This video is actually not about photon size but about coherence length. In this video I discuss the behavior of electromagnetic radiation, especially the aspect of interference. The experiment shows that there is no such thing as individual photons in EM radiation. The photon only exists as an energy exchange between radiation and matter.

0:00 General Intro
0:47 What do others say?
1:21 About wavelength and size
2:10 Interference in light
3:08 Electromagnetic waves and detection
5:25 Things that make you go Hmmm...
7:36 New experiment and setup
10:23 Calculation of single photon level (boring)
11:59 Result of the new experiment
12:41 Discussion of the result
16:29 About "shot noise"
17:16 EM field strength and probability of detection
19:18 So how big is it then?
20:02 Deleted scene

At 3:08 the Electric and Magnetic field components have been swapped accidentally.

Thanks to David Nadlinger, I was able to put my finger on what was experimentally wrong with the original experiment . The scientific explanation is actually very mathematical and way more complex: https://en.wikipedia.org/wiki/Degree_.... And although scientifically not very accurate, I tried to present a more intuitive description, based more on the classical description of EM waves rather than trying to explain the second order coherence function.

More about shot noise: https://en.wikipedia.org/wiki/Shot_noise

The "deleted scene" contains a 4 second clip of the movie "Crash Pad" (For preview see:    • Crash Pad Trailer 1 (2017) | Moviecli...  ) It also contains a short audio clip of "New York City" by the Trammps (   • The Trammps - (The Night The Lights W...  ). I would also like to thank Vicky Pollard for explaining Quantization in more detail. These clips constitute copyrighted material, the use of which has not been specifically authorized by the copyright owner. The material serves as an educational and entertaining resource and only small portions of the original work are being used. This should constitute a 'fair use' of any such copyrighted material (referenced and provided for in section 107 of the US Copyright law).

If you wish to use any copyrighted material from this video for purposes of your own that go beyond 'fair use', you must obtain expressed permission from the copyright owner.17 U.S. Code § 107

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