>>13042600no it definitely exists at full scale. Since gravity is always pulling down on everything, strings want to fall into the smallest flattest shape they can. Basically its just a bunch of loops on top of each other. Well a knot is a loop through a loop, so a pile of string being moved around will naturally create the situate for knots to form.
Scientifically speaking: I don't know but theres probably a theorem out there describing the possibility of self intersection with a certain length of string or other flexible element. Basically the longer you have a string the more likely it will cross over itself when piled, every point where it does cross over itself just has to be pulled in the right direction to grab hold and make a knot. Its really simple probability and im 100% sure there are already papers about this out there
