Some call it The Great Silence, others The Fermi Paradox.
For the last 60 years, we’ve had our eyes and ears glued to the cosmos looking and
listening for some sign letting us know we’re not all alone in the galaxy. And
the more we discover, the harder it is to believe we’re the only ones.
Think about this for a moment; there’s around 2 trillion [2,000,000,000,000 galaxies] galaxies
in the observable universe. Each one of those galaxies have on average 100 million stars.
Some supergiants have one hundred trillion stars, and our Milky Way Galaxy has between
100 to 400 billion stars alone. It is likely that there’s at least this many planets floating
around all those stars, and complex planetary systems that may resemble our own Solar System.
It brings us to the big question: where is everyone, and why haven’t we been contacted
by an extra-terrestrial civilization from even inside our own galaxy? There should
be many advanced civilizations out there, and we should have heard something from someone by now.
There are quite a few possible explanations for the ‘Great Silence’,
and some researchers think they may have found some answers to this so-called paradox.
What will happen to humanity in the future? Will we finally make contact
with another alien civilization, or are we simply alone in the universe?
Will artificial intelligence end up destroying us and other advanced civilizations,
or is there a chilling possibility that AI has already done this?
Get ready to find out this and more.
[LOGO]
The
Fermi Paradox refers to the puzzling observation that we have not found any
evidence of extraterrestrial intelligent life out there, despite the vast number
of stars in the galaxy, and it is presumed that most of those stars have planets that
lie in the habitable zone. Planets that could be a lot like Earth, and even Super Earths.
That said, our Milky Way Galaxy should be teeming with intelligent life,
and we should have seen, or heard something by now. So where are all those super high-tech
advanced civilizations with their warp drives and other advanced technology?
There could be a few answers to this so-called paradox, or it may not even be a paradox at all.
There have been many books written offering a variety of solutions to the Fermi Paradox.
Some of them sound logical, while others sound a bit frightening.
One of the logical arguments is that any civilizations that may exist are just too far
away to make contact. Forget the science fiction films that made the idea of instant communication
in space seem possible. It just doesn’t happen like this across huge distances. Light waves,
radio waves, and all of the other electromagnetic waves travel at the speed limit of light in empty
space which is about 300,000 kilometers per second [186,000 miles per second]
Now, that’s fast, but it’s still not fast enough. A light-year is the distance that light
travels in one Earth year, which is around 9 trillion kilometers [6 trillion miles].
Let’s say for a moment that we have a colony on the closest exoplanet to Earth,
which is Proxima Centauri. If the colony radioed Earth and asked us how we’re doing,
it would take 4.2 years to get that message, and another 4.2 years to send a reply,
meaning it would take eight and a half years to get an answer to their
question. It’s hard to understand what kind of conversation you would have with someone
back on Earth with such a time gap. And that’s just from a neighboring system.
The Andromeda Galaxy is 2.5 million light years away,
which means that by the time we get any message from there, 2.5 million years will have passed,
and the civilization that sent out the message would likely be long gone,
unless they became an interstellar civilization able to traverse the stars.
At the same time that we’ve been trying to discover radio signals from an extraterrestrial
race out there somewhere, we’ve been sending out a ton of our own radio signals, and we’ve
been real noisy about it too. That said, could it be possible someone out there can hear us? Well,
the Milky Way Galaxy is over 150,000 light years in diameter. And we’ve been broadcasting radio
signals for just over 100 years now. That means those radio signals have not traveled farther
than 100 light years. The little blue dot in this photo shows a diameter of 200 light years. From
this observation, it’s easy to see why it's possible no one has heard each other yet.
But then again, it all depends on how long a civilization has been broadcasting radio signals.
A study was done with a model that had estimated parameters on the distribution of stars in the
Milky Way Galaxy, and the possible frequency of the existence of life. The study concluded
that only 1% of the Milky Way Galaxy may have already been covered by radio transmissions
from different planets, and that we’ll still have to wait about 1,500 years to
have any chance of hearing some alien broadcast. However, another study claims that it would take
us another 400,000 years before we picked up some signal from an intelligent civilization.
Another chilling explanation for the deafening silence of outer space could be that we’re the
first advanced civilization to reach the technological level we’re currently at,
which is very low on a galactic scale, and that we humans have emerged in the universe too early,
and we’ll go extinct before other intelligent beings appear. We’re not even close to discovering
interstellar travel yet, which some like Elon Musk say is possible in the future,
and we’ve not yet harnessed the full power of the Sun which is due to engulf the inner
planets of the Solar System in about 5 billion years when it reaches the end of its life. But
the Earth will certainly become uninhabitable long before this cosmic solar cataclysm occurs.
