THE UNIVERSE, SIMULATION, AND GOD

Listen to Audio Version of Whole Service (mp3)
Listen to Audio Version of Sermon (mp3)

"The Universe, Simulation, and God"! This is probably the biggest topic I have ventured to discuss, so I hope you'll understand if I don't cover it completely in the next fifteen minutes.

I was led to this topic by a recent headline, which read "Physicists May Have Evidence Universe Is a Computer Simulation". Being a physicist, I decided to check this out, and found it was based on a scientific article entitled "Constraints on the Universe as a Numerical Simulation" published on-line November 12, 2012 by Silas R. Beane, Zohreh Davoudi, and Martin J. Savage, but apparently not yet published in a journal. (By the way, you can already see that the general media tend to distort, exaggerate, or sensationalize science - not that other topics are immune.)

The authors, by the way, are respected physicists, in the field called "lattice quantum chromodynamics". What is that, you may ask? Well, it's a branch of current theoretical physics very relevant to the question of whether the universe is indeed a super-cosmic computer simulation, or perhaps a totally realistic video game that God is playing. I'll explain a little bit about this field for you, and I'll give my criticism of their proposed experiments and of the whole concept of the universe as a simulation. And I hope to put this concept in perspective, as just the current contribution to an ages-old inquiry, whether from studying nature we can learn much about what, if anything, is beyond nature.

But I also wish to suggest some much more down-to-earth aspects of the topic. I see the most important related question as being the relationship between science and values - whether studying nature is helpful, or perhaps even decisive, in determining good values.

So, then, my ambitious outline for the next fourteen minutes is:
What is lattice quantum chromodynamics?
What would be the evidence that our universe is a computer simulation?
What is the historical context of efforts to scientifically look beyond nature?
What does science tell us about the supernatural?
What does science tell us about good values?
And, finally, what's wrong with the argument that our universe might be a computer simulation?

Simulation of the universe is actually a very common endeavor. Whenever we remember some past events, or imagine or plan some future events, we are simulating a small part of the universe in our minds. Simulating the entire universe has been attempted for at least two thousand years. The earliest mechanism known from archeology, called the Antikithera device from where it was found in a shipwreck, appears to be an orrery, which is a functioning model of the solar system. Until recently the solar system was believed to be the entire universe. Now days you can get an app for your favorite electronic device which calculates the positions of the planets. We may note that a mechanical orrery is an analog simulation, like a vinyl record, while an electronic app is a digital simulation, like an MP3 file, a distinction which Reverend Nickel drew on, in his sermon two weeks ago.

What "lattice quantum chromodynamics" is, is a digital simulation of the nuclear force which holds atomic nuclei together. The use of three complicated words of several syllables is required to indicate how erudite the subject is, but there is actually a sensible explanation for that name. Going from the end, "dynamics" means the process and theory of motion. The prefix "chromo" means color. This is because physicists discovered that there are actually three kinds of nuclear charge, rather than the two like electricity, which we call plus and minus. They decided to call the three kinds of nuclear charge by the three primary colors, so the theory of this triple force came to be called "chromodynamics" (it always sounds more intellectual in Greek). The term quantum means that this theory is a branch of the modern physics theory called quantum mechanics. This theory includes the famous uncertainty principle, which disturbed Albert Einstein.

Finally, why the word "lattice"? It turns out that the "color force" of chromodynamics is very difficult to calculate. Compare it with gravity and electricity. Gravity has only one kind of charge: mass. Isaac Newton wrote and solved the equations of gravity. Later Einstein improved them, making them more difficult to solve, but Schwarzchild, Hawking and others have still provided solutions. Electricity has two kinds of charge: positive and negative. A couple centuries after Newton, Maxwell was able to write the electromagnetic equations. They too can be solved. In fact, my job involves solving them, as part of telescope design, since light is a form of electromagnetic radiation. The nuclear force, however, has three kinds of charge, named after the three primary colors, as I mentioned. No physicist has yet been able to derive algebraic solutions. Therefore we have resorted to computer simulations, using a lattice to simplify the calculations. In using a lattice, only the forces at the intersections of the lattice lines are calculated. This is very similar to a digital recording of sound, in which only the acoustic pressure at successive instants of time is recorded.

Now we are ready to see what might be the evidence that the universe is a simulation. To be more exact, in the article I have referred to, the physicist claim we should be able to tell if the universe is a digital simulation. A digital simulation or recording has the advantages that it is easier to calculate, easier to record, and easier to preserve without alteration, but the disadvantages that it is not exact and is different depending on how closely spaced your calculation or recording points are.

The article suggests that, since the universe has three space dimensions, a digital simulation would have some sort of regular structure to the calculation points, like a crystal in which the atoms are arranged according to a lattice or grid, and like the calculational lattice which theoretical physicists use in lattice quantum chromodynamics.

