Why Our Universe is not a Simulation

In Digital Physics and the Software Universe and Is Our Universe a Computer Simulation?, we covered the idea that some claim that our Universe seems to behave like a large network of quantum computers calculating how to behave. Perhaps not in an actual literal sense as the realists would have us believe, but at least, perhaps, in a positivistic manner that makes for a good model that yields useful predictions about how our Universe seems to behave. Recall that positivism is an enhanced form of empiricism, in which we do not care about how things “really” are; we are only interested in how things are observed to behave. With positivism, physicists only seek out models of reality - not reality itself.

In this posting, I would like to showcase two of Dr. Matt O'dowd's PBS Space Time videos that deal with the topic:

Are We Living in an Ancestor Simulation?
https://www.youtube.com/watch?v=hmVOV7xvl58

Are You a Boltzmann Brain?
https://www.youtube.com/watch?v=nhy4Z_32kQo

I love Dr. Matt O'dowd's PBS Space Time videos because they tend to dive a bit deeper into the physics of the subject at hand than most lectures on the Internet.

Matt O'dowd points out that it is nearly impossible to prove that we are not living in a computer simulation or a Boltzmann Brain because any objection to those ideas can easily be refuted with a sufficient level of computer technology or a Boltzmann Brain with a sufficient level of imagination to circumvent the objection. Thus, given an infinite number of objections to the idea that our Universe is some kind of a Universe Simulation, there is also an infinite number of opposing arguments available to refute those objections. In that regard, both ideas seem to verge on solipsism. Solipsism is a philosophical idea from Ancient Greece. In solipsism, your Mind is the whole thing, and the physical Universe is just a figment of your imagination. So I would like to thank you very much for thinking of me and bringing me into existence! But in an infinite Multiverse that has always existed, one would think that such things must eventually arise - see The Software Universe as an Implementation of the Mathematical Universe Hypothesis for more on that.

Similarly, it is nearly impossible to prove that we are the lone form of Intelligence in the Milky Way Galaxy. Just because we see no evidence of other Intelligences does not mean they are not out there. As you all know, I am obsessed with the fact that we see no signs of Intelligence in our Milky Way galaxy after more than 10 billion years of chemical evolution that should have brought forth a carbon-based or silicon-based Intelligence to dominate the galaxy. Such thoughts naturally lead to Fermi's Paradox first proposed by Enrico Fermi over lunch one day in 1950:

Fermi’s Paradox - If the universe is just chock full of intelligent beings, why do we not see any evidence of their existence?

I have covered many explanations in other postings such as: The Deadly Dangerous Dance of Carbon-Based Intelligence, A Further Comment on Fermi's Paradox and the Galactic Scarcity of Software, Some Additional Thoughts on the Galactic Scarcity of Software, SETS - The Search For Extraterrestrial Software, The Sounds of Silence the Unsettling Mystery of the Great Cosmic Stillness, Last Call for Carbon-Based Intelligence on Planet Earth and Swarm Software and Killer Robots. The explanations for Fermi's Paradox usually fall into one of two large categories:

1. They really are out there but for some reason, we just cannot detect them.
2. We are truly alone in the Universe or at least we are alone in the Milky Way galaxy.

The first category of explanations is rather weak because it means that all forms of Intelligence in the Milky Way galaxy are intentionally, or unintentionally, hiding for one reason or another. The second category implies that our Universe is not very friendly to Intelligence of any kind. True, Intelligence could be rather rare, but more likely, our Universe is just a very dangerous place for Intelligence.

Another Approach
But after watching Matt O'dowd's Space Time videos I had another thought. Even though we cannot rule out being in a Universe Simulation or explain why we see no signs of other Intelligences in the Milky Way galaxy, could we use these two unprovable conjectures to null each other out? This is an old trick in physics. Probably the most famous example of this trick is Richard Feynmann's Path Integral formulation of quantum mechanics. Richard Feynmann's Path Integral formulation of quantum mechanics maintains that when a particle moves from point A to point B, it follows an infinite number of unknowable paths that interfere with each other both constructively and destructively. Richard Feynmann then showed mathematically how nearly all of these infinite paths cancel each other out with destructive interference. The only paths that really count are those that add up constructively and those paths have the particle move directly from point A to point B along a straight line. Now proving the idea that particles move directly from point A to point B along straight lines may not seem very profound, but Richard Feynmann's Path Integral formulation of quantum mechanics also does a wonderful job of explaining how quantum mechanics works for much more interesting problems. For more on this see Matt O'dowd's Space Time video:

Feynman's Infinite Quantum Paths
https://www.youtube.com/watch?v=vSFRN-ymfgE&t=1s

