Propagating solutions to Maxwell’s equations in classical electromagnetism and real photons in quantum electrodynamics. A superset of thermal-radiation.

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How is a CCD able to collect images in drastically different lighting conditions?

I have read the basics of how a digital camera works. As much as I have understood, the digital cameras have a device called a CCD on which photons coming from the lens are incident. The CCD then ...
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Can radio waves be stored in a device for future use? [closed]

Is it possible to store electromagnetic waves consisting of radio waves only without any other intermittent signals??
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Why is the susceptibility $\chi(t)$ real?

So my question is quite simple I suppose, and perhaps trivial. It is known that the frequency domain susceptbility $\chi(\omega)$ is complex, and that the two parts can be related with the ...
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Effectiveness of Layered EM wave shields [closed]

Which is best at shielding EM waves; a Faraday cage with sides made of blocks of metal, or layers of metal (with insulation ie plastic & without), or is there no difference between the three? ...
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Electromagnetic Shielding of radio waves

Would a radio wave beam (perhaps a cm in diameter) with the same frequency as ordinary AM or FM radio waves and also the same voltage (v/m) have the same skin depth for any metal utilised to shield ...
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Are wave fronts in double-slit experiments moving forward? [closed]

I ask a question about "What is a wavefront?" which follows the question "What makes the radiation behind a slit coherent". For the wavefront it was answered, that "In electromagnetics ...(that are) ...
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Does the wavefront in the double slit experiment represent the electric field of the EM radiation / light?

The question "What is a wavefront?" get the answer "A wavefront is a contiguous region of constant phase". This seems to be right for water waves as well as for electromagnetic radiation. But what is ...
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What is fundamentally happening that causes light to change its orientation when repeatedly polarized? (edited)

When light is passed through two polarizers successively, its intensity and orientation afterwards depends on the angle between the polarizers and the orientation of the most recent polarizer, ...
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What is a wavefront?

For this picture Anna wrote: "Incandescent light is incoherent because it comes from many sources and the same is true for sunlight. By passing the light through the one slit he created a single ...
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Optical chirality and its possible hierarchy of generalizations

Optical chirality refers to a constant of motion of the electromagnetic field, which measures in some sense how chiral a light field is. Specifically, the pseudoscalar quantity $$ ...
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How do Optically Active Compounds Rotate Plane Polarized Light?

I am not sure if this is more of a Chemistry or a Physics question, but in my Organic Chem class we discussed that chiral molecules will rotate plane polarized light. However, my professor did not ...
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Can I emit light from an inductor? [duplicate]

As I understand it, inductors create a magnetic field when current flows through them, and light is an electromagnetic radiation. So, is it possible for an inductor to generate magnetic waves of the ...
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What makes the radiation behind slits coherent?

Have a look on the sketch To get such a intensity distribution of light behind a slit we presuppose that all the light that moves on the two lines is coherent; of the same wavelength AND the same ...
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Electromagnetic scattering $T$-matrix in MATLAB

My problem with the inverse of the matrix T (in the photo) , the matrix consists of Bessel and Henkel functions in high order (the orders from 1 to 21), then the elements of this matrix arrived to ...
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can we bend EM waves with any fundamental force except with gravity

can we bend EM waves with any fundamental force except with gravity....like a machine invented by nikola tesla actually,wat my question is there is a auto biography of nikola tesla....he says that ...
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Does waving a magnet around create light?

If I wave around a bar magnet, the magnetic field in the space around it changes. Is this enough to go through the whole speed of light derivation implying that the motion creates an electromagnetic ...
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Scattering electromagnetic waves [closed]

I have a question about "Rayleigh Scattering efficiency", can you give me equations that describe it?
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Electric field due to a current carrying loop

I want to know how I can calculate the radiated electric field in the far zone of the loop. Knowing that the loop is in center at the origin of a x-y plane Knowing that the loop as a time-harmonic ...
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Doesn't this LED created by MIT violate the second law of thermodynamics?

Here is the article I am referring to: http://www.wired.co.uk/news/archive/2012-03/09/230-percent-efficient-leds In their own words (or at least the article writer's), "it appears to draw in heat ...
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How useful would mass EM communication be in Space? [closed]

Considering a Science Fiction question, it occured to me that in "populated" space, with no atmosphere, you might expect to find more EM interference than on Earth. Basically, if you are outside of ...
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“Optically performed” Fourier Transform

This article says that they are only able to achieve such extremely high fiberoptic data rates because the multiplex light and then use a Fourier Transform to split it up again. But they say that ...
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Increase Phase Velocity by Losing Power

I just read some words from the book Optical Waveguide Theory by Snyder, Allan W., p226. It says that However, although it is possible for the phase velocity of a mode to exceed the maximum speed ...
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128 views

Can kinetic energy in atoms result in emission of all types of EM radiation?

