Imagine you are coming to the edge of a river, you just see a bunch of reed at the river side.

You think of the word that man is a thinking reed. A soft wind blows up your mind and also the reed. The flexibility of the stalk makes the reed collide with each other softly, with no intention but out of the nature of random.

So that is why I made this simple and rough model.
The following video shows the randomness in LED.
The schematic diagram is as follows.