[greeniemax (OP)]

Hi JP great answer but there is a problem

Photo electric effect says that at time when Photon is if deep red color (almost infrared) it doesn't knock of any electron from metal. Problem is if light is photon and frequency of those photons gives it the frequency and if photon have 0 frequency, then it wouldn't matter they would still knock off electrons from material.

Secondly there is no mechanism described as to how this photon is produced, I could say that when I throw a stone in water it displaces some water depending on the size of the stone and this produces wave, there is no logical way it could be described that photon could be produced with the interaction of electron jumping from higher state to lower.

Should I consider that there is no mechanism at all that talks about this issue? Secondly please note that if photons are of 0 frequency than they wouldn't have color and would not be able to knock off or not knock off electrons based on color (as amplitude doesn't matter in this case).

Thanks man.

[Soul Surfer]

JP that is by far the best answer that I have ever received and I accept it as full answer because it is totally logical and fully fits with classical and quantum views.  The "zero" bandwidth definition also implies as with all other particles that all photons exist for all time throughout the whole universe it is only their "measurement" (by interacting with something else and creating a change) that defines their properties at that time.

To take things one step further.  Our universe clearly appears to have a time limit at the beginning although it may not have one at its end.  There is clearly at the moment a time bandwidth product for our universe (although because of inflation this may not be limited by the distance that light can travel since the big bang)  This implies that an absolute zero bandwidth cannot exist.  Now this is no problem for electromagnetic waves because they are on the whole quite high frequency but for gravitational waves this limit may prevent very slow things interactions happening in quite the same way because of the lower frequency limit.  I have never seen any thoughts by cosmologists in this direction

[greeniemax (OP)]

After reading what I have written I think I should re-explain.

If all photons are of 0 frequency and their frequency depends on distance between them as they are produced that means two photons are exactly same with no difference.

In which case it wouldn't make any difference what wavelength of light is used photoelectric effect will give same output at a particular amplitude of light. It wouldn't make any difference at different frequency as photoelectric effect was explained by Albert Einstein to give explanation of photon because it cannot be explained in classical way if we take light as wave.

So photons with 0 frequency isn't possible they have to have frequency to give it color otherwise its just like one crust of wave, there is no difference between a wave and particle theory of photon here.

Awaiting explanation of above.

[JP]

I'm not quite sure I follow, greeniemax.  There's no such thing as a zero-frequency photon, since it would have no energy and not exist. 

[greeniemax (OP)]

So as Cheese said before "Photon is packet of Waves", now I can imagine how wave could be produced from an atom, but if photon is a separate entity than it seriously doesn't make any logical sense how a particle is produced from any defined process.

I think I'll go through Optical Coherence and Quantum Optics, by L. Mandel and E. Wolf.

[JP]

No.  A photon isn't a packet of waves, but a packet of waves is made up of photons.  It doesn't make logical sense if you don't understand the logic of quantum mechanics, unfortunately, since quantum objects don't follow the rules of logic that dictate how everyday objects/waves behave. 

[Soul Surfer]

I have mixed feelings about that last statement JP.  I agree that the potential for a range of frequencies to be detected in a single given photon exists but to allow this a non linear detection process must be used.  If a linear detection process is used the photon observed is always the same frequency as the source that generated it.  If this was not the case spectroscopy would not be possible.  This tends to imply that a photon is a single frequency wave packet.

The time duration of the detection process therefore defines the bandwidth of the observation

[greeniemax (OP)]

You are right about that after studying QM for 5 years with different books (as I'm too old to go to college here), I find QM doesn't make logical sense from the day I started till today, read and heard lots of books, watched many lectures on iTuneU but seriously either my mind is not ready to accept it as logic or people just call it logic when its not at all.

Personally in my opinion logic should be something that make sense to you and has a well defined mechanics, I really couldn't find any answer for production of light on internet, it just simply isn't clear, its like coming half the way and it ends, its actually like watching half the movie so either you don't know what happened in start or how it ended.

Maybe we don't have complete information and just trying to come up with a picture that cannot be understood or we are on wrong path and trying to correct it with twitches from side.

Overall I'm totally confused, but thanks for your efforts to try to make me understand, specially JP and Cheese.