I would like to begin this intellectual journey into the wondrous world of idealist cosmology by stating the twofold purpose of this essay.
On one hand i would like to contemplate what would the current hypotheses regarding the fate of the Universe would entail from the idealist perspective.
On the other hand, i would like to contemplate what would overall idealist cosmology would look like with or without a postulated “purpose” or “meaning” for existence. For this analysis, i will use Bernardo Kastrup’s arguments, as stated in his book, Rationalist Spirituality (which i greatly recommend).
This being said, it is obvious that my worldview, the reigning ontological paradigm in which i operate is the idealist one. As opposed to realism, in a nutshell, idealism states that is not the mind an emergent phenomena of the reality “out there”, but rather the “reality out there” is a product of the mind. In other words, there is no reality outside consciousness. While it is not the purpose of this short article to bring arguments for this worldview, i (again) greatly recommend Bernardo’s works. Or, for the short brief, the Wikipedia article.
Possible scenarios for the fate of the Universe
I will begin by trying to classify the most well-known and scientifically sound scenarios regarding the ultimate fate of the Universe, based on how the metaphorical line of time looks in those scenarios. As you will see, i assume that the standard model of cosmology holds true (i.e. there was a Big Bang that started everything).
Closed loop (Eternal cyclicity):
1. The cyclic model of the Universe (eternal successions of Big Bangs and Big Crunches). Even if the initial model, designed by Einstein had an issue with the ever-increasing entropy, new models for cyclical universes, such as brane cosmology or Penrose’s conformal cyclic cosmology, offer explanatory alternatives to maintain an everlasting, cyclical universe possible.
Ray (half-line, with one starting point and infinite future):
2. Big Freeze (also called Heat Death of the Universe)
3. Big Rip (the timeline is blurry here)
Finite time segment:
4. Big Crunch
5. Big Slurp
What are the variables on which the fate of the Universe is decided?
The complete answer would be:
- The Universe overall shape
- Its density
- How much dark energy is the Universe truly made up of and how potent it is
Things, however, seem to be simpler. Although nothing is 100% certain (then again, what is?), it seems we have an answer about how the first two variables will play out. Even more, the answers are all connected:
The shape of the universe and whether it is finite or infinite depends of the struggle between the rate of its expansion and the pull of gravity. And the latter, depends in part of the density of matter in the universe. As such:
- If the density of the universe exceeds a specific critical value, then the universe is “closed” and “positive curved” like the surface of a sphere. This means light beams that are initially parallel will converge slowly, eventually cross and return back to their starting point, if the universe lasts long enough. If so, the universe is not infinite but has no end, just as the area on the surface of a sphere is not infinite but has no beginning nor end to speak of.
- If the density of the universe is less than this critical density, then the geometry of space is “open” and “negatively curved” like the surface of a saddle. If so, the universe has no bounds, and will expand forever.
- If the density of the universe exactly equals the critical density, then the geometry of the universe is “flat” with zero curvature like a sheet of paper. If so, the universe has no bounds and will expand forever.
Recent measurements suggest that the universe is flat with only a 2 percent margin of error. That means the ultimate answer depends on dark energy and what role it will play as the universe ages.
But what is dark energy?
On short, nobody knows for sure, but we do have some hypotheses. Under our current understanding of cosmology and based on the empirical data we have thus far, dark energy is a hypothetical form of energy which permeates all of space and tends to accelerate the expansion of the universe. Dark energy was originally discovered when scientists set out to find out how much the expansion of the universe was slowing down, due to gravity pulling it back inward. They found, instead, that this expansion is actually accelerating. This shocking discovery earned three astrophysicists the 2011 Nobel Prize.
According to the Planck mission team, and based on the standard model of cosmology, on a mass–energy equivalence basis, the observable universe contains 26.8% dark matter, 68.3% dark energy and 4.9% ordinary matter.
That’s a lot of something we don’t know what is!
Dark Energy – or how the fate of everything will be decided by something we do not understand
Even if we can make current day measurements, we have no data to be able to infer what the strength and influence of dark energy will be over aeons. Limiting the scenarios we consider based on the behavior of something we do not understand (dark energy) would be an epistemological shortcoming.
