We are only afraid of things we do not understand, cannot control. And with this ever-large universe, the most confusing and difficult thing to control is probably life. Why life can only be found on Earth, why until now, we have not found any signs of other life?
Where are the aliens? Do they exist? And if so, have they come for peace? These questions mankind cannot yet answer. However, there have been many theories, even paradoxes, to explain the mysteries of the universe. The most famous one is the Fermi paradox.
The conditions for life to exist and why the Earth is perfect
Looking at the blue planet in the Solar System, we must consider ourselves lucky. The Earth is perfectly positioned with the central star, in this case the Sun. This location is not so close that the Earth does not burn like Mercury, and it is not too far away to freeze our planet like Uranus.
This perfect location is called the Habitable Zone, which means the zone suitable for life to thrive. In this region, the climate on the entire planet would not be too hot or too cold.
Earth is not the perfect place for life
Although we have hot and dry deserts, such as Death Valley, in California, temperatures can reach over 55 degrees Celsius, or the town of Oymyakon in Siberia, Russia can be as cold as -40 degrees. C. However, this temperature is still considered much less extreme than the distant planets in the Solar System. That is, they are still enough for water to exist in liquid form, cells can grow and life can multiply.
However, Earth is not the only planet to enjoy a beautiful place in the galaxy. According to statistics, in every Solar System there is such a planet. For example, Earth is the only planet in the Habitable Zone of our Solar System; or exoplanet Proxima Centauri b – located about 4.2 light-years (1.3 parsecs) from Earth in the constellation Centaurus. It is considered the closest known exoplanet and is orbiting the habitable zone of its star.
Based on these theories, for aliens to exist, they also need to live in these perfect regions. From here, we only need to count the number of Solar Systems with Habitable Zones to find planets that are capable of harboring life.
According to NASA estimates, there are 250 billion stars in this galaxy alone, and if we look beyond the universe, we have more than 100 billion other galaxies.
That means that if the galaxies were all the same size, this universe has more than 70 trillion billion stars in the visible universe. If only 0.01% of the stars in it were to be used to create life, there would theoretically be too many places for life to proliferate.
According to Inverse.com, in 2013, astronauts counted at least 6 billion Earth-like planets in our galaxy. But the extraterrestrial life that we have found since the beginning of space exploration so far is a round zero.
This is where the Fermi Paradox – or the Fermi Paradox is mentioned, as an explanation for all that puzzling disappearance of life.
The Fermi Paradox and the “great selection process”
This paradox is named after the physicist Fermi Enrico, when he described the stark contradiction between the high probability of the existence of extraterrestrial life or the is the lack of evidence in corroborating this. What’s even scarier, he says, is are we really alone in this vast universe, or just because we can’t really “see” them yet.
To explain that paradox, Fermi has further proposed the existence of aliens called “The Great Filter”. Accordingly, our universe has existed for nearly 14 billion years and no one disputes how large it is.
But with all this time, the universe seems empty. There is no sign of advanced civilizations. From here, scientists think that there is “something” that is keeping us humans or other possible civilizations from developing to be able to communicate with higher civilizations.
This is a fact, a selection to see if the species has the capacity to grow taller. No one knows what will happen when we actually pass that test, but otherwise the civilization will be destroyed.
This is what “natural selection” is – a turning point that determines the development of a civilization or even its survival. However, “The Great Filter” theory is not just that. Scientists divide “The Great Filter” into two cases: One is that this selection process has already happened, the other is that it is still waiting for us ahead.
In it, each case leads us to a different assumption about the future of humanity. In the first case, when this selection process has already taken place, humans may be the only intelligent beings in existence.
In other places of life, the theory explains that during the development of living things, something happened that caused the other species to surrender. It could be a great epidemic that wiped out all life, it could be a giant meteor like what happened to the dinosaurs.
No matter what happened, we know that the human race has survived and that makes us the first, pioneering species in the universe to explore the endless world out there.
But there’s also the second case, when “The Great Filter” hasn’t happened yet. This theory is even more widely believed, because it explains why we have yet to find any extraterrestrial civilizations.
This time, “The Great Filter” could be an event that we most likely haven’t touched yet. Therefore, we still do not have the “passport” to reach the stars and communicate with high civilization.
One reason for us to believe this more, is that supernatural phenomena sometimes appear in life, and is believed to be when extraterrestrial civilizations have “accidentally”, causing us to accidentally see even if only for a moment.
“Fermi understands that any civilization with a modest amount of rocket technology and the most modest amount of imperial incentives can quickly colonize an entire galaxy,” said a representative of the Search Institute. Extraterrestrial Intelligence (SETI) in Mountain View, California, writes in an explainer Fermi Paradox. “Within a few tens of millions of years, any star system could be brought under the wings of an empire. Tens of millions of years may sound like a long project, but it’s actually quite short given the age of the galaxy. . roughly a thousand times”.
Helen Sharman – a British astrophysicist has an even scarier theory, that aliens may be standing among us, without anyone knowing.
“Are they like you and me, made of carbon and nitrogen? Maybe not. Maybe they’re here right now and we simply can’t see, but can only feel. ‘, Mrs. Helen explained.
Such life will exist in a new concept, temporarily called “Dark Biosphere”. These are not ghosts, Helen stresses, but undiscovered creatures that may have different biochemical makeups.
This means that we cannot research and find aliens in the usual way. In other words, we do not see them, because this is beyond human comprehension.
Likely also to be believed
In 2015, scientists analyzing data from the Hubble and Kepler Space Telescopes concluded that just 8% of all habitable worlds will existed in the surrounding universe, when the Earth formed about 4.5 billion years ago. Therefore, extraterrestrial civilizations, if any, will also be located very far away.
Another theory is that life is too “fragile” to last long on a planet, and that we are simply not at the same stage as them. Research in 2016 explains that the early stages of a rocky planet’s history can be very habitable, often appearing about 500 million years or so after the planet cooled.
The history of our Earth seems to support that conclusion, given that life arose about 4.1 billion years ago, but those good times may not last, due to a problems such as the greenhouse effect or other climate changes.
“Life may be so rare in the universe not because it’s difficult to start, but because the habitat does not allow it to persist beyond the first billion years,” researcher Aditya Chopra wrote in a study. and later published in the journal Astrobiology. “It’s like trying to ride a bison. Most of the life is lost.”
Some thinkers suggest that civilizations may tend to self-destruct as soon as they acquire technological prowess. Once again, the history of the formation of the Earth has provided material and can explain this hypothesis.
In fact, humanity came alarmingly close to nuclear war during the “Cuban Missile Crisis” in 1962. Alternatively, we might as well be in a process of “self-destruction.” himself” and most other life on the planet through climate change, global warming and the greenhouse effect. Scientists are working to prevent this, but can they?