Who am I to discuss such a profound question? Well, I am just expressing my surprise; I am not offering an answer. Besides, it would be just as surprising if there were Nothing rather than Something, wouldn't it? No energy, no matter, no space, no time, no laws of nature — Nothing!
Besides, I am not entirely convinced that the question even has a meaning. Could it be that the cause-effect relationship we seek is just a human construct and that there is no logical necessity for a cause?
Primitive cosmologies
Steady State vs. Big Bang
The classical Big Bang model
Cosmic Inflation
The Multiverse
The observer-friendly universe
Consciousness and other loose ends
Further viewing and readingMost cultures have developed a cosmology to explain how things got started. Not surprisingly, they tend to emphasize the superiority of the storyteller's own people and culture, and their special relationship with their god or gods. They are all highly anthropocentric: man is the purpose and culmination of creation.
Some primitive cosmologies seem quite bizarre, such as stories that a tortoise supports the world (or supports an elephant that supports the world), which recur on several continents. This may be the inspiration for this charming story:
An anthropologist visited a remote village. He explained how modern science had established that the earth orbits the sun, and that the sun orbits the center of the galaxy. Then he asked about the world model of the people he was visiting. An old woman told him: "The world is supported by a giant turtle, which prevents it from falling down." The anthropologist asked: "But what supports the turtle?" - "Very clever, young man! But it's turtles all the way."
Actually, it is only in the last few centuries that our world view has progressed substantially from that level. In the early 17th century Galilei was forced by the Church to renounce his view that the Earth orbits the sun. Later in that century Newton's theory of gravity explained the mechanics of the solar system. Well into the 19th century, many people believed that the world had literally been created in six days. (Some still do.) The distances to the closest stars were measured only in the mid-19th century, and less than a century has passed since the distance to our nearest neighboring galaxy became known (some 2.5 million lightyears).
It is noteworthy that modern science has demoted mankind from being the masters of the world, created in God's own image, to a zoological oddity on a small planet of one of some 1022 stars in the observable universe. If the Universe does have a purpose, it would perhaps seem more reasonable to see that as the rise of life and consciousness than specifically the evolution of man?
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Paul Gauguin's painting "D'où
venons nous, Que sommes nous, Où allons nous".
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When I grew up in the 1950s, a great debate was in progress about the origin of the universe. It was known that the universe is expanding. One school of thought, championed by British astronomer Fred Hoyle, held that the universe was eternal, that it had always existed, and that it was continuously being replenished with new matter to compensate for its expansion, so that it was in fact in a steady state. A competing theory, advocated by George Gamow, proposed that the universe had been created in a vast explosion (called "a big bang" by Hoyle) some 10 billion years ago and had been expanding ever since.
Initially, I rooted for a steady-state universe. Sudden creation out of Nothing in a gigantic "explosion" seemed less appealing. The Big Bang theory also seemed to lead to a bleak future: either expansion would stop and the universe would contract and collapse, or it would expand forever and progressively become a very cold and dark environment indeed, until the last subatomic event occurred in 10100 years or so. But gradually I became less convinced that an eternal universe was any more satisfying as an answer to the question "Why Something?" than a universe with a definite beginning.
The matter was settled in the 1960s, when two key predictions of the Big Bang theory were borne out: The abundance of light elements (hydrogen and helium) was in accordance with the model, and the background microwave radiation created by the Big Bang was detected (by accident). Besides, the expansion of the universe was more naturally explained by the Big Bang theory than by the Steady State theory. There were attempts to "save" the Steady-State theory. As usual, the leading proponents of a theory losing support did not switch sides; what happened was that the next generation of scientists tended to join the "band wagon".
In the late 1960s and early 1970s, great strides were made in astronomy and high energy physics. Singularities and black holes were found to be real and became mainstream areas of research. (It is expected that a theory of quantum gravity yet to be developed will remove singularities in the sense of "division by zero".) Quasars were shown to be cosmologically distant objects receding at substantial fractions of the speed of light. (The record is now about 96 percent of the speed of light.) In laboratories on Earth literally hundreds of new particles were being discovered in accordance with predictions by theorists such as Steven Weinberg, who won the Nobel prize for unifying two of the four known forces in nature, i.e. the "weak" and the electromagnetic forces.
