This is the an extended version of a talk that I delivered to the Agnostic Group in Melbourne, Australia, in February 2015.
(Multiverse, of course, is not about poetry.)
Here are two kinds of entities that are out of this world, other universes and supernatural entities.
More than half the world’s population has never heard of a multiverse, and most of those who know what a multiverse is are pretty sceptical about it. Almost all the people in the world who are old enough to understand the concept of the supernatural already know about it, and a lot more than half of them believe in its existence in one form or another. And this is odd, because the people here in this room would probably give as much credibility to a multiverse as to the supernatural.
The idea of a multiverse is that is there are other universes as well as the one that we are part of. The idea arises out of certain types of scientific theories that have been developed in the process of trying to resolve certain problems of science.
But if there are other universes, what else might there be? Something supernatural? The supernatural is something that I regard as an entity that might exist, separately from, and independent of, the material world.
My justification for thinking that there could be such a thing as a supernatural entity is that its existence might explain some things that I think may be beyond the reach of science.
All this raises questions, such as:
- What is the material world?
- What would the supernatural need to be like to be different in kind from the material universe?
- Why would we think there is a multiverse?
- In a multiverse, could there be both material and supernatural entities?
I will go through these questions later.
What is the material world?
The material world is what we continually find around ourselves, and see, hear, feel, taste, smell, touch, manipulate, describe, measure, explain and speculate about.
The material world is said to consist of matter, energy and free space. Also, the material universe has another feature, time. Time is something hard to grasp, in more ways than one, but it just as essential as matter, energy and space.
Despite its often-apparent haphazardness, the material world, in its underlying processes, seems to be consistently deterministic. That is, things always happen according to the same principles – which become codified as laws of science whenever they are discovered and confirmed. However, although we think the universe should be consistent, there are apparent inconsistencies that I would describe as scientific mysteries.
These mysteries relevant to this essay include the following:
- the two fundamental theories of science, relativity and quantum theory, appear to be incompatible, and yet each is very good at explaining the particular aspects of the universe that it refers to;
- but there is one part of quantum theory that gives an enormously different calculated answer from what has been found by measurement;
- some aspects of quantum theory seem to be illogical;
- we have no satisfactory explanation of how the big bang could have occurred.
And for the moment, that’s the material world.
What is the supernatural?
The supernatural is some entity that is significantly different, and separate and independent from the material world. It might be capable of affecting the universe, perhaps without us noticing, i.e., without appearing to break the observed laws of science. My concept is that the laws of physics need not apply to it, but it might observe some of them. It need not be dependent on the existence of space, time, matter or energy, but could contain some of them, or something quite different from all of them, perhaps some new capability.
Such an entity might possess some of the impossible powers that believers attribute to God, like being outside the constraint of time. But I can see no need for it to possess any of the human-like characteristics, such as emotions, that many people attribute to God or to other purported supernatural entities.
But why might we think the supernatural exists?
People have various reasons for thinking there might be such an entity, such as intuitive feelings, religious teachings or as an explanation of real or purported mysteries, some of which they might call miracles. The kind of supernatural entity envisaged by such people ranges from the small and familiar – like ghosts or fairies or the spirits of trees or places – to something as great, or greater than, the universe. It is the cosmic kind of supernatural that I am considering here.
I said earlier that this supernatural might explain some of the mysteries that seem to be beyond the reach of science. The particular things that I have in mind are:
- what makes the difference between a living organism and inanimate matter;
- what produces the consciousness, as distinct from the intelligence of living organisms;
- what process produced the very first progenitor of our universe and defined its characteristics.
Some scientists think that there are satisfactory scientific explanations of each of these. I have discussed this in my book on the Internet, and explained why I don’t agree with their explanations. But I have also said that there might be some as yet undiscovered science that could satisfactorily explain them. I think that new science would need to be as different from present-day science as present-day science is different from the science of the 19th century. But, in the absence of any such new amazing science, I will allow the possibility of a supernatural explanation. But could the supernatural be some kind of universe in a multiverse?