Crystals have many interesting properties. Many of us may have looked at a diamond, for instance, slowly turning it. A crystal's bending of light changes as you turn it. This is because you may be looking squarely down a row of atoms, and then at an angle to the row. Light is affected by the angle it makes with the rows of atoms. Similarly, the authors of the article suggest that very high energy cosmic rays will be affected by the angle they make with the lattice structure of the universal simulation. Maybe cosmic rays can travel slightly faster when moving along a line of lattice points than when moving at an angle with them. The authors also suggest a couple other ways we could detect the lattice of the cosmic simulation.

This proposal, to search for evidence of a super-cosmic computer which is calculating us as a simulation, is hardly the first attempt of mankind to try to look beyond our universe. This is illustrated by the picture on the cover of our Order of Service today. I had seen this picture before, and it came to my mind recently when my friend Nathan Holmes-King showed me one of his assignments. This was a diagram of the universe, on a piece of paper, with solar system, nearby stars, galaxies, etc. At the margin were the words "edge of the universe". Thanks to Wikipedia, I was able to find a copy of the engraving I was reminded of, for our cover. This is a wood engraving, and is not medieval, but rather a 19th century illustration in a book by Camille Flammarion, a respected astronomer and meteorologist. It was an illustration for a chapter on the history of science. It depicts a medieval legend of a monk who journeyed to the edge of the earth and peaked under the universe's enclosing sphere of stars. Look in the upper left. There are two intersecting wheels. It's assumed these are the wheels from the vision of the prophet Ezekiel. Or perhaps they are the cogs which operate the rotating celestial spheres of ancient concepts of the universe. Or perhaps they are components of a mechanical calculator, like what my grandfather showed me from before electronic computers, and this calculator is busy simulating the universe.

Similarly, there have been non-mechanistic concepts of the universe as something similar to a simulation. I started by discussing some thinking, such as remembering and planning, as being simulation. This is similar to the concept presented in our Story for All Ages this morning, in which the universe is dreamed by the god Vishnu. Another example with which I am familiar is in the play "Our Town" by Thornton Wilder. My wife and daughter and I were in a production in Newark. My daughter played the girl Rebecca who, at one point recites a postal address concluding with "... Western Hemisphere, the Earth, the Solar System, the Universe, the Mind of God".

This brings us to whether or not the nature of the universe, and what we may see from peeking beyond it, bears on the question of whether or not there is a god? Or the questions of what sort of god or gods might exist or what god is like?

Briefly, I believe science disproves some concepts of god, but not all.

For example, during the time of Pericles, the Greek philosopher Anaxagoras was banished from Athens for teaching that the sun was made of ordinary matter and shined because it was very hot. This was blasphemy to the citizens because it implied the sun was not the god Apollo, shining by godly glory. But Anaxagoras was right, and science can tell us a lot about what, within our universe, is not a god.

On the other hand, Saint Patrick, whose day this is, once showed from a scientific fact that his trinitarian god was at least not illogical. He used the shamrock, with a leaf divided into three parts, to show that a god, united but of three parts, was not disproved.

Yet another note: one biologist, contemplating the numbers of species in various groups of animals, concluded god is excessively fond of beetles.

I do not see that science could ever disprove such notions as pantheism, which says the universe is god, or panentheism which claims the universe is contained within god. There are certainly many more possibilities.

I would also point out that, throughout history, god has been constructed in the image of man. To ancient people, god was a super-emperor or a wise law-giver. To enlightenment-era scientists, god was a perfect clockmaker who had constructed the universe and set it running. But, as the ancient Greek philosopher Xenophanes pointed out, if cows or horses could draw pictures of god they would sketch cosmic cows and horses. Now, in the computer age, there seems to be a tendency to see god as a cosmic computer programmer.

As for myself, I consider my god to be my values. Thus I would ask the parallel question, what does science prove or disprove about our values?

I believe we should accept truth, rejecting falsehoods, to the best of our abilities, and that the best method of finding the truth about objects and events within the universe is the scientific method. Our actions must simultaneously be based on good values and good scientific evidence concerning our actual situation and the likely results of our actions. Those who deny scientific truths, such as human-caused global climate change, will take the wrong actions, regardless of how good their values may be.

As an aside, I would point out that politicians seem to have taken the place of preachers as deniers of science. Not only are many denying global climate change, presumably because they don't want to admit they have no good solution, we also hear politicians deny that a woman can get pregnant from rape, apparently because they don't want to take sides in the debate on availability of abortion to rape victims, and we hear them deny that the candidate who beat theirs in a Presidential election is really a United States citizen!

