﻿We May Have Found Evidence of Powerful Civilizations
Intro For the past few decades,
scientists have been puzzled over the possibility that a powerful alien civilization could exist
just outside the Milky Way. There are several indicators such as the Kardashev scale which
could help us deduce how advanced these alien civilizations may be. Let's talk about some
of the most significant pieces of evidence that point to the existence of powerful civilizations.
The Kardashev Scale Let's be honest—we've gone through our fair
share of impediments on our planet—wars, famines, floods, epidemics, environmental destruction, just
to name a few. Fortunately, we also have a lot of propitious things going for us—the proliferation
of electricity and the internet, expeditions to celestial bodies like the Moon and Mars,
and the discovery of the Higgs Boson at the Large Hadron Collider being just some of the examples.
An interesting question is how can we weigh all the uplifting scientific innovations and
discoveries against all the other mayhem and chaos? We are dealing with an ever-increasing
list of calamities coupled with a relentless quest for technological innovation. With such
an antithetical coupling of ghastly disasters and crafty innovations, how can we possibly
estimate our progress as a civilization? Russian physicist Nicolai Kardashev first
attempted to scale and categorize the progress of civilization in 1964. His model is called the
Kardashev scale, which measures civilization's degree of technological advancements based on
the amount of energy that the civilization can harness. The better the technology a civilization
has, the more energy it can utilize. With more energy utilization, civilizations can further
improve their technology. Kardashev reckoned that civilization would go as far as its technology
and ability to harness energy could go. While the original scale was limited to just 3 categories,
subsequent evolutions have added further levels to the scale as our technological horizons expand
with time. A Type I designation is a given to species who have been able to harness all the
energy that is available from a neighboring star, gathering and storing it to meet the
energy demands of a growing population. A Type II civilization – can harness
the power of their entire star, and not merely transform starlight into energy,
but control the star itself. Several methods for this have been proposed. The most popular of which
is the hypothetical 'Dyson Sphere.' This device would encompass every single inch of the star,
gathering most of its energy output and transferring it to a planet for later use.
A Type III civilization is where a species becomes galactic traversers with knowledge of
everything having to do with energy, resulting in them becoming a master race. Kardashev believed
a Type IV civilization was 'too' advanced and didn't go beyond Type III on his scale,
but a few believe there is a further level that could be achieved. Type IV civilizations would
almost be able to harness the energy content of the entire universe and with that, they could
traverse the accelerating expansion of space. Finding an Extraterrestrial Civilization
Since the Kardashev scale measures the amount of energy a civilization can harness,
it could be helpful to try and search for extraterrestrial species by looking for signs
of atmospheric pollution in nearby star systems. A new study by NASA looked at the presence of
nitrogen dioxide gas, which on Earth is produced by burning fossil fuels but can also come from
non-industrial sources such as biology, lightning, and volcanoes. However, the highest quantities
of the gas by far are emitted due to human activities. Astronomers have found over 4,000
planets orbiting other stars to date. Some might have conditions suitable for life as we know it,
and on some of these habitable worlds, life may have evolved to the point where it produces a
technological civilization. Since planets around other stars are so far away, scientists cannot
look for signs of life or civilization by sending spacecraft to these distant worlds. Instead,
they must use powerful telescopes to see what's inside the atmospheres of exoplanets.
Biosignatures to look out for include a combination of gasses like oxygen and
methane in the atmosphere. Similarly, a sign of technology on an exoplanet,
called a techno signature, could be what's considered pollution here on Earth. It is
the presence of a gas that's released as a byproduct of a widespread industrial process,
such as nitrogen dioxide. In their study, the team at NASA used computer modeling to predict
whether nitrogen dioxide pollution would produce a signal that is detectable by current and planned
telescopes. Atmospheric nitrogen dioxide strongly absorbs some wavelengths of visible light,
which can be detected by observing the light reflected from an exoplanet as it orbits its
star. They found that for an Earth-like planet orbiting a Sun-like star, a civilization producing
the same amount of NO2 as ours could be detected up to about 30 light-years away with about 400
hours of observing time using a future large NASA telescope observing at visible wavelengths.
They also discovered that stars that are cooler and far more common than our Sun,
such as K and M-type stars, will produce a stronger, more easily detected NO2 signal.
This is because these kinds of stars produce less ultraviolet light that can break apart
NO2. More abundant stars increase the chance that an extraterrestrial civilization might be found.
Since NO2 is also produced naturally, scientists will have to carefully analyze an exoplanet to
see if there is an excess that could be attributed to a technological society. While this research is
still in its preliminary stages, further studies are planned which will use 3D models to compare
how accurate their initial results are. Finding Evidence of Powerful Civilizations
The most popular method of harnessing the energy of a star for a type II civilization is the
hypothetical Dyson sphere. The tantalizing idea states that a super-advanced alien civilization
could build an enormous structure around its home star, to collect a significant portion of the
star’s energy. A new possibility suggests that the Gaia mission by the European Space Agency whose
primary purpose is to create a 3D map of our Milky Way galaxy may be instrumental in the search for
Dyson spheres. In the past, searches for Dyson spheres have focused on looking for signs of
excess infrared or heat radiation in the vicinity of a star. That would be a telltale signature,
but those attempts have come up empty so far. The new study uses a technique never employed before
which proposes looking for Dyson spheres with little or no infrared excess.
The new study suggests the possibility that the sphere might be composed of a different kind of
material than what had been previously supposed. If this turns out to be true,
the new measurements would suggest that the star is farther away than it is.
The size of a Dyson sphere could be determined by comparing the difference in distances between
both the old and new methods. The greater the difference, the greater the amount of the star's
surface that is being obscured by the sphere. Now, thanks to new data from the Gaia mission,
astronomers can do these kinds of comparisons, which could – in theory – detect a Dyson sphere.
Using this new method, astronomers have already found several candidate Dyson sphere
stars. The Gaia mission is currently charting a three-dimensional map of our galaxy, providing
unprecedented positional and radial velocity measurements with the highest accuracy ever. The
goal is to produce a census of about one billion stars in the Milky Way galaxy and throughout the
Local Group of galaxies. As it happens, this data is very useful when searching for Dyson spheres.
Using the difference in distances from the first data release of Gaia, scientists
have compared that data to previously measured distances from the Radial Velocity Experiment,
which takes spectra of stars in the Milky Way. This resulted in an estimate of what percentage
of each star could be blocked by Dyson sphere material. Upon further analysis, only six possible
candidates were selected for the study. Those, in turn, were then narrowed down to only two,
after eliminating four candidates due to problems with the data itself. One of those, the star TYC
6111-1162-1, was then considered to be the best remaining candidate. However, there is still
further research needed to conclude if it is a Dyson sphere. The star, a garden-variety late-F
dwarf, seems to exhibit the sought-after characteristics, but more data is needed.
No other glitch-related weirdness was found in the data, but the star was also found to be a binary
system consisting of two stars which might explain the results – but none of that is certain yet.
Additional study of the star will be required, including using future Gaia data releases,
to come to a definitive conclusion. Outro
It truly is an exciting time for space exploration, we may finally
be closer than ever to discovering an intelligent extraterrestrial species. If you liked this video,
please take a look at another one that further explains the Kardashev scale.
Question Do you think we will find intelligent
extraterrestrial life in the near future? Please share your thoughts in the comments section below.