Post by Andrei Tchentchik on Apr 5, 2019 12:39:48 GMT 2
(.#163).- Why do not the extraterrestrials show up ?
Why do not the extraterrestrials show up ?
Xavier Demeersman
Journalist.
We live in a galaxy populated by hundreds of billions of suns. Earth-type planets would be billions ... So, why in this vast space, have we not (yet) had contact with extraterrestrial civilizations? Here are 11 possibilities to try to explain it.
Is there life elsewhere than on Earth or are we absolutely alone in the universe? This question taunts humanity. We would tend to think that there are other inhabited worlds, especially if we consider that there are hundreds of billions of stars in our galaxy - and hundreds of billions of galaxies in the world. universe - and that most of them are surrounded by planets ...
In addition, 13 billion years have passed since the formation of the Milky Way, which, one is entitled to think, leaves a lot of time to life to emerge on a multitude of planets. So, as the famous Fermi paradox states, if there is life elsewhere and extraterrestrial civilizations (Carl Sagan predicted more than 10,000), why did not these beings come to find us? "But where are they? Exclaimed Enrico Fermi. Here are 11 possibilities that could explain this silence.
1. There are no extraterrestrials
One possibility is that we are absolutely (and desperately) alone in the entire universe. There would be no life anywhere but on Earth. All other worlds would be sterile, in short. Or else, life could have started and then be annihilated by a cosmic event. It is possible, but it is hard to believe when we know, according to the statistics, that there would be at least 40 billion living exoterres, just in our galaxy. We would rather want to think, on the contrary, that life abounds ...
2. There is no intelligent extraterrestrial life
First, how to define an intelligent extraterrestrial life? Are we part of it? After all, there may be life elsewhere but of a primitive ... microbial nature, for example, like the one that has developed on Earth for several billion years. Or plants and animals that would not (yet) have the ability to communicate beyond their planet (for Earth, this was the case until recently ... geologically).
3. Extraterrestrials do not use technology
Extraterrestrial civilizations may not have the technology to communicate with other worlds. Their development could be very different from ours, so they could very well not be interested. Or, do not want to use it ...
4. The extraterrestrials have a much more advanced technology than ours
Another case: their technology could be much more advanced than ours. It is possible that they use modes of communication that we do not know (yet) and that are impossible to decipher.
5. Extraterrestrial civilizations self-destruct
When we see the challenges facing humanity, particularly since the middle of the twentieth century, we can think that elsewhere, on other planets, so-called "intelligent" civilizations could have caused their own disappearance. As far as we are concerned, there are many threats of collapse and / or extinction: nuclear fire at the end of a world conflict, severe global warming (famines, droughts, diseases, wars, collapse of democracies, etc.). ) combined with the sixth massive extinction, epidemics, etc. Nevertheless, we can hope that Man will be able to avoid such issues ...
6. The universe is a very dangerous environment
As we saw above, a sixth mass extinction began on Earth. While the latter is caused by our species, the previous ones all had a natural origin: natural climatic changes and also ... asteroids, as was the case for the previous biological crisis, 65 million years ago.
Today, Homo sapiens knows that asteroids may one day endanger life on Earth and he also knows that there are still other cosmic events that could annihilate life, such as surpernovae, quasars and also, near us, violent solar eruptions. It is therefore possible that elsewhere, and frequently, life has not had time to develop. Consider, for example, that the red dwarfs around which rocky planets are often found (see Trappist-1 and its 7 planets) are obviously devastating stars. Their repetitive anger greatly reduces the chances that these planets are really habitable ...
7. The Milky Way is very big
To explain that contact with an advanced extraterrestrial civilization has not yet occurred, another possibility is that our galaxy - and still more, the universe - is so big that it has not yet been able to happen . With a diameter of 100,000 light-years, we can imagine that signals emitted at the other end of the Milky Way take several millennia to arrive. It all depends on the distance and also when it has been done. And let's not forget that there are hundreds of billions of stars ... We simply have not been (yet) spotted. We may not even be on their lists ... The choice is immeasurable. For example, if they emitted a signal 100 years ago and are 10,000 light years away, it will still take 9,900 years. Same problem for us, who are looking for (also) interlocutors.
8. We have been looking for extraterrestrials for too little time
It is not yet a century since humanity is able to capture signals from an extraterrestrial civilization via radio telescopes. It's been 80 years, and the active search for signals really began, just 60 years ago. This is an extremely short time in comparison with the age of the Milky Way.
In addition, there are so many possible directions that we do not necessarily listen to the right place. As Andrew Fain illustrates in a UniverseToday article, it's a bit like looking for a friend's frequency on a CB that has some 250 billion channels ...
