Nearly 40 years ago I came up with an explanation of the cause of our universe’s Big Bang, how/why our universe is expanding, and what will occur sometime in the future. I finally wrote it down in the epilog in the final volume of my Chronicles of Mearth trilogy. It’s not yet published, but here is an excerpt. I hope you enjoy it.
You can purchase the first two books in The Chronicles of Mearth trilogy on Amazon.com (search for cholmonco) or in my bookstore on this website.
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Mars looked at Hera and said, “Tell me. What do you think you know about the cycle of the universe?”
Hera looked puzzled but answered, “Well, the universe began as a singularity about thirteen or fourteen billion years ago. It then rapidly expanded into the universe we know today, which continues to expand at a constant rate, known as the Hubble constant. No one is sure whether it will continue to expand or whether it will collapse back into a singularity and, possibly, repeat the cycle again. In either case, however, it will certainly last billions of more years.”
Mars smiled and asked, “Is the universe infinite? And, does it have a center?”
Hera quizzically looked at him and answered, “Of course.”
Mars sighed and said, “You are so right and so very wrong. Listen to what you just said and ask yourself if it makes any sense.
“How can something expand if it is infinite? An infinitely long line can neither change length nor have a mid-point, because, by definition, it is infinite. Therefore, if our universe is expanding, then it must be finite. Also, how can it have a constant rate of expansion if it might collapse back into a singularity?
“You are correct that however far we travel, we cannot escape from our universe. This does become a bit of a paradox if you insist on sticking with three-dimensional thinking. However, it can be easily solved if you take a higher-dimensional perspective.
“You see, our universe exists in a 3:1 reality. In other words, we have three physical dimensions, forward/backward, right/left, and up/down, and one temporal dimension past/future. Furthermore, we are stuck traveling at a fixed speed and direction in our temporal dimension. However, our physical universe is neither linear or infinite. It is, instead, the finite, three-dimensional surface of a five-dimensional bubble intersecting a four-dimensional space.”
Mars grinned as though this clearly and succinctly explained everything. Hera, however, stared at him with a bewildered expression. So, he tried again.
“Four and five dimensions are hard for us to imagine, so let’s create some examples to simplify the concept. Imagine a group of dot-people living in a universe with only one dimension. They can move forward and backward on a line but cannot comprehend the notions of right and left or up and down. These guys happily live in their infinitely-long, linear universe. They make astronomical observations which indicate that their universe once started out as a singularity before rapidly expanding into its current state. They also observe that it continues to grow at a fixed rate and argue whether it will, or will not, someday collapse back into a singularity.
“So, their universal model is the same as ours, except only in one dimension. They, of course, cannot comprehend a second physical dimension, but we can. What if their linear universe isn’t really an infinitely-long straight line. What if it is, instead, a vast circle? Our one-dimensional friends can’t comprehend how traveling forward could bring someone back to where they started. They have no concept of second-dimensional bending. But we can envision a circle, so the answer is evident to us.
“Now, imagine that their circular universe is created where the surface of a three-dimensional balloon intersects a two-dimensional plane. Their universe would be a singularity as the balloon first intersects the plane and would rapidly grow in diameter as the balloon travels through it. Their circular universe would then shrink back to a singularity and eventually disappear as the balloon passes through and beyond the plane. This model allows their universe to appear to be infinite to them and still expand. And, it means that there is no single center point on their line. Everything in their universe is expanding away from everything else.”
Hera was following the model, so Mars continued.
“Now, let’s make it a little more complicated and imagine that our friends are two-dimensional critters. These guys believe they live in a universe that is an infinite plane, which also began as a singularity and is expanding.
“These two-dimensional people understand the concepts forward/backward and right/left, but cannot comprehend up/down. But we can. We can imagine their expanding, yet seemingly flat and infinite, universe really being the two-dimensional surface of a sphere.
What if their universe is really the surface of a three-dimensional balloon that expands as the balloon inflates and shrinks as it deflates? Like our one-dimensional friends, these guys could travel in a two-dimensionally straight line and wind up back where they started without ever turning right or left. That concept blows their minds because they cannot comprehend the third dimension, and the balloon is so gigantic that they cannot see all the way around it.”
Hera said, “OK, that makes sense, but how does the balloon inflate and deflate?”