However, this does not mean that science determines our values. From the truth about our origin through evolution by natural selection, for instance, various moral conclusions have been drawn. Some say, it's survival of the fittest, so we should discard other people who don't make the cut, just setting them adrift from our society and economy. Others say, we are all one family, and should treat others as our brothers and sisters. I'm on the latter side, but I can't prove it's right scientifically.

Another example came to my mind recently when Nathan showed me another of his assignments, a letter he had written to Albert Einstein. Einstein himself, of course, wrote letters, and one of them is perhaps his most important action. More important than the special or general theories of relativity, or his work on the photoelectric effect. It had become known to physicists, and even to author Philip Francis Nowlan who created the Buck Rogers character, that atomic energy could be released as an atomic bomb. There was grave concern among scientists that Hitler's Germany was capable of making one. Einstein, as the currently most prestigious scientist, was asked by others to lead the effort in informing President Franklin D. Roosevelt of this possibility. This was a very difficult decision for Einstein, who had been a pacifist before the emergence of Naziism. It is an example of a decision, strongly controlled by his scientific knowledge, but not completely determined by it. He still had to rely on moral values. Hopefully, none of us will be presented with this momentous or difficult a decision. Let us, nevertheless, do our best to know scientific truth and value our fellow creatures in the decisions we do make.

Returning now to the topic of the universe as a computer simulation, a decade ago Nick Bostrom of the University of Oxford published an article in the Philosophical Quarterly pointing out that, if it became possible to simulate the universe sufficiently to incorporate intelligent contemplation in the simulation, there would likely be many more simulations of the universe than the actual universe, so that it would be much more probable we are living in one of the simulations than in the original universe. This article is the first reference cited in the physics article I have referred to, and stimulated the present discussion of the topic.

The argument is that we presently simulate the universe, and various of its components. Presently we achieve only moderate accuracy. For instance, we do a relatively good job of predicting tomorrow's weather, but not next month's. Computers are getting faster and faster, and storing more and more data, so it shouldn't be long till we can do a very accurate simulation.

I disagree. I believe there are fundamental limits to the ability to simulate a universe within that universe.

Let me give you the example of my Mom's doll house. It's a very nice, large, doll house, occupying a whole wall in her home. My father built it for her. It has twelve rooms, each decorated for a month of the year, and is totally filled with dolls and doll furniture, and doll toys which we have all given her. It even has some smaller doll houses within it. One of these has a yet smaller doll house within, but that's the limit.

But could we make smaller and smaller doll houses to put inside, one after the other? These doll houses, whether made of wood, or plastic, or anything we could use, are made of atoms. Eventually we would have a doll house made of one atom, and it could not contain a smaller doll house.

If we were to simulate the universe, completely, it would have to contain our simulations, which would in turn contain simulations. This would end when we reached a situation of having only one atom to contain all the information of a simulation.

Or, to put it differently, computers cannot keep on getting faster forever. This is a result of the atomic nature of the universe. The matter in our universe is digital, not analog. The very quantum theory that is part of the premise of the article we are discussing puts these limits on simulation.

In fact. there is a branch of modern computer science called "computability" which has already cataloged many simulation problems into those which have been accomplished, those which are likely, those which don't know how difficult they may be, and those which are pretty hopeless ever to compute.

Nevertheless, there is a scientific result of interest which could come from the effort to detect a cosmic space lattice. Perhaps space actually does consist of individual points, and time of successive instants. This is actually not a new concept, and perhaps even feels intuitively correct. The great 14th century English philosopher John Wycliffe, also responsible for the first complete translation of the Bible into English, taught this. Wycliffe was more favorably received by nobles and citizens than Anaxagoras, and was an inspiration to the Reformation in England, though at one point after his death he was declared a heretic and his body was dug up to be burned. The very experiments proposed by the physicists, if performed, could tell us whether the space-time fabric of the universe is continuous, as in Newton's and Einstein's theories, or digital as in Wycliffe's. That would not, however, tell us whether god is a super-cosmic video game designer.

As well, our universe could be a simulation within a larger, or somehow more varied, universe. Another set of quantum mechanical theories, the Kaluza-Klein theories, call for a universe of ten spatial dimensions, for example.

My conclusions, then, are that science is important, in fact, science is essential, but science is not everything. We, whether we be humans or a sophisticated algorithm in a super-cosmic computer, as long as we make decisions, should choose values to guide our decisions. Our values and actions should be consistent with scientifically known truth, but we need more. We still need good values.

This sermon is copyrighted by myself, Paul K Davis, of Fremont California, but I would be happy for it to be distributed without modification, and with notification to myself at paulkdavis@earthlink.net.

Thank you for your attention, and I would be pleased to continue discussing these topics after the service, or in the future, if the super-cosmic computer keeps calculating us.