The End of Existence
Our world is toast, but not soon. In five billion years, Earth will crash into its dying sun. However, this is not going to be a problem for anyone. Eons earlier, all of life would have ended anyway. Earth will have baked in an oven created by the sun expanding into a red giant star. Thus, our planet will have been uninhabitable long before its roasted demise.
How much humans will have evolved by their end is unknown. Hominins seem to have appeared some six million years ago, and we are the current manifestation of their evolutionary journey. The next six million years will, most likely, bring about additional changes in human evolution. What five billion years might produce is unimaginable. One can guess, however, that our species, homo sapiens, will fade away early on, as newer adaptations to changing natural conditions sprout and grow on our evolutionary tree.
For now, we exist as homo sapiens, and we ponder our existence, asking many questions about what we are, where we are, how we got here, and where we are going. Each of us knows existence as the personal world in which we live, and we each experience our world differently as a unique body and personality. I call that personality, me. The me of my body is one experience of existence. That experience is unique among all of life on the planet, and like all of life—now and forever—it will end long before Earth burns. As a me of the body, I am very familiar with the world around me and somewhat aware of the vast universe in which it lies.
Cosmologists say that the universe started almost fourteen billion years ago when our cosmos blew out of an emptiness that is nowhere to become existence as we know it. The content of a hundred billion galaxies burst from a singularity smaller than an electron to become the ever-expanding storm of debris that we call home. Our galaxy, the Milky Way, is one of these billions of galaxies, each with its hundred billion stars. The planet we inhabit is but a nanoscopic speck whirling in the utter vastness of this cosmic storm.
Our earthly home is a minute particle of debris spinning on a physical field called space. This field curves and bends under Earth’s weight, giving the planet an orbit around its star, the sun. The fusion of its travels with the field in which it lies forms spacetime, in which we sense our existence as bodies ticking along in unison with a myriad of other objects on our wee planet inside the explosion that is our expanding universe.
But how do cosmologists describe the end of existence? Katie Mack, who is a noted theoretical cosmologist, presents five possibilities in her recent book, The End of Everything. But first she says not to worry. We will not be around to see the end. Earth will die eons before the universe disappears. Earth’s demise will come as the sun runs out of fuel and expands into a red giant. The expanding sun will engulf Mercury, perhaps Venus, and char Earth beyond recognition. Earth will then spiral into the sun, its atoms dispersing in the fiery furnace. The grand finale is the sun, along with the atoms that once were Earth, collapsing into a dense white dwarf. That will be the end of our blue marble.
What about the end of the universe? Five billion years from now Earth will die by fire, as Mack puts it. Then, she says, it will be at least another 200 billion years before the universe goes kaput. She gives us five scenarios that she and other cosmologists study.
1. Big Crunch (not likely anymore)
For a time, the Big Crunch seemed to be the answer. It was determined that the combined gravitational attraction of all matter, including dark matter, would overcome expansion and the universe would fall back into itself, collapsing to a single point like when it began. Since the discovery of dark energy and an ever-increasing expansion, this has become an unlikely ending.
2. Heat Death (most likely)
Cosmologists now think that the expansion will go on forever because of dark energy. As galaxies grow farther apart, they will come apart. Gravitational forces will lose the strength to hold them together. In the end, atoms will be ripped apart and the subatomic debris will remain in an expanding emptiness.
3. Big Rip (not likely, but possible)
If dark energy expands the universe at a faster rate than expected in Heat Death, then gravitational forces will fail to keep the universe intact and the universe will rip apart, galaxy by galaxy, star by star, atom by atom down to its foundational subatomic particles.
4. Vacuum Decay (extremely unlikely, but discussed)
Cosmologists like to discuss this rendition of the end, but do not see its possibility. In this ending, a vacuum bubble forms when something goes wrong in the Higgs field, which gives mass to particles. The bubble would expand at the speed of light destroying everything along the way, ending the universe.
5. Bounce (intriguing new idea)
The Bounce has different possible scenarios, but the idea goes like this. In the far, far future the universe will stop expanding, reverse itself, and come roaring back toward its beginning, much like the Big Crunch; but instead of collapsing into a final point, it will bounce off a similar, but invisible, parallel universe. The bounce will result in another Big Bang as our universe once again expands. There is much speculation around this nascent idea of a recurring universe among many similar universes.
Mack says (p. 206), It’s impossible to seriously contemplate the end of the universe without ultimately coming to terms with what it means for humanity. We encounter death throughout our lives, and then must face our own. Our entire species will disappear at the end of its evolutionary cycle. Personal legacy often survives individual death. The legacy of homo sapiens may survive its extinction by being chronicled among succeeding species, but human legacy will die for certain when the expanding sun chars Earth to a crisp. At that point, it will certainly not matter that we ever lived (unless we have moved off Earth by then to another planet or even to another universe). In about 200 billion years, it will not matter that there ever was a universe. Meanwhile, we give importance to ourselves and our world.