If the (relative) strength of dark energy will diminish over time, the expansion of the universe will stop accelerating and eventually slow down. If dark energy is comparatively weak enough, gravity will win and the Universe will fall back on itself, resulting in a Big Crunch – the entire matter and energy, as well as the whole space-time frame pulled back into a dimensionless singularity.
Now, as our understanding of physics (namely quantum gravity) is incomplete, we cannot state if that is the final state of the Universe (thus the existence forming a closed segment) or that that will be the beginning of a new cycle, and the Big Crunch will be the Big Bang of another Universe, like a Phoenix reborn from it’s own ashes.
For some reason, this scenario of eternal death and rebirth of the Universe, like proposed in the conformal cyclic cosmology or other cyclical models, sounds very appealing, from a metaphysical perspective. An eternal cycle of symmetrical processes sounds a lot more intuitive than something with a start and no end. But I will come back again to the metaphysical interpretation later.
If the prerequisite doesn’t hold true, i.e. if dark energy maintains its apparent strength, we are most likely facing the Big Freeze scenario.
In this scenario, the present day accelerated expansion is maintained and the universe continues to expand at an ever increasing speed. As this happens, due to the laws of thermodynamics, the heat is dispersed throughout the space as all known astronomical bodies are pulled apart by the expansion of the universe (as currently observed through the red shift effect). Consequently, the Universe will get colder and colder until the temperature throughout the space will asymptotically go towards absolute zero. Since the sources of energy in the Universe are limited, there is no process to counter this loss of temperature. Pulled apart, even the remaining raw material for star formation will be inaccessible, and the lights of the Universe will go dark one, by one.
After all stars will be dead (either black holes, neutron stars or white/brown dwarfs), the Universe will become a stellar cemetery of black holes, which themselves will disappear over time as they emit Hawking radiation.
This end state of the Universe was also called the Heat Death of the Universe. The big culprit is entropy. Considering the Universe an isolate system, the entropy in it will continuously increase until it reaches a maximum value. The moment that happens, heat in the system will be evenly distributed (and close to absolute zero), allowing no room for usable energy (or heat) to exist – hence the term ‘heat death’. That means, mechanical motion within the system will no longer be possible. All life, as we know it (or as we could conceive it) would cease to exist.
Unfortunately, it seems that (under nowadays data, like i said before, we cannot be certain of what future holds us, because we do not know all the laws of physics) this is the most likely scenario. Accurate measurements made by the WMAP (Wilkinson Microwave Anisotropy Probe), which picks up cosmic microwave background radiation (CMBR), indicate a density that is much less than the critical density. This is very consistent with observations at the outer regions of the Universe; that being, increasing outward velocities of galaxies as they are further from us.
Metaphysically, this scenario seems very intriguing and counter-intuitive. Something with a beginning, but no end? Or, rather said, an end in function, but a continued existence as a dead, cold husk? It is true, some scientists say that it would be possible that, even in this scenario, Random quantum fluctuations or quantum tunneling can produce another Big Bang in years or entropy, could decrease, over an infinite time. But that sounds short of ludicrous. ? Really? That a 10 with 10^56 zero after it.
Nonetheless, the most scary and violent two scenarios are still to come.
If the dark energy is actually stronger that we assumed (or will somehow get/act stronger), as in the case of the hypothetical Phantom Energy, it will, over time, increase the rate of acceleration (“accelerate the acceleration“), leading to a steady increase in the Hubble constant. As a result, all material objects in the universe, starting with galaxies and eventually (in a finite time) all forms, no matter how small, will disintegrate into unbound elementary particles and radiation, ripped apart by the phantom energy force and shooting apart from each other.
The end state of the universe is a singularity, as the dark energy density and expansion rate becomes infinite. What is poetic in this scenario is not only the absolute dissolution of the Universe, but rather the possibility (under Penrose’s theory) that the Universe to start again from that point.
Credit: Discovery Enterprise
These are the main theories regarding the ultimate fate of the Universe. Basically, in all of them the question boils down to the evolution of Dark energy. If dark energy maintains the present strength (or ratio within the structure of the universe), we are facing the Big Freeze Scenario. If it increases, we are facing the Big Rip Scenario. If it decreases, we are facing the Big Crunch Scenario.
