All Questions
Tagged with optics electromagnetic-radiation
125
questions
34
votes
4
answers
21k
views
Explain reflection laws at the atomic level
The "equal angles" law of refection on a flat mirror is a macroscopic phenomenon. To put it in anthropomorphic terms, how do individual photons know the orientation of the mirror so as to bounce off ...
- 697
116
votes
6
answers
115k
views
Why is glass transparent?
Once I asked this question from my teacher and he replied "Because it passes light.". "And why does it pass light?" I asked and he said, "Because it is transparent.".
The same question again, Why ...
- 5,377
6
votes
2
answers
4k
views
Why one should follow Snell's law for shortest time?
whenever two media and two velocities are involved, one must follow Snell's law if one wants to take the shortest time.
Why snells law must be followed to travel diffrent media in shortest time?
...
user102917
13
votes
1
answer
26k
views
Why does the refractive index depend on wavelength? [duplicate]
Why do different wavelength get impeded more or less when in different materials? Moving with the same speed, but a longer physical distance would imply that the fields oscillate less times in the ...
user24082
311
votes
2
answers
30k
views
What is Chirped Pulse Amplification, and why is it important enough to warrant a Nobel Prize?
The 2018 Nobel Prize in Physics was awarded recently, with half going to Arthur Ashkin for his work on optical tweezers and half going to Gérard Mourou and Donna Strickland for developing a technique ...
- 134k
8
votes
2
answers
2k
views
Principle of Reflection on atomic level
This well-observed phenomenon has, besides several others, always been a fascination to me. We are well aware of several theories, experiments, and practical applications of this well-known phenomenon,...
- 5,481
156
votes
1
answer
15k
views
What is an "attosecond pulse", and what can you use it for?
The 2023 Nobel Prize in Physics was announced today, and it was awarded to Pierre Agostini, Ferenc Krausz and Anne L’Huillier, for
“experimental methods that generate attosecond pulses of light for ...
- 134k
21
votes
2
answers
74k
views
How does the grid on the microwave oven window prevent microwave radiation from coming out?
If I look through the microwave window I can see through, which means visible radiation can get out. We know also that there is a mesh on the microwave window which prevents microwave from coming out.
...
- 17.1k
17
votes
2
answers
3k
views
If light rays obey to the wave equation, why can they be thought as straight lines?
I'm a newbie with physics but I'm wondering how a ray of light can essentially be represented. I have always known that a ray of light proceeds in a straight line until it encounters another object (...
- 281
10
votes
5
answers
21k
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 ...
- 211
17
votes
5
answers
8k
views
What causes atoms to have their specific colors?
I understand that light (color) is part of the electromagnetic spectrum, and that it depends on what wavelengths are reflected/absorbed. Though what property of an individual atom gives it its color? ...
- 173
16
votes
5
answers
8k
views
Phase added on reflection at a beam splitter?
If we have light of a particular phase that is incident on a beam splitter, I assume the transmitted beam undergoes no phase change. But I thought that the reflected beam would undergo a phase change ...
9
votes
2
answers
51k
views
Why does the light travel slower in denser medium? [duplicate]
Wikipedia says that "in general, the refractive index of a glass increases with its density." And the refraction index of water vapor is less than ice, and even less than liquid water. Is there any ...
- 1,168
7
votes
3
answers
5k
views
How can I get the axes of the polarization ellipse from the Jones vector of the light?
I am analyzing the polarization state of a monochromatic, coherent light source, for which I know the Jones vector of the polarization,
$$
\mathbf E
=\begin{pmatrix}E_x\\E_y\end{pmatrix}
=\begin{...
- 134k
5
votes
2
answers
4k
views
Why is the atmosphere transparent in the visible spectrum?
One of the great 'coincidences' in physics is that the Sun happens to shine most brightly at exactly the wavelengths our eyes can see; it's an easy explanation that our eyes evolved to make the most ...
- 134k