In marketing, simultaneity is one of the characteristics of a service which differentiates it from a product. It refers to the idea that the production and consumption of a service occur simultaneously, making it impossible to produce and store a service prior to consumption.
Important ideas and inventions are often created 'simultaneously' by independent, contemporary individuals when 'the time is ripe'. (Note: a coincidence does not prove a relationship.) This phenomenon is referred to by the saying 'Great minds think alike' — though it is not limited to great minds. In modern times it has led to many patent squabbles and 'who was first' controversies. Some examples:
Simultaneous chess summary and related information.
Simultaneity is the property of two events happening at the same time in at least one reference frame. The noun Simult means a supernatural coincidence, two or more divinely inspired events that occur at or near the same period of time that are related to each other in both noticeable and unnoticeable characteristics [Latin simul, at the same time; see sem-1 in Indo-European Roots + English -taneous(as in instantaneous)].
In mathematics, a system of equations or a set of simultaneous equations share variables; a solution is a set of variable values for which all these equations are satisfied together.