Revelations of the nature of existence, through humans’ cognitive systems, have been evolving since the development of language. Part of such revelations, appearing early in the history of civilization, were geometrical forms and numbers, whose beauty and order, both wondrous and mysterious, conveyed a sense of unreality beyond the physical reality normally discerned; and to Plato, these were indications of the “other reality” of which only a few glimpses had occurred. Access to all the attributes of this reality required breaking out of the shackles of (mental) captivity; beautifully portrayed in Plato’s cave allegory. The present era’s sense of wonder about the effectiveness of mathematics in formulating the discoveries of the fundamental and natural laws of existence, on the one hand, and advances in computation, especially in artificial intelligence (AI), on the other have revived the Platonic idea, in one form or other. This revival is supported by some ardent adherents among the very minds who have contributed to furthering our understanding of the physical universe. The work presented here is an attempt to prove that a “physical world” precludes the prospects for “mathematics” to be its “other reality.” This end is achieved by bringing to light the processes involved in the perceptions and discernment of the world by humans and, for that matter, by any creature with a physical central nervous system. The process involved makes it clear that the phenomena of the “physical universe” are played out (one way or other) in our “physical brains” as electrochemical operations, which are (fundamentally) physics-based computations. Therefore, the historically configured “symbolic language of mathematics” is the physical brain’s “machine language” for the specific outputted expressions (formalisms) of the underlying physics of some of the (physically) sensed phenomena behind such computations. This rapidly developing language, much of it emerging in “appearances” foreign to the physical reality, has been taken by many great minds, including Plato, Galileo, Kant, and Wigner, as an indication of an incontrovertible mysterious mathematical world, or its language. However, it is inadvertently the “machine language” whose progress is owed to the successful efforts of the “computational brains” that are blazing the trail for discoveries of more novelties in the physics of the physical universe. The overall claim in this work is based on the ideas that (1) brains only sense the world physically and operate physically, and (2) mathematics has been known on occasion to be predictive of physics, and the latter of new frontiers in the former.