In 1977, Weinberg published The First Three Minutes which opened the eyes of many of us laymen to the progress that had been made in understanding how the Universe was formed. For the first time a credible scenario was offered for the history of our universe from as early as 10-43 seconds after the instant of creation up to the present time (some 13.7 billion years later). It also discussed the probable fate of the universe: either an end to expansion and a collapse into an inverted "big bang" (the "big crunch") or eternal expansion.
The scenario offered in The First Three Minutes was roughly this:
When the universe was 10-43 seconds old, its temperature was about 1032 K and the four forces (Gravity, the Strong force, the Weak force and Electromagnetism) were unified, but just 0.01 seconds later, the temperature had dropped to 1011 K, and the four forces had separated. "The universe is simpler and easier to describe than it ever will be again. It is filled with an undifferentiated soup of matter and radiation, each particle of which collides very rapidly with the other particles." The only particles present in large numbers were photons, electrons, neutrinos and their corresponding antiparticles. Complex nuclei were destroyed as fast as they formed. He then gives an additional five "snapshots" explaining how particles were formed and interacted during the first 3 minutes. ("It sounded better than The First Three and Three-quarter Minutes.") Atomic nuclei began to form at the end of this period. After another 700,000 years (the present estimate is ~ 370,000 years), the universe had been cleared of free electrons and become transparent to light. Atom formation (mostly hydrogen and helium) had been completed. From now on, gravity began to dominate, ultimately causing atoms and molecules to form galaxies and stars. All the heavy elements were created in the interior of the stars.
Weinberg then goes back to speculate about events during the first one hundredth of a second, when there was an abundance of exotic particles known from high energy physics. Calculations become difficult because of the dominant role of the Strong force at high temperatures. Hundreds of hadron varieties, made up of "quarks", would have been present. Also, according to theory, phase transitions would take place at 1015 K, triggered by a loss of symmetry between the weak and the electromagnetic interactions. As we move further back in time, gravity becomes increasingly important. Gravitational waves may create particles out of empty space, although the very term "particle" may not yet have had any meaning. "We do not know enough about the quantum nature of gravitation even to speculate intelligently about the history of the universe before this time."
He then goes on to offer some thoughts on the instant of creation itself:
"One possibility is that there never really was a state of infinite density. The present expansion of the universe may have begun at the end of a previous age of contraction, when the density of the universe had reached some very high but finite value. — However, although we do not know that it is true, it is at least logically possible that there was a beginning, and that time itself has no meaning before that moment."
Although a third of a century has passed since Weinberg's book was published, it is still considered an accurate account of the evolution of the universe from about 10-32 seconds. The main advances since then have been inflation theory and the development of string theory, and the discovery of Dark Matter and Dark Energy.
The temperature of the cosmic microwave background, measured by two satellites launched in 1989 and 2001, is isotropic to within ± 0.0002 K.
In his book, Weinberg pointed out one difficulty in particular with the Big Bang theory: the great homogeneity and isotropy of the Universe, which remained unexplained. Throughout the observable universe, conditions are remarkably similar: there are galaxies everywhere we look, with similar properties. The background microwave radiation from the Big Bang is homogeneous to better than one part in ten thousand. According to theory, there would simply not have been enough time to even out the inhomogeneities caused by quantum fluctuations before the different parts of the universe had already been separated beyond the event horizon defined by the speed of light.
Sometime in the early 1980s, I came across an article on cosmology in Scientific American, written by Andrei Linde, a Russian professor who was unknown to me. It made a deep impression on me for a number of reasons. First, it introduced me to the idea of cosmic inflation, i. e. that there had been a brief instant in time (~ 10-32 sec) when the Universe expanded by an incredibly large factor (at least 1050). Cosmic inflation had recently been proposed by Alan Guth, and Andrei Linde had refined the idea. It solved the problem of the Universe's homogeneity and isotropy and flatness. By reducing the size of the Universe in its earliest moments, there would have been sufficient time to even out quantum fluctuations before they passed beyond the event horizon. But the old problem was replaced with a new one: What had caused the universe to inflate? Unfortunately, the explanation was beyond my understanding.
Even if I could not understand the physics and the mathematics (although this Linde presentation gives me a cozy feeling), the article was inspiring at another level. Just coming across sentences such as "At this time the diameter of the Universe was 1 meter" was thrilling to me. I naively tried to imagine our Milky Way the size where I could hold it in my hands, realizing of course that there was no Milky Way and that the Universe was still unimaginably compressed and hot at that time. Besides, there was no space external to the Universe. Contrary to my intuitive image, the Universe did not expand into space; space itself expanded along with the Universe. (No credit for thinking "outside the box" in this case!)
