# Tag Info

## New answers tagged reflection

0

This system is actually a little more complicated that I first thought because the path length to both eyes must be the same to "clone" the light source.

0

The first thing to note is that the angle of incidence and refraction are equal only for elastic collisions. In such a case, the kinetic energy and momentum of the ball-plane system will be conserved. The motion of the plane is a factor on how the ball moves. Let us assume here that the plane has a mass significantly greater than the ball. The angle of ...

5

The light from the observation point that hit the mirror and returned would be two years old by the time it returned to the observation point, but there is a very big problem with this set up. The mirror would have to be huge and curved to reflect enough light from the observation back again so that it could be seen. (Imagine tyring to brush your hair in a ...

2

Check the principle of relativity of Galileo (there are no absolute velocities, only relative ones). Both scenarios are the same and the only difference is how you choose to a stationary frame. One usually assumes that the surface/wall doesn't move at all, given the eventual very high mass (compared to the ball), to simplify the analysis.

0

Why do you say there is a phase shift at transmission into the first medium? You get a 180 degree shift at both the reflection on the front surface (air - coating) and on the second surface (coating - glass). You want these two reflections to be out of phase, so the round trip in the coating needs to be 180° also. That means total thickness of $\lambda / 4$ ...

-1

By inspection, R approaches 0 as $n_2$ approaches 1. This should make sense intuitively, as 1 is the refractive index of a vacuum, which would not reflect light at all.

0

That is interesting. At the very least, you should be able to tell the difference between the mirror and the world if you put your hand out to it - the mirror should be cold. Also you could blow on the mirror - it will either come back at your face (the atoms in each version of you's breath will bounce off each other) or show up as condensate, depending on ...

0

Without the phase change energy conservation would not be satisfied. To see why this is true you can think of a simple Michelson interferometer; without one of the fields having a phase flip you could get constructive (or destructive) interference at both sides of the beam splitter which would result in twice (or none of) the energy which you sent into the ...

0

It helps to realize that for the string, "hard boundary" means the displacement dy/dt=0, whereas for a soft boundary it means the force F=0. In the non-extreme cases, neither dy/dt nor F is zero. Their ratio will determine the phase. It's fairly clear that you can't have both F = 0 and dy/dt = 0 at one end, and there aren't any other relevant variables ...

1

For example aluminum, even though in the Thorlabs mirror it has been coated to prolong the life of the mirror, the base is the reflective aluminum. Check also Refractiveindex.info for reflectance of materials.

3

What you are seeing is stress in the window resulting in birefringence: the speed of propagation of polarized light depends on the direction of polarization. In the setup you have, the light in the sky is partially polarized because that's how Rayleigh scattering works; this partially polarized light is transmitted through the window where it rotates ...

1

Metals refractive index is always complex number (and not only for metals). Imagine part shows the extinction coefficient $k$ - absorption in a material. Real and imagine part isn't connected. P.S. For engineering calculations real part sometimes is less than 1. Theoretically even for Fresnel reflection in dielectric we must use full formula with complex ...

1

The problem with this question (although your question is still a natural one for those thinking about light to ask) is that it mixes the ideal and the real. You describe an ideal situation with your mirrors, but then ask for what would happen in real life. No actual mirror has reflection coefficient of 1 (which would represent 100% reflectivity) and so any ...

2

(This type of question has been asked by 4 users but in those questions they either gave an example of a wooden box or a room and they got answers that the light is absorbed by the wood or the walls of the room. But in my question its the case of mirrors.) In this case, the light would be absorbed by de "viewer". You would need some type of device ...

2

When your book says energy it should say radiant intensity. I didn't read Lambert's Photometria myself, but multiple sources say that this is how Lambert defined his law. A lambertian surface follows Lambert's cosine law, so for this surface we have: $$I_\theta=I_n \cos\theta$$ Radiance's definition can be written as: L=\frac{\partial I}{\partial ...

-2

Internal reflections from the facets of the object

0

The central idea is that you can translate probabilities from a single-particle picture into fractions of particles in a many-particle picture (assuming no interaction). Consider $T$ for a moment for a single particle. Let's just, for ease of writing, say $T=.9$. So if you send in a single particle from the far left, 90% of the probability density ...

1

If the bottle and liquid are made of dielectric material, then the interfaces between different mediums reflect light, they don't absorb it (i.e. dissipate it as heat in the glass). This is probably a good approximation for your bottle. As a first approximation, once you have worked out your incidence angles with Snell's laww, you need to use the Fresnel ...

0

Most likely what you are seeing is a thin film of oil floating on the surface of the water that comes either from natural underwater sources, runoff from the shore, or from ships. The oil breaks the surface tension of the water and reduces traction forces from the wind - thus ripple amplitudes are reduced or entirely diminished. This phenomena has been ...

0

I've also seen this, and wondered what it is! I thought they may have been some sort of surface currents as they looked like "rivers" to me. However, I've just done some searching and found this and this. So the answer is biogenic slicks, oily substances exuded by algae washed off from the shore! These don't dissolve well with water and form a thin film over ...

0

Thinking about it, maybe what selects the special direction is that the creases in the water that have wavefronts perpendicular to the line of sight cover each other up while the ones with wavefronts parallel to the line of sight don't. This may mean that as diffraction off small features causes the large features in the angle distribution (as it's a ...

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