Purple Magazine
— The Cosmos Issue #32 F/W 2019

the origin of the universe

theory ÉTIENNE KLEIN
THE ORIGIN
OF THE UNIVERSE

First, a remark: if we are to take the word “origin” seriously, and if we are discussing the origins of the universe, we must envisage the need to describe the transition between the absence of something and the appearance of another thing. Thinking about the origin of the universe requires, first of all, thinking about the absence of a universe. The origin is the transition between a total absence of a universe and the appearance of a first thing. The real question is whether we are capable of conceiving this idea of an absence of universe — that is to say, a kind of nothingness, which Henri Bergson said was a destructive idea in itself, meaning that as soon as you start to think of nothingness, you involuntarily attribute to it properties that it cannot have, since it is nothingness. To think nothingness, therefore, is to make it into something that it cannot be. And so, the idea of nothingness is an idea that destroys itself, in the sense that the moment you evoke it, you nullify it.

Next, if you say that in the beginning — which is to assume that the origin has a beginning, as most ancestral cosmogonies claim (Gaston Bachelard called these songeries, or dreams) — we are told there was this or that, this or that possibly being a primordial ocean or some kind of virgin matter… This could be chora, as in Plato’s Timaeus, or it could be all kinds of other things. “In the beginning there was this” raises all sorts of questions. Was “this” always there? In that case, we cannot say the universe has an origin. Or alternatively “this” was not always there because it was the effect of a cause that went before it, in which case it is not the origin. So, when you say, “In the beginning, there was,” you are not describing the origin because you are positing an “already there” whose status is ambiguous. Either it derived from something else, in which case it is not the origin, or it was always there, in which case it isn’t the origin, either.

Let us consider how the origins of certain things have been understood in physics. In the 20th century, we understood the origin of all kinds of things. We understood, for example, that there were no atoms in the primordial universe. Atoms have not always existed, and neither have stars. Things appeared in the course of cosmic evolution, and we are capable of describing all kinds of genealogies for objects that exist in the universe. Take the example of atomic nuclei: they are made up of protons and neutrons that clustered together in small quantities in the primordial universe to form very light chemical elements such as deuterium and helium.

After that, as the universe expanded, collisions between protons and neutrons became rare. As a result, primordial nucleosynthesis stopped, until stars appeared and, by gravitational condensation, caused the centers of the stars to heat up, triggering nuclear reactions so that, by a series of fusion reactions, all the chemical elements were produced — going, broadly speaking, from lithium to iron in Mendeleev’s periodic table. For heavier chemical elements, stars reaching the end of their life were needed, which are what we call exploding supernovas; they caused major neutron flows. Through neutron capture, beta radioactivity, we obtain all the chemical elements from iron to uranium. So, we have understood nucleosynthesis as a whole. One can observe in this case that the origin of things is a part of things — that is to say, these nuclei were built by the successive agglomeration of their constituents.

There are cases when a thing’s origin is not part of the thing itself, but is also a physical object, if the thing whose origin is being described is a physical object. What I mean is that the story about the appearance of an atom’s nuclei is also the conclusion. So, to talk about the origin of atoms is to talk about the history that went before the appearance of atoms. To put it another way, the word “origin” means “completion” or “conclusion.” To describe the origin of something is to tell the story of which that thing is the conclusion. And so, the meaning of “origin” here is contrary to the commonsense one.

Maybe you’ve heard about the Higgs boson, a particle that was discovered in July 2012 after 48 years of research. We understood where the mass of elementary particles came from. We understood the origin of mass because our equations in the Standard Model of particle physics suggested the idea that elementary particles have no mass. This contradicts what we actually observe. When measurements were made, we found that the mass of electrons, for example, was not zero. Some people said, “Maybe the equations are right, and we have misunderstood the concept of mass.” They came up with the idea that the mass of elementary particles is not a property that they possess in themselves,
but an indirect, secondary property that results from their interaction with the void, which is not empty.

In the void, there’s a field, the Higgs field, in which the quanta are the Higgs boson particles. Thanks to the coupling of zero mass particles with this field, the particles acquire a mass proportional to this coupling that is more or less strong. They are more or less impeded by the field, which means that their inertia varies. You can say that here the origin of mass is explained by invoking another physical entity, which is the Higgs field. Here, too, we are telling a story in which the appearance of mass is the conclusion.

