Linked Questions

3
votes
1answer
724 views

Are virtual exchange particles real or just mathematical? [duplicate]

When an electron exchanges a virtual photon with another electron or proton, is the virtual photon a real particle or just a mathematical construct? In string theory, the force carrier particles of ...
1
vote
1answer
419 views

Do virtual particles pop in and out of existence in the space just outside the nucleus? [duplicate]

This question is similar to one asked if virtual electrons exist outside the nucleus, but please note, my question says virtual particles. It is not a duplicate. I read so often that matter is mostly ...
0
votes
2answers
202 views

Do the virtual particles have any mathematical meaning in vacuum in absense of real quanta? [duplicate]

I have edited this question with its title. Virtual particles, as I understand, arise as intermediaries in the calculations describing interactions such as scattering between real particles and in ...
204
votes
19answers
33k views

What exactly is a photon?

Consider the question, "What is a photon?". The answers say, "an elementary particle" and not much else. They don't actually answer the question. Moreover, the question is flagged as a duplicate of, "...
90
votes
8answers
28k views

What is $\Delta t$ in the time-energy uncertainty principle?

In non-relativistic QM, the $\Delta E$ in the time-energy uncertainty principle is the limiting standard deviation of the set of energy measurements of $n$ identically prepared systems as $n$ goes to ...
43
votes
5answers
4k views

Why do many people say that virtual particles do not conserve energy?

I've seen this claim made all over the Internet. It's on Wikipedia. It's in John Baez's FAQ on virtual particles, it's in many popular books. I've even seen it mentioned offhand in academic papers. ...
36
votes
4answers
6k views

Why have our eyes not evolved to see “gluons”? [closed]

The photons are the propagators for QED, and we rely on photons to see the world around us. The gluon is the propagator in QCD. Why have our eyes not evolved to see gluons (either on top of being ...
34
votes
7answers
1k views

Do Maxwell's equation describe a single photon or an infinite number of photons?

The paper Gloge, Marcuse 1969: Formal Quantum Theory of Light Rays starts with the sentence Maxwell's theory can be considered as the quantum theory of a single photon and geometrical optics as ...
19
votes
10answers
5k views

How does light behave within a black hole's event horizon?

If the event horizon of a black hole is the distance from the center from within which light cannot escape, imagine a person with a flashlight falls into the black hole. He points his flashlight in a ...
16
votes
2answers
47k views

What is the difference between an electric and a magnetic field? [closed]

This question is a consequence of another question of mine which is about spin. Here is my spin question. What is the difference between these two fields? How do they occur? Am I right if I say that ...
9
votes
5answers
3k views

How does gamma-gamma pair production really work?

See the Breit-Wheeler process, wherein two gamma photons are converted into an electron and a positron via a process that's the reverse of electron-positron annihilation. I do not doubt this process. ...
9
votes
4answers
2k views

Are virtual particles only a fictive tool in equations?

There is no "action at a distance" in nature. Attraction of a piece of iron by a magnet, attraction between distant electric charges of opposite sign, have to be mediated by something. The virtual ...
10
votes
4answers
2k views

Can virtual particles be 'boosted' into becoming real particles by fields other than gravity?

On the wikipedia page for Hawking Radiation it states: Physical insight into the process may be gained by imagining that particle-antiparticle radiation is emitted from just beyond the event ...
10
votes
5answers
997 views

If particles get mass from the Higgs field, why do we not see Brownian motion?

If an electron would otherwise be moving at the speed of light if it weren't constantly interacting with the Higgs Field, how is conservation of momentum preserved if it's constantly bouncing off of ...
10
votes
3answers
1k views

Why is the action dimensionless in natural units?

As I understand it, a natural system of units is one in which the numerical values of $c$ and $\hbar$ are unity, i.e. $c=\hbar =1$. What I find confusing is that they are still dimensionful, i.e. $[...

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