Many years ago, Carl Sagan confidently stated that there should be at least 10,000 advanced extraterrestrial civilizations in our galaxy. After more than 60 years of unsuccessful searches in the ranks of scientists, it is rumored that life on Earth can be the result of a chain of happy events that happened at the right time in the right place and are unlikely to be repeated again. It turns out they are right? Very unlikely.
Earth is a typical solid planet, in the most typical solar system, located in the spiral arm of the most ordinary galaxy. All events and elements that have gathered and built our world take place almost everywhere in the galaxy and there is nothing unusual in the evolution of life on this planet. There are billions of stars in the galaxy, and the laws of numbers dictate that intelligent life should exist everywhere. Why haven't we found her yet?
There may be many reasons for this.
Finding a radio signal in a galaxy in a galaxy of 400 billion worlds spread over 100,000 light years, from billions of radio frequencies - a needle in a haystack will be immeasurably easier to find. Imagine that you are driving with a friend in different cars, armed with radios for 250 channels, but forgot to agree on a common communication channel. In an attempt to communicate with each other, you will cycle through each of the channels, each at a different time. What is the chance that you will hear a friend? Small. Multiply this situation a hundred billion times and get a little idea of the problems of finding extraterrestrial intelligence in the radio band.
At the same time, developed civilizations, apparently, will actively transmit radio messages for a relatively short time in the process of their development - after all, technologies are developing. Searching in the radio range will require observing each frequency around the clock for many years (so as not to miss anything), and telescope time is too expensive for such a pastime. And while you are sitting on the same frequency, 20 extraterrestrial signals will pass through other channels, and you will not recognize.
Trying to prove that aliens do not exist, many skeptics use the Fermi paradox. Fermi suggested that a galaxy with such a potential for life should be teeming with it. And he noted that since most stars are much older than our sun, extraterrestrial life should be millions of years older than us - and smarter technically. Fermi calculated that even moving at sub-light speed, one of these civilizations should have colonized the entire galaxy by now, and we would have already observed traces of its presence.
True, this logic has a problem.
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In 50,000 years, people are likely to look slightly different. In 10 million years it will be very different. Imagine a civilization that was very different from us from the very beginning and existed for 10 million years. Perhaps we would not even see signs of life in her, let alone any evidence of her existence.
Arthur Clarke once said that with sufficient development, technology would be indistinguishable from magic. The same can probably be applied to extraterrestrial civilization. Trying to hear a radio message from them can be like trying to read a signal in a drumbeat, while the space around us every second is filled with information in a colossal volume. Then, in a few light years, a galactic Olympiad may take place, and we will not know.
The distances in our galaxy are incredibly great. The best of our spacecraft travels 20 times faster than a bullet. While at first glance it may seem like a fast speed, at that speed it will take a spacecraft 75,000 years to reach the closest star to us - just 4 light years away. In space, distances are measured in light years, and if we could accelerate to 300,000,000 meters per second, then yes, then we would get to this star in four years.
Looking at a star 1000 light-years away is like sitting in a time machine. You see a star not as it is now, but as it was a thousand years ago. According to modern theories, there should be at least a billion terrestrial planets in our galaxy. If even one tenth of them has life, we have about 100 million worlds with at least one-celled life.
If even a tiny fraction of them (one hundred thousandth) can give rise to advanced races of beings, there will be 1000 extraterrestrial civilizations in our galaxy. Little or many, but the fact remains: at least one technically advanced extraterrestrial society exists for every hundred million stars. Our closest extraterrestrial neighbor may be out there, far, far away. In films, we often see how warp drives, hyperspace and wormholes allow spaceships to be on the other side of the world in the blink of an eye, but in practice, even the nearest extraterrestrial civilizations can find interstellar travel difficult and undesirable.
Another reason why aliens don't give themselves away might be that the galaxy is full of all kinds of bizarre creatures and amazing races. In that case, why would advanced life forms come here, to our village? There are surely many more interesting places to visit. After all, we hunt exotic butterflies, not noticing the anthills under our feet.
Stephen Hawking once said: “I believe that extraterrestrial life is very common in the universe, albeit intelligent and to a lesser extent. Some say that it may still appear on Earth."
Many people think that once a civilization gets to radio technology, it enters a small window of a couple of hundred years, after which it will begin to integrate artificial intelligence into its own biology. Machines cope with everything much easier, risk nothing and are essentially immortal. Perhaps some alien life forms have long since turned themselves into something more mechanical than biological.
Recently, the organization SETI, which is engaged in listening to the skies, decided to move from passive listening to actively broadcasting messages into space. One of the smartest people on this planet, Stephen Hawking, thinks this is a bad idea. In his opinion, our messages can attract the attention of not the most pleasant creations of the Universe, which will happily drive us back into the Stone Age. He gives the example of Native Americans when they first met Columbus. Aliens may well use similar methods when meeting Aboriginal people. Perhaps we should, on the contrary, think about how not to send something extra into space.
Many scientists think that SETI needs to look for new methods to search for extraterrestrial intelligence. Paul Davis suggests exploring places in our own solar system - the moon, planets, asteroids and the Earth - for possible alien traces. Also, do not discount the possibility that we received a message from the stars, but did not understand it. Physicist Vladimir Charbak believes that life has spread across the galaxy according to a higher plan and the code of this plan is encrypted in our own DNA, waiting for us to unravel it.
Finally, we may not have found extraterrestrial life because there is nothing to look for. That is, we are the only ones at this celebration of life. But how logical is that? There is the highest chance that life has settled on at least one world outside our solar system (and even in ours). In a galaxy with a billion potentially inhabited planets, life will definitely be found. Perhaps hundreds or millions of worlds are inhabited. How logical is it that we are the only ones who broke through the bottleneck and became an intelligent species?
We humans tend to see things from a human point of view. That is, to humanize everything, wherever you look. We are used to the fact that life needs water, oxygen and a carbon base. Or that the advanced race must use radio and use repetitive signals. Look at the aliens in the movies: they're almost human. This is done so that we can recognize their emotions and go to the movies more often. Aliens will likely be as much like us as we are like nettles, and their motivation will be an absolute mystery. One of the reasons that we did not find anyone may lie in the fact that we do not understand it at all.
What is left for us?
Wait and endure.
If we liken the 4.5 billion years of the Earth to a 24-hour clock, humanity appeared a little less than a minute before midnight. Our search for extraterrestrial life for 60 years is 20-30 seconds by the standards of civilizations that could have appeared millions or billions of years before us. We are not even a drop in the ocean against the background of this galaxy - a molecule.
In the near future, new, more powerful listening devices and sophisticated instruments will be put into operation, which will be able to analyze the atmospheres of exoplanets in search of traces of life. The search for aliens will expand in new directions, and scientists will be given more time to work with the telescope, thanks to Project Breakthrough. Russian billionaire Yuri Milner has set aside a large sum to send tiny robotic vehicles to the nearby star system Alpha Centauri. Stephen Hawking expects that with next-generation technology, this journey will only take 20 years.
SETI's Natalie Cabrol believes the time has come to restart SETI. She thinks that "SETI's vision was limited by the fact that the technology of extraterrestrial life, we believed, should be similar to ours." But this is not a search for extraterrestrial life, but … terrestrial. Many new scientists from other disciplines will have to be brought in to develop new search methods: astrobiology, geology, cognitive sciences and mathematics, among others. We were looking for life, but now we may first have to think carefully about what this life might be according to our and not our standards.
In 10 or 1000 years we will definitely find them.
ILYA KHEL