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We know that in the photoelectric effect experiment, the particle nature of light was proved via photons. Again, we know that photon has energy $h\nu$ where $\nu$ stands for wavelength. After searching for a few posts in this wavelength, I came to know that the $\nu$ is actually the wavelength of light and not that of a photon,it is an elementary particle which the light is made up of. But since we are talking about the wavelength of light, do we mean that a wave is made up of particles? Also does that mean light has wave and particle property both simultaneously? If that's the case, is thinking light of infinite photons which are travelling in a way that looks like wave correct? Please enlighten me.

Roger V.
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madness
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    $\nu$ is frequency, not the wavelength. Photons are better thought of as light quanta than particles, since the letter term invites intuition base on classical particles (yet, of course photons are called particles in QFT). – Roger V. Jul 13 '22 at 10:16
  • No requirement for many or infinite photons to give photons wave properties. Even an individual photon has wave properties (color, frequency). You can think of an individual photon as a localized wave (contained a small space) that is travelling in the EM field ( the EM field is everywhere). Because the photon wave is small and localized it behaves like a particle or a quanta as Einstein said. – PhysicsDave Jul 13 '22 at 15:49

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is thinking light of infinite photons which are travelling in a way that looks like wave correct?

No, light is composed out of a calculable number of photons per volume, not infinite. The classical electromagnetic wave emerges as a quantum addition of those photons. The quantum wave function of the photon controls the probability of finding it at (x,y,z,t) and probability requires an accumulation of events .

The best way to understand this is this single photon at a time experiment that in accumulation displays the wave properties characterizing the classical em wave.

singlphotdblslit

Camera recording of photons from a double slit illuminated by very weak laser light. Left to right: single frame, superposition of 200, 1’000, and 500’000 frames.

So the random looking footprints of the photons in the first frame on the left, builds up the classical double slit interference pattern after a few million of dots.

anna v
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  • Thank you,i have a silly question. You mentioned that there are a finite number of photons per volume,but how does it mean that the total number of photons in that case is not infinite?What if the volume of light infinite?In that case even if photons per volume is finite,the total number of photons can surely be infinite,can't they? – madness Jul 13 '22 at 15:12
  • @madness if you have infinite energy to generate the electromagnetic light, yes, I means dV – anna v Jul 13 '22 at 16:50