Are we alone? Of course not. Will we ever prove that? Of course …NOT.
I propose that the planetary characteristics necessary not only for the evolution of life, but for its ability to persist and so eventually develop complexity and intelligence, are extremely rare. In fact, so rare that even in the almost literally infinite immensity of the known universe and the similar scale of deep time it would be unlikely that humanity would be so fortunately positioned to ever detect such alien life. I think this is the only reasonable explanation of the Fermi Paradox.
I include as an important factor in evaluating a planet’s ability to nurture the possibility of the evolution of life the capture of a large moon early in its formation. A moon large enough that it provides stabilization of the earth’s rotation characteristics such as rate and the “wobble” of axial tilt (or precession), protection from large impacts, tidal effects and so many other vitally important “life friendly” features of our planet that make it so unique. If you multiply the “astronomically” remote possibilities of such rare billiard ball type glancing impact with the perfect “english” to these other probabilities, even in an almost infinite universe, it would be highly improbable (at least in in the Milky Way or any “close” neighboring galaxies, much less near space) And I’m not even going into the need for a giant planet like Jupiter to be present to stabilize all the other smaller planet’s orbits and clear out the solar system of extinction event debris! These and so many other clearly unique characteristics of our planet and its solar system are too numerous to mention in such a brief essay. Now, with the immensity of the universe and of time, even such rare coincidences and occurrences can’t be unique, and in fact may be relatively numerous, that’s obvious, so there must be other planets that support life, even intelligent life SOMEWHERE IN THE UNIVERSE. But even in the immensity of creation, of almost literally infinite time and space, is it reasonable for humanity to arrogantly assume that it will be in our vicinity?
Putting aside the actual question of the existence of alien life, much less an alien intelligence, what relevant meaning does that same existence have to our civilization IF WE NEVER CONTACT THEM (other than the philosophical implications of the knowledge that we are “not alone”?) If they are out there, are they going to be close enough for their existence to be really meaningful, i.e. for us to be able to detect them, much less communicate any realistic manner? Yes, the same immensity of time and space that makes alien life “somewhere” inevitable also insures that it’s almost literally a certainty that we will NEVER actually have evidence of their existence, much less be in contact. The speed of light constrains our knowledge of the universe to such a small sphere of SPACE TIME that the odds of being close enough to another advanced civilization, in a coincident time frame is almost nil (yes, we can see almost back to the big bang but we can’t really “see” anything far away (in reference to the limitations of causality) that would be useful for communication much less the detection of advanced civilizations. Unless we were almost literally “neighbors” which, as my previous my previous argument explains, are extremely unlikely. Worse yet, as our universe expands, eventually to the point that other galaxies are beyond the “edge” of the know and visible universe, this problem is only exacerbated. Eventually the Milky Way be almost literally alone in the detectable universe. We will be accompanied by the Andromeda galaxy, which is gravitationally bound to our galaxy and so immune to the expansion of space time which only occurs in intergalactic space. This is due to the overwhelming influence of such a large collection of gravitationally bound baryonic matter on dark energy. Actually, in a few billion years we will have collided and become one irregular galaxy, but only after our sun has burned out and destroyed the ear
The most important and very relevant question is that, even if intelligent life is common, unless those civilizations last million or even billions of years, what are the odds that a current civilization exists so close to one another as to be detectable? The Fermi paradox is, like Moore’s law, seemingly an incontrovertible rule and hard to discount. Imagine the universe pictured as a movie as it travels through time to the present. Now, imagine the existence and expansion of an intelligent star traveling civilization as a bright expanding light, a flash in the darkness. First, keep in mind the speed of light and the immense distances. Now, fast forward. What will you see? Bursts of light flashing and expanding everywhere but eventually and inevitably fading away, as if they were antique flashbulbs popping up briefly only to disappear, unseen. As time progresses, others “briefly” brighten and die in uncounted multitudes over millions and billions of years. But NEVER at the same time at the same place! Close your eyes and imagine this as a movie in your mind. How often will these bright bursts of intelligence and expansion last before they fade away. Will they be close enough and also persist long enough for each one to be able detect one another within the limitations of causality? Remember, these flashes expand at the speed of light and the universe is “Billions and Billions” (and even more and more billions) of light years across. And this is a worst case scenario. What if it IS possible to travel faster than light? The expansion of a galactic civilization would be exponentially faster. Get it?
But, the reader may ask, what if these civilizations last millions of years and expand into multiple galaxies? Well, how likely do you think that is? Yes, may there be type 1 civilizations that harness entire Galaxy’s energies, even Galaxy clusters? Possibly. But even galaxy clusters are like grains of sand in the immensity of the universe, and like grains of sand that are miles apart, not conveniently nestled together on a beach. So many people carry the analogy, “There are more stars than there are grains of sand on a beach” too far and tend to ignore the ramifications of the immensity of the universe. This becomes clear when one stretches the but the analogy to the breaking point by the realization that the beach is not the crowded expanse of an oceans beach full of sand. Realize, each of those grains of sand are exploded into space and each grain is separated by immense distances. Enter again the villain, the speed of light, causality. And if you consider the concept of Von Neumann machines as technology that is almost certainly to be developed by any advanced technological civilization, why hasn’t the universe already been “pollinated”? This incontrovertible absence literally ensures that the Fermi Paradox question of “why are they not “already here” even more relevant. Even with the immensity of the universe, the accompanying immensity of time makes it statistically impossible for us to not to be essentially alone.
Are there other worlds with intelligent life and civilizations? Statistically, considering the age and size of the universe, the probably is near unity, or 100%. Will we ever know? The probability of them being close enough to have any meaning or impact on our civilization i.e. for us to detect and communicate with them are close to null, or 0%. For that to occur they would have to be so common that we would already have detected them, the paradox so eloquently proposed by Fermi himself. Several years ago, Dr. Paul Davies, of the Beyond Institute at ASU quoted a study by SETI which revealed that, considering the current progress in detection capabilities, if we do not detect* other civilizations (by radio waves) in the next 20 years, WE NEVER WILL!
To summarize, I think that evolution of alien life would be such an extremely rare event so to be almost impossible for humanity to discover. Considering the facts presented herein, if simple life has occurred in the hostile environment of the universe it is even more unlikely for such life to have survived long enough to become complex, much less to have evolved into an intelligent form. Has this event occurred in this almost literally infinite universe? Undoubtedly. However, for our civilization to be fortunate enough to detect such life or intelligence one must consider that it would also need to exist in close enough proximity to the Earth in space AND in our current time frame. The Fermi paradox seems not to be so paradoxical after all?
Yes, they exist. No, we’ll never know!
*Don’t take this to mean that I think Dr Davies has unequivocally stated that “they” are not out there, it just means that it has been demonstrated statistically that if we (SETI) do not detect them in this time period we’ll never find their radio signals (whether because they’re not there OR nobody out there really uses radio for very long, advancing to better technology.)
T.A.Kiehl©2016
(REPOSTED 20 APR 2020)
“ALONE IN THE UNIVERSE: Why Our Planet Is Unique” by John Gribbin
Here are some good videos I think support my theory that the “dual planet “Earth/Moon system is a necessity for complex life to evolve, making intelligent life a truly rare event even in such an immensity of our galaxy that it is improbable we will ever detect such.
“The Most Important Collision Ever” https://youtu.be/pjn4nLUnNCw
“What if there was no Moon” https://youtu.be/QHwLopLUrB8
“Evolution of life without a Moon” https://youtu.be/p-YZAIECTrA
Here is a series of lectures from SETI with more scientific information:
http://www.seti.org/weeky-lecture/rotation-moonless-earth-who-needs-moon