Photons in Radio Waves and Visible Light

This video shows single-photon interference with 2 slits and 2 paths having different lengths. Unfortunately, i contains a few errors, sorry about this. 1) The explanation in the video at 13:23 was based on speculation without any scientific proof. For a better explanation, please refer to the follow-up of this video, which can be found here: 2) Another flaw in the video is the conclusion about the 2-laser interference experiment (which I confusingly refer to as the 2-photon interference). Basically the average intensities should always add up, regardless whether there is visible interference or not between the 2 lasers. The fact that we don’t observe it is caused by the relatively large difference in frequency between the two lasers.