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Stopping for lunch at the usual time I made my way to my seat in the corner of the canteen beside the rack of journal articles. One thing I love about working for a CRO is the plethora of sciency-related readings available in the staff library. The August issue of New Scientist caught my eye with its intriguing title; “Spooks in space“. Now before we get started I would like to make one thing clear; I am not a physics guru, mathematical representations of physical theorems not only confuse me but I also question the usefulness of over complicating a subject that already holds such a stereotype of requiring intellectualism and genius in order to fully appreciate it. Therefore, while the first section will outline a (very) basic foundation of the theories, I hope that the second part is more thought provoking and practical for discussion.

Boltzmann brains, named after the 19th century thermodynamicist Ludwig Boltzmann, are a hypothesised phenomenon arising from the cosmological interpretation of the second law of thermodynamics (the complexity of the universe will always increase). Boltzmann’s original idea was that random thermal fluctuations may have been responsible for the creation of our universe. Delving deeper, Boltzmann proposed that our observable universe (with its low level of entropy and thus higher organisation) may be a figment of our own imagination; we may simply be the result of a ‘random fluctuation’ within another universe of higher entropy (lower organisation, higher chaos).

The Boltzmann paradox is thus; if we are the result of a a random fluctuation, our likelihood of existing is much less probable than a universe full of Boltzmann brains. In short, the billions of self-aware brains that make up humanity (remember, if we are due to random fluctuations) are less likely than a single, self-aware and conscious entity with false memories and perceptions of the world around it.

The good news is, we aren’t Boltzmann brains! I believe the argument here is that in order for Boltzmann brains to arise, the target universe from which they are formed must be at a high level of entropy. Due to the fact that we exist in a universe with low entropy (being relatively young) tends to rule out the likelihood of so many brains spontaneously arising all with false memories and perceptions of the universe. The Boltzmann scenario is only salvageable if our portion of the observable universe is a small ‘bubble’ within one much larger that has high entropy (chaotic and prone to random fluctuation).

Boltzmann brains have vast theological implications, if correct. They may form the basis for a rationalised and scientific explanation for the existence of a god. As a devout atheist (who has gained some tolerance for religious discussion over the years) I do hold an active interest in rational theological discussion. The Boltzmann hypothesis seems to be the first plausible (although still highly unlikely) explanation for the existence of god that doesn’t involve mindless devotion and ‘leaps of faith’. Below is a post I found that outlines a basic theory, which I hope to develop further.

“Getting back to Boltzman Brains, it occurred to me that a Boltzman Brain could provide a naturalistic explanation for the existence of God.
The first cause proof of God is that there has to be a first cause to our universe. Atheists, however, always retort: “Oh yeah, then what caused God?”
So, a theist can now say that God was a spontaneously-formed Boltzman Brain formed from the formless chaos of Nothingness.
This response also rescues God from the charge that if He exists, then He is Nothingness itself; God would really be a Something rather than a Nothing if He were a Boltzman Brain.
Since there is no existence more lonely than being a disembodied, utterly alone, Boltzman Brain, God created the world and us in order to have some company. . ” – Warren Plats, link.

Thus the requirements for a Boltzmann-based god would be;

  1. A sufficiently old universe (infinite age?) to allow for the spontaneous formation of a being with self-awareness and omniscient capabilities.
  2. Methods for that being to interact with its universe or itself in order to create the target universe.
  3. A desire on the god’s behalf to create the target universe.
  4. Allowance of the god’s existence for a sufficiently long enough period to both formulate and enact the creation (random fluctuations in chaos can more easily remove order than create it – a cup is more likely to drop and smash than it is to jump up and reform).

Moving on from these requirements, a possible Boltzmann god may then arise from the constituents of an infinitely old universe rearranging themselves spontaneously so as to create order from chaos and in the process, give rise to an all knowing, all powerful entity. As a side note I would like to make the point that the name “Boltzmann Brains” is slightly misleading; our ideas of what constitutes consciousness is often clouded by our own experiences. So far, humanity is the only fully conscious entity in our observable universe, therefore we tend to describe consciousness in terms of ourselves. Boltzmann brains, and in fact other more exotic forms of alien consciousness need not necessarily be made up of the same stuff that makes up our brains. Nerve cells, blood vessels and electrical impulses can give way to, and are less likely to produce consciousness than more simple models such as silicon chips and even clouds of interacting atoms (such as Hydrogen, the most abundant element in the universe). Given enough time, anything that can happen, will. In this case, a universe that has existed for an infinitely long period has a higher likelihood of producing such a conscious entity.

But the question remains of how such an entity can spark the creation of a universe that is suitable to lifeforms like us. Was it external manipulation such as a conscious and purposely directed fluctuation that gave rise to our universe? Or was it an internal rearrangement of its own constituents (eg; the creation of a singularity); a self-directed suicide on behalf of the entity that created our reality? The latter opens up the possibility of a cyclic universe, in that everything that has come to pass will happen again. The eventual creation of a god-like Boltzmann brain serves as the eventual catalyst which prevents the perpetual darkness that an infinitely expanding universe would bring and starts everything afresh.

I hope to revist the topic of Boltzmann brains sometime in the future. What seemed as a relatively ‘goofy’ and niche area of philosophical physics quickly spills out into a question of reality itself, the implications of Boltzmann brains as typical observers (can we really be sure that our measurements of the universe are ‘really real’) and the usefulness of Boltzmann brains as a theological model for creationism (albeit in a distinctly more science-heavy form).