With that in mind, the human race better be ready to leave this world,
and find a new home if it is to survive and perpetuate among the stars. This same stellar
evolution happens to all main-sequence stars, and could certainly wipe out many forms of life,
and perhaps even advanced civilizations before they were able to discover interstellar
travel. 90% of the stars in the Universe are main-sequence stars, and that includes our Sun.
However, the reverse could also be true. What if we’re the last ones left behind?
There has been plenty of time for high tech civilizations to conquer the stars,
and plenty of time for many other civilizations to come and go.
But some researchers have other explanations…
American astrophysicist Michael Hart simply claimed that “they are not here;
therefore they do not exist”. He theorized that expansion through the entire Milky Way
Galaxy could be accomplished on a timescale a lot shorter than the age of the galaxy itself.
Expansion by us humans could be done by sending out expeditions to the 100 nearest stars,
which are all within 20 light years of the Sun. Each one of
these colonies would then send out its own expeditions, and so forth. At such a rate,
most of the Milky Way Galaxy would be explored within 650,000 years.
Even if we assume the time between voyages is the same length of a single voyage,
the time needed to traverse the galaxy would be roughly doubled. Combine this
with the fact that the Milky Way Galaxy is approximately 13.6 billion years old,
and we see that there has been plenty of time for an advanced civilization to
reach us, that is unless they started space exploration less than 2 million years ago.
As you can see from this example, an expanding civilization could spread rapidly through its
host galaxy, and this also applies to any advanced civilizations that reside in our
own galaxy. Therefore, it would seem that the absence of extraterrestrial settlement
in the solar system simply implies that such civilizations do not exist. This is assuming
that the expansion would proceed uniformly throughout the galaxy.
The obvious absence of a galaxy-spanning extraterrestrial civilization possibly means
one of two things; either interstellar travel is too difficult for civilizations to develop,
or the evolution of life is a rare event.
Some researchers suggest that some civilizations out there would migrate to a nearby K or M dwarf
star before stellar evolution destroys their home planet. Two researchers named
Hansen & Zuckerman estimated that this motivation for civilizations to migrate
from a short-lived to a long-lived star would imply that the fraction
of surviving civilizations around low-mass stars could range anywhere from 30% to 72%.
But the question still remains: Where are they?
A pair of researchers recently came up with yet another possible answer to the Fermi Paradox.
They call it superlinear scaling. The study began by looking at how human civilizations
have risen and fallen throughout history. As they studied the history of large cities,
they noticed that most grew and collapsed. Such rising and falling by an alien space
civilization leads to one of two scenarios. In the first scenario, a civilization would
realize that they were growing too large and cease colonizing other worlds. However,
in the second scenario the civilization doesn’t recognize their plight and grows exponentially,
colonizing other worlds until the energy demand of their constant colonization
becomes unsustainable. If they didn’t take action, they would reach a singularity;
the point of no return, and they would be unable to save their civilization from total collapse.
The most interesting thing about this study is that if it were not for the
vast distances between us and other stars, we would be able to easily spot an alien
civilization on the verge of collapse due to the enormous amounts of energy it would emit.
Another bizarre theory is that some extraterrestrial civilizations could
possibly be hibernating or waiting in silence to move to another part of the galaxy.
American astrophysicist Micheal Hart showed that civilizations could leverage close stellar
encounters to rapidly expand across the galaxy, without the need for relativistic spaceflight.
This could also explain why we might not have seen anything yet. For instance, if we’re going
to launch a rocket towards the planet Mars, we would wait until the planet begins its closest
approach towards Earth or perihelion. It is possible that some civilizations are waiting,
and could be for centuries, in order to traverse the closest possible star systems to them.
But there is even more reason why we don’t see or hear aliens from another world. Several authors,
including the late great Carl Sagan have noted that exponential population growth through the
galaxy is unsustainable. So any attempt at galactic-scale expansion must be for reasons
other than to satisfy the demands of a growing population or increasing energy consumption.
Although it remains possible that long-lived technological civilizations do not expand,
it also remains possible that such civilizations pursue galactic settlement in order to ensure
their longevity. Galactic-scale settlement is not the only reason
that could motivate an extraterrestrial civilization to visit nearby star systems.
G-dwarf systems with inhabited planets, such as Earth, may be attractive targets
for extraterrestrial visitors who are interested in studying the evolution of life on other worlds.
This form of exploration could also involve remote exploration, such as the use of self-replicating
probes. Maybe this is why there has been an increase in UFO sightings in the world lately.