But if the question that interests you is the origin of the universe, then of what might that be the conclusion? When we talk about an origin, it is always a story in which the origin of the thing is the conclusion. If we are talking about the origin of the universe, then that means that before the universe, there was a history whose conclusion is the appearance of the universe. That means that before the universe, there was something else.

In the dictionary, “origin” — which is in fact a singularity, a kind of absolute instant of creation — very soon starts to dilate in time, to fizzle away into histories and processes, thickening into a succession of phenomena or events, and mixing with other concepts. For example, in the Grand Robert dictionary [the largest French-language dictionary], the word “origin” is associated with creation, cause, beginning, formation, genesis, foundation. So, we can see there is a kind of polysemy around this term, and its meaning is not well defined.

Fortunately, there are philosophers who have helped to clarify things and distinguish two meanings of the word “origin.” The first meaning is based on the idea that the origin is the dynamic source of the totality of what exists. Therefore, origin is a cause preceding everything that followed, which it makes no sense to try to get beyond. It is the first cause that is itself the effect of no other prior cause. Therefore, it is an origin that is chronologically the first and absolutely creative; it is by essence distinct from everything that it produced and preceded, and it stands for an absolute, autonomous reality — a transcendent reality. Therefore, the origin of the universe is not part of the universe. It is transcendent in relation to the universe. This origin may, in monotheistic cosmogonies, be God. But if you say that the origin of the universe is not part of the universe, or that it is transcendent in relation to it, then that makes the universe contingent, which means that it could also not have been in existence. Whereas in the traditional cosmogonies found in many cultures and civilizations, there is something at the outset that is formless and evolves in a determinate way so as to produce the actual universe… Therefore, if the cause is external to the universe, the universe is contingent and therefore could have not been made to exist if the power in question had decided not to create it.

The second meaning is not the effective, historical original cause, but the primary logical foundation of all that exists. This foundation can be a particular being that is immanent and that has the potential to project outside itself in order to be embodied, and to become something other than itself. First case: primary cause. In the other case: foundation. We can see, then, that ancestral cosmogonies always refer to a foundation — that is, to something that is already there — whereas the three religious cosmogonies, the three monotheisms that we know today, base themselves on the first definition of the word, the transcendent origin that is outside the universe. Depending on which hypothesis you choose, the origin will be more or less knowable. If the origin is in the universe, if it is immanent, then you can hope that physicists may one day be able to grasp it. But if it is outside the universe, if it is transcendent, then it eludes the physicists’ grasp.

I shall illustrate with a very simple example. Here, we leave the universe and look at language. There are people who are interested in the question of the origin of language. In the 19th century, there was a fashion for writing manuscripts explaining how language came about. It was not long before the Paris linguistics society decided to stop reading these manuscripts and even started returning them to their senders, for the reason that the question itself was not clear. Why? Because there were people who said that finding the origin of language meant finding the first language, from which the 6,000 languages spoken in today’s world originated. What they were looking for, then, was the proto-language, the first language to have appeared on Earth.
It appeared at a certain moment, in a certain place.

But other people understood this idea of the origin in another way, namely: what were the cultural, environmental, intellectual, and even cerebral and political conditions obtaining in a human group that made it necessary to be able to talk? Those people who talked didn’t immediately come out sounding like Shakespeare. In the early days, it was all inarticulate mumblings, cries perhaps, and out of those, they eventually isolated sounds that meant something, and little by little, language took shape. Here, the origin is understood in accordance with the second meaning given by philosophers — we look for the conditions in which language came into existence, bearing in mind that language could therefore have appeared in several different places around the planet and in several different periods.

The point is to make it clear that the origin is a very complicated question. Now, this brings me to cosmology. Quite often, we hear it said that it was only in the 20th century that we understood that the universe has a history. This is obviously false… In the 19th century, there were physicists who wrote the history of the universe. Physicists tried to apply thermodynamics to the universe and said, “The entropy of the universe will increase; we are heading for a thermal death,” which means that there is a history of the universe. Even before that, Immanuel Kant wrote a short book on the history of the universe in which he explained how the solar system had been able to form by the gravitational contraction of a nebula with antigravity, which made the planets what they are. He related a kind of history of the universe. Books that tell you that we only discovered the universe had a history in the 20th century forget all these earlier episodes. To their credit, though, it has to be said that when physicists in the 20th or 21st century say that the universe has a history, they do not mean exactly the same thing as when 19th-century physicists uttered the same words. Why? Because between the 19th and 20th centuries, there was Albert Einstein. And when 19th-century physicists said that the universe has a history, they meant that the universe is the envelope containing all physical objects and that what has a history are the objects, not the universe itself.

