Linked Questions

76
votes
7answers
39k views

What is the relation between electromagnetic wave and photon?

At the end of this nice video (https://youtu.be/XiHVe8U5PhU?t=10m27s), she says that electromagnetic wave is a chain reaction of electric and magnetic fields creating each other so the chain of wave ...
33
votes
5answers
17k views

Amplitude of an electromagnetic wave containing a single photon

Given a light pulse in vacuum containing a single photon with an energy $E=h\nu$, what is the peak value of the electric / magnetic field?
33
votes
3answers
7k views

Do photons occupy space?

Total noob here. I realize that photons do not have a mass. However, they must somehow occupy space, as I've read that light waves can collide with one another. Do photons occupy space? and if so, ...
18
votes
7answers
3k views

Are coherent states of light 'classical' or 'quantum'?

Coherent states of light, defined as $$|\alpha\rangle=e^{-\frac{|\alpha|^2}{2}}\sum_{n=0}^\infty \frac{\alpha^n}{\sqrt{n!}}|n\rangle $$ for a given complex number $\alpha$ and where $|n\rangle$ is a ...
10
votes
3answers
7k views

Properties of the photon: Electric and Magnetic field components

Consider an electromagnetic wave of frequency $\nu$ interacting with a stationary charge placed at point $x$. My question concerns the consistency of two equally valid quantum-mechanical descriptions ...
9
votes
4answers
3k views

What exactly is meant by the wavelength of a photon?

I've been thinking about this for quite some time, and from looking online I haven't found a satisfying answer. Lots of photons, such as visible-light photons have very small wavelength (which from ...
5
votes
2answers
1k views

Relation between Wave equation of light and photon wave function?

Suppose in our double slit experimental setup with the usual notations $d,D$, we have a beam of light of known frequency $(\nu)$ and wavelength $(\lambda)$ - so we can describe it as $$ξ_0 = A\sin(kx-\...
4
votes
4answers
3k views

Radio waves and frequency of photon

How radio waves create the current in antenna in terms of photons? If it is Compton scattering then why is not changed the freuency of photons?
2
votes
1answer
6k views

Photons of a radio wave

It has been said that RF consists of IR photons (here; however opinions seem to differ): The smallest energy for photons is in the range of the infrared radiation. Longer wavelengths are related to ...
2
votes
3answers
2k views

Reconciling refraction with particle theory and wave theory

I have searched the web for good answers to why refraction occurs when light moves from one medium to another with different density. I have limited background in physics and want to know if there is ...
6
votes
3answers
1k views

How is the classical EM field modeled in quantum mechanics?

On the one hand, classical electromagnetism tells us that light is a propagating wave in the electromagnetic field, caused by accelerating charges. Then comes quantum mechanics and says that light ...
2
votes
5answers
2k views

Radio waves within an atom

What effect does the quantum world have on radio waves? For example, if I could shrink myself down and stand on the nucleus (or even smaller sub atomic particles making up the nucleus) with a device ...
3
votes
2answers
357 views

Electromagnetic waves and photons

In water waves, the wave is transmitted through vertically moving water particles which face no displacement nonetheless the wave is moving. So does the same happen with photons in electromagnetic ...
3
votes
1answer
716 views

What is the physical nature of electromagnetic waves?

I've been trying to work out what the physical nature of electromagnetic waves is, since I reasoned that given electromagnetic waves have wavelengths that are given in distance units, rather than ...
2
votes
3answers
156 views

Frequency Chirp, Instantaneous Frequency and Photons

I understand ideas coming from Optics, such as the concept of frequency chirp and instantaneous frequency, and their use in nonlinear optics. However, I am struggling in giving them an intuitive ...

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