Tagged Questions
0
votes
1answer
40 views
Reflection of a polarised beam
The past days I've been trying to understand how AutoFocus(AF) works on photographic cameras. There is a statement that says AF systems are polarisation sensitive. This means that they can only work ...
4
votes
1answer
40 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 ...
0
votes
2answers
151 views
Light Ray Reflection from concave mirror
Suppose a ray of light hits a concave mirror and is parallel to principle axis but far away from it such that it doesn't follow paraxial ray approximation. Will it pass through focus or between focus ...
0
votes
1answer
55 views
Confusing mirror problem
A piece of thin spherical shell that has a radius of curvature of 106 cm is silvered on both sides. The concave side of the piece forms a real image 79.5 cm from the mirror. The piece is then turned ...
0
votes
1answer
34 views
Can the choice of reflection angle for light can be derived from a minimality condition?
When the light hits on a surface, it reflects with the "same" angle as the one that hits the surface. I was wondering if this choice of angle can be explained by a minimality condition?
0
votes
0answers
47 views
Trigonometry in the plane mirror [closed]
I was trying to solve a problem taken from an Physics Olympiad when I came across a curious and complex mathematical expression. I can not prove with what I know so far about mathematics, does could ...
3
votes
1answer
79 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
2answers
115 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 ...
2
votes
1answer
31 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 ...
0
votes
0answers
22 views
Why the mirror changes the sides [duplicate]
Why the mirror changes the left with the right side but not the top with the bottom? Go to the mirror and check this out.
0
votes
1answer
74 views
Seeing a mirage through mirror?
Okay, I am not really good in physics (rather terrible), but nonetheless.
So, I was just wondering if you can see a mirage, is there something special in our eyes that we can see it or what? I mean, ...
1
vote
2answers
74 views
All mirrors always shrink to 50% scale?
I have this geometric optics exercise here, in which a man is looking at himself in a mirror.
Determine the minimum height at which the bottom of the mirror must be placed so the man can see his ...
0
votes
1answer
62 views
Ratio of distance between mirror and person
In perspective of a given example, if a man was to stand $2\ m$ away from a mirror which was $0.9\ m$ in height and was able to see his full reflection, what would the height of the mirror have to be ...
1
vote
1answer
71 views
How does light get into a stable optical cavity in the first place?
It is supposedly possible to trap a beam of light bouncing back and fourth between two mirrors in a stable configuration. As I understand it, this means the configuration will prevent further spread ...
1
vote
1answer
50 views
How reflected objects are composed and who is responsible for that?
Please refer to this image. The scene contains an object close to a mirror in the wall and a window, note that the reflected object is receiving more light than the object itself.
I read some ...
0
votes
0answers
40 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 ...
0
votes
0answers
78 views
Reflection in Convex mirrors [closed]
A monkey starts chucking polished stainless bocce balls at you. The bocce balls are 6cm in radius. Where does your image form as a function of bocce balls distance and what is the size of your image ...
1
vote
1answer
44 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
2answers
2k 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
162 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 ...
6
votes
2answers
286 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 ...
2
votes
3answers
493 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
1answer
320 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 ...
0
votes
2answers
338 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
92 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 ...
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 ...
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 ...
10
votes
3answers
295 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 ...
1
vote
2answers
647 views
How to calculate the temperature of a receiving point from concentrated solar power?
I'm exploring a DIY project about solar power and found very little resources that can explain in a not too simple but not too advanced way how to go about calculating important values in solar power, ...
2
votes
0answers
118 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
357 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 ...
4
votes
2answers
464 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
464 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 ...
4
votes
2answers
744 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 ...
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 ...
5
votes
5answers
584 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 ...
1
vote
2answers
784 views
How do you calculate the intensity of light around the focal point from a focused collimated beam of light?
Problem/Purpose of me asking this question to you people who know more than me:
So I'm doing a science project where I'm collimating a beam of light to a focus point in a light medium (water vapor or ...
4
votes
1answer
309 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
3answers
426 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 ...
11
votes
1answer
873 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, ...
4
votes
3answers
1k 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 ...
