The second law of thermodynamics, the universal law of increasing entropy, states that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium, or complete homogeneity.
Therefore, any system that maintains a heterogeneous state with complex structure must have a frequent flow of energy into and out of itself. We see this kind of variety on every scale in our universe. Even the organizations of the largest structures in it, galaxies, have great variations in density. One possibility as to why this might be is that the universe is indeed an isolated system, and that its entropy will increase in time, approaching a state of equilibrium, and that the great variety of interesting structures that we see increasing over time are simply the result of a chaotic, perhaps one-time event.
But there is another possibility to explain why our universe doesn’t seem to be approaching equilibrium, and that in fact, seems to be doing quite the opposite – achieving a greater and greater amount of complexity. It is simply that our universe isn’t an isolated system, and that it maintains a steady flow of energy with its surroundings. Before we discuss how this might happen, we need to imagine what could be outside our universe to exchange energy with. There is, in my opinion, only one theory regarding this question which both a) fits with everything we already know about the universe, in particular that we see structure, complexity, and beauty in every scale we’ve ever looked at, not to mention similar patterns on all scales and b) answers so many fundamental questions, in particular why the parameters of the universe are so finely tuned so that this amount of complexity results, let alone so that the universe is not simply a gas in equilibrium, which is overwhelmingly more likely if the parameters were chosen randomly. That theory is heralded by Lee Smolin in his book “The Life of the Cosmos,” and it goes something like this:
The fundamental laws of the universe we live in are the result of natural selection, in which the universes that create the most black holes are selected for, because black holes give rise to new ‘universes’ or progeny.
Just as our bodies are the result of a long history of evolution, and our genes 'program' our bodies to behave in a way that is most likely to produce offspring, the universe we live in has parameters that are the result of a history of evolution, and it 'programs' our universe to behave in a way that produces the most offspring, and black holes are its method of reproduction. Lee Smolin does a great job of explaining this theory and backing it up in the aforementioned book, so I will not, but I will say that I expect that it will become commonly accepted. My response when I originally heard it awhile ago, and in finally reading the details later, was much like many scientists’ initial response to Darwin’s original proposal of the theory of evolution: “It’s so obvious. Why didn’t I think of that?”
This theory gives us an answer to the question I posed earlier, which was, if it is necessary for a non-equilibrium system to maintain an exchange of energy with its surroundings to prevent its entropy from increasing to a state of thermodynamic equilibrium, what could our universe possibly be exchanging energy with to maintain its state of non-equilibrium?
With the theory of cosmic evolution, we find ourselves to be quite literally one of very many exploded black holes within another universe, just as all black holes within our universe have exploded in turn into ‘new universes’. So, what could possibly be flowing into and out of a black hole? Not even light can escape a black hole once it reaches its event horizon, which is why we can’t see them or anything that goes on in them. The only thing that seems to be able to leave a black hole is gravity.
The most important and enlightening thing to understand about gravity is that it is the only force that is universally attractive, and has infinite range. Everything that has mass communicates with everything else that has mass over and infinite range through gravity. Right now, the world of physics is in a major crisis, because they have found no way to unite gravity together with electromagnetism and the strong and weak nuclear forces in a cohesive theory of quantum gravity. There has, however been great progress recently in the quantum field. The overwhelming trend is the discovery of a great many extremely small particles. The Large Hadron Particle Collider that went online this fall, and then offline shortly there after, hopes to find the theoretically inferred Higgs Bozon which essentially adds mass to elementary particles that find themselves caught in their Higgs Field. If there were no Higgs particles, the electron would have no mass. It would move at the speed of light, like a photon. But if it finds itself surrounded by a gas of Higgs particles, the electron is not able to move so quickly. The electron seems to gain mass because it is moving, not through empty space, but through a muck of Higgs particles. It becomes heavier because when one pushes it, one also pushes all the Higgs particles around it. To the universe, an electron and a neutrino are the same thing, except that one has mass because it finds itself in a field of Higgs particles. The choice is made one way or another by the system itself. When this happens we say that a symmetry of the laws has been spontaneously broken. To see what this means, imagine a pencil balanced on its point. It cannot stay that way long for it is unstable, a little push to one side of the other and it will fall. If it is perfectly balanced, the law of gravity cannot tell us which way it will fall; any way is s good as another. But any small disturbance will break the symmetry, leading to a choice of a more stable, but less symmetric configuration, in which the pencil is lying on its side.