Another point that struck me about the article was the sheer "chutzpah" of its author in presuming to know what occurred in the time frame 10-35 to 10-32 secs after the creation of the universe, and in speculating about conditions in the unobservable part of the universe. After all, scientists in general, and physicists in particular, take great pride in abstaining from speculation about matters that by definition are inaccessible to the scientific method, such as philosophy and supernatural intervention. That is how they have achieved their position at the top of the scientific totem pole. Weinberg, for instance, writes defensively: "I cannot deny a feeling of unreality in writing about the first three minutes as if we really know what we are talking about." Linde is less apologetic, clearly enjoying occasional forays across the border line between science and pure speculation.
According to inflation theory, the Universe expanded by at least 50 or 60 orders of magnitude (perhaps much more, see Linde presentation above) in just 10-32 sec. It is unclear to me if this refers to an expansion to a billion lightyears, as the diagram seems to imply, or to the size of a grapefruit, as another source suggests. Perhaps the latter refers to just that region of the universe which corresponds to our presently observable universe. The main point is that inflation must have been sufficient to ensure a strongly homogeneous, isotropic and flat universe in accordance with observations. (Inflation also offers a solution to another puzzle: the absence of magnetic monopoles.)
As early as 1982, Linde noted that the equations describing inflation arising from quantum fluctuations in scalar fields allow the creation of many inflating regions in different parts of the universe, each with its own set of constants of nature. These regions would be separated and have no influence on each other. He described the process as an infinite chain reaction which has no end and which may have no beginning. One may picture the model as a boiling soup, where bubbles form and expand, each bubble corresponding to a separate "universe". In fact, it would no longer make sense to call our universe by that name, as there would be an exponentially increasing numer of universes. (The term "multiverse" is sometimes used to describe an aggregate of independent universes.)
This concept strongly resembles the many-universes model in quantum mechanics, where every single event at the quantum level would cause the universe to split into a large number of parallel universes! The question "Did God have a choice in the creation of the Universe" is answered in the negative: all choices have been realised. The concept also appears to resurrect the steady-state universe: The universe could once more be seen as existing for all eternity, constantly rejuvenating itself (even if the sub-universes, such as the one we live in, could be doomed to a "big crunch" or a drawn-out cold and lonely expansion forever).
To some, a virtue of the model is that there would not necessarily have been a moment of creation. The universe may have existed forever, regardless of the Big Bang. — It also makes life easier for scientists, who would not have to search for an answer to why the laws of nature and the associated constants of nature happen to be as they are. "We just live in a universe where it happened by chance."
If you ask me, I find the theory less than satisfying. Just as I had gotten used to the idea that there is no time and no space outside our universe, and that its age is 13.7 billion years, I am told that each universe out of an infinite number has its own dimensions, which may or may not have some resemblance to our spacetime, and that the universe and its predecessors (!) may have existed forever. On top of that, the diagram seems to suggest that there is some form of time external to the universe(s). I fail to see why the hypothesis of eternal existence makes the universe any easier to understand than a first moment. Since Einstein, we have understood spacetime as a single entity intimately interwoven with the observable universe. (St. Augustine agreed: Time was created together with the universe.) Are we now being asked to revert to a model with time as an eternal flow, independent from physical reality?
Linde has likened the efforts of cosmologists and particle physicists to two teams of tunnelers working from opposite ends of the tunnel. Cosmologists work on the grandest scale imaginable, while particle physicists explore the smallest components of the universe. To make progress, both approaches are necessary. — In particle physics, great strides have been made in the last decades. Hundreds of subatomic particles have been discovered. Most of them are unstable and decay within 10-10 to 10-20 sec. They are built up of even more fundamental particles, quarks, which come in six different flavors. Theories are keeping pace with experimental results, so that physicists are on the lookout for particles predicted by theory to exist, such as the Higgs boson, with properties that are roughly predictable by theory. Currently, there is great excitement surrounding the recently completed Large Hadron Collider at CERN in Geneva, which should provide answers to some of the most burning questions in particle physics.
