Reflectance of Round Moon vs Flat Moon

Treating the moon as an ideal, bright Lambertian reflector, I was trying to compare its efficiency as a light source to an equally-sized flat sheet of drywall. It's pretty straightforward to set the ...
0
votes
1answer
1k views

reflection, refraction and diffraction occur in radio waves, which one occurs the most?

One of the things about Radio waves is that they undergo different behaviors such as reflection, refraction and diffraction when in contact with obstacles such as walls, buildings etc. what i want to ...
13
votes
4answers
718 views

Is there a limit to the resolving power of a mirror telescope?

Like, if you hammered out the asteroid 16 Psyche into a 1 mm thick iron foil disc telescope mirror with 2.4x the radius of the Sun, could you resolve details on the surface of an exoplanet? At what ...
3
votes
2answers
786 views

What's it like in a sphere mirror? [duplicate]

Possible Duplicate: What happens to light in a perfect reflective sphere? I was working on my toy ray tracer when I pondered on this: Say we build a hollow sphere big enough to fit a ...
2
votes
2answers
2k views

How to calculate the temperature of a receiving point from concentrated solar power?

I'm exploring a DIY project about solar power and have found very few resources that can explain, in a not too simple but not too advanced way, how to go about calculating important values in solar ...
3
votes
2answers
258 views

Light and parabola

I know that parallel light beams hitting a parabola will be focused at the focus of the parabola (f = 1/4a) and a light source at the focus of the parabola will ...
2
votes
5answers
4k views

Reflection At Speed of Light

I have looked online to no avail. There is two competing answers and I am curious to know which one is right. Someone asked me this question. If you are traveling at the speed of light can you see ...
2
votes
0answers
150 views

Modeling a spray painted polyurethane surface reflection

I'm modeling light interaction/reflection from a fiberglass surface with polyurethane epoxy (that is very reflective) that has been spray painted with a matte black paint. I'm looking for some input ...
3
votes
2answers
969 views

How to make mirrors give more authentic image of myself

My friend bought two normal mirrors from some shop probably IKEA, looking like this one: My images are different from the two. One is a little fatter and shorter, and the other a little thinner and ...
5
votes
2answers
770 views

Distance of objects in car mirrors

We've all seen that label on our passenger side mirrors that says, "Objects in mirror are closer than they appear." Why is this? Further, why does it only apply to the passenger side mirror, and not ...
-6
votes
1answer
738 views

Light Energy Absorption In Mirror

Let the amount of energy in one pulse of (laser) light be $E$, and the wavelength be $\lambda$. This pulse goes straight to the mirror, and it is reflected by the mirror. Let the reflectivity of ...
6
votes
4answers
2k views

What happens to light in a perfect reflective sphere?

Let's say you have the ability to shine some light into a perfectly round sphere and the sphere's interior surface was perfectly smooth and reflective and there was no way for the light to escape. If ...
11
votes
6answers
3k views

How come an anti-reflective coating makes glass *more* transparent?

The book I'm reading about optics says that an anti-reflective film applied on glass* makes the glass more transparent, because the air→film and film→glass reflected waves (originated from a paraxial ...
5
votes
5answers
1k views

Why does light reflect more intensely when it hits a surface at a large angle?

I mean, what is happening at a microscopic level to cause this behavior? Here's what I got from Wikipedia: On Reflection (physics)#Reflection of light it says that "solving Maxwell's equations for a ...