Are we alone in the universe or are there other intelligent beings somewhere looking
up into their night sky from very different worlds asking the same question do they wonder
about extraterrestrial life the same way when they tried to detect thousands of exoplanets as we do
if they are it would take them some time to reach us a pair of researchers believe
humanity has to survive yet another four hundred thousand years to get the first
interstellar email from another extraterrestrial civilization welcome to Factnomenal and today
let's find out what's taking other intelligent civilizations so long to hit us up with a hello
Why Has Humanity Never Been Visited by Aliens? We have been pondering this question for decades
if not centuries in our limited experience of studying life that is available on earth
we have tried to fantasize about what intelligent life would be like on distant planets
as mars is a close neighbor and has a lot of similarities with our earth the fathers of
science fiction wrote stories of extraterrestrials living on the neighboring planet waiting to invade
us later as we confirm that all other planets were barren in our solar system although one of
Saturn's moons may still hold potential for life we began imagining et's traveling thousands of
light years to visit us we envisioned them coming in peace and communicating with us through music
we also dreaded that they were cruel invaders looking to colonize us by destroying the white
house we also imagined them as refugees who we exploited in turn and we also wished they were
just some lost soul who befriended us and needed a little help to get back home but in reality
nothing like that has happened at all no ship from outer space has invaded us declaring war nor have
they tried to ask our leaders out for a game of top golf to discuss alliance so where are they the
question has confounded scientists for decades but two pairs of researchers have come up with
a possible but disturbing explanation they think advanced civilizations could be doomed to either
stagnate or die off before they get the chance the new hypothesis suggests that as space-faring
civilizations grow in scale and technological development they eventually reach a crisis point
where innovation no longer keeps up with the demand for energy what comes next is collapse
quite interesting where did they get that idea definitely not looking back at us humans right
right well anyway back to the subject the researchers believe that the only alternative path
is to reject the model of unyielding growth in favor of maintaining equilibrium but that
means it can only be achieved at the cost of a civilization's ability to expand across the stars
given that there is a substantial cry over recent multi-million dollar space tourism
enjoyed by uber-rich personalities while the rest of the world battles
global tensions and economic collapse these researchers do seem to be onto something here
nobel prize-winning physicist Enrico Fermi explored the possibility of life beyond earth
in 1950 with fellow physicists Edward Teller, Herbert York, and Emil Konopinski during their
walk to lunch the group of colleagues discussed the recent rise in rumors about ufo sightings
and also explored the idea of faster than light travel frustrated by the mismatch of the high
probability of life possible in the galaxy and the complete lack of evidence to support such numbers
fermi exclaimed but where is everybody there have been many attempts to explain the fermi paradox
primarily suggesting that intelligent extraterrestrial beings are extremely rare
that the lifetime of such civilizations is short or that they exist but for various
reasons humans see no evidence this suggests that at universe time and space scales two intelligent
civilizations would be unlikely ever to meet even if many develop during the life of the universe
recently Wenjie Song and He Gao from the department of Astronomy at Beijing Normal
University have explored the number of possible cities within our galaxy
and the communication probability among these studies CETIs mean communicating extraterrestrial
intelligence civilizations did they explore the possibility of weather as the only advanced
intelligent civilization on the earth humans existence is unique in the universe or not
like many other studies on extraterrestrial civilization in the past few decades
the first challenge for these two researchers was the difficulty to study something we're not even
sure exists a highly advanced civilization as we mentioned earlier in the video there is only one
data point available in this field and that is us humans on earth which makes studying other
civilizations in any way quite ridiculous however researchers have from time to time
dabbled in this thought experiment albeit using rigorous scientific guidelines
one such study from the year 2020 even concluded that there are at least 36 CETIs in the milky way
then how come not a single one contacted us yet according to song and Gao how
many cities might exist is tied up with how long we might have to wait to hear from one
hello is it me you're looking for astrophysicists have always been curious to know the answer to
