2
votes
1answer
81 views

Linear vs. quadratic dispersion relation

In wave mechanics the dispersion relation between frequency $\omega$ and wave number $k$ is linear: $$\omega_n=c k_n$$ But in quantum mechanics, based on Schrödinger's equation, one can show that we ...
0
votes
1answer
53 views

Why can't de Broglie waves be electromagnetic in nature?

We know that the wavelength of de Broglie waves for a photon is same as that of the wavelength of the electromagnetic radiation that carries this photon. Doesn't this prove that matter waves are em ...
0
votes
2answers
57 views

How hot particles can get [duplicate]

One way in which an object is affected by temperature rise is that the wavelength of the radiation it emits is gets smaller and smaller. Another way of looking at it is that as an object gets hotter, ...
2
votes
2answers
76 views

Blackbody radiation through quantum mechanics perspective

While explaining black body radiation, the body is assumed as a cavity radiator and the radiations are due to the oscillating electrons. But we know that the electromagnetic radiation emitted is ...
1
vote
1answer
89 views

Blackbody and standing waves

I'm reading articles about black body radiation and why classical mechanics fails to explain it. My question is: Why do EM waves have to be standing wave in a cavity?
6
votes
3answers
643 views

How is temperature related to color?

I spent some time studying about temperatures and color of objects. It turns out that as we heat something it turns to red, then yellowish white and if we heat it more it turns to bluish-white. Like ...
1
vote
2answers
213 views

Interesting relationship between diffraction and Heisenberg's Uncertainty Principle?

I recently came across an interesting explanation of diffraction through an aperture which does not use Huygens' Construction but instead relies on Heisenberg's Uncertainty Principle: The ...
2
votes
1answer
67 views

Can a single photon induce current in a very small coil?

As I know from Lenz's law, I can induce current in a coil just by changing the magnetic field flux inside the coil. As I know from physics course, photons are electromagnetic waves (so they are the ...
2
votes
3answers
188 views

Do ionisation of atoms release photons?

I was reading through my text book about Fluorescence. It said "inside a fluorescent bulb, the mecury atoms collide with each other and with electrons get excited and ionised. During de-excitation, ...
6
votes
2answers
81 views

Energy in electromagnetic radiation

I learned that power intensity in EM (electromagnetic) radiation is $$ I=\frac12c\varepsilon_0E_0^2 $$ This equation implies that the energy in EM radiation is frequency-independent I also learned ...
0
votes
2answers
98 views

Is light electromagnetic waves or quantumn particle waves? [duplicate]

Is light electromagnetic waves or quantum physical particle waves. Or are they the same? Note: My question is specifically how electromagnetism plays into the quantum physics and the double slit ...
0
votes
1answer
75 views

black body radiation graph [duplicate]

I got really confused about the graph of the relationship between wavelength and intensity of black body radiation. What does the peak stand for? And what does the graph tell us?How can we analyze it? ...
1
vote
1answer
110 views

What really is reflection? [duplicate]

What really is reflection? Is it just the reemission of EMR? I asked my teacher, he said in quantum sense, it is true. But when I read something about emissivity in Stefan Boltzmann's equation, it ...
4
votes
2answers
135 views

Does the photon emitted by an electron falling to a lower energy level have a direction?

When an electron falls from an energy state to a lower one, electromagnetic radiation is emitted. Is this equally emitted in all directions (as a spherical wave) and can we only give it a direction ...
0
votes
1answer
665 views

Can electron exist as a standing wave inspite of successive superposition?

With the development of quantum mechanics, it was found that the orbiting electrons around a nucleus could not be fully described as particles, but needed to be explained by the wave-particle duality. ...
3
votes
2answers
248 views

If photons don't interact directly, how can electromagnetic waves interfere?

If photons don't interact directly, how can electromagnetic waves interfere? I know that photons can scatter via higher order mechanisms, but not directly. Does those mechanisms explain the classical ...
2
votes
3answers
195 views

What is the Bremsstrahlung or dipole radiation mechanism involved in the emission of radiation by the rotating or moving charge?

