Virtual Definition and 545 Threads

What is the difference between real photons and virtual photons?

So De Sitter Space has a constant scalar curvature in the absence of energy or mass where positive curvature corresponds to a repulsive force and negative curvature corresponds to an attractive force. My question is could "virtual particles" be replaced by De Sitter and Anti-De Sitter spaces? I...

So as I was taught in Modern Physics virtual particles are allowed to exist in virtue of "borrowing" energy from the vacuum as long as it is "re-paid" in a short enough time to satisfy the Heisenberg Uncertainty Principle. However after doing further research this doesn't seem to be the whole...

I'm planning on doing my 4000-word extended essay for International Baccalaureate on virtual particles (theoretical and particle physics really interest me). I'm starting to get quite stressed, though, as summer is half over, and we were advised to have, at the least, our research done by...

Virtual particles or not only found spontaneously apearing in a vacuum, but also inside atoms via the strong force. My question is are these virtual particles always considered (as far as we know) the same, or do they come in documented/reasonably theorized variatys. Any other examples of...

Hello there, I have to do an essay for my university class, and want to use virtual particles (or virtual eletrons)... And i want to know if people here have good sources (good universities) about this issue. Thanks all

First time poster, more of a nerd than an academic. So virtual particles, can they pop into and out of existence inside the event horizon of a black hole? What about in the black hole itself? If nothing can escape and matter is torn apart, what happens to those quantum particles? Or maybe...

Homework Statement The diagram below shows rays come from object O are reflected by M1 and M2 in turn.Thus I2 can be seen by an eye. Homework Equations I am confused by I2,how does it form? My book said that I2 is the image of I1 However,I1 is a virtual image,no light rays reach I1...

I often hear or read of virtual particles appearing because they borrow energy from the vacuum fluctuations, but they "return" the energy back to the vacuum so that there are no imbalances. Wait a minute. Doesn't the insights of relativity tell us there is no such thing as just energy or mass...

images in a diverging lens are always virtual. when an objectis placed betweenthe focus and optical centre of a converging lens, the image is also virtual. what are the differences between these virtual images? explain by studying the 4 characteristics of each image. i have no idea of...

Homework Statement 33. This experiment projects a red laser light beam of wavelength λ through a diffraction grating labeled 750 lines/mm onto a screen that is positioned a distance l from the diffraction grating. The diffraction grating has a distance d between adjacent lines. The...

I am unsure about the virtual displacement and work definition even after looking through the definition and seeming to understand it. If we have ## \delta W = \displaystyle \sum_{i} \vec{F}_i \cdot \delta \vec{r}_i ##, I can use, ## \delta \vec{r}_i = \sum_{i} \frac{\partial...

Good morning. I am wondering what is the nature of virtual particle production beyond the event horizon of a black hole. When a particle-antiparticle pair is created from the vacuum, it takes time for them to attract electromagnetically and annihilate; but since the event horizon separates...

By looking at layman's books on physics I have picked up the idea that "virtual" particle-antiparticle pairs continually pop out of the vacuum and then back into it again. Apparently according to the Heisenberg Uncertainty Principle the time that the particle pair can exist, \Delta t, is...

Question about analytical mechanics. Suppose we have a system with N degrees of freedom, and hence N generalized coordinates {q_i}, \ i=1...N. A virtual displacement is defined as an infinitesimal change in a generalized coordinate without producing a change in the generalized velocities...

I have heard of the phenomenon of virtual particle-antiparticle pairs popping out of the vacuum and then back into it within a time \Delta t \approx \hbar / \Delta E. Do virtual photon-antiphoton pairs pop out of the vacuum in a similar way? I understand that antiphotons are the "same" as...

In class, our instructor talked about a pecularity of black holes. When virtual particles come into existence for an instant at the event horizon, sometimes one is trapped by the black hole, while the other is able to escape. My question is, what determines the rate at which particles are...

Layman here. Two questions on Virtual Particles. I am not trying to make some claim to spontaneous generation, just curious about how to expand the holes in my knowledge... which is about the level of a post grad engineer who likes to buy the popular physics books in stores to read. 1)...

I have seen an argument that the time-energy uncertainty relation allows heavy particles to exist for short periods of time as virtual particles: (ΔE Δt)>h Δt>h/ΔE However, shouldn't the inequality be the other way: Δt<h/ΔE to suggest that a heavy particle with large ΔE can exist...

(First off, I'm not sure that I'm asking this question in the right area, but there does seem to be other questions associated with the topic, so hopefully I'm ok, but if I'm wrong, apologies.) I understand that virtual particles are... virtual, a mathematical construct that is used to describe...

I have a few questions I thought I'd post together instead of making separate threads, hope that's ok. They are more or less unrelated... 1. Are there 2 conceptual ideas that use the term "virtual work"? I am familiar with the one from intro level physics, but I read there is also one from...

A recent story on Forbes.com reported on a new study about the effects of playing massively-multiplayer online games on one’s cognitive abilities. Conducted on a small sample group of 39 adults between the ages of 60 and 77, the study … Continue reading...

Hi, so we have just started doing some physics of fundamental particles etc at school. i am reading a lot about the exchange of 'virtual' photons etc. i am confused about whether these particles actually exist in a physical sense or whether they just have to be there to conserve...

Would it be fair to describe the Unruh effect by saying that from the perspective of an accelerated observer, some virtual particles in an inertial frame become real particles in the accelerated frame? Wald talks about how the appropriate transformations between inertial and accelerated...