We ponder our existence and give it meaning and purpose. We find value and guidance in family, culture, religion, philosophy, science, and the arts. While doing so, we extoll our significance and virtue. However, considering the humongous scale of the universe, humans seem to count for very little, except that we are here. It is safe to say that the universe does not care whether we are or not, but we do exist, and we give ourselves value. Because we are aware and curious, we raise existential questions and attempt to answer them. Physicists work hard to answer the how questions: How did the universe come to be? How is the universe structured? How does it work? Metaphysics attempts to give us our meaning and purpose. Who are we? Why are we here? What does it all mean? The answers have varied over millennia, but the legacy of humans is that we do matter, at least to ourselves.
Answers to existential questions may vary widely, but in general, we seem to know a great deal about who, what, where, and why we are—and how we came to be. Whereas metaphysics produces—let’s say—the poetry of mythology, philosophy, and art, physicists work within nature’s reality, which is an organized system that follows universal laws. These laws can be represented by fundamental equations. There is little poetry in physics. Theories are proven through verifiable experimentation.
Some quantum physicists venture to answer the question What am I? from an empirical viewpoint. They say that we are our bodies, a bundle of subatomic particles, and nothing more. For them, there is no consciousness outside of the physical realm. Brian Greene, a noted physicist, puts it this way in his recent book, Until the End of Time (p. 120): I anticipate that we will one day explain consciousness with nothing more than a conventional understanding of the particles constituting matter and the physical laws that govern them…. physical law reaching arbitrarily far into the outer world of objective reality and arbitrarily into the inner world of subjective experience. I think he is saying that life at its foundation, including consciousness, is particles governed by physical law. That may be true at the physical level of existence, but—unlike Greene and others—I think that there is more to what I am than just my body. Otherwise, why bother?
Humankind has spent its entirety giving meaning to its existence so that our being here has purpose. If we accept humans as evolved objects with no meaning and purpose, other than their legacy on this planet, then what? Is it enough to be only an earthly form that ends in a void, or do we continue to foster a reality beyond the body that survives the end of our existence?
Philosophy, spirituality, and religion have for millennia taught that we are more than our body. At the least, they say that we are a body with a soul that survives death. Physicists may want to find the critical building-block particle of the universe and tie it into a single, most-exquisite formula to explain, once and for all, what we are, but I suspect that they will be no more successful than metaphysicians at finding the ultimate answer. Odds are that Earth will become a charred ruin without our ever having found a conclusive answer to What am I?.
Whether or not we are only a body, our existence in form is going to end. In the short term, we will die as individuals, then, ages later, as a species. Mid-range, Earth will be swallowed by the sun in a fiery death spiral. Long-term, the universe will fragment into its basic subatomic particles, returning to an emptiness that is nowhere. Is there any meaning or purpose to our being on this journey called existence? My answer is—only what we give it. To me, its meaning and purpose come from our awareness as a me of the body. Do we transcend our existence in form? Probably. At least we seem to want a life after death. If there is no spiritual reality, then why bother with our suffering? We seem to struggle with existential issues in order to save ourselves from the oblivion that we face at death. We extend ourselves beyond our natural form. We offer with great faith that we are more than a random, transitory bundle of particles.
Do we go on forever after our body dies? Even after the end of Earth? How about after the end of the universe? I think so. I think these endings are insignificant in the eternal reality of what we are in consciousness. To me, that which I am transcends the body and all of existence. Metaphysics has taught this for millennia. You cannot turn around without bumping into someone’s belief in an afterlife. But I also agree with Greene, and others, that we are a random, transitory bundle of particles. That bundle is the body with its personality. This truth about our existence cannot be denied. It is found in the mathematical formulas that physicists/mathematicians have derived to explain the universe. But being limited to a body is not the whole story for me. I cannot accept existence in the physical universe as a limitation. I am certain that I am not my body. I know existence as the universe. I experience existence as the world around me. But my body, with its personality, is not my true nature. The me of the body is transitory. I am eternal.
Not to worry, says Mack about the end of existence. She reminds us that the demise of humankind and the ultimate end of the universe is eons away. Let us take her thought further and know that the emptiness at the end is eternal. Again, we need not worry. We are forever. In the reality of consciousness, there is no end. In my mind, we are not our bodies and Earth is not our truth. We are the eternal I AM. That is my truth. So be it.