The question hit me when I saw this question which I know two brilliant youtube answers for it. I already posted my answer, but it would be much nicer if I could embed and include the videos in my answer, so there would be no need to open another link to get the whole answer.
Looking around in the mother meta, I've found this post; and in an answer there is pointed that embedding videos has been enabled in some sites like music and scifi. Can we discuss the pros and cons of allowing videos on Physics SE, and make a decision about it?