Subhash Kak - The Nature of Physical Reality

This book was written with two objectives in mind: to present a summary of the current scientific understanding of the physical world, and to show that man's questioning across the ages has had continuity in terms of preoccupation with paradoxes. Science makes it possible for us to see the unity that lies underneath seemingly unrelated phenomena. This unification does not always resolve difficulties related to interpretation and meaning. Each advance in science resolves paradoxes at one level, but only at the cost of new paradoxes that appear at other levels.

The word paradox comes from Latin paradoxum or Greek paradoxos , literally contrary to opinion, and it may mean a statement that appears self-contradictory. A Sanskrit cognate is paroka (antonym of pratyaka , clear to the eye) which has the meaning of being apparently contradictory but leading to a deeper understanding of the subject. There are many paradoxes at the levels of the individual self and the cosmos.

The gveda, perhaps man's earliest extant composition that is dated variously from 3000 to 1500 BC, articulates the problem of paradox and reality. According to it, rational science can describe the material world but not consciousness. The phenomenal world is characterized by duality but at a deeper transcendent level the universe has a unity. The paradoxes of the gveda concern time, space, agency and language. These paradoxes are to awaken the reader from a sense of certain knowledge so that he can obtain a deeper understanding of reality.

The Upaniads, which explain the philosophical problems of the gveda, claim that there are two kinds of knowledge: the lower, and the higher. The lower knowledge concerns material things whereas the higher knowledge is about the experiencing self. The Upaniads deal with the paradox that inert matter transformed into living form becomes capable of self-awareness and of free-will. They suggest that certain contradictions can only be resolved through intuition and not by reason. To point out the limitations of rational knowledge, the Kena Upaniad says: He who thinks he knows it not, knows it. He who thinks he knows it, knows it not. The true knowers think they can never know it, while the ignorant think they know it.

The atomic school of Kada points out the paradox of divisibility: If matter consists of atoms, each atom must be point-like because otherwise it would be further divisible. The enlargement of point-like atoms to gross matter with size is another paradox.

Zeno, in ancient Greece, argued that space is neither continuous nor discontinuous. If space is continuous, Achilles, the fleetest warrior, can never win a footrace against a tortoise who starts ahead. It will take him time to reduce the distance to half in which duration the tortoise would have moved further ahead and this will go on ad infinitum. If space is discontinuous, an arrow cannot move because it is either at one point or the next and there is nothing between.

The modern resolution of this paradox is that while space is continuous, Achilles overtakes the tortoise because the infinite series representing the time taken by him has a finite sum. But this raises the question: What is infinity? A hundred years ago, Cantor presented a set-theoretic approach to infinity in which points in a small line can be put into a one-to-one correspondence with the points in a longer line or in a solid. Some mathematicians reject the idea of Cantor's infinite sets, and believe that the only mental constructions permitted should be the ones that are intuitively reasonable. Thus the idea of a potential infinity is reasonable, but not that of an object with an infinite number of members as in Cantor's sets.

Aristotle discussed the liar paradox. Is the statement I am lying true or false? If the man is lying, he is speaking the truth, and if he is speaking the truth, he is lying. In the 1930s Gdel showed that for mathematical systems of sufficient complexity there exist propositions that can be neither proved nor disproved. This implies a denial of the law of excluded middle, which is a basic axiom of logic.

The cosmic edge riddle of the ancients was: What happens to the spear when it is hurled across the outer boundary of the universe? This riddle points to a difficulty in viewing the universe as a whole. One modern version of this riddle, when we consider the time boundary or the beginning of the universe, is: Are the laws of nature the same now as they were at the big bang? Another version: What existed before the big bang?

The paradox of consciousness is not addressed by any discipline of science. If natural laws govern the evolution of the universe, then the behavior of human beings should be completely pre-determined. But human beings do make choices. Is the person visualizing the universe a part in an endless loop?