A rotating charge such as the electron classically orbiting around the nucleus, will constantly lose energy in form of electromagnetic radiation. I asked my teacher about how this radiation ...
2
votes
2answers
79 views

Are there any known, non-spectroscopic effects of EM directly on Light?

Photons have no charge. Light is a form of electromagnetic energy. All spectroscopic effects (to my knowledge) are due to changes in electron state, induced either through an interior or exterior EM ...
3
votes
2answers
152 views

When light is only considered as a particle, is it still considersed to be oscillating electic and magetic waves?

I have my head around wave-particle duality, however people tend to refer to light as either a wave or a particle in different situations. If I were to consider light as a particle am I still ...
0
votes
0answers
54 views

Has advanced radiation been detected experimentally?

I would like to know whether there has been an experimental detection of advanced radiation. I seem to recall reading about such an experiment but I can't find any reference to it on the interwebs so ...
1
vote
2answers
127 views

Why don't charges move transverse to an EM wave?

Image we have an ultra-high intensity, ultra low frequency laser, with wattage on the order of terawatts and a wavelength on the order of a lightsecond. We rotate it that the electric field component ...
-1
votes
3answers
136 views

Quantum mechanics: How do the atoms in an electronic circuit enter a smaller orbit on the filament of an incandescent light bulb?

Bear in mind that this is not a homework question, and I have put together some stuff to work on from below: http://www.doublexscience.org/how-fluorescent-lights-work-quantum-mechanics-in-the-home/ ...
1
vote
3answers
428 views

What is the energy of a standing EM wave? Is it probabilistic?

In a cavity, the standing wave will constructively interfere with itself, so its energy gets higher while the oscillator is still vibrating. Since the vibration time is not a constant value, and ...
3
votes
1answer
749 views

Decay of metastable state: spontaneous vs. stimulated emission.

I have a question about the upper laser level (the metastable level) in a 3-level laser system. I will call the ground level of the 3-level laser system by "g" and the metastable level by "m". The ...
3
votes
1answer
301 views

Why electron clouds in atoms don't radiate? [duplicate]

I was reading that Bohr assumed electrons in orbit simply did not radiate, and my professor told me that the actual case is that electrons are clouds of probability. Even so, aren't they still moving ...
2
votes
1answer
66 views

Radiation interactions: how is the transition from the “electric” regimen to “particle-like” regimen?

When we study the interaction of the electromagnetic radiation with free electrons we can find two different approaches in the literature: for low frequency (RF, light...) a classical view is used and ...
-2
votes
3answers
213 views

How “things” radiate electromagnetic radiation? [closed]

How things radiate electromagnetic radiation? I don't ask why they radiate (higher temperature than 0K) but how they radiate this electromagnetic waves?
0
votes
2answers
872 views

Why electrons can't radiate in their atoms' orbits?

It's an old-new question (I found only one similar question with unsatisfactory (for me) answer: Where did Schrödinger solve the radiating problem of Bohr's model?) It's strange for me how all books ...
-4
votes
2answers
253 views

Conceptual doubts in EM waves and old quantum theory [closed]

I have a few questions. I know that EM waves transfer energy. So when they are generated why do they form curves? Are energy packets moving in a curvy path, or energy packets (quanta) not considered ...
5
votes
1answer
206 views

Photons: Collection of Wave Packets that produce a plane wave

Is it possible mathematically for photons, which behave as individual Gaussian wave packets, to combine in such a way that the approximate result is a plane wave at one particular frequency (i.e., the ...
1
vote
1answer
218 views

Super High Frequency Electromagnetic Radiation - String Theory

I am a serious high school student with one year of physics class experience, so please point out if there are any flaws in my question or reasoning. Thanks! Gamma ray radiation possesses a ...
1
vote
0answers
27 views

Does quantum mechanics depend solely on electromagnetic waves? [duplicate]

I am beginning to learn quantum mechanics. Since determining the position of an object involves probing by electromagnetic waves and since i have read a simple derivation of Heisenberg's uncertainty ...
5
votes
1answer
697 views

Is the de Broglie wavelength of a photon equal to the EM wavelength of the radiation?

