How come ketchup comes out faster when you hit the 57 symbol on a Heinz ketchup bottle?”
Ketchup (catsup) is a material which displays a resistance to movement when it is still — it is thixotropic! Smacking it upsets the gel-like structure of the bulk structure. For convenience, let’s call them gel-bonds, they are not molecular or atomic bonds yet they relate to these aspects of the material in bulk. A sitting blob of uncured concrete, a bottle of ketchup, and a bucket of paint all exhibit thixotropy. Press, shake, stir, or otherwise stress them and they move! This is great for wet concrete, while being mixed it moves almost as water — very convenient, All we need to do is keep it moving until we get it into a form we want it to maintain for eternity (or until we recalculate those distances we were concerned about earlier), then we stop stressing it, so it pretty well stops moving, and starts curing. Paint is likewise helpful – in a bucket, it is pretty well gelatinous — dip a brush into it and stress it by pulling the brush along a wall and it deforms into a thin layer
