Tagged Questions

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1answer
68 views

What properties make a good barrier for microwave (oven) radiation?

Suppose I have plenty of food I want to heat (which will provide load) in the microwave, and one item I don't want to heat. What properties would make a material a a good shield, to reduce or prevent ...
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0answers
42 views

EM-wave hits a brick-wall, $\pi/2$ -phase-shift? [duplicate]

Possible Duplicate: Phase shift of 180 degrees on reflection from optically denser medium If I have a cord-wave, I get a phase-shift with attached cord but do I get such a phase-shift with ...
2
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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
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1answer
287 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 ...
3
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2answers
596 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 ...
7
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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 ...
2
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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 ...
0
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1answer
140 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
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1answer
490 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 ...
3
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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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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
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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 ...
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1answer
473 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 ...
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2answers
752 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 ...
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2answers
791 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 ...
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1answer
447 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 ...
4
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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?
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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 ...
2
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3answers
1k views

UV reflective surfaces

Do surfaces that reflect visible light efficiently also reflect UV light? If not, are there surfaces that do? (I have a large array of UV LEDs that I need to make larger and more diffuse, so I'm ...
3
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1answer
377 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 ...
1
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1answer
996 views

Can you see yourself in a mirror when you are riding on top of a light stream?

What happens if you would ride on top of a light stream and you would look into a mirror that is in front of you, could you actually see your own face? I am asking this because I heard that nothing ...
1
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1answer
566 views

What determines how much light is reflected and refracted?

I'm currently working on a physics-based puzzle game with light refraction. I've read about the reflection/refraction incidence ratio, and how it's the proportion of the sine values of the angle of ...
2
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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 ...
4
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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 ...