I already know the fact that when solid objects heat up, they emit thermal energy which is also known as infrared radiation. However, if the atoms in that solid were to begin gaining more or less ...
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1answer
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EM Wave shielding of different frequencies

Is more aluminium required in Faraday cages to block AM or MW radio waves compared to FM frequencies (of equal power)? If yes, is this difference directly proportional to the decrease in frequency (FM ...
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Near Energy In the Null of a Hertzian Dipole

Since $\mathbf E = -∇Φ - ∂\mathbf A/∂t$ one expects an oscillating $\mathbf E$ field even in the null of a Hertzian Dipole unless the two right hand side terms cancel -- which they do in the far field ...
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Uniform Electric field cannot propagate a wave of finite wavelength? [closed]

While going through the proof of the transverse nature of electromagnetic waves using gauss' law for electricity, I encountered a statement that I couldn't comprehend. They used an argument that ...
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Why is there a longer time lag if light behaves as a wave?

In this problem: According to a model based on the electromagnetic theory of light, the electron absorbs all the energy that is incident on the surface within a distance of $5.0\times 10^{-11}\ ...
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Electro magnetic Wave? [duplicate]

I understand the fact that a static charge produces an electric field around it. I accept the fact(without questioning) that a moving charge produces a magnetic field. Question 1 : If a moving ...
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Can one see radioactive substances with an X-ray detector?

I was wondering the other day an X-ray detector (like the ones used at airports) can detect gamma-rays lets say from a sample of uranium. I know its all electro-magnetic waves but I'm really unsure ...
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Is an x-ray maser possible?

I was wondering if lasers evolved from masers. They applied the same principles to a different wavelength. Would it be possible to create a maser at a higher wavelength, using x-rays, gamma rays, ...
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1answer
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Huygens principle and wave propagation

I have seen the following illustration online and had a brief lecture about Huygens principle. As far as I understood, it suggests that every point in a wavelet acts like a point source to wavelets, ...
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Dispersion of light in metals and the plasma frequency

I've been reading about the dielectric function and plasma oscillations recently and I encountered the following dispersion relation for EM waves in metals or in plasma (Is it correct to treat those ...
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Is it possible to create a magnetic field camera that resolves magnetic fields to their source?

Is is possible to build a camera that is composed of an array of compasses that can resolve its magnetic field readings to sources outside of the sensor similar to the way an optic camera creates ...
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1answer
33 views

Name and unit for the amount of electromagnetic radiation

Is there a name or unit for the amount of electromagnetic radiation? By this, I mean the number of photons, or the number of photons emitted per second, of electromagnetic radiation. If you were to ...
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How in detail the rotation of the electric field component of light during transition through a polarizer takes place?

I ask "After a slit, are photons polarized?" and later found two answers for the question "Why does the electric field dominate in light?". From this two answers I have concluded or summarized, that ...
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131 views

Wavelength of electromagnetic waves [closed]

How can you determine experimentally the wave length of an electromagnetic wave having wave length in the visible range and that in the ultra violet range?
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1answer
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Qualitative difference between bremsstrahlung and thermal bremsstrahlung

Hopefully this is an easy question. I hear the terms bremsstrahlung and thermal bremsstrahlung being used. However, I, incorrectly, thought that they were used interchangeably. So, what is te ...
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How do EM waves propagate?

I have read about this and what I surmise is that when charged particles such as electrons accelerate they produce time-varying electric fields. These E-fields produce H-fields and the process goes ...
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Why do our eyes only pick up electromagnetic radiation which has been classified as visible light?

My understanding: Electromagnetic radiation is carried via photons - which enter our eyes and activate receptors depending on the amount of energy the photons have when hitting them. At what point do ...
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How to detect transient X-ray?

I have a Mercury UV lamp (ENF-260C/FE) which is supposed to emitte UV light with wavelength of 254nm and 365nm (http://www.chescientific.com/ecat/Eng/spectroline.pdf). However it is found that during ...
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Earnshaw Theorem for ionic solids

Is a single molecule of sodium chloride (say) or a cluster of molecules of NaCl unstable, although macroscopically NaCl is in fact, stable? How can I reason this based on Earnshaw's theorem?
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How do we know that these radio bursts are from billions of light-years away?

NASA just announced that they detected the first radio bursts from outside of our galaxy. Astronomers, including a team member from NASA's Jet Propulsion Laboratory in Pasadena, Calif., have ...
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What is the trajectory of a photon moving through a vacuum?

Since electromagnetic energy is carried by photons and moves in forms of waves, does it mean that a single photon when propagating through space doesn't follow the straight path but instead always ...
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What symmetry is associated with conservation of Lipkin's zilch?

The 'zilch' of an electromagnetic field is the tensor $$ Z^{\mu}_{\ \ \ \nu\rho}=^*\!\!F^{\mu\lambda}F_{\lambda\nu,\rho}-F^{\mu\lambda}\,{}^*\!F_{\lambda\nu,\rho} \tag1 $$ given in terms of the ...
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1answer
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Low frequency video transmission

Can a video signal be transmitted for a short distance ($30\,\mathrm{cm}$) by a very low frequency carrier ? Here my concern is about frequencies $1\,\mathrm{hz} - 100 \,\mathrm{hz}$ . Transmission ...
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What are the properties of the electromagnetic radiation from a magnetron?

There are different modes of EM radiation. A bulb emits photons in a wide range of wavelengths and without polarisation. Radio waves are polarized modulated radiation. What is about the radiation ...
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Threshold voltage for townsend avalanche effect [closed]

I have an assignment to estimate the minimal voltage required for an avalanche effect to occur. All data I am given is electron energy (10eV) and pressure of the ...