How big is big?
I have always been fascinated by scale… the size of things… or more specifically, the relative size of things. I suppose I could just as well ask, “How small is small?”, but the root of my curiosity is actually, where do I fit in the spectrum of big and small?
As a kid I was always eager to see the new mark on the doorjamb when, from time to time, my mother would check my height by placing a pencil atop my head to mark the doorjamb with me standing as straight and tall as I could possibly stretch myself. Somewhere, somehow, I got the idea that bigger is better.
You may think I am talking about my size relative to my peers. When I was younger, that certainly was the focus of my concern. Over time, my interest in scale turned to astronomy, and the study of things that are vastly bigger than I am. I know there is probably as much to learn about things on an atomic scale, but it is the astronomical scale that really fascinates me. Many of the things I’ve learned about scale now inform my philosophy of life, and inspire me to ask, “What is my significance within the scope of the universe and time?”
To some degree, the size of everything we perceive is measured in the context of our own human size. We compare ourselves to pretty much everything that is part of our daily lives. But we don’t often contemplate where we fit compared to things that are much smaller or much bigger than we are? For that matter, how often do we contemplate our place in the span of time. If we go on a long road trip or travel to some faraway country, we probably contemplate the size of our journey or the time it takes for our travels, and we can probably grasp the scale of those experiences. Can we properly comprehend our place in the vastness of all time and space?
Our ideas about our place in the universe are constrained by our perceptions, the information that comes to us through our 5 senses. In the early part of the 17th century the first telescopes and microscopes extended the range of our perceptions. Today our perceptions have been extended far beyond the limitations of our human bodies by the electron microscope, the Large Hadron Collider, the Hubble Space Telescope, the European Extremely Large Telescope, and the soon to be James Webb Space Telescope. These instruments allow us to see things that are less than one ten-billionth of our size and things that are about one octillion times bigger than we are. One octillion! That is one thousand-million-million-million-million times bigger than we are. Do you have any idea what such a number represents? I sure don’t! I can’t even begin to comprehend things that are so much smaller and bigger than I am. I can see and touch a grain of sand… I am roughly 1,000 times bigger than a grain of sand. A grain of sand is 10,000,000 times bigger than an atom. I can’t really wrap my arms around the planet, but I can travel all the way around it, so I have some reasonably tangible way to comprehend its size. The circumference of the Earth is about 20 million times my height. It would take roughly 4 days to fly around planet Earth on a commercial airliner. I’ve never traveled to the moon, but a handful of people have, so as far away as the moon may seem to me, perhaps that distance is something I can grasp. The distance to the moon is about 200 million times my height, and it took the Apollo astronauts about 3 days to get from the Earth to the moon.
Most of us rarely think about things we can’t touch, places we can’t go, and things outside of our personal spatial and temporal experience. We may think, “I’m bigger than my dog, and smaller than my house.” If we then think, “I’m bigger than an atom, and smaller than the known universe.” Well, that’s true… but do I really understand what that means?
I exist somewhere on the spectrum of size and time, but where is that? Nearer to one end or the other, or more or less in the middle? Actually, how can I be sure there are any limits to the spectrum of space and time? The notions we have about the world in which we live are based entirely on our perceptions. Our senses evolved to help us survive as creatures living in the wild… on planet Earth. Even with the recent amazing technological extensions of our perceptive abilities… How do we know there is not more to be perceived, if only we had better technology? Let’s not forget that, due to the limitations of our perceptive abilities at the time, we once thought the world was flat. It was less than 100 years ago that our very best technology suggested the Milky Way Galaxy was the entirety of the universe. Today we know the Milky Way, as unimaginably vast as it is, is only one of hundreds of billions of galaxies, just a grain of sand on the beach of the “known” universe. What about the “unknown” universe?
We look up at the sky on a moonless night and are often compelled to ask, “Is there life out there… somewhere… in the known universe?” We think, “The universe is so vast, surely there is other life beyond planet Earth.” Given the vastness of the universe, it seems highly improbable that we, here on Earth, are the only life to be found in the whole universe. Even if there is life beyond planet Earth, I am compelled to ask, “Why should it matter to me or anyone whether or not there is life outside planet Earth?”
We fail to comprehend just how unique planet Earth is. When we are born, we know nothing about the world we inhabit. As we grow from infancy to adulthood, we learn about our surroundings… we learn what we need to survive… we learn what makes us feel good. Our primary focus is ourselves and those closest to us. Eventually, probably early on, we learn about our impermanence. The notion of our personal mortality is at least a little disquieting to most of us. The uncomfortableness of that idea is built into our DNA. It helps us survive… not necessarily so much as individuals, but more so as a species. As a way to quell the discomforting idea of our mortality, some of us adopt the belief that we carry on in some way even after our bodies die. Others may find comfort thinking that even after they are gone… after the sun has turned into a red giant incinerating planet Earth and all that live on it… there is still life out there… somewhere in the vast universe. Still others imagine that, with all our technological know-how, we can figure out how to escape our solar system, traveling to other habitable planets, before the sun dies.