the aforementioned question this is where the drake equation comes in based on our growing
knowledge of the milky way the drake equation tries to estimate how many cities there may be
in our galaxy as many critics have explained the drake equation has its flaws for example some of
its variables are little more than conjecture so the number of civilizations it calculates
isn't reliable but the drake equation is more of a thought experiment than an actual calculation
yet we have to start somewhere and it gets song and Gao started taking inspiration from the
previous scientific efforts in a similar direction specifically the one that mentioned there are
approximately 36 cities in our galaxy they dealt with two important parameters the first concerns
how many terrestrial planets are habitable and how often life on these planets evolves into a setting
the second is at which stage of a host stars evolution would a communicating extraterrestrial
intelligence civilization be born giving each parameter its own variable in their calculation
song and Gao ran a series of Monte Carlo simulations using different values for
these variables they arrived at two scenarios an optimistic outlook and a pessimistic outlook or
in simpler terms ladies and gentlemen we have good news and bad news the good news is that if a star
has to be at least 25 into its lifetime before a city can emerge and for each terrestrial planet
there's only a 0.1 percent chance of a city appearing then we get over 42,000 cities that
is a huge number but this is a very optimistic scenario that makes the whole universe look like
a life-supporting paradise which definitely isn't the case and that's where the bad news comes in
if stars have to be at least 75 percent of their life cycle to host the city the probability of any
single terrestrial planet hosting a CETI drops to a miniscule percentage of 0.001
one thousandth of one percent in that case we will be left with around 111 cities in the Milky
Way now that doesn't sound like a bad number given that it is still three times more than the number
suggested by the study in 2020 but if one scatters that 111 cities across the vast span of our galaxy
we are millions of light years apart even worse we'd need to survive another whopping 400,000
years to have two-way communication with him for perspective the creators of star trek traveling
where no man has gone before by the mid 22nd century yeah we could forget about that scotty
song and Gao also added about the great filter and how it proposes that the lifetime of civilizations
is very likely self-limiting due to many potential disruptions such as population issues
nuclear annihilation sudden climate change rogue comets ecological changes etc if the doomsday
argument is correct humans may not receive any signals from other cities before extinction
and they are not the only ones pondering over such questions researchers Michael l
Wong and Stuart Bartlett are the latest in the long line of people who have
attempted to find a solution to the fermi paradox according to the duo civilizations
either collapse from burnout or redirect themselves to prioritizing homeostasis
a state where cosmic expansion is no longer a goal making them difficult to detect remotely
either way the civilization would be unable to reach out to other exoplanetary civilizations
institute of technology came to their hypothesis by researching studies of the
super linear growth of cities these studies suggested that cities increase in size and
energy consumption at an exponential rate as their populations grow inevitably leading to
crisis points or singularities that cause rapid crashes and growth followed by an even more
precipitous potentially civilization-ending collapse Wong and Bartlett hypothesized that
once a planetary civilization transitions into a state that can be described as one
virtually connected global city it will face an asymptotic burnout an ultimate crisis where the
singularity interval time scale becomes smaller than the time scale of innovation however these
close to collapse civilizations would be the easiest for humanity to detect as they would be
dissipating large amounts of energy in a wildly unsustainable way so the initial indications of
the first extraterrestrial life we may find might be intelligent but not very wise kind of like us
both pairs of researchers point out that while such civilizations may not completely abandon
space exploration for survival they would not expand on scales great enough to make contact with
earth likely will humanity ever encounter another civilization it's one of our most compelling
questions and it's almost certain that nobody alive today will ever have the answer first first
there have to be other studies and then we have to exist simultaneously with them and communicate
somehow it's possible that another city had already detected life on earth before they
were wiped out by the great filter or possibly by a natural calamity like a supernova explosion
but maybe maybe if we survive long enough we may get a call from an unknown planet a sign of life
beyond our world tell us in the comments what you think about people who claim
that they have met extraterrestrials already and as always thanks for watching Factnomenal