Difference between Instantaneously and Instantly

Instantaneously

Part of speech: adverb

Definition: Without any delay; in an instantaneous manner.

Instantly

Part of speech: adverb

Definition: At once; without delay.Urgently; with insistence.

Example sentence: You see something happen to a population whereby everyone adopts something that's just preposterous in a way that makes it normal instantly. If any one person prior to the rash of puka shells, for example, was seen wearing puka shells, he would look like an idiot. But when everyone is wearing them, it instantly makes them normal.