Mars answered, “Good question, and this is where it gets a little more complicated. You might not be able to visualize my answer but think about it mathematically. If the surface of a three-dimensional sphere creates a circle where it intersects a two-dimensional plane. What do you think happens where a four-dimensional sphere, called a glome, intersects a three-dimensional space?”
Hera tentatively answered, “You get a sphere?”
Mars exclaimed, “Precisely! Now, it might be hard, or impossible to visualize a four-dimensional sphere, but what do you think happens when a glome balloon passes through this three-dimensional space? Remember what happened when our spherical balloon passed through the two-dimensional plane.”
Hera answered, with a little more confidence, “I suppose their universe would appear to start out as a singularity. The surface of the sphere would rapidly expand into an apparently-infinite plane with no center. And it would eventually collapse back into a singularity and disappear as the balloon passed out of the three-dimensional space.”
Mars grinned and said, “I think you’re getting it. And, while there is no center on the two-dimensional surface of the balloon, the three-dimensional balloon does contain a center. However, our surface-dwelling friends cannot comprehend it because that center point is below them in the third dimension. Again, they cannot visualize up or down.
“Now, let’s extend our model one more time to bring it home. What do you think the ‘surface’ of a five-dimensional sphere passing through a four-dimensional space would be?”
Hera guessed, “Well, I suppose that the next step up from a two-dimensional surface would be a three-dimensional space.”
Mars agreed, “You are right again. And, as this five-dimensional bubble passes through the four-dimensional space, everything in this, apparently infinite, three-dimensional space will expand and contract with no center.
“Our universe is not infinite, but it is enormous. If we were able to see far enough, we would see our butts, although they would be billions of years in the past.
“I realize, of course, that this concept makes no more sense to us than it does to our one- and two-dimensional friends. But, you see, the fourth, physical dimension not only has forward/backward, right/left, and up/down. It also has in/out. The center of our expanding and contracting universe is inside this four-dimensional balloon upon which we are riding.”
Hera said, “I suppose that makes logical sense. But, even if you are right, then our universe will still have billions of years left before the bubble or balloon passes through.”
Mars sighed and said, “Yeah, wouldn’t that be nice? Unfortunately, we have this pesky physical law called ‘the conservation of mass and energy,’ which isn’t entirely correct but is accurate enough to mess everything up.
“You see, we can’t change the amount of mass or energy from within our universe, but it can be added or removed from higher dimensions. After all, that is where all our mass and energy came from at the beginning of the universe, right?
“Now, think about our one-dimensional friends. How much matter is there in their universe as it is created by the balloon passing through a plane?”
Hera said, “Well, the balloon’s skin is the same thickness everywhere, and more of the balloon’s skin intersects the plane as it passes until it reaches its widest point. So, the amount of matter in their universe should increase until the middle of the balloon passes through the plane and then decrease until it disappears.”
“Right again! So, the amount of mass and energy in their universe would always be changing. But let’s say that the law of conservation of mass and energy also applies to them. In other words, their universe also has a fixed amount of mass and energy. Can you think of a model where their one-dimensional universe expands without the amount of mass increasing?”
Hera thought for a while and posited, “Well, a balloon’s skin stretches as it inflates. So, the amount of mass will remain constant while the circle grows if a stationary balloon inflates within a plane. In that situation, its skin would maintain the same amount of mass, while becoming thinner as its diameter increases.”
Mars agreed, “Yes, and what happens if you overinflate a balloon?”
“It pops.”
“Yes, it pops. Which is what will eventually happen to our universe. You see, once you accept this model, you realize that EVERYTHING in our universe is expanding. We can use powerful telescopes to observe galaxies and stars spreading apart at vast distances over billions of years. It is much more challenging to see what is occurring at a subatomic level. But everything is expanding in our universe at every level. That means that the distances between atoms, molecules, and subatomic particles, are stretching apart just like the distances between our galaxies.
“This is why the physics of the early universe was different than it is today. It is also why our current universe’s physics will eventually break down. There is a constant we call the Maximum Universal Stress Point where the distances between subatomic particles become too great to sustain attraction. Universal Stress is so small and changes so slowly in micro-physics that it is almost impossible to measure. However, at some point in time, the distance between all subatomic particles in the universe will become too large. At that moment, the forces binding them will lose cohesion, and our universe will pop. And, when that occurs, everything we know will dissipate very quickly.”
They both sat quietly, listening to a pair of birds twittering in the rafters above them as Hera contemplated what she had just heard. She eventually said…