Photons Definition and 1000 Threads

I'm reading Adam Becker's QM book "What is Real?" At one point he says: "The single wave function shared by the two entangled photons guarantees that they will always behave in the same manner when encountering two polarizers with parallel axes. It does not specify what they will do. But merely...

Can the suns photons accelerate the plasma/solar wind away from the sun? or is there no interaction between them?

Is there a text, or set of texts, on how to predict what frequency of photon is released when a particular molecule is brought to an excited state and then relaxes? So for example if you were to put, say, benzene into an electrical tube and excite it what frequency would be released and more...

Homework Statement The laser cavity is formed by two mirrors separated by 15 cm. One of the mirrors has an ultra-high reflectivity and the output mirror has the much lower reflectivity of 99.5 %. How many photons are there in the cavity?[/B] The power of the laser is 1mW and the wavelength is...

Hi all, I'm trying to understand how to describe the quantum state of entangled photons, including their phase, if one of them encounters a double-slit. Here's a simple example: Suppose you have two polarization-entangled photons A and B in the following Bell state: \begin{equation}...

Homework Statement Suppose two polarization-entangled photons A and B in the following Bell state: \begin{equation} \Phi=\frac{1}{\sqrt{2}}\bigl(\left|H_{A},H_{B}\right\rangle + \left| V_{A},V_{B}\right\rangle\bigr) \end{equation} 1. What is the state if the photon A passes through a...

I'm not sure where this thread belongs; it is essentially a topic at the intersection between quantum optics, human physiology and even psychology, but I will focus more or less on the implications for quantum physics, so I just opted for this subforum. There is a recent article over Scientific...

I understand the concept of stimulated emission and how it works as light amplification, but a certain technicality in its process eludes me. How is the inciting photon actually interacting with the electron that falls to a lower energy level? In every physical interaction that I know of there...

1) are all particles/photons theoretically entangled at birth but we just never or will know? Or is it under specific conditions? 2) how much of the photons that the sun emits entangled particles/photons?

What is the mass of all photons emitted in the universe since the Big Bang?

If I have a beam of protons that go into a block of water, how can I know how many photons will be produced along the beam path?. I'm assuming all the photons have the same energy. I know that the energy deposition will follow a Bragg Curve, and I think that energy deposition is probably...

Hi, I have come across the word coupling a few times looking at surface plasmons and surface plasmon polaritons. I was wondering if anyone could give me a better understanding of what it means for something like a photon to couple to a plasmons to creating a plasmon polariton. From what I'm...

I was wondering what would happen if you shun light onto a super cooled area. Would it mean that the photon's energy would be absorbed and would not be re-emitted? Or put otherwise, can you cool an area to a point that it would absorb all light?

https://www.livescience.com/10288-kind-light-created-physics-breakthrough.html I was reading here that you can freeze photons. What does it mean to freeze up a photon, are you slowing down it's motion, changing it's energy levels. Or are you changing the state of the particles around it and...

Simple question. Are photons reflected as is from a surface like a mirror, or is the reflecting surface atoms capturing the photons and re-emitting them?

Homework Statement Homework Equations (1) E2 = p2c2 + m02c4 (2) E = γm0c2 (3) E = Eγ1 - Eγ2 (4) p = E / c (5) E = hf (6) λ = c / f The Attempt at a Solution a) Using eqn (1), rearranged p = (E - m0c2) / c , I obtained 2.9 MeV c-1. Not sure if I have the right answer here as I...

Ok guys, so let's suppose we have a mass of 1kg. We can calculate the energy that matter could deliver. E=mc², roughly 10^8c. Supposing this energy was delivered from a photon (supposing it exists such a processus that could delivery such energy in a single photon), we can calculate the...

Hello all, after thinking about properties of electromagnetic waves, especially concerning the electric field of them, I ran into some serious understanding problems: 1) photons are electromagnetic waves and vice versa and they convey electrical force. Let's now do a thought experiment: let's...

To summarize, my current understanding of how Heisenberg's uncertainty principal works suggests that there would be a contradiction (somewhere down the line) with any way that it applies to (or doesn't apply to) photons, due to the fact that they must always travel the speed of light. I...

Hi, I'm sorry if this question has already been answered somewhere and I'm just too incompetent to find it, buuut: As the title already says, I really do not get that part of quantum physics (if you can even say I'm getting ANY part at all...). As I searched all Google for an answer I just...

After I read Martin_K's post of 4:14 Oct. 30 on the frozen image of an object just before it fell through a black hole's event horizon, the next few minutes I was jumped by a handful of related ideas. First, the frozen image scenario is illustrative because when photons are frozen in place...

Hi, I know that entanglement is real and that it tells us something profound about the nature of quantum objects like electrons and photons. I can't explain to a family member how we know that two twin photons in the EPR experiment started off in a superposition. In other words, how do we know...

