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I request clarification The sun are stars radiates electromagnetic energy we experience as light. Is that the nature of the photon? Physicist refer to photons as if it was sometimes a particle.


marked as duplicate by ACuriousMind Oct 1 '17 at 11:02

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Light comes in the form of both. In some cases we can observe it acting as a particle and in some cases it can be observed to act like a wave. However light is actually in both forms at the same time. This is what is known as wave-particle duality and it is seen in all fundamental particles.

The first proof for light behaving as a wave came from Young's Double Slit experiment which was first performed by Thomas Young in $1801$. Light was passed through two slits and diffracted causing patterns that would only come from a wave passing through the slits.

Then in $1905$ Albert Einstein published a paper proving that light in some situations light also behaves like a particle. This is due to the photoelectric effect - where individual photons $($particles of light$)$ hit electrons which can then be detected. Due to the nature of how this worked it could only come from light behaving like a particle.

From this the idea that light is actually both a wave and a particle came around and due to the work of many physicists in the early $20^{th}$ century the concept of wave particle duality was formed.

  • $\begingroup$ I can see where you're going with this, but I can't say that I care for treating the two points of view as distinct categories which light can 'come' in. Light is never uniquely a classical wave or a classical particle and is always a quantum phenomena that can exhibit the properties of either depending on how you examine it. In every context where we talk about photons you could measure the wave properties of the light and in every context where we talk about electromagnetic wave you could measure the quantized properties of the field. $\endgroup$ – dmckee Sep 30 '17 at 17:13
  • $\begingroup$ @dmckee Yes I understand what you're getting at however I suppose this is how I was first taught this idea and certainly it seemed to me that the OP hadn't been taught these concepts so I decided to answer this to give the OP a somewhat basic understanding of the way light behaves in different situations. Perhaps I shall edit a few words to give an overall wave-particle feel as opposed to its current state of 'sometimes wave', 'sometimes particle'. $\endgroup$ – CooperCape Sep 30 '17 at 18:00

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