All Questions
Tagged with speed-of-light visible-light
300
questions
5
votes
3
answers
2k
views
Is it possible to get an electromagnetic wave equation if the speed of light were infinite?
In an old question: How would night sky look like if the speed of light was infinite? the best answer was voted down to negative credits.
I cannot understand why. From Maxwell's equations, we derive ...
0
votes
1
answer
108
views
Can the velocity of an image produced by a plane mirror be greater than that of light?
We are currently studying ray optics in school and it made me wonder if the velocity of an image produced by a plane mirror can theoretically be greater than that of light.
Using the relation $v_i = 2 ...
0
votes
0
answers
32
views
What is the speed of light during reflection? [duplicate]
What is the speed of light in a vacuum when the light reflects off of a mirror?
3
votes
1
answer
109
views
How is it possible that photons already move at the speed of light the moment they pop into existence? [duplicate]
This is a thought experiment and I might be horribly wrong. If we have an electron-positron annihilation a photon pops into existence. This photon is then supposedly moving at speed of light at the ...
1
vote
1
answer
94
views
When light passes from one medium to another. Depending on the density, it would experience a change in velocity. Why would its vector change as well?
For example, when light passes through water its velocity decreases and refraction occurs. Why? Why is there a change in direction. If I slow down a car I don’t suddenly turn left.
0
votes
2
answers
134
views
Phase difference in Michelson Interferometer
I'm currently taking a quantum mechanics course in university and our professor introduced us to the Michelson Interferometer (or at least what I believe is an apparatus based on it), where a light ...
1
vote
0
answers
75
views
Why did Einstein include reflection of light from a moving mirror in his paper? [closed]
Einstein, in his 1905 relativity paper, allocates a section to the issue of reflection of light from a moving mirror and derives three formulas (angle, frequency, energy). What was his reason or ...
2
votes
1
answer
119
views
What is the speed of light in case of Critical Angle?
When light travels from an optically denser to a rarer medium, it bends away from the normal and at a specific angle of incidence, the angle of refraction is ${90}^{\circ}$. When the angle of ...
-2
votes
2
answers
80
views
Amateur Shower Thought Question About Time and Space
Apologize in advance if this is the wrong group. I often watch Netflix shows about blackholes explained in a nutshell or laymen’s terms.
I had a recent thought/scenario that may relate to some ...
4
votes
5
answers
488
views
Is the speed of causality slower in water?
I've recently read that what most people learned to think of as the 'speed of light' is actually the 'speed of causality', and that light just happens to travel at that speed (through free-space.) I'...
-1
votes
1
answer
122
views
Relativistic momentum for light
In special relativity,momentum $p$ is defined by $\gamma mv$ where $\gamma=\frac{1}{\sqrt{1-\frac{v^2}{c^2}}}$. Again,we are aware of the relation $E^2=(mc^2)^2+(pc)^2$. Now,the momentum of light is ...
0
votes
0
answers
45
views
Does Color change happen under a prism? [duplicate]
I was watching this video.
It Showed that light ( green ) changes its color to red after incidence of light. I couldn't think of how this happens because light's color is dependent on frequency rather ...
0
votes
2
answers
222
views
What's wrong with this One-Way Speed of Light experiment? [duplicate]
I can't tell what's wrong with it.
Imagine the wheels of a car, jack the car, put a sensor on one wheel, a laser on another, start rotating, with enough speed the sensor will start to detect the laser ...
0
votes
1
answer
22
views
How do i calculate change of momentum when I send a photon in the direction of travel
Say a spaceship is traveling at a certain velocity v (>>c) and it emits light from the nose of my spaceship in the direction of travel. The speed of light is finite and hence there should be a ...
0
votes
0
answers
24
views
Apparent violation of laws of reflection for an inertial observer [duplicate]
I am actually having an introductory course in Special Relativity in which I was looking at the Michelson Morley experiment. And I have this silly confusion.
The setup for the Michelson Morley ...