In the last 10 years astronomers have found that the expansion of the universe is actually accelerating, rather than decelerating. Even if the universe is going to expand forever, it was expected that the rate of expansion should decrease due to gravity. This has led cosmologists to invoke "dark matter" and "dark energy" to explain observations, but these phenomena remain mysterious at the present time. It is now believed that atoms make up less than 5 percent of the mass of the universe.
On the theoretical side, progress is being made in understanding subatomic particles as manifestations of vibrations of more fundamental 1-dimensional objects called strings. Theoreticians also work with more generalized objects called "branes" (derived from "membranes"), which is why you may run into speculations such as "The Big Bang may have been caused by two colliding branes." The mathematics involved requires that our universe have 11 dimensions: the familiar 4 dimensions of spacetime and an additional 7 space dimensions curled up at the Planck size (~ 10-35 meters.)
A. Linde, B. Greene, A. Guth, N. Bostrom and R. Krulwich contemplating a 2-dimensional projection of a 3-dimensional representation of one model of a 6-dimensional universe. (See ref. 1)
It is of course impossible to subject such theories to experiment, and some skepticism may be in order. In addition, the theories can accommodate almost any physical realization of the universe. Linde mentions that the underlying equations may well have 10500 solutions. However, physicists claim that the mathematics is "beautiful", and they hope that further high-energy experiments will soon drastically reduce the number of possible descriptions of our observable universe. Still, string theory as such is about 18 orders of magnitude beyond our present capabilities of experimental verification, and the mathematics is said to be complex enough to require years of training before original contributions can be made.
In this context it is tempting to point out, that only in cosmological literature do you run into statements such as: "Most Kaluza-Klein theories based on supergravity in an 11-dimensional space lead to vacuum energies of order -MP4 ~ -1094 g • cm3, which differs from the cosmological data by approximately 125 orders of magnitude. . ." [ref. 5]. This reminds me of 19th century attempts to reconcile the sun's energy output with what was known about chemical energy. "We seem to be off by a factor 107..."
The observer-friendly universe
It would be nice if our universe could be shown to be the expected outcome of some simple basic assumptions about the laws of nature, just as the law of gravity explains planetary motion or Maxwell's equations explain the whole range of electromagnetic phenomena. Unfortunately, this does not appear to be the case. There are a number of constants of nature that seem to have been picked out of a hat — at least scientists have thus far failed to derive them from first principles. On the other hand it is becoming increasingly clear that almost any combination of those constants other than the one that rules our universe would have extremely unfortunate consequences from the perspective of a human observer. They would result in universes that were extremely short-lived or completely chaotic. There might be no atoms or no stars or planets. Molecular biology might be impossible. The vast majority of possible universes would be lifeless. Our universe seems fine-tuned to allow the development of life (and ultimately ourselves).
O King of Gods. I have known the dreadful dissolution of the universe. I have seen all perish, again and again, at the end of every cycle. At that terrible time, every single atom dissolves into the primal pure waters of eternity, whence originally all arose. Everything then goes back into the fathomless, wild infinity of the ocean, which is covered with utter darkness and is empty of every sign of animate being.
Ah, who will count the universes that have passed away, or the creations that have risen afresh, again and again, from the formless abyss of the vast waters? Who will number the passing ages of the world, as they follow each other endlessly? And who will search through the wide infinities of space to count the universes side by side, each containing its Brahma, its Vishnu, and its Shiva?
The fact that we find ourselves in a "benevolent" universe is not in itself surprising. We could not exist in any other type of universe! But the improbability of our particular universe raises three possibilities:
1. Our universe was designed to allow our existence (or we could be the byproduct of a universe designed with a purpose).
2. We are just very, very lucky that the one and only universe happened to suit us just by chance.
3. A lot of universes have been created randomly. We should not be surprised to live in one of the few that suit us.
Nobody really believes in the second alternative. That leaves creation by design (not necessarily by God!), or random creation of a multiverse. The first alternative, of course, is the position of most religions. The third alternative is the one advocated by most scientists.
And that is where it stands. We should not expect science to find proof one way or the other, as there can be no way for us to confirm the existence of other universes than our own (barring speculations about "wormholes" or past collisions between "branes").
