Martians? Little Green People?
We're going back to the moon after fifty years. And not just to kick dust or gather rocks, but to look at the moon as a launch platform for exploring our solar system and perhaps the first in a chain of roadside rest stops and refueling stations on other planets and asteroids on our way to the stars.The question is, will we find life elsewhere in the universe? That question is better answered if we understand our expectations for life outside the cocoon we call Earth.
We live on a unique planet. Life has risen, gone extinct, and risen again five times in about five billion years, that we have discovered so far. Extinctions have been a part of our planet's evolutionary history. 99% of the four billion species that evolved on Earth are gone. Most species have gone extinct. That can be a bit unsettling; we think we're here forever. Maybe we are, maybe we're not.
Human evolution began two million years ago in Africa, long after the last great extinction sixty-five million years ago. Anthropologists still don't know how the different groups of humans interacted and mated over our long stretch of prehistory, but they're starting to fill in some of the blanks. A "human" is defined as anyone who belongs to the genus Homo, (Latin for "man"). Scientists don't know precisely when or how the first humans evolved, but they've identified a few of the oldest ones.
What is clear to me, is that we humans didn't appear until after the last extinction, suggesting the earth's environment wasn't conducive to providing our place on the evolutionary tree before that time. There was too much oxygen in the atmosphere, and other factors delayed our grand entrance. I'm sure archeologists, other ologists, and mathematicians might find fault with my logic, but if 99% of four billion species bit the dust, the odds are not great that we would survive or come back if we had another extinction.
It is generally accepted that a couple of things enabled us to rise to a position of dominance over the rest of the animal kingdom. Our manipulative hands with opposable thumbs, for sure, and our extraordinary brains. Our brain is remarkable for its cognitive skills, allowing us to remember things, think critically, reason, hold attention, solve problems, and read and learn, perhaps most importantly, to change.
We obviously share our planet with other species having large brains. Chimpanzees, elephants, and dolphins have brains as big or bigger than ours. Growing evidence indicates the brain's evolution might be separate from physical evolution. For example, if you are an elephant living in an elephant's unique body, with all its skills, challenges, and limitations, your brain will evolve to serve your physiology and environment. However, if you have manipulative hands, that places a demand on your brain to evolve methods to make use of those hands. If, like a dolphin, evolution puts you in the water with fantastic swimming abilities, your brain evolves to serve you in your physical form and world.
Assuming I haven't lost you, and yes, we will get to life elsewhere in the cosmos, why haven't chimpanzees, our very close cousins, evolved in the way we humans have? Ongoing studies are attempting to understand this, but the missing link in my mind - and I don't mean that ,it is, missing from my mind - is curiosity. I don't know when we humans developed our curiosity or if it's always been part of us. It just seems that chimpanzees are content to stick around their territory and throw poop at each other. We, humans, want to see what is over the next hill. I see little evidence that other animals share our level of curiosity and desire to make changes or explore the unknown.
Curiosity and a passion for more knowledge have been significant factors in human evolution. When we did develop that thirst for knowledge, I don't know, but it's a critical element of who we are and what we've accomplished so far.How does this relate to finding life on other planets, or faraway galaxies?
First, we need to find a world where all the right conditions come together to produce the opportunity for intelligent life or life of any kind. And, we do have to be careful how we define intelligence. That extraterrestrial life has to have evolved in a way that allows it to not only be curious - of course, we don't know for sure that dolphins aren't curious - but also have a passion for the pursuit of knowledge.
Suppose this new species has a brain that allows for the pursuit of knowledge and the curiosity to pursue the unknown; they also need the physiology, such as our hands, to use their knowledge and curiosity. We might be surprised, but it's inconceivable that you can build machines, cities, computers, etc. without something resembling hands that are linked to a brain that can invent, plan, and execute the end product of the imagination.
Curiosity about what is growing on a tree is of no use to a dolphin because it has no way to climb the tree and explore what it thinks might be up there. Therefore, it seems unlikely that dolphins are swimming around wondering what is growing on a tree; that would be a waste of brain space and energy. Likewise, if we find life on another planet someday, unless all the right factors come together, it is unlikely they will be as, or more intelligent than we humans. If a species as, or more intelligent than humans exists out there, it would need knowledge, curiosity, and the physical attributes to apply that knowledge to space travel.
I know there are science fiction tales that present the notion of a species that can manipulate their world, and perhaps ours, by strictly controlling everything with their mind. With all due respect to Tom Cruise, and Scientology, Tom is rumored to have acquired supernatural powers such as telekinesis - I have my doubts about that possibility.
If an intelligent species exists, such as we humans, and who have mastered interstellar travel, they would almost certainly have made themselves known by now. Imagine that in the future, we humans are exploring planets in other solar systems and see evidence of life roaming on a planet. We are probably not going to keep our presence a secret. We would most likely send down probes to explore the planet to a), give us more information and b), see how that life reacts to our being there. With our innate curiosity, I don't see how we could remain "invisible"; we would have to explore the new planet and life thereon. I don't believe you can have the intelligence needed to accomplish what humans have without curiosity and the pursuit of knowledge.
Following that logic, I don't believe we will find life out there more intelligent than us, or if there is, it might be locked inside a body that cannot apply that intelligence to pursue interstellar travel.
Given my previous argument that a dolphin has no use for being curious about something growing in a tree, I don't believe you can have that much intelligence without curiosity, the pursuit of knowledge and the physical capability to follow up on that knowledge.
Will we someday find life in the universe? I think we will, but it will most likely be similar to us discovering a new species of life on our planet, whether on land or in the sea. It will be fascinating and beautiful, but probably not at our level, intellectually.