The viscosity of a non-Newtonian fluid. can generally be affected by the application of. what is called a shear stress. Examples of. shear stresses are squeezing, stirring, agitat-. ing, or applying mechanical pressure to the. surface of a fluid.
A newborn senses all of these tastes except one: Experiments suggest that babies canât taste salt until they are about 4 months old (Beauchamp et al 1986). But newborns love sugar solutions--the sweeter, the better. In fact, when babies are given a sugar solution immediately before a painful procedure--like a heel prick--they cry less. Newborns also seem to like the taste of glutamate, which is found in breast milk (Beauchamp and Pearson 1991).
Also, if you try to feed your son solids before this age, you may notice that he pushes food out of his mouth just as quickly as you put it in. Babies start to lose this natural tongue-thrusting reflex at the 4- to 6-month mark, which makes it easier for them to start eating solid foods.