Is there life in the universe? Are we alone?

The famous science fiction writer Arthur Clark oncesaid: “There are two possibilities: either we are alone in the universe, or not. Both are equally terrible. ” Humanity is fascinated by the idea that life can exist outside the Earth. For more than fifty years, the SETI extraterrestrial intelligence project specialists have been scanning the galaxy to no avail. It would seem that the answer is obvious, but the series and prospects of the discoveries of exoplanets again and again inspire us with hope that someday the searches will succeed.


  • 1 Do aliens exist and where are they?
  • 2 Drake equation
  • 3 Kardashev Scale
  • 4 Possible Solutions to the Fermi Paradox
  • 5 Zoo hypothesis

Do aliens exist and where are they?

Since one of the "fathers" of the atomic bomb andEnrico Fermi, Nobel laureate in physics, has formulated the famous question “Where is everyone?” decades have passed. There is still no answer, but there is a paradox named after the scientist.

The paradox can be formulated as follows: the universe is more than 14 billion years old, which means that other creatures had a lot of time to contact us. So where is everyone?

Physicist Enrico Fermi

Of course, a series of the greatest spaceachievements ahead - imagine what awaits us after the first interplanetary flights and the launch of interstellar probes to alpha Centaurus. In the end, the first manned flight into space took place only 58 years ago - children's time on the scale of the universe.

What do you think? Why is man in space superfluous?

Drake equation

However, to state with confidence thatwe are alone in the universe, we need evidence. And to put it mildly, they are not enough. Not to say that it does not exist at all. Moreover, far from everyone is satisfied with the talk that the laws of physics do not allow spacecraft to reach speeds above a certain speed. Read more about space exploration on our channel in Yandex.Zen

Drake equation

In 1961, scientist Francis Drake recordedequation for evaluating technologically advanced and messaging civilizations in the Milky Way galaxy. Drake’s idea turned out to be ingenious due to the fact that he wrote down a lot of parameters that can be estimated and then multiplied.

According to the equation, the number of civilizations (N) in our galaxy with which we could make contact can be determined by the following formula:

N = R * x fp x ne x fl x fi x fc x Lwhere:

  • R * is the average star formation rate in our galaxy
  • fp - the proportion of stars that have planets
  • ne - the number of planets on which life is possible
  • fl - the number of planets on which life can develop
  • fi - the number of planets on which intelligent life can develop
  • fc - the number of civilizations that will develop data transfer technologies
  • L - the length of time during which these civilizations must transmit their signals to space

Many astrophysicists have long tried to calculateeach value, but there is no final decision to date. In addition, the Drake equation refers only to technologically advanced civilizations. But despite the fact that all parameters in the equation cannot be indicated with absolute accuracy, the more we learn, the more accurate the equation will become. As they say, enthusiasts, do not lose heart!

Kardashev scale

Talking about solving the Fermi paradox, it’s impossiblenot to mention the Soviet astrophysicist Nikolai Kardashev. He proposed a classification of civilizations by the amount of useful energy that they can use. The scale divides civilizations like this:

  • Type 1. Civilization, able to use all the energy available on its planet
  • Type 2. Civilization, able to use all the energy emitted by its star
  • Type 3. Civilization, able to use the energy of the entire Galaxy

Representatives of the civilization of the second or thirdtype should be able to move around the galaxy at a speed close to the speed of light. They are unlikely to succeed faster, since this will have to violate the existing laws of physics.

According to modern calculations, duringIn a few thousand years, we will be able to become a civilization of the second type, but until the third we still have to grow and grow - this process can take humanity from 100 thousand to a million years. Astronomer and popularizer of science Karl Sagan believed that we are somewhere 70% of the path to the first type of civilization, but we can only reach this level in a couple of centuries.

Possible solutions to the Fermi paradox

There are no aliens and never existed. That is one of the possible solutions to the Fermi paradox. Last year, physicist Alexander Berezin published a paper in which he proposed the darkest scenario. According to Berezin, the first technologically advanced civilization that mastered interstellar travel will destroy everyone else. Having absorbed all possible resources for the sake of its own existence, it will begin to deplete the worlds in which there is already life, thereby destroying other civilizations in its path. The scientist is convinced that humanity is the only rational civilization in the universe that has gone so far in its development.

There is life. But she is unreasonable. The discovery of water on Mars last year promises previously unprecedented discoveries, for example, the identification of the simplest alien microorganisms, such as algae or microbes. Most likely, in 10-20 years, humanity will know for sure that life outside the Earth exists. Today, many scientists suggest that a variety of life forms can inhabit the icy worlds, like Saturn’s satellite Enceladus and other recently discovered exoplanets. All that remains is to look for answers to eternal questions - what makes unreasonable life forms reasonable?

Zoo hypothesis

In 1973, American astronomer John Ballsuggested that other civilizations are well aware of our existence, and numerous attempts to contact us were unsuccessful. Imagine what you meet in the forest of chimpanzees. Will you talk to him, and if so, will your conversation take place? The answer is obvious, and according to Ball, we are simply not worried, preferring to watch the animals at the zoo. It sounds rather insulting, especially since no one can refute this hypothesis.

Today the question is “are we aloneUniverse ”has no answer. However, biology on Earth can tell a lot about the likelihood of life and the conditions leading to the development of intelligence. In the end, the lack of observable intelligence does not mean that developed civilizations do not exist for long or do not exist at all.

Do you think there is anyone else in the universe besides us? Share your opinion in our Telegram chat.

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