Cosmological Fantasies

The American philosopher Charles Sanders Pierce somewhere remarked that unfortunately universes are not as plentiful as blackberries. One of the most astonishing of recent trends in science is that many top physicists and cosmologists now defend the wild notion that not only are universes as common as blackberries, but even more common. Indeed, there may be an infinity of them. (Martin Gardber [1])

The seeds of the Many Worlds Interpretation (MWI) were sown in 1957 with the Ph.D. thesis of Hugh Everett III under the supervision of the celebrated physicist and cosmologist, John Wheeler, at Princeton. The objective was to do away with the Copenhagen Interpretation and the quantum measurement (observation) problem. If an event has more than one outcome (say tossing of a coin), all these various outcomes exist with their associated probabilities in the wave function which collapses when a measurement is taken and results in the outcome with the highest probability, according to the Copenhagen Interpretation. This interpretation was considered by many physicists unsatisfactory, shallow and superficial. To do away with the collapsing of the wave function at the instant of measurement, Everett suggested that all the various outcomes exist in various different worlds (universes), which are as real (or illusory) as our own. When a coin is tossed, our universe immediately splits into two ‘parallel universes’ in one of which the coin falls face up and in the other it falls tail up. By the same logic, Schrodinger’s notorious cat is dead in one universe and alive in the other. If there are more than two outcomes of a given event (coin falls sideways, for instance), the universe splits up into as many number of universes as the outcomes, accordingly. These universes contain not only the outcomes of the event, they also include a copy of you (doppelganger) and the associated equipment. Your copy is only nominally different from you. As a consequence, our universe is splitting up into infinite number of other universes and they are as real as our own. However, we can not communicate with the other universes. What can be more bizarre than this? This is not mere theoretical speculation (daydreaming), many distinguished physicists actually believe in it. If there ever was a pressing need for empirical verification, it is for such cosmological theories.

Can these theories be tested and empirically verified? Majority of the physicists agree that they can not be verified directly; however the proponents, mostly the theoreticians, believe some indirect verification will be possible in the future.

What is a parallel universe? It is a universe which splits from its parent universe and is exactly similar to it at its creation but may later evolve differently from the parent universe.

There are many puzzling questions about this concept. One of them, which came to my mind, is this: Our universe came into being some 14 billion years ago as a result of the big bang. Our universe is considered to be infinite in extent. The visible universe which is at least 14 billion light years large (because the light from its remotest extremity took 14 billion years to reach us) and is still expanding at a helter-skelter rate, is believed to be only a tiny part of the whole universe which includes the ‘invisible expanse’. How can another similar universe come into existence instantly with the toss of a coin? And that is not all. According to Jim Holt (2), “Physicists who buy into this interpretation (MWI) – and many distinguished ones do – claim that each universe splits into something like 10 to 100th (10^100, author) copies every second, all of them equally real. Yet, since quantum theory forbids these parallel worlds from interacting, there is no experimental way to confirm their reality.” How big is 10^100? It is 1 followed by 100 zeroes. So many universes come into being every second. Phew! This is not physics but metaphysics, pure and simple.

Another thing; I never felt so infinitely empowered before as this theory makes me because with the flip of a coin, I can split my universe and create another ‘parallel universe’. Physicists refuse to give this power to God; they don’t accept that God created our universe and others if there are any. Yet you can create as many as you like by flipping coins.

In one of my earlier papers, “Physical Theory and Empirical Verification,” on chowk.com (October 21, 2004), I had written, “As more and more diverse phenomena were related in the threads of mathematical theories, these theories became ever more sophisticated and complex. For this reason, they were getting farther and farther away from the comprehension of a common literate person. In order to be able to comprehend Maxwell’s theory of electromagnetism and Newton’s theory of gravity, for instance, disciplined education in a school and college is required for many years.” Theories of relativity and quantum mechanics are much more complex than the theories of gravitation and electromagnetism. Many professional physicists find it hard to think in terms of the four dimensional space-time what to say of ten or eleven dimensions of the string theories. The theoretical physicist and popular science writer, Paul Davies, confessed in his book, “The Matter Myth”, that even though he understood the mathematics of the theories of relativity, it was very hard for him to understand the inherent physical reality of the relativistic time and the space-time. He did not say if he understands it now. See note n.1 at the end of the article.

We are at a stage where we can construct sophisticated mathematical theories and successfully use them for making predictions but are unable to have realistic insights into the physical reality of the predicted events and phenomena. Considered in this perspective, the MWI may be a useful contrivance to do away with the Copenhagen Interpretation; its extension to the real parallel universes however appears to be intellectual ‘hogwash’. If however physical reality is just an illusion then any thing goes. According to Martin Gardner (3), “If all these countless billions of parallel universes are taken as no more than abstract mathematical entities – worlds that could have formed but didn’t – then the only ‘real’ world is the one we are in. In this interpretation of the MWI the theory becomes little more than a new and whimsical language for talking about QM (Quantum Mechanics). It has same mathematical formalism, makes the same predictions. This is how Hawking and many others who favor the MWI interpret it. They prefer it because they believe it is a language that simplifies QM talk, and also sidesteps many of its paradoxes.”

