Galaxies like the Milky Way have at least 2 trillion in the universe, and there are at least 200,000 Earth-like planets in the Milky Way, but we have not found any other life so far, why?
Please spend 2 minutes reading my analysis.
The age of the universe is currently thought to be about 14 billion years, while the age of the solar system is about 5 billion years, and the Earth was born about 4.6 billion years ago.
At the current level of human technology, the observable universe range is 46 billion light-years in radius, of which there are 2 trillion galaxies similar to the Milky Way, 300-500 billion stars in each galaxy similar to the sun, and almost every star has a large number of planets.
According to modern probability and statistical methods: the Milky Way alone should have 200,000 Earth-like planets in the Earth-like habitable zone, of which 1% may evolve intelligent life, and in the most conservative calculation, the Milky Way should also have more than 2,000 intelligent civilizations.
But what about the facts?
With the exception of Earth, no signs of life have been found on any other planet.
The vast universe, as if only the earth is noisy and noisy, constantly sending out various signals to the outside world, and the other starry sky is deep, a dead silence, quiet enough to make human beings feel afraid.
Is it true that everywhere the light goes, there is silence and emptiness? Why can't we find traces of extraterrestrial life? Where did they go?
In 1950, nobel laureate Fermi raised a rhetorical question: "Theoretically, humans can fly to the planets of the milky way in 1 million years, so as long as aliens evolve 1 million years earlier than humans, they should now come to Earth, but where did they go?" ”
This is known as the "Fermi Paradox".
Soon after, Fermi died.
In 1959, Frank Drake proposed the 7 factors formula for the birth of civilization on the basis of Fermi.
(For the sake of being easy to understand, I'll simplify it)
N=1*2*3*4*5*6*7
N: The number of civilizations the Galaxy may have come into contact with us
1: Number of stars in the Milky Way
2: The proportion of stars with planets
3: A similar proportion of planets to Earth
4: Proportion of planets with life
5: The probability of evolving higher organisms
6: Probability of being able to communicate
7: The existence of civilizations accounts for the proportion of the life cycle of the planet
From the current point of view, N (the number of alien civilizations) is infinitely close to 0, and the base of 1 (number of stars) 2 (number of planets) 3 (number of terrestrial planets) is extremely large, so the problem lies in the four factors of 4, 5, 6, and 7.
If the probabilities of 4 (planets have life) 5 (the probability of evolving higher life) and 6 (being able to communicate) are low, it means that we are likely to admit that "human beings are unique beings in the universe."
However, at present, the possibility of the view that "human beings are extremely special beings" is basically 0, so the probability of 4, 5, and 6 should not be very low, while 1, 2, and 3 have been proved to be very large, and the key to the conclusion that N is infinitely close to 0 lies in the 7th factor.
Factor 7 (the proportion of civilizations that have existed in the lifetime of the planet).
I take earth as an example:
Human civilization: 3 million years old (Ethiopian ape-man fossil)
Earth life cycle: 4.6 billion years (U-Pb isotope)
What is the approximate proportion for everyone to calculate for themselves?
Perhaps there are many intelligent civilizations in this universe, but no civilization has ever been able to cross the galaxy, and the difficulty of interstellar navigation is far beyond our expectations.
And each planet's resources are limited, the mass is conserved, before there is no interstellar navigation capability, this civilization will be due to insufficient resources and civilization regression, under the limit of the speed of light, the speed of human evolution can never catch up with the escape speed of the cosmic tear.
Countless civilizations, like the earth, develop rapidly at a point in time, until the mother star cannot withstand the resource needs of the civilization, nor find a way out of the sea of stars, and finally die in despair and helplessness on the mother star, repeating the cycle, and constantly circulating...
So can't humanity be the first civilization on Earth?
The age of the Earth is 4.6 billion years, and the earliest fossils of life are currently 3.4-3.8 billion (fossils of single-celled organisms discovered in Australia in 2011).
Since then, more than 3 billion years, from the Archean to cambrian to the Cretaceous to the Holocene, life has evolved from single-celled protozoa to complex primitive plants (algae, ferns) to molluscs, chickadenopods (trilobites), vertebrates (fish), and then to two reptiles (dinosaurs) to mammals (Archaeopteryx) to primates (humans), until nearly 10,000 years before the prototype of human civilization appeared, as for the rapid development of science and technology, It was only 200 years since 1765 (the Industrial Revolution).
In the 3.8 billion years of the evolution of life, we have not found any traces of the existence of another civilization in the earth's crust, so the possibility that humans are the first civilizations on earth is extremely high.
Taking a step back, there are only two theoretically possibilities that may indicate that humans are not the first civilizations on Earth.
1. The solar system is only 5 billion years old, and the Sun is a star born in the residual nebula of previous generations of stars, before that, were there any earth-like living planets? But even if there is, it does not belong to life on Earth.
2. In the 4.6 billion years of the birth of the earth - 3.8 billion years of the birth of single-celled organisms in the 800 million years before the birth of human civilization, provided that in the planet has just been born, in various extreme environments, evolved a human-like civilization, human beings used 3.8 billion years, they only took 800 million years.
What's more, do you really think that as long as it is life, you can evolve a higher civilization?
Dinosaurs existed for 260 million years, much higher than the 3 million years of humans, but what about higher civilizations?
There are four conditions for the birth of a higher civilization on Earth:
1. Predator's eye. The eyes are located in front of the face and provide a three-dimensional field of vision, generating a person's spatial imagination and abstract thinking ability.
2. Opposing thumbs. Tools can be used, fire can be used, and agricultural civilization was born.
3. Be curious. Pushing human beings to constantly question, constantly moving forward.
4. Well-developed vocal cords. An important condition for the birth of a language makes communication and communication more convenient.
How many creatures on Earth meet these four conditions at the same time?