But the very best source for Richard Feynmann's Path Integral formulation of quantum mechanics is, of course, Richard Feynmann himself, and is available in his very accessible book QED – The Strange Theory of Light and Matter (1985). In QED Feynmann explains that when a photon reflects off of a mirror, it actually reflects off every point along the mirror and not just off the center point in the middle as we were taught in school. In Richard Feynmann's Path Integral formulation of quantum mechanics, individual photons do not do what we were taught in school. Instead, each photon follows an infinite number of unknown paths between the source and receiver. Each path has a quantum amplitude that can be denoted by a little arrow spinning in the complex plane. When the little quantum amplitude arrows line up in the same direction, as they do near the middle of the mirror in Figure 2, it means that those paths contribute the most to the ultimate arrival of the photon to the receiver by means of constructive interference. Notice that the little quantum amplitude arrows that are not close to the center of the mirror point in all different directions and, consequently, cancel each other out by means of destructive interference. Now if you think that a single photon cannot possibly follow an infinite number of paths between the source and receiver, try removing some of the mirror! Simply cover part of the mirror surface with a set of parallel strips of black paint as shown in Figure 3. Such a mirror with many little parallel stripes is called a diffraction grating. Now when a photon bounces off the mirror, the angle of incidence will no longer be equal to the angle of reflection. Instead, the angle with which photons reflect off the diffraction grating will depend on the frequency or color of the photons. You can see this effect when photons reflect off of a CD. The rainbow colors come from individual photons reflecting off the shiny flat strips of undisturbed aluminum between the tracks of data pits in the CD at different angles.

Figure 1 – In school we were all taught that light rays bounced off of a mirror midway between a source and a receiver and that the angle of incidence was equal to the angle of reflection.

Figure 2 – But in Richard Feynmann's Path Integral formulation of quantum mechanics, individual photons do not do that. Instead, each photon follows an infinite number of unknown paths between the source and receiver.

Figure 3 – To prove that photons bounce off of every part of the mirror, simply cover part of the mirror surface with a set of parallel strips of black paint. Now when a photon bounces off the mirror, the angle of incidence will no longer be equal to the angle of reflection. Instead, the angle with which photons reflect off the mirror will depend on the frequency or color of the photons.

Figure 4 – You can see this effect when photons reflect off of a CD. The rainbow colors come from individual photons reflecting off the shiny flat strips of undisturbed aluminum between the tracks of data pits in the CD at different angles.

Do the Universe Simulation Hypothesis and Fermi's Paradox Cancel Each Other Out?
Now let's try to use Richard Feynmann's Path Integral formulation of quantum mechanics to deal with the nearly infinite number of paths that the Simulation Hypothesis and Fermi's Paradox can follow. Suppose that our Universe actually were some kind of Universe Simulation that we cannot distinguish from a "real" Universe because whatever test we perform on the Universe Simulation yields the same result that a "real" Universe would yield. This yields an infinite number of possibilities. Similarly, the number of possible explanations for Fermi's Paradox is nearly infinite in number too. Now let's add up all of the little quantum amplitude arrows for each. For example, if our Universe really were a Universe Simulation, then our Universe Simulation should most likely be a Universe Simulation that resembles the most common Universe Simulation. And I would suggest that in that Universe Simulation we should find a Universe dominated by Intelligence because we have Intelligence. Otherwise, this Universe Simulation is hugely wasteful and filled with way too much unnecessary cosmic real estate. Now if a Universe Simulation did not contain any Intelligence at all, we would not be here pondering it, and it could be any size at all. This is reminiscent of Brandon Carter’s famous Weak Anthropic Principle (1973):

The Weak Anthropic Principle - Intelligent beings will only find themselves existing in universes capable of sustaining intelligent beings.

but with a twist:

The Simulated Weak Anthropic Principle - Intelligent simulations in a Universe Simulation will only find themselves existing in Universe Simulations capable of sustaining intelligent simulations that dominate the Universe Simulation because they are intelligent and capable of doing so. Thus, Universe Simulations should never have a Fermi's Paradox.

This hypothesis means that we should only suspect that we are indeed simulations in a Universe Simulation when we do not have a Fermi's Paradox. Since our Universe does have a Fermi's Paradox, it means that our Universe is most likely not a Universe Simulation! Granted, given an infinite number of Universe Simulations, a very few will contain a sole Intelligence observing an otherwise sterile Universe Simulation. But far fewer will contain a sole Intelligence surrounded by 7 billion other simulated Intelligences all residing by themselves on a single planet in a vast Universe Simulation. On the other hand, if we did observe a Universe just chock full of intelligent beings running the joint, we should be very suspicious of being in a Universe Simulation. First, because most Universe Simulations should either contain no Intelligence at all or should contain huge amounts of Intelligence spread out all over the place. Secondly, if we really did find ourselves in a Universe dominated by Intelligence, such a Universe would have levels of simulated technology capable of creating Universe Simulations in an infinite loop!

Comments are welcome at scj333@sbcglobal.net

To see all posts on softwarephysics in reverse order go to:
https://softwarephysics.blogspot.com/

Regards,
Steve Johnston