Photon Definition and 1000 Threads

Is a photon fully absorbed by a electron in metal? Ejected electron is a free electron or bonded one? Is it possible to have a zero work function? If not why? I want to study about this detaily ,can you prefer some reference papers?

Homework Statement Photons incident upon free electrons that are essen- tially at rest are scattered by the electrons. As a consequence, the electrons gain kinetic energy. How do the frequency and speed of the photons present after the scattering compare to those present before the scattering...

Homework Statement If X represents the intensity of monochromatic blue light and Y represents the energy of each photon of the light, which one is the correct graph below? Homework Equations KE=hƒ-∅, where ∅ is the work function Energy of a photon= hƒ The Attempt at a Solution Increasing the...

Hi I am surprised to know why only one photon in photoelectric effect ejects one electron only. What if a high energy photon (not necessarily x-ray or gamma ray, which may cause Compton effect or pair production)hits the metal, say it has energy double or triple of that of the work function? Why...

In order to calculate X and Gamma shielding of I should like use the NIST XCOM online at https://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html In the Xcom tool it is obtained a graph and table of scattering in cm2/g. In order to calculate as example the shielding from 1e19 gamma rays of...

The question is; In an experimental small universe, a photon is released from a source. It continues its path as a probabilistic wave function. if it interacted with mass, we could say the wave function collapsed and observe a particle photon hitting an object. But what happens when the photon...

Just saw this article from a highly respected research team, and thought some might enjoy seeing how the state of the art continues to develop rapidly: 12-photon entanglement and scalable scattershot boson sampling with optimal entangled-photon pairs from parametric down-conversion Han-Sen...

Homework Statement An electron moving to the left at 0.8c collides with an incoming photon moving to the right. After the collision, the electron is moving to the right at 0.6c and an outgoing photon moves to the left. What was the wavelength of the incoming photon? Homework Equations p=γmv...

Is it reasonable to assume that the energy of the electrons used to power a diode, equals the energy of the photons emitted from the diode? If so, why?

I have come across a questions which reads "Why does even photon travel?". After reading special and general theory of relativity, this one bugs me all over. For a particle moving closer to speed of light, clock slows down and the space around it contracts. I see a photon travel and I see things...

I’m trying to understand how a solid body changes the wavelength of radiation it re-radiates from that which it originally absorbed. I’m thinking in context to the way that the Earth absorbs higher frequency radiation from the sun, but when it re-emits the energy it’s at a much lower frequency...

Earth is moving through space. If I throw a ball straight up, it falls down to me and is not left behind. This is obviously because it already carries the momentum of Earth's movement. But if I fire a photon straight up, does it also carry a velocity component in direction of Earth's movement...

Homework Statement What is the speed of a photon with respect to another photon if: the two photons are going in the same direction. they are going in opposite direction? 2. The attempt at a solution I think the answer to the first question should be zero and to the second one be 2xC; C⇒speed...

Radio waves are usually not viewed as streams of photons but according to quantum mechanics that is exactly what they are. But what does the wavefunction of an RF photon look like? If we consider a dipole radiator, say of 10 Mhz, that emits a single photon, my guess is that the wavefunction of...

As far as I know, a object will experience time slower when its speed is close to the speed of light. But photons themselves moves at the speed of light, does that mean that they experience no time?

Is there a process that can artificially change the direction of photons?

Homework Statement Find the mass of photon in motion. Homework Equations E=hf p=hf/c The Attempt at a Solution I just started studying modern physics and am aware of the above two equations. However equating E to 1/2mv^2 gives a different (wrong) answer while equating p to mv gives the...

I read an internet meme: I was going to respond that photons are "massless" particles, but then I realized that photons have energy, and thus must have mass. What's the proper explanation here?

Hi, stuck on this question, hoping someone could help 1. Homework Statement Two identical photons of wavelength 4.22x16^-7m are created when a certain amount of matter M, is converted into energy, calculate the Mass (M) The Attempt at a Solution E= hf which is hc/wavelength E= 4.71x10^-19J...

I am thinking about a problem. Consider the forward Compton scattering process e(p)+γ(k) -> e(p)+γ(k), as shown in the following figure. If we consider the initial red photon is emitted by another electron which then goes to anything, then how can we write down the whole amplitude for this...

So I'm kind of confused. The way I understand it, an electromagnetic field is just a regular electric field viewed from a relativistic point of view, meaning that since we see the charges moving relative to us, we feel like the particles and the fields created by them come closer together (I...