The most important implications of Higgs particles is that even when we look at the smallest, currently theoretical levels, we see something as fundamental as mass being determined by individual entities interacting with their environment. The theory of quantum gravity, I think, most likely will be uncovered with the type of research. I think that as we look closer and closer, we will see the properties of subatomic particles being defined by smaller particles in environments they find themselves in, who themselves gain their properties through environmental interactions, until we realize that the laws of the universe are not separate from the particles they govern; there is no fixed background against which things interact , and all properties that we observe are about relationships. My theory is that all of the attractive forces are the result of extremely small particles, and their attractive force is proportional to their mass. The electromagnetic force, we know, is transmitted by photons. The nuclear forces result from particles which are large enough to interact strongly with the dense environment of atomic nuclei, so that they have a strong effect, but very few of them escape and their effect therefore dissipates quickly, and the gravitational force results from smaller particles which have a much smaller likelihood of interacting with other particles, which is why their effects dissipate after much larger distances, while their effects are weaker. An almost exact analogy can be made to the example of the dense core of a collapsed massive star. The core is too dense for photons to travel far; only neutrinos, which interact very weakly with matter, can get out. Thus, as the star collapses, many neutrinos are created that carry energy out of the core. On their journey out, about 5% of them do interact along the way while the other 95% of them escape the dense environment.
The rest of my argument doesn’t rely on the details of this theory (what details?), but it does rely on gravity having a particle nature. This, at least, is the opinion of almost all scientists. For all other forces that we are aware of (electromagnetic force, weak decay force, strong nuclear force) there have been particles identified that transmit the forces at a quantum level. Of course, when I say particle, I mean one that have a particle-wave duality, just like the others. Perhaps the particle that transmits gravity is not even much further down this chain of interacting particles than the Higgs particles, maybe it’s even around the same size, maybe there are many different types, and maybe it’s only one more step down an infinite line of smaller particles.
If the cells of our bodies did not have a membrane which allows it to control the exchange of energy and materials between it and its environment, diffusion and heat flows would quickly result in a mixing of the matter and energy between the inside and the outside of the cell, killing it. Instead, the cell is able to control exchanges between its interior and exterior to its own advantage, in order to maintain a high level of internal organization. Likewise, our biosphere is kept isolated from the rest of the universe by Earth’s gravitational field, while the atmosphere and ozone layer serve partly to control its exchange of radiation with the outside universe.
Our black hole universe also has a clear boundary between itself and its surroundings. Our universe’s equivalent to the cell membrane, or the Earth’s magnetic field, is its event horizon. The universe ‘cell’ produces its ATP, or energy source in high energy events such as stars, galaxies, and supernovas, which can all be thought of as its organelles. The energy which these structures produce, namely light, cannot achieve the escape velocity of a black hole, and so it is restricted to the volume dictated by the event horizon (again, our cell membrane). And the building blocks it absorbs and emits with its surroundings are gravity particles. It sends these particles out in all directions and receives them from all directions. When it is actively feeding on much larger particles, like matter, it ‘metabolizes’ them by breaking them down into these fundamental building blocks, using its own massive gravitational force, and it uses these building blocks to create its organelles. The reason why gravity particles are such good building blocks is simple. Since gravity is universally attractive, and has infinite range, systems that it holds together do not evolve over time to uniform and unorganized systems. As time goes on, the system separates into different components. One group of stars, for instance, will fall towards the center while others gain energy they lost and move further out. Such systems become increasingly heterogeneous, rather than more homogeneous, over time. A system with gravity as a building block will develop variety, and interesting and beautiful structures. Such a system will also tend to repeat their basic structural patterns on a wide range of scales, exactly like we see in our universe, and consequently in the universes contained in the black holes within our universe, and so on.
*The main premise of my idea, the theory of cosmic natural selection, is not the only thing in this paper that is owed to Lee Smolin. Many explanatory passages are more or less lifted from his book with little change in wording. There are three reasons for this near-plagarism. One – it’s a blog. Two – The man is a fantastic explainer. And 3 - I was in a hurry to just get in writing the main idea that is fleshed out in the last four paragraphs, which is the only truly original part of the paper. The other 2 pages or so were just a scramble, and I’m well aware that it is far from logically acceptable, but I wanted it to be at least conceptually understandable. I recommend wholeheartedly his book, “The Life of the Cosmos”, to hear his convincing arguments for a theory that to many might seem bizarre and unwarranted.