Is the de Broglie (matter) wavelength $\lambda=\frac{h}{p}$ of a photon equal to the electromagnetic wavelength of the radiation? I guess yes, but how come that photons have both a matter wave and an ...
2
votes
1answer
2k views

Where is the amplitude of electromagnetic waves in the equation of energy of e/m waves? [duplicate]

Does the amplitude of the photon oscillations always stay constant and if it is not - what are the physical differences between the photon with higher amplitude in comparison to the one with the less ...
2
votes
0answers
203 views

Analytical solution of two level system driving by a sinusoidal potential beyond rotating wave approximation

A quantum mechanical two-level system driving by a constant sinusoidal external potential is very useful in varies areas of physics. Although the wildly used rotating-wave approximation(RWA) is very ...
4
votes
4answers
367 views

Are photons deterministic?

I propose the following scenario: At $t=0$, a photon is emitted from a star. At $t=n$, said photon is received and interpreted by some detector. My question is whether or not it is accurate to say ...
19
votes
6answers
2k views

What are the various physical mechanisms for energy transfer to the photon during blackbody emission?

By conservation of energy, the solid is left in a lower energy state following emission of a photon. Clearly absorption and emission balance at thermal equilibrium, however, thermodynamic equilibrium ...
4
votes
1answer
566 views

Two photons transition

if an atom in its ground state is coupled to an electromagnetic field it can absorb a photon if the EM field contains one with the right frequency. These transitions depends on $⟨f|H_i|i⟩$ (from ...
20
votes
4answers
4k 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?
2
votes
0answers
218 views

How to calculate radiative transition rate of exciton in a quantum dot with specific dimension?

I am writing rate equations for a nanophotonic system including three quantum dots. I need to calculate that radiative transition rates of exciton in ground state in those quantum dots. In the paper ...
4
votes
1answer
165 views

Finding the energy levels of an electron in a plane perpendicular to a uniform magnetic field

Suppose we have an electron, mass $m$, charge $-e$, moving in a plane perpendicular to a uniform magnetic field $\vec{B}=(0,0,B)$. Let $\vec{x}=(x_1,x_2,0)$ be its position and $P_i,X_i$ be the ...
2
votes
0answers
663 views

What happens with photon when it is slowed down substantially?

In a dispersive media light's velocity can change substantially. Imagine we can slow it down to near 0 what the wave would look like? Frequency of light does not seem to change even at v=0 (at least ...
1
vote
2answers
282 views

Quantum Mechanics- Antenna emitting electromagnetic radiation

Radio signals are being transmitted in a frequency of $ 8.4 \times 10^9 s^{-1} $ and being received by an antenne that is capable of receiveing power of $ 4 \times 10^{-21} watt $ ($ 1 watt = 1 J ...
2
votes
2answers
543 views

What is the difference between Quantum teleportation and Radio waves?

Quantum teleportation over 143 kilometres using active feed- forward What is the difference between Quantum teleportation and radio waves?
5
votes
1answer
1k 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
votes
4answers
2k views

Bohr's model of an atom doesn't seem to have overcome the drawback of Rutherford's model

We, as high school students have been taught that-because Bohr's model of an atom assigns specific orbits for electrons-that it is better than Rutherford's model. But what Rutherford failed to explain ...
3
votes
2answers
686 views

Frequency and wavelength of photons

I try to better understand how electromagnetic radiation works. So I have some questions. If an antenna emits at 100MHz (the charges on the antenna oscillate at 100MHz) what frequency will have the ...
2
votes
1answer
931 views

A two-level system absorbs a detuned photon. Where does the extra energy go?

Let's consider simple two-level system with frequency gap of $\omega_0$ between ground and excited state. Now, when we turn on external electromagnetic field with frequency $\omega < \omega_0$, ...
3
votes
2answers
395 views

Is the electron wave function defined during photon emission

I have heard the term quantum leap to describe the (instantaneous?) transition from a higher energy orbital to a lower energy orbital. Yet, I understand that this transition time has now been ...
0
votes
3answers
259 views

Light Rays that are Perfectly Parallel

I just heard this simple reasoning in a documentary film: Light rays from distant stars are perfectly parallel. This is pretty interesting thought. In nature, it is hard to find something really ...