Commenting on the parallel universes, Fred Alan Wolf, a theoretical physicist and a popular science writer wrote (4), “In the old physics, this was nothing more than a technical problem. The electron had a single location – it had to be somewhere – and your job was just to find it. But in the new quantum physics, the electron has no definite position or, in other words, it has all possible positions simultaneously. But, in a self-consistent manner, each possibility must exist in a separate universe. When you find it, each of those possibilities manifests simultaneously. That’s right, all infinity of them. In each possibility or, if you grant me the license, universe, there will appear a single electron and a single viewpoint – your own….Yet, surprisingly nothing strange is going on. No splitting is felt. In fact, all the splitting occurs only in your brain.”

The idea of many worlds or multiple universes caught on. The new developments, e.g., the string theory and the initial inflation of our evolving universe led to the formulation of the concept of coming into being of the countless other universes. Our universe began from a tiny bubble which exploded with a big bang. It is theorized that countless similar bubbles explode every second as a consequence of quantum fluctuations in the preexisting space-time which is called the multiverse – a universe enveloping all the other universes. Billions of new universes are born every second. All these universes have their own universal laws with different values of the cosmic constants. Majority of these universes are incapable of supporting life as we know it – they are just out there. Our universe is ‘finely tuned’ in the sense that if its constants had slightly different numerical values, life wouldn’t have evolved here. This is called the anthropic principle.

Creation scientists use this principle to justify the existence of God who is responsible for creating our universe with divine intelligence with just the right values of the various constants. The physicists balk on this suggestion and assert that our universe is the result of a lucky accident. Among a myriad of the other universes, there is a probability for all the constants to have all kinds of values. Our universe happens to have just the right values for the evolution of life. All these other universes exist out there somewhere in the space-time but we don’t have the means to detect or communicate with them.

The original theory of inflation was developed by Alan Guth but soon after its publication he realized that there were still some loose ends in it which needed to be tied properly. A. Linde, along with several others, also found these weaknesses. Linde published his theory which he called the new theory of inflation. These theories, as it appeared later on and as happens every so often, had weaknesses of their own. Finally, Linde developed his theory of chaotic inflation. It has found favor with many distinguished physicists and cosmologists. For instance, Steven Weinberg (5) commented on it as follows: “Chaotic inflation opens up the possibility I mentioned earlier, of a new view of what happened before our Big Bang. If the scalar fields (see note n.2 at the end of the article) don’t evolve in lock step everywhere in the universe, the very far away there may have been other big bangs before our own, and there may be yet to come. Meanwhile the whole universe goes on expanding, so there is always plenty of room for more big bangs. Thus although our own Big Bang had a definite beginning about ten to fifteen billion years ago, the bubbling up of new big bangs may have been going on for ever in a universe that is infinitely old.”

Much of it is largely speculation; however this shows the direction in which the present thinking is pointing to. Speculation is an essential ingredient of theoretical research.

According to Wolf (8), “The main problem in quantum physics is its interpretation. How can we believe that there exists an infinite number of universes, one appearing every time anyone happens to observe something? And further, that these universes are not just possibilities, but possibilities that somehow conspire to produce the world we do experience.”

One thing that needs to be clarified here is that the concept of parallel universes has nothing to do with the multiplicity of the universes indicated by the chaotic inflation. The parallel universes were conjectured to resolve the undesirable issue of the collapse of the wave function which was at the foundation of the Copenhagen Interpretation. The multiple universes are the result of the big bangs occurring in the countless bubbles (like our universe) existing in the invisible universe. The former is a consequence of the present inadequacy of knowledge to satisfactorily explain the “measurement (observation)” problem and the latter is a speculation from the chaotic inflation theory. The inflation theory was formulated by Guth in the late 1970’s while the parallel universe hypothesis was given in 1957 as already mentioned.

Notes

n.1: Paul Davies (6) wrote in his book, “Today, I have grown used to dealing with the weird and wonderful world of relativity. The ideas of space warps, distortions in time and multiple universes have become everyday tools in the strange trade of the theoretical physicist. Yet in truth I have come to terms with these ideas more through the familiarity of repeated use than through the acquisition of an esoteric power of intuition. I believe that the reality exposed by modern physics is fundamentally alien to the human mind, and defies all power of direct visualization. The mental images conjured up by words such as “curved spaces” and “singularity” are at best grossly inadequate models that merely serve to fix a topic in our minds, rather than informing us of how the physical world really is.”

n.2: According to Steven Weinberg (7), the scalar fields “are made up of quantities that like the air temperature are purely numerical, in contrast to gravitational and magnetic fields, which like wind velocity point in a definite direction. Scalar fields do not tug at anything, so we are not normally conscious of them, but physicists think that they pervade the present universe. In the simplest version of the Standard Model of elementary particles, it is the action of scalar fields on electrons and quarks and other elementary particles that gives these particles their masses.”

References

1.Martin Gardner, “Are Universes Thicker Than Blackberries,” W.W. Norton and Company, New York, 2003, p. 3.
2.Jim Holt, “My So-Called Universe,” http://slate.msn.com/id/2087206, August 20, 2003.
3.Ref. 1, pp. 1-2.
4.Fred Alan Wolf, “Parallel Universes,” Simons and Schuster, New York, 1988, pp. 76-77.
5.Steven Weinberg, “Facing Up,” Harvard University Press, Cambridge, Massachusetts, 2001, p. 172.
6.Paul Davies, and John Gribbin, “The Matter Myth,” A Touchstone Book, Simons and Schuster, New York, 1992, pp. 109- 110.
7.Ref 5, pp. 167-168.
8.Ref. 4, p. 300.