Ketchup - a very popular sauce had so many fans because of its pleasant taste. But ketchup - it is also something more.
Ketchup is a Newtonian fluid: this fluid narrows or expands depending on the shear stress. Simply put, ketchup is almost frozen state when it is in the bottle. When you are shaking the bottle, then you put pressure on him, and ketchup jetted because the shear viscosity decreases.
But even with modern technologies and scientific advances is still a couple of things that we still do not know about ketchup. For example, why the liquid tapers? Because particle motion and move along the way becoming ordered layers? This is possible, but not proven. If this is true, then the same can be attributed to the expansion of the liquid - the layers are broken and the particles collide with each other.
Researchers from Cornell University, this explanation does not like. These experiments demonstrated that the number of layers is not changed so much that it could be explained by changes in the behavior of non-Newtonian fluids.