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).
By 4 months babies are able to grasp and hold large objects such as blocks, but they are still not able to grasp small things such as peas. Between 4 and 7 months, babies start picking up things and put them in their mouth.