While getting ready to cook some lentils recently, I noticed an interesting phenomenon. I had the dry lentils in a pot. I picked up the pot by its handle, tilted it slightly and then shook it gently to move the lentils around. I was looking for anything that might have been mixed with the lentils that I would rather not eat, usually bits of unidentified objects and an occasional tiny piece of rock.
Instead, I noticed that the shaking of the pot had forced the lentils into a peculiar configuration. There was an irregular band of lentils standing on their sides surrounded by mostly flat ones.
Here is a close-up of the "zone of sideways lentils".
I think what's going on is that when the lentils are pushed against each other they flip sideways and stack up against the denser pile in the lower end of the pot. If you look at the 1st picture carefully you will some other clusters of lentils turned sideways. There is probably some sort of lentil packing density optimization process (LPDOP) going on here. The densest packing may be achieved when there is a mixture of sideways and flat lentils.
Here is the finished product. The orange things are pieces of temperature-tested tomatoes from the backyard. It was good.