As I said earlier, for anything to be supernatural I think it would need to shed at least some of the laws of physics, and perhaps the element of time. It would probably also need characteristics that we could not understand. But there would be no reason to believe that something was supernatural if all its characteristics were derived from the material characteristics of our universe.
And that, for the time being, was the supernatural.
What does the proposed multiverse look like?
I know of six different theories that have been put forward to justify the existence of a multiverse. They are:
- String theory
- Inflation, and production of matter out of radiation
- Zero-point energy
- The anthropic (or fine tuning) principle
- The “many worlds” interpretation of quantum theory
- Interacting universes
String theory was developed in an attempt to unite the theories of relativity and quantum mechanics, which in their present form are incompatible. The assumption underlying string theory is that the fundamental constituents of all that exists are vibrating strings. According to the mathematics arising from this theory, there could be an infinite number of solutions to the equations that describe the universe. It is assumed that there are about 10500 or more solutions that might describe universes that could actually exist, and that some or all of these universes actually do exist, each operating under its own laws and its own fundamental constants.
String theory has not been successful in uniting the theory of relativity with quantum theory, but until very recently no other theory offered any greater promise. String theory has evolved into many different forms, some of which produce mathematical solutions compatible with some aspects of the standard model of quantum theory. But most of the equations seem to be too hard to solve, and those that have been solved do not provide sufficient compliance with observed phenomena to give the theory any scientific status – at least in this universe.
Since string theory uses concepts that relate entirely to the material universe as we know it, there is no reason to believe that any of its universes would be supernatural.
Inflation, and production of matter out of radiation
Quantum field theory describes how matter would have been produced out of radiation during a period of massive inflation almost immediately after the Big Bang. (Creating matter out of radiation, and radiation out of matter, is partly what Einstein’s equation e = mC2 is about.) There is a theory that proposes that some radiation was left over from the big bang, and subsequent creations of other universes continue, perhaps indefinitely.
Matter is being continually converted into radiation, but there has been no observation of any phenomenon by which matter has been produced by radiation, although a process of producing it has been suggested.
Radiation being produced out of inflation means that inflation contains energy. The nature of this energy is unknown. There is strong evidence that the universe is expanding, that is, undergoing inflation. The energy to do this is known as dark energy. It has been calculated that this dark energy is the equivalent to about 13.6 times the mass of the universe. There is no satisfactory theory to explain how dark energy occurred, or how the big bang occurred.
There is no reason to assume that any of the radiation associated with the big bang and the continued expansion of our universe was left over and created other universes. There is also no reason to assume there could not have been any left-over radiation.
The conjectured additional universes would presumably be similar to ours, although their size and some of their fundamental constants might be different. None of them would be supernatural because they all arise out of material process of matter condensing out of radiation.
Zero point energy
We usually think of the empty vacuum of outer space as being just nothing, apart for the odd particle of matter that happens to be in it. But the vacuum is a lot more than nothing. Its characteristics determine the speed of light and the way that mass distorts space-time. It causes the fleeting appearance and disappearance of sub-atomic particles. So it must contain some form of energy. The amount of this energy in a given volume of space is referred to as the zero-point energy of the quantum vacuum. The value of the zero-point energy has been measured, and also calculated using quantum field theory. To the embarrassment and perplexity of the relevant scientists, the calculated value is enormously greater than the measured value – about 10120 times the measured value.
One way of explaining this paradox is to say that the calculated zero point energy is the correct value, but the energy is spread over an enormous number of universes, and the measured value is our share of it. To me this seems like a cop-out, because all the other calculations of quantum theory match the measured values and are not shared. If there was some theory to show how the zero point energy was shared but the measurements of other aspects of the universe matched the predictions of quantum theory, this might resolve the paradox, but it would not necessarily confirm the existence of the other universes.
But cop-out or truth, if all of these hypothetical universes were sharing the same zero-point energy, then none of them would be supernatural.