It is said that if one shoots photons in a double slit experiment, and place a detectors around the slits to find which slit the photon went, one will not see the photon interfere. However, to detect a photon, one must absorb it. So how does the photon detectors work by detecting the photons and...

So I read a couple of explanations of how night-vision equipment works. Unfortunately I don't remember the sources but my recollection/understanding is that infrared light is converted into electrons and then into visible light. So my question is how does the information by which I mean (the...

If I have a box evacuated of air with 5 of the sides mirors and one side a heat conductor. will the photon gas inside have photons that get absorbed by the heat conductor and re-emitted when the photons strike the heat conductor

Hello, new here with lots of questions and minimal knowledge of physics. If I understand this correctly, when spontaneous emissions take place within a LASERs resonance chamber, they are not of the desired frequency nor are they paired with other coherent photons. So are they still desirable in...

I was watching this video ( ), and around the 1:52 mark the woman said that it is impossible to image molecules with visible light. By her demonstration, I took this to mean that we can't use visible light to image molecules because visible light is too large to be reflected by the molecule...

How wavelength of photon is measured experimentally?

Just read the FAQ post "Do photons have mass?" and I'm still confused. The post says that all of the photon's energy is in the pc term of the energy-momentum equation. (1) But isn't p equal to mv, implying there is mass? (2) The post also says there is no inconsistency with E=mc^2 but doesn't...

Homework Statement Compare and contrast a 2.2 eV photon with a 2.2 eV electron in terms of wavelength (m).[/B] Homework Equations p = h/λ λ = h/mv The Attempt at a Solution For photon: p = h/λ λ = h/p λ = (6.63 x10-34) / (1.17 x10-27kgm/s)** λ = 5.67 x10-7 m **I have already...

If it takes anywhere between 5,000 to a couple of hundred thousand years (various internet sources have various values) for photons generated in the sun’s core to reach its surface and radiate out, what is the estimated mass equivalence of all these photons making their way out from the core to...

Homework Statement Calculate the fraction of photons absorbed from an attenuated beam of 0.5 MeV photons after it has gone through 1.3 cm of lead? The linear attenuation coefficient of lead for 0.5 MeV photons is 0.5 cm-1. Why is lead a good choice as a material for shielding? Homework...

Homework Statement Calculate the momentum of a 140 eV photon. Homework Equations p = E/c The Attempt at a Solution [/B] First, convert eV to Joules 140eV (1.60 x10-19J) = 2.24 x10-17J Now for momentum: p = mv p = (E/c2)v p = E/c In my course, however, it says for photons E = hc/ λ...

What is a good simple metric for a single photon?

My understanding is that the amount of heat energy a parabolic reflective surface generates is not the volume of surface area of the mirror, but essentially the volume of surface exposed perpendicular to the suns rays. This effective surface can be also described as the area of shadow that is...

Homework Statement The total spin of an Mg atom is zero and remains zero after absorption or emission of a photon. To which states can one of the electrons in the outer shell get by absorption of a single photon: 4s, 5s, 3p, 4p, 3d, 4d?2. The attempt at a solution I am not sure which of the...

A photon acts like a wave and a particle. In the double slit experiment the photon seemingly interferes with itself which is troublesome to me. To help better understand this, I would rather think of the photon as a particle and the wave as something that is independent of the photon where the...

hi are the path lengths to the slits strictly equal? If the difference of the path lengths is progressively increased, how evolve the fringes visibility?

I was wondering if it would be feasible to set up something like the following experiment to validate the pilot wave theory. The idea here is to set up a double slit experiment, but control the initial conditions of photons emitted from a source (i.e., their directions) such that one can...

When a pair of photons is formed after annihilation, they have opposite directionality as cos2(θ). If one of them is detected, it collapses immediately, being absorbed by an atom. Does this mean that its peer has its directionality changed to a 'needle'-like pattern?

Per Wikipedia (Outer Space) referencing Davies, P. C. W. (1977), "...the mean free path of a photon in intergalactic space is about 10E23 km, or 10 billion light years." Per Lawrence Krauss (1999), it is longer than the size of the visible universe. What is the current thinking about this?

I am studying Quantum Cryptography and I am quite new in Quantum area. I have read an article and I found this confusing statement: My questions: 1. The three stage protocol implementing multiphoton. What is the meaning of coherent states of mean photon number? 2. How to describe the quantum...

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