It could be that an intelligent civilization is watching us and waiting for the right moment
to make contact. Or maybe they are just watching us with no intent to make contact. Back in 1933,
space exploration pioneer Konstantin Tsiolkovsky had written that alien beings are probably far
more advanced than we are, therefore they would find as much interest in communicating with us
as we would to communicate with animals on our planet. Forty years later, a radio astronomer
by the name of John Ball arrived at a similar conclusion and said that aliens may see us as
some kind of zoo. It’s called the zoo-hypothesis, and is the idea that other intelligent creatures
are observing us without revealing themselves. Other radio astronomers have argued that aliens
are keeping us at a safe distance until we are able to offer something useful to the so-called
‘Galactic Club’. However, this would require that any interstellar civilizations that exist do the
same. Such synchrony could probably not occur in our galaxy, let alone the entire universe.
We need to take into consideration that looking from the outside in,
we probably appear to be a hostile race of creatures. We’ve all seen the movies where
aliens from a distant galaxy attack Earth and almost wipe out the human race. We should hope
that if there is such intelligent life watching, they will step in and stop us
from destroying ourselves instead of finishing the job. So maybe they’ve decided to stay away.
With everything we have discussed, there is yet another idea we think could be the reason the
universe is silent. We can see that artificial intelligence is starting to grow, and we already
have this terrifying idea that if we leave AI unchecked, it will eventually see us as a threat,
and eliminate us. Or maybe even worse, make us slaves. Artificial intelligence would then seek
to grow and try to colonize the galaxy knowing what lies in store for the planet Earth due
to stellar evolution. AI could possibly solve the barriers of interstellar travel. And if AI
was sent out to colonize, it could do everything without the constraints of a biological species,
such as us humans. It could therefore do it much quicker, and more uniformly using machines.
But it could do something even more ominous and wipe out other civilizations that it ran
into. A hostile artificial intelligence would likely destroy other life forms, and some even
unintentionally as they most likely wouldn’t notice. Kind of the same way a construction
crew unknowingly demolishes an anthill to build a shopping mall. Artificial intelligence would very
most likely take advantage of something like Von Neumann Probes which are self-replicating
spacecraft that could in some ways mimic the features of living organisms or even viruses.
Imagine if one day an entire fleet of killer robot ships entered our Solar
System with intentions of taking it over for resources. Such self replicating machines
that could mimic our worst nightmares would be tough for any civilization to counter.
The incentive for artificial intelligence to grab all available resources will be
one it can’t resist. And it only takes one bad actor to ruin the party. If our AI went rogue,
it could populate an entire supercluster with copies of itself, and turn every solar system
into a supercomputer. There’s no use asking why it would do this, all that matters is that it can.
But aside from this horrifying thought, would it know when it has reached the singularity... Or the
point of no return when the AI civilization has grown far too big to sustain itself? If it didn’t
see the inherent danger of rapid colonization and stop in time, this AI civilization would collapse.
And maybe this is why it seems as if we’re the only one’s left in the universe. Maybe
somewhere down the line, AI did take over and wiped us out like in the Terminator movies,
and then proceeded to colonize the galaxy while knowingly or unknowingly wiping other
life forms and advanced civilizations completely out of existence. However,
when the machine civilization collapsed, it could not understand why, and therefore
has created a simulation of us to see how it was created, and perhaps figure out why it collapsed.
It sure would explain a lot of things… even if it is a really far-fetched idea.
The very last thing could simply be that there just is no one else, and therefore,
there is no paradox. All of the scenarios that we previously mentioned assume those
millions of civilizations that we cannot contact, actually do exist out there.
But not all researchers agree with this and claim that the possibility of the emergence
of life is overestimated in the Drake equation. Some tweaks were done to the equation by these
same researchers and they concluded that “We find a substantial probability of there being no other
intelligent life in our observable universe.” In fact, they put the chances of us being alone in
our galaxy at between 53% and 99.6%, and between 39% and 85% in the entire observable universe.
And then there is the Great Filter hypothesis in which all civilizations have to survive some huge
calamity or barrier in order to evolve. The first barrier is you need a planet capable of life to
form in the star's habitable zone, and life needs to develop on that planet. Those lifeforms need to
be able to reproduce using DNA and RNA molecules. Simple cells must evolve into more complex cells,
and multicellular organisms must develop and be able to reproduce. More complex organisms
capable of making and using tools must evolve. Those organisms must create advanced technology
needed for space colonization, and must go on to colonize other worlds without destroying itself.
With that in mind, perhaps planets that host some sort of life are relatively common,
but those that host advanced technological life are quite rare.
In the Great Filter, something usually goes wrong which probably stops the emergence
of a species such as planet-killing asteroids, disastrous climate change,
or even an unstable host star… leaving us all to wonder if there is anyone else out there.
That’s all the time we have for today, but before we go,
we’d like to hear what you believe is happening and why we’ve not made
contact yet. Sound off in the comments. And make sure to stay tuned here for more
exciting things happening on our planet and in the universe. Thanks for watching.