Intellectual Pursuits of the Universe

The Cosmic Limit of Finite Life

We Are Invisible

There have been many attempts to measure the frequency that which intelligent life exists in the Observable Universe, including a modified version of the Drake Equation, where astrophysicists demonstrated (using some of the most “pessimistic” estimates) that the likelihood that Alien life exists in the Milky Way Galaxy is far greater than the likelihood that we are alone in the Milky Way Galaxy: by a margin of 60-billion to 1.

Furthermore, another study, taking into account time, states that more than half-a-trillion alien civilizations have existed in our Galaxy’s billions-of-years-long history.

But these fascinating realizations only beg the question: If other Alien civilizations are so incredibly likely, then why haven’t we discovered any yet?

First Contact

There are three conventional ways or means that the discovery of alien civilizations could actually occur: Space Travel, Visual Confirmation and Radio Signals.

Discovering an Alien Civilization by way of Space Travel is a scenario that is obviously far off-the-table for us (humans) right now. For as a species we have only been able to travel the distance of our own Moon, which equates to humans having physically traversed less than .0001% of our own Solar System. Even by way of unmanned spacecraft the prognosis of First Contact is inordinately dim; with our current technology as it is, it would take us an impassable 78,000 years for a robot to reach our nearest neighboring star system, Alpha Centauri.

Perhaps, given enough time we will develop technology to reduce this limitation, but with the current state of humanity, discovering intelligent life by Space Travel is all but an impossibility.

Visual Confirmation is a lot more plausible, but the main impediment holding back a Visual Confirmation of ET is that we quite simply, just haven’t been ‘looking’ for very long. Humans first started looking up into the heavens above 400 years ago, which might seem like a long time, but for Homo-sapiens (modern humanoids), a species that has been around for about 200,000 years, that would be the equivalent of an average human expecting to find an alien civilization during his 70-year life span while spending less than 1-day ‘looking’ up at the stars.

Moreover, any substantial chance at discovering alien life via observation doesn’t start until the global scientific effort of SETI (Search for Extraterrestrial Intelligence) founded in 1984, and their hunt for Exoplanet candidates. At this point in their search they have identified around 4,000 Exoplanets, and about 380 of them are viable candidates for life; in a Galaxy containing at least 100-Billion stars, that doesn’t equate to much progress at all. If each star only contained the highly “pessimistic” estimate of 1 orbiting planet, that would equate to a percentage, with so many zeroes following a decimal point, that I don’t even have the time or patience to write out… so, in essence, not only have we not began to scratch the surface in the search for alien life, we haven’t even felt the itch yet.

Seeking Self Reflections

SETI as of right now, is only able to detect the chemical signatures of the molecules around Exoplanets that are necessary for life to emerge, such as hydrogen, carbon, nitrogen and oxygen etc., and that only reveals a potential for alien life -not a-confirmation of alien life. For confirmation, we would need something more, something along the lines of a clear-cut ‘indicator’ of life.

But what would a clear cut ‘indicator’ of alien activity look like?

To answer that question we can look no further than ourselves, as we are our only real example of what we should be looking for; with Earth as our sample, we could think about what ‘indicators’ potential Alien Civilizations, who are also on the hunt to find extraterrestrial life, might see when they happen to turn their gaze upon our planet: Satellites, Telescopes, Space Probes, the International Space Station etc.

The problem with these sort of ‘indicators’ is that they are just too insignificant. With our current telescope technology right now, these things would be impossible to identify, as our current methods of identifying Exoplanets centers around the slight dimming of their Stars’ light as the planets pass between our view and their home star, giving us, in most cases, incredibly spread out and small windows of observation; and a Satellite or Probe (or Space Station) would be so tiny that they would hardly make a difference in that dimming at all.

However something that would serve as a good ‘indicator’ of Alien Activity, which is Science Fiction according to us right now, but it is entirely possible to accomplish in the future given enough time, say in a couple hundred years, is a Dyson Sphere; which is a hypothetically possible man-(or alien)-made space-structure that would be built around a Star (such as our Sun) in order to harvest or harness its energy (power).

Something like this would make a considerable difference in the dimming of a Star, and serve as a good indicator of an Alien Civilization. It is something that was considered as a possibility by actual astrophysicists who witnessed the extremely irregular dimming pattern around Tabby’s Star in 2011.

However as interesting as that is, the Scientific community remains unconvinced, our ability to observe the cause of this dimming just isn’t advanced enough for confirmation, and the dimming of the Tabby Star remains an inconclusive mystery.

An Empty Mirror

Another deterrent to the Visual Confirmation of Alien life has to do with the aspect of Time. The term “light-year” gets thrown around a lot in discussions about space, without really conveying its true implications appropriately.

Let’s consider what a light year is for a second. A light year is a measure of distance. It is the distance that light can travel in a year’s time. So when we say a Star we are observing is 10,000 light years away, that means that the light of the star we are observing took 10,000 years to reach our eyes, so we are not actually observing the Star as it appears today, we are observing the Star as it appeared 10,000 years ago.

This phenomenon complicates things; 10,000 years might just be a blip of time in a cosmological scale, but on a Human timescale 10,000 years has made a big difference. Aliens looking at our planet from a distance of 10,000 light years would be looking at our planet as it appeared during the Stone Age. A time when not only all of our insignificant indicators, such as Satellites and Space Craft weren’t even a twinkle in our eyes, but all of our grand Cities and Metropolises weren’t as well.