The anthropic principle
One version of the anthropic principle, (which is more accurately called the fine-tuning principle) refers to the values of the fundamental physical constants that determine the characteristics of our universe. It is claimed that if their values were slightly different from what they happen to be, then the universe could not have produced galaxies, planets and life. Most, but not all, cosmologists accept this claim.
One conclusion from this principle is that the chance of having such a precise set of constants is so small that they could not have occurred by chance. Therefore, the universe must have been specially designed by a supernatural entity.
People who don’t accept this conclusion but accept the basic premise of fine tuning, have two alternatives. One alternative is to say that the universe just happened to be the way it is, and it is just our good luck that it did. One way of accounting for such luck is to say that there is a great (or infinite) number of universes with different characteristics, and ours happens to be one that supports galaxies and planets and life. This is not a theory based on the anthropic principle but a proposed explanation of what might otherwise seem to be an extremely unlikely coincidence. It is not itself a justification for a multiverse.
An alternative explanation is that the universe is the evolved result of a succession of previous universes, each more complex than its predecessor. Some of these previous universes might still exist, since each new universe might have formed inside a black hole in its parent universe. This was proposed a couple of decades ago as an explanation of the origin of our universe. And there is nothing supernatural about it.
So here there are four choices relating to the anthropic principle; the supernatural creator, the unexplained good luck, the evolved material universe or an unspecified but presumably material multiverse. Take your pick.
The Many Worlds interpretation of quantum theory
Quantum theory deals with phenomena that relate to very tiny things, at atomic size and smaller. It describes some strange phenomena. Causality does not mean that things always happen the same way. There are probabilities of what will happen with individual particles, but the probabilities ensure that at larger scales causality seems to behave consistently.
In one version of quantum theory, the Copenhagen interpretation, this probabilistic behaviour of particles is attributed to superposition. Superposition means that a quantum particle is in all of its possible conditions until it reacts in some way, and when it reacts it displays one of these conditions. The actual outcome cannot be known until after the reaction has occurred. This idea that, for example, a particle can be in two different states of energy or two positions at the same times seems absurd.
There is also the observed quantum phenomenon of entanglement, in which two particles can share their probabilities, no matter how far they then travel, and that when one is detected we immediately know the condition of the other. The Copenhagen interpretation of this implies that there is “instantaneous action at a distance”, i.e., action at a speed that violates the principle that no material or force can travel faster than the speed of light. This is a fundamental problem for the Copenhagen interpretation.
An alternative version of quantum theory that avoids the problems of superposition and entanglement is the Many Worlds interpretation, which says that superposition is just an illusion, and each of the other quantum conditions that were possible but did not happen in our universe must have occurred in some other universe. So there is a multiverse. The other universes in this multiverse are just displaying the different possibilities that quantum probability could have allowed to arise in our universe since the big bang.
So, with this interpretation, every quantum interaction of every particle and photon in our universe has an effect on as some other universes. The number of affected universes, including ours, is equal to the number of alternative quantum possibilities in each event. This is because each affected universe gets a different alterative. But all universes, including ours are of equal status, that is, some intelligent entity on another universe would think that its universe was the one that affected the others.
All of the affected universes would need to be so closely identical with each other that the particular interaction to be feasible in them. Whenever there were not enough of these, a new, almost identical, universe would come into being.
There could be no end to the increase of universes until all of the universes had reached a state of maximum entropy, i.e., until no more interactions could occur.
This idea raises questions that have no plausible answers. Where does the additional mass come from whenever a new universe comes not being? What source of knowledge and intelligence guides and coordinates this continuing rearrangement? Where are the different universes located? Would there be additional dimensions for each universe?
Since all of these universes, if they do exist, are just different versions of what could have happened in our universe, none of them would be supernatural.
Interacting Universes (officially, the Many Interacting Worlds theory)
The theory of interacting universes was proposed as a way of avoiding some of the apparent illogicalities of the Many Worlds interpretations of quantum theory. The interacting universes theory says that there is a huge but unchanging number of universes and they are able to interact with each other. All these universes have the same laws of physics and precisely defined sets of properties and structure, but without any quantum uncertainties. No two universes are identical but some are almost identical with some others. These universes all began at the same time. All universes are equally real. All universes are completely deterministic.