There are hypotheses regarding the evolution of the entire Multiverse, such as the eternal inflation model, but I do not see the reason to analyze them, as they say nothing new in regards with the Fate of THIS Universe. Under this model, while any given universe eventually reaches heat death, there are always other regions that haven’t, and new universes being produced within the inflationary volume, so the Multiverse as a whole never ends.
I kept for the end one last model… which doesn’t really fit with the others. This is one of the more interesting ones and maybe the richest in metaphysical speculations.
It is called the Big Slurp.
I starts from the following question: What if the vacuum in our Universe is not TRUE VACUUM? I.e. what if the vacuum is not in its lowest energy state possible? Maybe the entire space-time is in a state of instability? (well, technically, metastability). Then it could, at any given time and without any warning, to undergo a vacuum metastability event, that could destroy everything, starting from an microscopic bubble, anywhere in the Universe, eating away the Universe at the speed of light.
As physicists Michael Turner and Frank Wilczek put it, in an article in Nature back in 1982:
“without warning, a bubble of true vacuum could nucleate somewhere in the universe and move outwards at the speed of light, and before we realized what swept by us our protons would decay away.”
Having your protons decayed out of existence at the speed of light, along with the entire Universe, would ruin anyone’s day.
So, how can we frame and analyze these scenarios within the idealist paradigm?
For once, all the Universe is in the Mind. That means that an end of all things would either mean the end of the Mind (1) or the end for any need for which the Universe existed (2).
Postulating that the Mind is a non-physical, fundamental Entity (at loss of better words), that would make it outside the space-time. Thus, without end (since the concepts of time should not apply). Then the first conclusion should be falsified and we come up to the second one.
But why would Mind abandon Universe? The concept of Meaning, or purpose for existence comes in mind.
Lets go scenario by scenario.
1. Cyclicity (infinite timeline): This cosmological model sounds very familiar. Not only it is in line with ancient spiritual traditions, such as the vedic cycles of Birth and Death (which are actually an archetypal motif throughout many religions and spiritual teachings), but it resonates with the idea of a Mind practicing the material world, as for a purpose, such as gathering knowledge (i cannot thing of any other ultimate purpose).
2. Finite time scenarios: It would entail the idea that the physical world is no longer needed. Be it, at the end of a long and gradual evolution, like in Big Rip, or like a sudden universal Satori, like in the possibility of a Big Slurp.
What puzzled and troubled me for a long while was a scenario such as Big Freeze or Big Rip. While in Big Crunch there was a possibility that an advanced civilization could open a wormhole towards another universe in the last moments of our universe, in Big Rip or Big Freeze, there was NO CONCEIVABLE WAY (maybe except Dyson’s eternal intelligence, which is debatable) for intelligent life, and civilizations to find a safe haven from utter obliteration.
I was toying with nihilism. Under materialism, there would be no escape from Big Rip or Big Freeze and all the progress of humanity and other possible civilizations was doomed to nothingness. What would have been the point? And i am not talking about the obliteration of an individual, or a species. We are talking about the futility of the entire Universe. And recursively, from the end of time to the present days, any action would have been futile.
However, idealism offers a meaningful alternative. For example, we could view Big Rip as the dissolution of the physical world, after there is no longer the need for it. Here, i am borrowing Bernardo’s hypothesis for meaning: The Mind was initially unable to reflect itself and we are fragments of it, trying to gain a complete knowledge of itself.
And when the process (which can be conceivably finite) ends, there would be no longer need for duality. No longer need for a projected outside reality and individuality. It will be Oneness, Omniscience and Bliss. Doesn’t sound so bad, isn’t it?
As an ending to this essay, however, i would like to throw an intellectual challenge, questioning the very premises on which we build so far. I also got this insight from another thinker, so i cannot claim it myself, but I enjoy expanding on it:
Bernardo was showcasing in Rationalist Spirituality the main arguments for which the Mind was perfectible and thus the process, dynamic. Because, if it would be perfect and omniscient from the start, what would be the point of this projected reality?
How about this alternative: The Mind knew EVERYTHING from the beginning, but the purpose/meaning in Existence is not the gathering of knowledge, but rather the sheer enjoyment of (previously only imagined) events? Like going to a movie you already saw. And you know the ending. You know everything about it. And you still enjoy the emotions awakened by it.
Maybe that’s the purpose of living. Or maybe, it is indeed the gathering of knowledge.
Either way, the End of Everything doesn’t sound so bad anymore.