Tariq Zafar Khan
What is the reality of the universe?
Is reality multifaceted?
An acknowledgment regarding the nature of reality
An admission that reality cannot be grasped through scientific theories
A long-standing, lost quest
In the early years of the 20th century, modern scientific theories emerged. The astonishing reach of instruments—coupled with the capacity to measure the boundless expanses of the cosmos and the intricate, profound depths of atomic structure—enabled scientists of that era to observe the governance of two radically different natures within the vast universe and the incredibly minute atomic realm. These observations challenged existing scientific theories, mathematical equations, and calculations. This situation compelled scientists to engage in rigorous intellectual inquiry and sparked heated debates among eminent scientists, such as Einstein and Schrödinger, at scientific conferences.
This conflict compelled the scientific community to seek a unified theory capable of integrating the entire cosmos—from subatomic particles to the vastness of space—into a single whole, thereby providing a logical foundation for understanding the universe. This quest continues to this day. Surprisingly, the scientific endeavors resulting from this pursuit did not yield a single theory but rather five distinct ones—each accounting for a specific physical scenario and substantiated by a mathematical model. However, a system of mathematical connections links these theories into a unified framework known as "M-theory." Is this system itself the ultimate theory? No one knows.
No definitive observational evidence has yet been found for any single theory.
The story is not over yet!
In their recently published book *The Grand Design* (2010), authors Stephen Hawking and Leonard Mlodinow present a concept of the physical reality of the universe in light of known discoveries, observations, and mathematical models to date. The essence of this work was summarized in the October 2010 issue of *Scientific American* as follows:
Consider this modern scientific concept from 2010.
Mathematical models of the same physical situation can be constructed using different fundamental elements and concepts. It may well be that to understand the universe, we need to employ different theories for different physical situations—with each theory offering its own version of reality. This diversity is acceptable under the concept of "model-dependent realism"; no single version can be deemed more "real" than another. While this neither aligns with the traditional expectations of physicists regarding a single theory of nature nor reflects our everyday perception of reality, it is possible that the universe operates in precisely this manner.
This amounts to an admission of abandoning the concept of a "Theory of Unification"—a quest that began some 70 or 80 years ago. A new form of realism has been defined, termed "model-dependent realism."
Acknowledging the non-reality of apparent reality
Before discussing this admission, let us examine how modern science defines "apparent reality":
The October 2010 issue of *Scientific American* (page 70) outlines reality in three ways, as follows:
Objective Reality or Realism
Most people believe that objective reality exists and that our senses and our science directly transmit information regarding the material world.
Classical science is founded on the belief that an external world exists with definite characteristics that are independent of the observer's perception; in philosophy, this belief is known as realism.
Idealism or Anti-realism
One possibility is that the concept of reality depends on the mind of the person perceiving it. This perspective is known—with subtle distinctions—by terms such as anti-realism, idealism, and so forth.
According to these philosophies, the world we know is constructed by the human mind—using information (signals) received through the five senses as raw material—and is shaped by the interpretive structure of our brain. Accepting this perspective may be difficult, but understanding it is not. There is no way to separate the observer—that is, us—from our perception of the world.
Model-Based Reality
The direction in which science is heading is making it increasingly difficult to uphold the aforementioned views of reality. Science has discovered that all matter and light are composed of minuscule particles—such as electrons and photons—that cannot be directly observed and do not obey the physical laws known to us through Newtonian classical science. In this microscopic realm, particles possess neither a definite location nor a definite velocity; indeed, in many instances, they do not even possess an individual existence unless they are part of a collective whole.
Furthermore, modern science has transformed the very concept of the past. In classical scientific theory, the past exists as a sequence of distinct and definite events; however, according to modern science (specifically physics), the past—like the future—is indeterminate and constitutes a collection of potential events. Indeed, the universe does not possess a single, unique past or history. This implies that modern science (quantum physics) points to a reality distinct from that of classical science—even though classical science aligns with our intuition and continues to serve us in the construction of buildings and bridges.
These examples provide us with a crucial framework for interpreting modern science. We hold the view that there is no concept of reality independent of thought and theory; instead, we adopt a perspective we term "model-dependent realism." The underlying idea is that a physical theory—or a picture of the world—is a model (typically a mathematical one), and a set of rules connects its elements to observations. Under the definition of model-dependent realism, it is meaningless to ask whether the model itself is "real"; rather, the pertinent question is whether the model aligns with observations. If two different models are consistent with observations, neither can be considered more real than the other. - Any model can be utilized provided it is readily applicable to the situation under consideration.
Why did the need arise to formulate a new definition of reality? That is the question we face. The immediate and apparent reason is clear: each of the five string theories possesses its own mathematical proof, and ing them required such a definition of reality. Since mathematical proof is regarded as definitive, the definition of reality was altered to accommodate all five theories—despite the lack of observational or experimental validation—thereby moving away from the concept of a unified theory in favor of a multifaceted view of reality. However, in our view, this too is merely a provisional arrangement. If the "particle accelerator" in Geneva—which has been upgraded at immense cost—observes a reality in the near future that contradicts string theory, what will become of the definition of reality based on that model?
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