An essential aspect of this theory is that all quantum processes are manifestations of interactions between universes. It is not the universes as a whole that interact but individual particles. All interactions are between corresponding particles in the various universes, for example, a particular electron in a particular part of a particular cell of a particular leaf of a particular tree in all of the near-identical universes that have that cell. The more different two universes are, the less they interact, because they have fewer corresponding particles. The particular interactions are not all the same: they correspond with the probabilities of the different possible states of superposition, as described in standard quantum theory.
But according to the Many Interacting Universes theory, entities, such as scientists that exist in their particular universes, can never be sure which of many similar universes they are in. But they can estimate the probabilities of each being the one among the universes that appear to be compatible with their observations. Because the entities that are doing the observing must be complex enough to make observations, they would be too large to register individual events on the scale of subatomic particles. And so they can never be entirely sure of the accuracy of observations of the different universes. So in each precisely defined universe there is still uncertainty. It just isn’t Heisenberg’s uncertainty. And it is not an uncertainty for most of us: most of us are pretty sure that we are in the only universe that exists.
The process of observing and comparing the details of several universes that we can’t see, particularly when the observer is unsure of which universe the observations are being made from, seems to be just as weird as the aspects of quantum theory that this theory claims to get rid of.
And none of these interacting universes could be supernatural.
What can we make of all this?
We have now looked at seven otherworldly things, six multiverses and the supernatural. We have also looked at two kinds of mysteries; those that may be solved by novel approaches to present-day science in one case, and by supernatural explanations in the other case. Do they or can they have anything in common?
I have already postulated the possibility of a supernatural in order to explain three matters that I think may be intrinsically inexplicable to science. They are:
- what makes the difference between a living organism and inanimate matter;
- what produces the consciousness, as distinct from the intelligence of living organisms;
- what produced the very first progenitor of all universes, and defined its characteristics.
I think the first of these might be a bit shaky. The difference between living and inanimate matter could just be the way organisms are constructed. But I think there may also need to be something to switch on the new organism at some stage of its development.
And while I can understand how material processes create intelligence in both computers and brains, I am unable to imagine a theory that would explain how the electrochemical intelligence of a living brain could produce all the sensations of our consciousness. I have looked at this I more detail in other essays.
And I cannot see how there could be any ultimate beginnings in a world based on our present concepts of mass/energy, space and time.
But, as I have said earlier, if the supernatural must, by definition, have very different characteristics from the material world, that means that the supernatural must be free of at least some of the constraints of our science, such as mass/energy, space and time. So the supernatural could provide an answer to these three mysteries – provided we were willing to accept that possibility without having any details of how the supernatural did it.
But I have also said that an alternative explanation of mysteries that are beyond our present-day science might be found in some new kind of yet-to-be-discovered scientific theory that also was free of at least some of these same constraints of our science. Just as geometry has been freed from the constraints of Euclid to allow parallel lines that intersect, and just as we have glimpsed the contraction of space and the lengthening of time in the theory of relativity, and particles being in two different places at the same time, so we may find a new science that dispenses with some of our present restrictions, or provides new capabilities. So what is beyond the reach of science now, may become explicable in due course. But I see no reason to believe that this must be inevitable.
All six multiverses have been postulated as ways of trying to resolve other kinds of scientific mysteries. These mysteries are:
- the apparent incompatibility between the theory of relativity and quantum theory;
- problems with quantum theory;
- and what led to the big bang.
All of these seem to be mysteries that ought to be resolved within the body of science. So all multiverses are based on space, mass/energy and time. Nevertheless, the multiverses would contain universes that could be vastly different from the universe we think we know. But none of them could contain anything supernatural.
Also, to me, none of these multiverses seem very convincing.
Perhaps we need a more convincing new kind of science to resolve the mysteries they are addressing, a science with fewer constraints and additional capabilities. If such a science is discovered we may then be able to dispense with both the supernatural and the multiverse.
Who knows when or if that will occur?