Let’s take a close look at the idea of interstellar travel. Starting from very simple single-cell creatures, we became the creatures we are today by acquiring characteristics from one generation to the next over the course of billions of years. Each one of those characteristics gave us a survival advantage within the context of planet Earth’s environment. We are quite literally tailor-made to live specifically on planet Earth.
If we are going to travel to other planets with the intention of living there, there are two important factors to consider:
A. The characteristics of a planet that are vital for human survival, including gravity similar to Earth, temperate climate, the presence of water, an atmosphere with oxygen, and the presence of resources for food and energy.
B. What is involve in getting to another solar system with an Earth-like planet?
So far, the fastest manned space craft is Apollo 10, which traveled about 25,000 MPH on part of its journey from the Earth to the Moon. The nearest star to Earth other than the Sun is Proxima Centauri, which is about 4.25 light years, or 25 trillion miles, from Earth. At the Apollo 10 maximum speed, traveling to Proxima Centauri, the very nearest star outside our solar system, would take 114,000 years … about 5000 human generations.
It has been reported there is a planet orbiting Proxima Centauri, known as Proxima Centauri b. Our best guess suggests that its gravity is roughly equal to the gravity on Earth. Even though Proxima Centauri is smaller and cooler than our sun, this planet’s orbit appears to be closer to its star, and therefore possibly in the temperate climate zone. We don’t know whether there is water, an atmosphere with oxygen, or life sustaining resources on this planet. Do you want to be the five thousandth grand parent of the human who will definitively answer all the questions about the habitability of Proxima Centauri b?
Yes, the universe is unimaginably vast, and yes, it seems reasonably plausible there is more life out there somewhere… even planets much like Earth on which we could survive… if we could somehow get to those planets… but the distances are too great. If you want to believe we will soon figure out how to travel at light speed… fine, I won’t argue, even though many scientists tell us that would be impossible. I will simply remind you that at light speed more than 4 years is needed to reach Proxima Centauri, the very nearest star outside our solar system. Other solar systems are farther yet, most of them, unimaginably farther. My point is this… We ain’t goin’ anywhere! Most especially, we will never leave our own solar system.
As I said, we are literally tailor-made to live specifically on planet Earth… so is every other creature living on this planet with us. The current human impact on planet Earth is not sustainable. We do not need to focus our attention on some impossibly distant planet. We need to focus on living here sustainably… on planet Earth… in harmony with all the other creatures with whom we share this place. Doing so will require us to make sacrifices. We need to recognize that planet Earth does not belong to us… No matter how our human characteristics may differentiate us from other creatures, that does not give us the right to trample the rights… the very survivability of the other creatures.
We are clever creatures. In my view, we are actually a bit too clever for our own good. In a 2008 essay I wrote…
We are clever enough to contrive how to transport men to the moon and bring them back alive and well; but not wise enough to see we are changing the world so rapidly that the survivability of all life is threatened.
Our highly-developed brains have been so effective at bringing us the comfort and security that was so scarce for the predecessors of our species that now we are overrunning the planet and stressing it beyond its capacity to support us.
We want to believe we have the wits and the means to invent whatever may be necessary to fulfill our wildest dreams. But so many of those dreams ignore our responsibilities… to ourselves, to future generations, and to all the creatures of this planet. We must learn to discipline ourselves… or perish!
Better than anything else I have ever said, those words still express my deep concern for the impact we clever humans are having on the environment and all the creatures of this exceedingly rare place… planet Earth. The human race is thundering across planet Earth like a runaway train. If we don’t apply the brakes very soon, when we do finally stop, it’s not going to be a pretty scene.
To many creatures, the Earth, if they were to perceive it in its entirety, would be seen as a very big place. For those of us who have extended our perceptive abilities to see far into intergalactic space I offer another line from my 2008 essay…
This quintessential planet, Earth, is but a speck of dust in the vastness of the universe… and it is the only speck of dust we have to live on.
I asked, “What is my significance within the scope of the universe and time?” My significance is limited to the brief time I am living here on Earth. Humans have shared this planet with millions of other species for many millennia. For the vast majority of that time we have lived quite symbiotically as members of the planetary ecosystem. Over the course of human existence, we have used our intellectual power and dexterity to develop tools, each one of which has given us some advantage for survival. Over time, we use our tools to create ever more sophisticated tools. We call this progression of sophistication technology. Now, with our unique combination of body form and reasoning power, and with technology, we manipulate the environment more than any other creature on the planet. We do so to the detriment of all species… including our own. We have no more right to the resources of this planet than any other creature living here. We are no longer healthy symbiotic members of the Earthly ecosystem.
Having made those observations, I want to offer an apology on behalf of myself… and all the members of my species. It seems unlikely that those to whom my apology is directed will ever understand it. Nevertheless, they deserve an apology.
To you, dear junco, wary deer, crafty wolf, great humpback, majestic eagle, tiny ant, giant sequoia, wispy prairie grass, stealthy snow leopard, wise elephant… and to all the creatures of planet Earth, big and small… I humbly offer my apology for all the trouble I and my fellow humans have brought to you. I apologize for the selfish and arrogant ways we have usurped the resources on which you depend. I apologize for the terrible ways we have polluted the environment in which we all must live. And to those species who have been completely exterminated by our selfish and careless human actions… pathetically inadequate as it is, I offer my apology.