Consciousness and other loose ends
Among the many interesting speculations by Andrei Linde, one is that the phenomenon of consciousness may have a role to play in cosmology. The Copenhagen school of quantum mechanics accords a fundamental role to the observer of an experiment. The observation itself triggers the outcome. In inflation theory, quantum fluctuations have a central role, and the question arises whether any description of reality can be complete without including an observer. He writes:
"... the thrust of research in quantum cosmology has taught us that the mere statement of a problem which might at first glance seem entirely metaphysical can sometimes, upon further reflection, take on real meaning and become highly significant for the further development of science. We would like to take a certain risk and formulate several questions to which we do not yet have the answers. Is it not possible that consciousness, like space-time, has its own intrinsic degrees of freedom, and that neglecting these will lead to a description of the universe that is fundamentally incomplete? What if our perceptions are as real (or maybe, in a certain sense, are even more real) than material objects? What if my red, my blue, my pain, are really existing objects, not merely reflections of the really existing material world? [Cf. my thoughts on color perception. /SZ] Is it possible to introduce a "space of elements of consciousness," and investigate a possibility that consciousness may exist by itself, even in the absence of matter, just like gravitational waves, excitations of space, may exist in the absence of protons and electrons? Will it not turn out, with the further development of science, that the study of the universe and the study of consciousness will be inseparably linked, and that ultimate progress in the one will be impossible without progress in the other?"
This certainly qualifies as "sticking your neck out". Regardless of how this will be judged (and Linde's reputation prevents us from dismissing such thoughts out of hand), it may revive the discussion of the role of the observer in quantum physics.
The feeling that something is missing has been expressed by Stephen Hawking: "What is it that breathes fire into the equations and makes a universe for them to describe?" And Ludwig Wittgenstein, who wrote "The limits of my language mean the limits of my world" and "What we cannot speak about we must pass over in silence", also wrote "It is not how things are in the world that is mystical, but that it exists" and "There are, indeed, things that cannot be put into words. They make themselves manifest. They are what is mystical."
Even if everything can be explained in terms of quantum fluctuations, the question arises: Was there a pre-existing law of quantum physics? When Linde describes a multiverse with a different set of laws of nature in each "universe", doesn't he assume the existence of more general principles? Physicists like to define a Hamiltonian or a Lagrangian to describe the nature of a physical system and to derive laws governing its development, but these concepts build on our observations of how the world works. How can we be confident that similar concepts would apply at the very beginning of the universe, or even "before"? I have a feeling that when cosmologists use the word "before" (the Big Bang), they are not speaking of time in the conventional sense, but perhaps in the sense of an ordered sequence, just as 72 comes "before" 73, or the moves in a chess game come in a certain sequence; this has nothing to do with minutes or seconds. But the equations describe change with respect to conventional time?
Among Linde's "outrageous" speculations, the possibility is mentioned that we might be able to trigger an inflation event in the laboratory, i.e. to create a universe. He addresses the problem of communicating with future inhabitants of such a universe and concludes that the only message that could get through would be the set of constants of the laws of nature. In an interview, he said: "You might take this all as a joke, but perhaps it is not entirely absurd. It may be the explanation for why the world we live in is so weird. On the evidence, our universe was created not by a divine being, but by a physicist hacker."
Which raises the question: Could it be hackers all the way?
1. "Infinite Worlds: A journey through parallel universes", World Science Festival 2009 (for laymen). Video (104 min). Participants: Brian Greene, Robert Krulwich, Alan Guth, Andrei Linde, Nick Bostrom. Illuminating and entertaining!
2. "Where did it all come from?", Anthony Aguirre, Univ. of Calif., Santa Cruz. Sky & Telescope, Nov. 2006.
3. "The Observable Universe and Beyond". A cosmological primer for the layman by an anonymous retired physicist. (There is much more information to be found at the root of that web site.)
4. Andrei Linde's web pages with many links to his own papers, publications and presentations, and those of others. (He is also a photography buff.)
5. "Particle Physics and Inflationary Cosmology", Andrei Linde, Stanford Univ. 1990, 270 pages. Rather technical, but lots of interesting stuff between the equations... Precedes the discovery of Dark Energy.
6. "A Designer Universe?", Steven Weinberg, 1999. Examines and dismisses the case for an intelligent designer of the Universe. "I am all in favor of a dialogue between science and religion, but not a constructive dialogue."
7. "Why is Existence Mysterious?" Video interviews with experts on this and other fundamental subjects.
8. "What creates consciousness?", World Science Festival 2024. Video (45 min). David Chalmers and Anil Seth interviewed by Brian Greene. Exciting!
