Why do scientists think that we can never find extraterrestrial life?

Uncontrolled climate change will ultimately lead to a large-scale devastation of our planet. Coastal cities will be flooded by oceans, the level of which is constantly growing, severe heat will increase the rate of human mortality, and acidic oceans will become unsuitable for the existence of fish and corals, and only small jellyfish will survive.

Such consequences of human activity can prevent our civilization from developing. In a particularly extreme scenario, they can even lead to the disappearance of a person from the face of the Earth.

Although this seems unlikely, it seems that anthropogenic climate change is the answer to a question that more and more scientists are beginning to ask: why have we not been able to detect extraterrestrial life?

The Fermi Paradox

We live in a galaxy that has 100 to 400 billion stars, each of which is potentially surrounded by planets. Until recently, scientists thought that in our observable universe there are about 200 billion such galaxies, and each of them contains hundreds of billions of stars and trillions of planets, but new NASA studies show that they are probably 10 times larger.

Even if inhabited planets are a rarity and extraterrestrial life is unlikely, these staggering figures suggest that somewhere in the universe there should still be an intellectual life. If we assume that in our galaxy there is only 0.1% of potentially suitable planets, one can still count on a million inhabited planets. But where are they?

This question was asked still Nobel Prize winner physicist Enrico Fermi. Why have we not yet discovered aliens or even any evidence of their existence? This question is known as the Fermi paradox, and it has several potential answers (although most of them may seem strange).

Critical steps for civilization

One of the hypotheses is that before intelligent life can spread beyond its original planet to other nearby worlds, it must pass the "Great Filter".

As the philosopher Nick Bostrom explains, this idea suggests that there are several "evolutionary transitions or steps" that life must go through on a planet like Earth before it can communicate with civilizations in other stellar systems. However, any obstacles or barriers can make it impossible to go through all these steps for such intelligent species as ours. This explains why we never found confirmation of the existence of extraterrestrial life.

Bostrom writes: "It all began with billions and billions of potential points of existence of life, and the total sum of zero extraterrestrial civilizations was formed. Therefore, the "Great Filter" must be powerful enough (that is, critical steps should be unlikely) so that too many worlds can not intersect with each other. Since we still do not see aliens, space ships and any signals, it means that humanity has not yet passed these critical steps.

"Great filter" for humanity

Climate change, caused by the development of advanced civilization, may well be such a filter in our case.

David Wallace-Wells proposed this possibility in his recent work for the journal New York: "In a universe that is billions of years old, when star systems are separated in time and space, civilizations can quickly emerge and evolve, and So quickly burn themselves, which means they do not have enough time to search for extraterrestrial life. "

Peter Ward, a paleontologist who studies the mass extinctions caused by greenhouse gases, calls it the "Great Filter": "Civilizations are constantly evolving, but there is an environmental filter that makes them disappear. If you look at the history of our planet, you will see that the mass extinctions that occurred in the past were part of this filtration. Mass extinction, which we are now seeing, has just begun, so we will face many more trials. "

Mass vomiting

Scientists are currently discussing whether our planet is at the height of the sixth mass extinction, or whether it is just approaching it. In any case, the situation is terrible: the risks that we all faced as a result of climate change were too real. If these risks become serious enough and act as a "Great Filter", it may be too late for humanity to seek an intelligent life outside of our planet.