The Scientific Search for a Final Theory
At this point, I will turn from religious explanations to scientific explanations of the beginning of the universe. Most competent scientists agree on the account of the origin of the universe that modern cosmology provides. There seems to be plenty of evidence to suggest that our universe began to exist about 13.7 thousand million (an American, but not a British, billion!) years ago. From a microscopically minute region of stupendous heat and energy, without any consciousness, without any stars or planets, without even any subatomic particles, the material universe exploded into being. As it expanded and cooled, the first wave-particles—photons, neutrinos, and positrons—came into being. Over the next few hundred thousand years, atoms formed, condensed to form stars and galaxies, and, in the nuclear furnaces of the stars, forged the heavy elements like carbon that were to become the basis of life.
Many cosmologists, however, are unhappy at the thought that the universe begins from an initial "singularity"—a one-time event that precedes all the laws of physics and, thus, does not fall under any of them. Stephen Hawking has proposed that, in the very early universe, the dimension of time becomes more and more space-like, so that there is no need for a "first moment of time" to be explained. Edward Tryon suggested in 1973 that, since positive (rest mass and kinetic energy) and negative (gravitational) energies precisely balance one another, the universe may have come into being as a random quantum fluctuation from a zero-energy state. Thus, the universe might be a "free lunch," and we could get the ultimate human dream—something for nothing.
In quantum theory, particles flash into and out of existence, and the early universe is small enough to act in accordance with quantum laws. So, the whole universe may have quantum-fluctuated into existence and "frozen," at least for a while (a few billion years, it turns out), into a physically enduring material system.
Such theories aim to show how something could come from nothing, but do they really do so? Quantum theory consists of a very complex set of laws, and it does not seem sensible to say that the counterbalancing of positive and negative forces is equivalent to nothing at all. This zero-energy state is full of forces that balance each other exactly, and it is a very dynamic and constantly changing state.
It may look as though the universe has progressed from a very simple initial state to its present complex structure. But it is doubtful whether the initial state was simple at all. True, it did not consist of complex and integrated physical structures. There were not huge numbers of particles organized in intricate arrays. So, it was simple in physical structure and complexity. Even then, however, we now believe that the early universe contained dark matter and dark energy, so things were not as simple as they might have been!
Quantum theory utilizes an extremely complex set of laws, dimensions, possibility states, and fluctuating energy fields of various sorts. It involves Hilbert spaces, operators, commutators, symmetry groups, the Dirac equation and interaction potentials, Lagrangians and Hamiltonians, broken symmetries and associated particles. That does not seem very simple. Can it really be said that, at the big bang, there were just a few simple laws and particles? No, because there were no particles at all. And without particles, how or where were the laws supposed to exist? Perhaps they did not exist but just suddenly came into being out of nothing.
But if something can come into being out of nothing—and I mean really nothing, not some sophisticated balance of physical energies—it does not really matter whether it is complex or simple. It is not easier for a simple state to come into being than for a complex state to do so.
In fact, since there are infinitely more complex states than simple states, it seems more probable that a complex state would come into being, if probability has any sense here at all.
The idea that a simple state is more likely to come into being possibly arises from the physical principle of minimal effort—nature uses minimal effort to do what it does. But when nature does not even exist yet, that principle cannot exist either. If absolutely nothing exists—no states and no principles or laws—then it is impossible to say what might come into existence and whether it will be simple or complex.
This seems to imply that there could be no reason for the first state of the universe. And that is deeply unsatisfying for a physicist since a fundamental belief of physics is that there is a reason for everything. So, if there is no reason for the big bang, physics seems to have met its nemesis.
Some would just say, "So what? You can't hope to explain everything. And there just is no reason for the existence of the universe. Once you have explained how all its parts interact, there is nothing left to do." As Karl Popper wrote, "There can be no explanation which is not in need of a further explanation" (1972, 195). So there can be no such thing as a final or ultimate explanation.
But others feel that there has to be a reason for the big bang, or the whole basis of science—a belief that we can explain the universe—is undermined. So some cosmologists look for laws and energy states that precede or lie outside of the physical universe, that just have to be what they are, to which there is no alternative. Such laws, like the basic axioms of number theory, would just have to be what they are. Sooner or later, they will generate a universe, or perhaps many universes, of which this is just one. Einstein made this point by saying, "The enterprise of physics is . . . to reach as far as possible the utopian and seemingly arrogant aim of knowing why nature is thus and not otherwise . . . thereby one experiences, so to speak, that God himself could not have arranged these connections in any other way" (1929, 126).
Steven Weinberg, in Dreams of a Final Theory, writes, "[I]t is possible that there is only one logically isolated theory [a theory so rigid that "there is no way to modify it by a small amount without the theory leading to logical absurdities"] . . . that is consistent with the existence of intelligent beings" (1993, 191).
All attempts to provide an explanation for the big bang, however, seem to end by saying that underlying our present universe there is something beyond our space and time, something very mysterious— sets of quantum laws (and where are they supposed to be?) and complex energy states (and what is energy really?). We are almost back to the Babylonian primal deep.