Electricity was discovered a little less than 150 years ago. We launched our first Satellite in 1957, the first powerfully advanced deep space telescope, Hubble, was launched into orbit in 1990, and the International Space Station was launched in 1998.

So any Alien Civilization looking at our planet from more than 50–60 light years away would not even have the opportunity to see these minuscule indications of our presence. They would be seeing our planet as it appeared 50–60 years ago, before we launched any of these modern technological marvels. For all our excessive pride, in our accomplishment and stature as a species, we would in effect be invisible.

And the same would be true for us looking out at any potential Alien Civilizations in the cosmos, as the further away an Alien Civilization is poses a greater reduction in the potential for visual indicators because of this aspect of time and distance associated with light years.

But what about the Trillions of Alien Civilizations that have existed in our Galaxy’s history? Wouldn’t this aspect of “looking into the past” increase our chances of seeing them?

The Great Filter

There is a limit to the value seeing into the past provides in that sense. The Milky Way Galaxy is 100,000 light years in diameter, so (due to our position in the galaxy) we would only be able to see as far back as 75,000 years ago, and with the historical timescale of the Galaxy being 13.5-billion years, most of the images of these historical alien civilizations would have whizzed by our planet billions and millions of years ago; the amount of historical alien civilizations we’d have the opportunity to be able to see would be presented by a fraction similar to the one I hadn’t had the time nor patience to even write out earlier.

But what about super advanced Alien Civilizations? Surely with so many out there and so much time, one of them would have found us by now?

This is the main argument of the Fermi Paradox, which states that based on the high probability of the existence of Alien Life, and so much time having passed, it is incredibly likely that an advanced Alien Civilization would have colonized the entire Galaxy by now.

But the main error in this train of thought is the assumption of species’ immortality. The assumption of the Fermi Paradox ignores what astrophysicists call the Great Filter, which has to do with the lifespan of a species, stating that the more advanced an Alien Civilization becomes the closer it moves toward its own destruction.

The average lifespan of a species, from origination to extinction, is about 1-million years; but the lifespan of an intelligent species (that develops the means to destroy itself) is likely a lot shorter.

Modern Humans have been around for about 200,000 years, and the Doomsday Clock, which estimates just how close we are to our demise, is already at 2-Minutes to Midnight. If a 24-hour day represented the existence of Modern Humans, then mathematically that break down would equate to us having less than 200 years left to exist, and that’s assuming nothing happens, critical or influential events- such as the launching of a nuclear warhead, to push the clock even further toward midnight. It is far more likely that we die out long before we ever develop the technology necessary to find Extraterrestrial life, and this is likely true for all intelligent life in the cosmos.

The Great Filter is an impenetrable barrier and inescapable doom, that all intelligent life forms, given enough time, immutably and unanimously reach.

Intelligent life existing in the universe just does not become advanced enough to find one another. And the relatively short amount of time that it is actually around for renders it all but unnoticeable, as compared to the age of the Galaxy, it isn’t even a ‘bat-of-a-cosmic-eyelash’.

Cosmic Fossils

Humans have been emitting radio waves from Earth for a little more than 100 years now. Radio Signals are somewhat promising in the arena of discovery, because like light, they are electromagnetic waves traveling out into the cosmos at great speeds in all directions eternally. And it would be entirely possible for an Alien Civilization out there, within range, to have picked up those signals.

Now whether they would be able to identify that those signals were generated by another life-form is highly debatable; in fact, on Earth, SETI detects mysterious radio signals emanating from the far reaches of space all the time, but the signals that we are able to pick-up have to be considerably strong, and some are, but in almost all cases so far, with our current technology, they have been nearly impossible to decipher, let alone serve as a direct confirmation of the existence of Aliens.

The Radio Signals Humanity has broadcast out into the Milky Way Galaxy over the course of our history have traveled out to a diameter range of less than 100-light years. So only Alien Civilizations within that range would be able to detect them, and if they did, without more advanced technology than us, it is just as likely they would mostly present an interesting mystery, just as they do when we (humans) detect interstellar radio signals ourselves.

It is true that radio signals, like light, will travel forever, but the further they travel the more they decay, or the weaker, and the less detectable, they become.

And considering that all species will at some point die out, and thus cease emitting Radio Signals, their reach or range becomes an ever-weakening Ring, with a Beginning (representing the start of a species’ radio signals) and an End (representing the extinction of a species), a small window of opportunity to be heard, rather than a continuous Sphere emanating from its source.

All that will remain of us (humans) after we are gone will be a faint echoing ‘donut’ of indistinguishable sound, maybe a few hundred light years wide, slowly fading away as it expands out into the dark void of space. The window of opportunity for discovering intelligent life in the cosmos is just so damn indefinitely small- among a grand scale. It would take a cosmological perfect storm of countless improbable variables for existence to even afford an opportunity, and even then it is certainly no guarantee.

Consider the analogy, if the Milky Way Galaxy were the size of the United States of America, our Solar System would be the size of a Quarter. Then sprinkle a million Quarters randomly out across the entire country; the only way one Quarter could even have a chance of finding another within the United States, a distance of 3.8-million square miles, is if they had just happened to fall within a few inches of another. And even then, considering the lifespan of an intelligent life-form compared to that of the age of the Milky Way, it would be like having one second out of an entire year to realize they were within a few inches of one another.

Discovering intelligent Life in the cosmos would not only be harder than finding a needle in a haystack, but it would be harder than finding an “invisible” needle that was only in the haystack for a Nano-second.