Therefore, in the 20th century, when we say, “The universe has a history,” we mean that the universe as a physical object has a history. What may have made this possible is Einstein’s theory of relativity. Einstein published his papers between November and December 1915. General relativity was a new theory of gravitation, allowing us to think of the universe itself as a physical object — that is to say, an object that has overall properties that cannot be reduced to local properties. For example, the general curvature of spacetime is a property of the universe and not of something in the universe. In this way, the universe becomes a veritable physical object, and Einstein’s theory of gravitation encourages us to think that gravitation is not at all a force that is exerted in the space between bodies with mass, as we learn at school. It is not a force; it is a deformation of the spacetime metric that is induced by the contents of spacetime, which is to say that the container, spacetime, is deformed by what it contains, so that gravitation is something that fits into the structure of spacetime. History tells us that in 1915, Einstein thought that the universe was static, that it did not have a history. And when, in 1917, colleagues demonstrated to him that there was no static solution to his equation, that put him in a quandary because he was convinced the universe was static. So, he did something rather odd: he introduced into physics a new constant that would be known as the cosmological constant, the effect of which is a kind of antigravity that causes space to push itself back and offset the attraction of gravity, so that if the constant is properly adjusted, the universe can be stationary.

Many figures worked on solutions to Einstein’s equations — four people in particular. Father Georges Lemaître, in the 1920s, put forward the hypothesis of what he called the “primitive atom”: the idea that all matter was created in the explosion of a great nucleus containing a huge quantity of protons and neutrons that were scattered to form matter as we know it. Another mathematician, Alexander Friedmann, was a Russian who died very young but was still able to show that there were solutions that fit with Einstein’s equation and were coherent with an expanding universe. This was viewed as a mathematical calculation with no physical applications. Then, in the 1920s, there was an astronomer who earned his living as a wrestler but observed the sky at night. His name was Edwin Hubble, and he used the telescope on Mount Wilson in the US. He observed the movement of the nebulae (the old name for galaxy). When you look at the part of the sky that he observed, it’s tiny compared with what we know today, but in that small part of the sky, he was able to see that the galaxies, the nebulae, were moving away from each other, and that the velocity at which they did so increased the farther apart they were. Therefore, thinking as he did that the universe was static, that space was static, he interpreted this phenomenon as galaxies receding into space. There was space, which was static, and there were galaxies moving away from each other at speeds that increased with their distance. He called this the recession or redshift of galaxies. However, if you interpret these observational data in the context of Einstein’s equations, which is what Father Lemaître did, that totally changes the interpretation.

The facts are always interpreted. Father Lemaître showed that if we interpret the data obtained by Hubble within the framework of Einstein’s theory, we would have to consider that these nebulae, which appear to be moving, are in reality static. They are immobile in space. It is just that the space between them is dilating. The space separating them is expanding, with the result that we see them moving, when in reality they continue to occupy the same point in space. This is the phenomenon that would come to be called the expansion of the universe. In 1931, Einstein wrote a paper in which he recognized this expansion and acknowledged that in denying it in 1917, he had made the biggest mistake of his life because his equation gave him the means to predict the expansion of the universe.

The fourth figure is a Ukrainian, George Gamow, who understood that the universe had been hotter in the past. Based on the work of Lemaître and Friedmann, this can be worked out on paper, taking Einstein’s equations, adding the newly discovered Hubble’s Law, and extrapolating toward the past. We can see that the observable universe, when we look into the past, gets smaller and smaller and more and more dense, with an increasing density of matter and energy and an increasingly high temperature. When you extrapolate this all the way, you come to a zero-size universe — that is, the universe as a point. In mathematics, we call this a singularity, with an infinite density and an infinite temperature. This model was more or less defined by 1949 and was named the “dynamic evolution of the universe” hypothesis. Then one day, the BBC invited an astronomer, Fred Hoyle, onto a show. He was talking about this model of the evolution of the universe; he didn’t believe in it one bit, and he described it as I have just done, as if to mock it. The journalist didn’t find what he said very clear, so at the end of the interview he asked Hoyle to sum up his idea in a more limpid way.
And Hoyle, now a bit annoyed, said, “It’s like a big bang.” He thus coined this expression, which would be used by so many others. Since the 1950s, people have talked about the Big Bang as the original explosion that engendered everything that existed: space, time, matter, energy, radiation. Obviously, this discovery raised all sorts of metaphysical questions — first of all, because it wasn’t long before people were likening it to the Fiat lux [“Let there be light”] of the Bible, and people asked what there was before the Big Bang, what had served as the “cosmic match,” etc.