We know light made up of photons which is massless, but why it can absorbed by black hole? Is it becuz the Einstein's relativity about every object can curve time space

how do I calculate the energy of to photons moving in the opposite direction. starting from the same origin.

Something I've been thinking about lately. If so, how'd we detect high frequency gravitons? I have Bachelors in physics so you may get a little technical ;)

What happens to the UV photons that strike the photovoltaic cell but do not take part in the photo electric efect, do thay reflect? apparently the best comercial solar cells are only 24% eficiant.

The photons generated by a conventional quantum laser are all in the same quantum state. Doesn't that mean that they all have the same exact energy? Yet, because of energy-time uncertainty, the exact energy of any particle can never be measured. Also, the Copenhagen Interpretation says that...

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...

Homework Statement The possible (normalized) eigenstates of a photon in a given system are written as: $$|\psi_1>,|\psi_2>,...|\psi_m>$$ Let another state be $$|\phi> = \frac{|\psi_1>+|\psi_2>+...+|\psi_m>}{\sqrt{m}}$$ and denote: $$|n>=|\psi_1>|\psi_1>...|\psi_1>$$ which represent a state...

Homework Statement (Note: this is the last part of a longer problem, so I hope I won't miss anything important) We have a laser with 2 energy levels, so the emitted photons will have the energy ##\omega##. For this given energy there are ##m## states in which the photon can be, denoted...

So, I have a pretty basic (for this forum, not for me) question: how will two entangled photons behave in the opposite-configured Mach–Zehnder interferometer systems? One of the photon goes through the closed system while the other goes through the open one. Do they simply lose their...

Can anny body tell me how do I find the average number of photons in an atom at a given temprature for say lead.

I did look it up , but couldn't find anything that explains this in a simple manner.

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?

Assuming no conduction and no convection will a colder body be able to send photons to a hotter body while the hotter body is sending photons to t. We all know that an equilibrium will result with a temperature somewhere between the two bodies but do the photons emitted by the cooler body...

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...

In the last paragraph of these notes, https://ocw.mit.edu/courses/physics/8-04-quantum-physics-i-spring-2016/lecture-notes/MIT8_04S16_LecNotes3.pdf, it says how a state with large number of photons is not classical. Why is that? I thought quantum mechanics' laws were most applicable when we...

Can an on board laser be used to propel a solar sail spacecraft if the laser is pointed at the sails ? Would Newtons third law affect the laser and maybe prevent the ship from moving ? Thank you for answering my very ignorant questions. NineNinjas911

The photoelectric effect occurs when light causes electrons to fly off atoms. An equal number of electrons to protons gives an atom a net charge of 0. If I left a piece of metal in the sun for a long time, that would mean a large number of electrons would fly off. This should, in theory, give...

I'm looking to get into the realm of science fiction writing and am currently working out how the main "SciFi energy source" works in this world I'm trying to make. Fusion reactors are the obvious go-to, but I wanted to get creative, that said: how plausible/effective would it be to directly...

We all know that the photons have a wave-like motion,if the waves on the water form because of the motion of the particles inside the air(oxygen+nitrogen gas and %1 another gasses) so in the beginnig of this process,photons hit the air and make particles jiggle and that make air jiggle and air...

An issue arose in another thread about photons and gas in equilibrium. I made an effort to find an answer searching the internet, but my researching skills are not up to the task. The following is one example of the question for which I would like to learn how to calculate the answer. Given one...

Homework Statement Homework EquationsThe Attempt at a Solution No . The number of photons should decrease . As the rate of heat transfer decreases with time , the net electromagnetic radiation from the hot body to the surroundings decrease . Heat radiations are composed of photons ...

Homework Statement Homework EquationsThe Attempt at a Solution I am surely making some very silly mistake in this problem . Presuming linear momenta means magnitude of momentum , to me all four options look correct . a) since wavelengths are same , energy is same which means momentum is...

The way I understand this is that Relativity says space-time is like a field that's affected by the way mass moves through it. Photons are massless so is this why the speed of light is the same in all reference frames?

I mean there is this division between virtual (in static situations) and real photons as the quanta of the EM field, but aren't all photons essentially "virtual" in the sense that they are purely made up by us in order to explain why we see discrete impacts of specific energy for a given EM...

As far as I understand, two electric fields can interact with each other (for instance, two charges being brought close to each other will either repel or attract). A photon is an EM wave and when it comes in contact with a charged particle, say, an electron, the electric field of the wave...

In basic electrostatics any charged particle will produce an electric field at every point in space, and will have electric filed lines spreading out radially. E = kQ/r^2 The Standard model of particle physics says that the Photon is the force carrier for the Electromagnetic force, just like...

Hi all! Sorry for the bad english! Please, can someone help me understand the setup from "entanglement between photons that never coexisted "? So, we start with a bean from a laser, that hits a bbo crystal, makes two entangled photons (1 and 2), 1 gets measured (lets say its vertically...

What is the difference between the photon interaction mechanisms in emission due to absorption and reflection?