The reflection tag has no wiki summary.
131
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14answers
41k views
A mirror flips left and right, but not up and down
Why is it that when you look in the mirror left and right directions appear flipped, but not the up and down?
34
votes
1answer
3k 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 ...
20
votes
6answers
2k views
What is the difference between a white object and a mirror?
I was taught that something which reflects all the colors of light is white. The function of a mirror is the same, it also reflects all light. What's the difference?
Update:
But what if the white ...
13
votes
4answers
453 views
Thought experiment regarding an object approaching a mirror
Here's a thought experiment I came up with in class today when my mind drifted (I however highly doubt I'm the first to think about this since it is pretty rudimentary) :
Let's say superman ...
11
votes
3answers
1k views
Why can't my eye see itself in the mirror through polarizing 3D-glasses?
I found a pair of polarizing "3D glasses" lying around, and tried to look at myself in the mirror while wearing them.
To my utter confusion, when closing the left eye and only looking through the ...
11
votes
1answer
877 views
Why does my watch act like a mirror under water?
I have a digital watch, rated to go underwater to $100 \rm m$. When it is underwater it can be read normally, up until you reach a certain angle, then suddenly, it becomes almost like a mirror, ...
10
votes
1answer
223 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 ...
10
votes
3answers
296 views
Is there a limit to the resolving power of a mirror telescope?
Like, if you flattened out Ceres to a 1 mm iron foil telescope mirror with 20x the surface area of the Sun, could you resolve details on the surface of an exoplanet? Could you make it arbitrarily ...
8
votes
4answers
408 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 ...
8
votes
6answers
1k 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 ...
7
votes
3answers
3k 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 ...
7
votes
2answers
2k views
How does reflection work?
In Newton's model of light as being composed of particles, it's easy to imagine reflection as being the rebounding of individual corpuscles off a surface. However, since light can also behave like a ...
6
votes
2answers
302 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 ...
5
votes
5answers
588 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 ...
5
votes
2answers
1k 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 ...
5
votes
1answer
446 views
Polarization and mirrors
When a light beam reaches a dielectric surface, the incident and reflected beams have different intensities depending on polarization. For the so-called Brewster's angle, the reflected light is ...
5
votes
1answer
108 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 ...
5
votes
1answer
153 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 ...
5
votes
1answer
42 views
Reflectivity of a glowing-hot metal surface
When a polished piece of metal (or steel in particular) is heated to incandescence, how do its reflective properties change?
Given a mirror-like surface, would the object temporarily cease to act ...
4
votes
3answers
2k views
How can I determine transmission/reflection coefficients for light?
When light rays reflect off a boundary between two materials with different indices of refraction, a lot of the sources I've seen (recently) don't discuss the relation between the amplitude (or ...
4
votes
5answers
810 views
Focusing Light with Flat Mirrors
What is the best way to focus (sun)light using flat mirrors? My goal is to start a fire. Cutting the mirrors is easy.
4
votes
2answers
917 views
What is the color of a mirror?
Ok, 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?
4
votes
2answers
472 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 ...
4
votes
1answer
313 views
Why can't I see far when I look in a mirror?
I'm myopic.
It's a fact.
I understand exactly how it works because Internet told me light rays encounter themeselves too soon in my eyes... that is why I can't see far objects even if I see near ...
4
votes
4answers
721 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 ...
4
votes
2answers
297 views
How long do reflections take?
How long does it take for a photon to be reflected? Starting with the photon being absorbed by some atom to the point it's reemitted?
And what's the same point with pressure waves, like sound?
4
votes
3answers
428 views
Virtual images in (plane) mirrors?
The following image is taken from teaching physics lecture Was man aus virtuellen Bildern lernen kann (in German):
Now the cited paper claims that the left hand side is the correct picture to ...
4
votes
2answers
751 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 ...
3
votes
2answers
358 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 ...
3
votes
1answer
360 views
Two mirrors facing each other
I have a question that I would like answered.
What happens when you place two mirrors facing each other? Is it possible to have an infinite amount of reflections?
3
votes
2answers
595 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 ...
3
votes
2answers
166 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 ...
3
votes
1answer
81 views
How to create visible reflections in shallow water?
Assumption: The only lights I have are candle, table lamp, and sunlight.
What would I need to create visible reflection of an object in the shallow water contained in a 5 liter bucket? Is it even ...
3
votes
1answer
376 views
The Interactions of Light and Matter
So basically, I was trying to find a good answer to the question of how light interacts matter. Namely on the quantum level what causes matter to appear transparent, reflective, opaque, etc
I came ...
3
votes
2answers
119 views
How does this trick with mirrors work?
Imagine two mirrors, set touching each other at right angles to one another. There is a 90 degree arc in which reflections can be seen, and a person standing in that arc can see himself reflected in ...
3
votes
1answer
376 views
How does the aluminium foil do the thermal and WiFi isolation?
Aluminium foil is widely used for thermal isolation. As far as I know it reflects the thermal infrared radiation. Also I've seen a lot of guides about strengthening WiFi signal by putting the ...
3
votes
1answer
191 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
2answers
326 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
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3answers
7k views
2
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2answers
136 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 ?
2
votes
4answers
187 views
Does light accelerate or slow down during reflection?
After all, it does change direction when reflection occurs. So shouldn't it also accelerate? And since the acceleration cannot increase the speed of light, mustn't it slow down?
2
votes
2answers
186 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
1answer
36 views
How much refraction occurs as a fraction of all reflection and refraction?
When light reaches a boundary between materials below the critical angle, some of it refracts and some of it reflects. For example, glass acts as a partial mirror with a dark background.
Assuming ...
2
votes
3answers
495 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 ...
2
votes
2answers
104 views
why does a mirror show what is in front of it?
the only answer I can think of is that light is reflected from the objects in front of the mirror (visible color) and then reflects again off of the mirror to our eye, but im not quite satified with ...
2
votes
1answer
286 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
335 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
1answer
354 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 ...
2
votes
3answers
451 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 ...
2
votes
2answers
529 views
What type of electromagnetic wave can pass through silver or aluminium standard mirror?
I have been told (not sure if it is true), that mirror (and glass) do not allow to pass the electromagnetic signals of mobile signals.
but for a standard mirror what type of wave can pass through ...