These metaphysical questions are interesting but premature. All kinds of things have happened between 1950 and today; as a result, we need to rethink the way we talk about things. The reason we are being led toward a different conclusion is easy to understand: when you extrapolate toward the past using Einstein’s equations — which, as I said, describe only gravitation — your calculation will be exact as long as gravity is the dominant force in the universe. However, gravity is a force whose intensity is very weak but that dominates on a large scale because it is cumulative: it always attracts. So, when an object is big, it is dominated by gravity, but there are other forces in nature. There are nuclear forces, weak and strong. And then there is electromagnetism. These forces are not described by Einstein’s equations. So, you are doing calculations that are accurate mathematically but incomplete in terms of physics because they do not describe the interactions of the particles. The Higgs boson was discovered at the LHC [Large Hadron Collider, built by the European Organization for Nuclear Research, or CERN, in Geneva]. Protons are put into the machine and made to collide, and each proton has as much energy as a flying mosquito. The difference is that the proton has all this energy on its own, whereas with the mosquito the energy is distributed over the billions of particles that it contains. In other words, the energy is extremely dense. When you collide protons that have the energy of a mosquito, you recreate the physical conditions of the universe 10 to 25 seconds after the Big Bang — defined here as the singularity we associate with a moment zero. There are equations, and the Standard Model of particle physics works very well. The equations of particle physics predicted the Higgs boson.

However, if you look at the physical conditions just a bit before, you come to situations in which the energy of the particles was not that of a flying mosquito, but of a TGV train at full speed — tens and tens of orders of magnitude greater than the mosquito’s. These are the densities of energy that we are capable of reproducing in the laboratory. Our equations show us that the moment before these equations collapse is what we call the Planck wall, which is associated with a certain energy, time, and length. The energy is precisely that of a high-speed train. Intellectual honesty compels us to say that between the Planck wall and the present day, we are more or less able to say what happened, but to describe what happened before the Planck wall, we would need a theory that unifies general relativity, which describes gravity, quantum physics, and the three other forces, electromagnetic and weak and strong nuclear forces. Now, such a unifying theory is precisely what we do not have. Research is therefore under way. You have heard of superstring theory, which comes down to saying that if we could look at particles through a very powerful magnifying glass, we would see not discrete particles, but little strings, either open at both ends or looped. The virtue of string theory, or so some people think, is that it provides a formal structure that is capable of unifying interactions and therefore describing the universe before the Planck wall. Except that before the Planck wall, the density of the particles is such that calculations are impossible.
We must make do with approximations. There are people who try to apply string theory to the primordial universe, which leads them to some big surprises. For example, string theory predicts that the maximum temperature in the universe is necessarily finite: at any point in its space and any moment in its history, its temperature cannot have exceeded a certain value, which may be extremely high but is not infinite. The moment zero from the 1950s Big Bang model is in for a bit of a bruising here — because, according to string theory, the moment zero that we associate with an infinite temperature cannot have existed, which means that when you apply string theory to the primordial universe, you realize that the singularity associated with the moment zero has been replaced. It has been replaced by a phase transition that goes from a universe that was before and that is contracting and heating up, right up to the maximum temperature allowed by string theory. When it reaches this, it cannot contract any more because that would heat it up. It therefore bounces back and produces our expanding universe.

In these models, then, there is no longer any origin, or at least the origin is not where we thought it was; it is displaced. Obviously, this conclusion that I have come to is valid only if string theory is right, which we don’t know… The interesting point is that today, whenever someone sketches out a theoretical direction that would make it possible to unify general relativity and quantum physics, and this model is applied to the description of the primordial universe, the original singularity, the moment zero, disappears or shifts; this means that today, contrary to what people everywhere say, we do not have scientific proof that the universe has an origin or that it did not have one. In other words, the question of the origin is an open question that is always presented as closed because we have always postulated that the universe had an origin. But this has not been demonstrated, which means that we need to think of changing the way we talk about the Big Bang.

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