*Alan Lightman’s book with this title, a collection of thoughtful essays on the universe was published in 2013. In it he lays out an assortment of ways of looking at and interpreting the universe, some according to the standard models of physics and cosmology, some in more philosophically, even poetic ways. My concern, and my use of the title here, is more in the sense of the real, physical basis of how this universe that we perceive, and of which we are a part, may have actually come into existence as a real accident, one that may have occurred only once, or perhaps many times, something we may never really know.
The current, accepted by most in the field, standard model of the origin and growth of the universe is the Big Bang, inflationary model is that originally proposed by Alan Guth, now at MIT. Lightman describes Guth’s revision of the previously accepted big bang model in this way. “We now have a great deal of evidence suggesting that our universe began as a nugget of extremely high density and temperature about fourteen billion years ago and has been expanding, thinning out, and cooling ever since. The (Guth’s) theory of inflation proposes that when the universe was only about a trillioth of a trillionth of a trillionth of second old, a peculiar type of energy caused the cosmos to expand very rapidly. A tiny fraction of a second later, the universe returned to the more leisurely rate of expansion of the standard Big Bang model.” Guth’s modification of the standard model, it seemed, cleared up some serious gaps in the standard model, like the perceived homogeneity of the observed universe today.
If looked at with a truly critical eye, however, a number of unanswered questions arise, like:
“Whence cometh that original nugget?”
“If such a thing actually existed, what caused it to explode?”
“What was the nature of that ‘peculiar type of energy’ that caused the “expansion?”
“Why did the expansion then stop after a fraction of a second?”
There are more questions than we can count as to the verification of the “Big Bang” and its “inflation” modification, but it answers many questions researchers have expounded on for many years. But here is my main question. What if the logic underlying those “questions” has itself been based on faulty assumptions? For example, the principal evidence assumed to confirm the Big Bang theory was the discovery. by Wilson and Penzias in 1964, of the so-called CMBR, the cosmic microwave background radiation, that could be interpreted, if you assume, without evidence, as the echo of a great explosion, some 13.8 billion years ago, the “aha” of the Big Bang theorists. But that discovery itself ignited inconsistencies in the original theory that required Guth’s “expansion” insight to explain away.
But let’s imagine that Georges LeMaitre had not, in 1927, speculated that the apparently expanding universe could, if one traced that expansion back in time, be led to an imaginary beginning? What then would the discovery of a cosmos filled, the same in all apparent directions, with an almost but not quite uniform level of energy, be attributed to? Is there another theory, another model of the universe in there somewhere? One in which such an energy field might fit and where it might answer some other questions that physicists and cosmologists have long been seeking answers for? Like, for instance, what is the explanation for the constancy of the maximum speed of light? Why is that also a constant for all forms of electromagnetic radiation? How is it that we are detecting the effects of something that for want of a better term we are calling “dark energy”? Dark matter? If those exist, what are they made of?
Le Maitre’s scheme needed an assumption, one that, of necessity, could not be proved. I have a friend who, whenever I explain the origin of some aspect of physics or cosmology, invariably responds with, “But where does that come from? What preceded that?” I have finally given up and tend to respond with, “Well, of course, it’s turtles all the way down,”after the apocryphal story quoted by Steven Hawking in “A Brief History of Time”. The real answer is that in any model there must have been a state or condition of origin , perhaps, at a scale such as that of the origin of the universe, must be an assumption. For example, in the Big Bang theory, there was something called spacetime, an invention by Einstein out of the three required spatial dimensions which are the minimum needed to describe an object, an event, or a phenomenon, along with a fourth, that of the time or duration of such an entity. (see “How many dimensions make a universe”, ) However, the problem with these is that none of them, taken by themselves, is actually a real object, event, or phenomenon, and are only invented tools for the description of such values. So the Big Bang has its origin in a non entity. Then it begins as this “nugget” of intense mass and energy with no known predecessor. It is described variously as a quantum fluctuation in “spacetime” (that again), as a “singularity” (meaning which, I suppose, as something which happened once and will never happen again), another assumption unsupported by any antecedent, that explodes or expands or both, together or in sequence, all by means unexplained or unexplainable by reference to any of what we know as the laws of physics. This is explained by saying “Oh, those did not exist before this.” But what did?
Oh! One other thing. This was all created out of nothing! This seems to violate one of the earliest laws of physics. Think Democritus, Lucretius, Aristotle.
So let’s back up and start over. If we assume (easily checked, based on what can observe all around us) that the universe was made from something, what could that something be? It’s another reasonable assumption that whatever it was made from must be still around. Well, there are one or two constants of modern physics that we have learned to rely on. One is the speed of light in a vacuum. We’ve observed and tested for generations and that one seems safe. The second is what may turn out to be Einstein’s greatest single contribution, E= mc2. That may not be as certain but seems reliable enough. The second of these tells us that matter, that is, what makes up what we perceive as solid, physical stuff, is, in some form, equivalent to energy. They can be converted, one into the other. And what is here now, in sufficient quantity, and that might have been here at the beginning of this, our universe? What exists in all directions as far as we can detect both from here on earth and from satellites that we have sent out to detect it? Why that CMBR, of course. Energy, as far as the detector can see, in every direction. At low levels, of course, about 2.7° Kelvin, but unlimited in extent. And once we get past the notion that it is just the echo of a hypothetical big bang, we can see it as a source. It was here at the beginning, is here now and will probably be here as long as we can imagine.
How, then do we get from here to an accidental universe? That sea of energy, of course, is its source. Limitless in extent, turbulent as any sea, constantly tossing up orderly events in the midst of its chaos, orderly events that sometimes reverberate, reinforce and resonate. Each time creating higher energy foci that become points of stability causing higher energy density distortions in the field. Finally, we see order arising in the field, and ultimately what we call matter and masses, planets, stars, galaxies, clusters of galaxies as far as light can travel and the eye can see.
And, in at least one case, in a remarkable, real, unimaginably vast, rich, beautiful , dreamlike instance, an accidental universe.