Hello. On the "Ask an Astrophysicist" page on the NASA site, one can read the following: This raises three questions for a layman such as me: 1. Do the scientific community agrees with this answer? 2. Can the virtual gnomes break any rule and fulfill any wish as long as we don't detect...

Virtual image?? Nvm I got it. Thank you anyways virtual image is not the actual distance kk.

First I would like to apalogize if this is not right thread for my question, but I am not sure where to put it. If I understand it right, vacuum is actually full of virtual particles and antiparticles popping into existence and anihilating again and that always particle and antiparticle are...

I wasn't sure where to put this question, since it didn't seem to fit any category. However, because it brings up the topic of virtual particles, I'll ask here. From what I understand, virtual particles can travel faster than light, and it is virtual photons that are responsible for the...

All I ever hear about Feynman’s virtual particles is that they are created then destroy each other in a short period of time. I was wondering what else we know about these particles? How often is this occurring? How big are these particles? What if any affects do these particles have on...

http://img267.imageshack.us/img267/9636/qw5e64a2d1sda54.png Hi guys. i have a question that needs verification. Referring to the above diagram, Please determine the Moment, M (Nm) needed in order to hold the mechanism in equilibrium state as shown above by using "Method of Virtual...

I refer to the figure: Is it true that affixing the rope at the point A isn't the same of affixing it at the point B? (I consider the rotation movement around O since the disk is rolling, and so the radius of rotation is different in the two cases) I'm sorry because my english is not very...

I know that Hawking Radiation is caused by the separation of virtual particles on the event horizon of a black hole, but I do not understand why the antiparticle is always the particle from the pair that falls into the black hole. It seems to me that the gravitational effects of the black hole...

Is it possible to calculate the lifetime of a virtual particle? For example is an electron and a proton form a virtual neutron that is off shell by 0.8Mev how long will it last? Is this something we can calculate? At first I would think it would be short lived because of the 0.8MeV energy...

Im a grade 12 student and I just started reading black holes aint so black in the brief history of time. However, I'm having a hard time distinguishing a difference between these two particles. What is a difference? thanks!

I can see the answer being no for large particles, but what about strings? What stops them from expanding to make up the universe as we know it?

The problem statement is "each of the four uniform links has a mass m. determine the horizontal force P required to hold them in place in the vertical plane as shown." I attached the solution, but I don't get when a force causes a +/- virtual work.

On yahoo I asked if "since virtual particles cone to existence out of nothing. Is it possible that anything else ( discovered or not yet discovered in any universe) would be able to do the same, besides other virtual particles " And I got this answer Is it correct? "No. Virtual...

Using a simulated rapid-moving mirror, scientists provided evidence the existence of virtual photons by coaxing them out of a vacuum by means of the dynamical Casimir effect: http://www.world-science.net/othernews/111117_casimir.htm As a layman, I will reserve judgement until the experts...

Not sure if this is the right forum but hey ho.. I have been reading about Hawking radiation in Black Holes, whereby virtual particles are created at the event horizon and of the particle and anti particle pair 1 can escape before it is annihilated. Why are the particles which make up the...

I'm a bit confused about how the uncertainty principle allows for the spontaneous creation and annihilation of virtual particle pairs. I can understand that energy conservation can be violated for a very short time as per delta_e*delta_t > h_bar/2. However, when the virtual particle pair...

Forgive that to many here this will sound like a dumb question. I have searched and searched and failed to find an answer. Give the constant creation/annihilation of all forms of particles in ZPE, it seems likely to me that some among them would collide with each other before either had a...

It's my understanding that virtual photons are 'allowed' because their existence does not violate the uncertainty principle (the form using ΔE and ΔT). If this is the case though, how is the electromagnetic force transmitted over large distances?

Hello, Recently I have learned that magnetism causes the Lorentz force. The electric force makes sense to me in terms of virtual photons. But how do virtual photons give rise to magnetism and the Lorentz force. Is it because when the charged particle moves through an magnetic field it comes...

PROBLEM 1 Homework Statement The frame in the figure is supported by a hinge in A and a roller in G. It is loaded by a couple = 14 kN*m in B, a force = 12 kN in D and a distributed force = 4 kN/m on section EG. = 1.4 m. Calculate the normal force in C. Use the correct signs...

sorry, no specific homework question, although it is related to my homework in general. I don't understand what makes an image real or virtual. thanks for the help :) joe

I have been reading Classical Mechanics by goldstein for over 2 months. I have encountered the concept of Virtual Disolacement in that book. Some of my friends have told me that it means a very small desplacement that you cannot see.. However, I am not sure if it is right. Then what is the...

Why in telescopes and microscopes the ocular distance is such that it creates virtual images instead of real images?

Imagine I am sitting on a lead ion and fly happily through the LHC tube :approve:. Suddenly I feel an strong force pushing me sideways to the left. A physicist sitting in the lab frame tells me later, that I have been going through a dipole magnet yoke with field lines from top to bottom...

I am told that the space surrounding me is filled with virtual particles, popping into and out of existence. I could believe that they exist for such short times and at such low energies that sophisticated equipment is needed to detect them. However, a collision between even 1 virtual electron...

the virtual particles that are created are the result of a quantum fluctuation ..but the energy of this fluctuation must be zero so 1 particle has positive mass and the other has negative mass ...so that if they annihilate the mass is zero and they go back to not existing but if the one with...