9. Extraterrestrials do not emit or few signals
It is still possible that the extraterrestrial civilizations listen without sending strong signals, just like what we do. On our side, we send some to some stars. In fact, we have become less known.
10. The extraterrestrials avoid us
We do not know their ways of thinking of course. But, we can imagine that in fact we do not interest them at all, nor besides our planet. The conditions may be too hostile for them. Unless, too, that we seem to them too dangerous and unchallengeable. Who knows ? Maybe we scare them!
The potentially habitable exoplanets known (May 2017) and their distances from the Earth in light-years (ly). © Planetary Habitability Laboratory, @ UPR Arecibo.
It is also possible that they apply a galactic policy of non-interference with worlds like ours, populated by primitive beings ... (as in Star Trek). Perhaps they feel then that a contact would be too premature and deliberately chose, at least for the moment, to leave us alone, to our business, taking care not to interfere.
11. The extraterrestrials are already there
Last but not least: perhaps the Visitors are already there and we have not even noticed them. So, perhaps they observe us in all discretion. On the other hand, from there to convince oneself that extraterrestrials have made agreements with the governments of several countries, as they assail it at the end of the field and at the top of the list (not without ridicule and not without knocking us out) the conspirators on the Web, it seems more laughable than probable.
So, are we alone in the universe or not? In any case, consider several astronomers and exobiologists, we should soon know if there is life elsewhere. Researchers are confident of making such discoveries in the coming years. On the one hand, within our Solar System, via probes and landers on Mars, Europe and / or Encelade. And, on the other hand, beyond, by studying the atmosphere of the rocky exoplanets that we explore with ever more acuteness ...
F I N .
Why do not the extraterrestrials show up ?
Xavier Demeersman
Journalist.
We live in a galaxy populated by hundreds of billions of suns. Earth-type planets would be billions ... So, why in this vast space, have we not (yet) had contact with extraterrestrial civilizations? Here are 11 possibilities to try to explain it.
Is there life elsewhere than on Earth or are we absolutely alone in the universe? This question taunts humanity. We would tend to think that there are other inhabited worlds, especially if we consider that there are hundreds of billions of stars in our galaxy - and hundreds of billions of galaxies in the world. universe - and that most of them are surrounded by planets ...
In addition, 13 billion years have passed since the formation of the Milky Way, which, one is entitled to think, leaves a lot of time to life to emerge on a multitude of planets. So, as the famous Fermi paradox states, if there is life elsewhere and extraterrestrial civilizations (Carl Sagan predicted more than 10,000), why did not these beings come to find us? "But where are they? Exclaimed Enrico Fermi. Here are 11 possibilities that could explain this silence.
1. There are no extraterrestrials
One possibility is that we are absolutely (and desperately) alone in the entire universe. There would be no life anywhere but on Earth. All other worlds would be sterile, in short. Or else, life could have started and then be annihilated by a cosmic event. It is possible, but it is hard to believe when we know, according to the statistics, that there would be at least 40 billion living exoterres, just in our galaxy. We would rather want to think, on the contrary, that life abounds ...
2. There is no intelligent extraterrestrial life
First, how to define an intelligent extraterrestrial life? Are we part of it? After all, there may be life elsewhere but of a primitive ... microbial nature, for example, like the one that has developed on Earth for several billion years. Or plants and animals that would not (yet) have the ability to communicate beyond their planet (for Earth, this was the case until recently ... geologically).
3. Extraterrestrials do not use technology
Extraterrestrial civilizations may not have the technology to communicate with other worlds. Their development could be very different from ours, so they could very well not be interested. Or, do not want to use it ...
4. The extraterrestrials have a much more advanced technology than ours
Another case: their technology could be much more advanced than ours. It is possible that they use modes of communication that we do not know (yet) and that are impossible to decipher.
5. Extraterrestrial civilizations self-destruct
When we see the challenges facing humanity, particularly since the middle of the twentieth century, we can think that elsewhere, on other planets, so-called "intelligent" civilizations could have caused their own disappearance. As far as we are concerned, there are many threats of collapse and / or extinction: nuclear fire at the end of a world conflict, severe global warming (famines, droughts, diseases, wars, collapse of democracies, etc.). ) combined with the sixth massive extinction, epidemics, etc. Nevertheless, we can hope that Man will be able to avoid such issues ...
6. The universe is a very dangerous environment
As we saw above, a sixth mass extinction began on Earth. While the latter is caused by our species, the previous ones all had a natural origin: natural climatic changes and also ... asteroids, as was the case for the previous biological crisis, 65 million years ago.
Today, Homo sapiens knows that asteroids may one day endanger life on Earth and he also knows that there are still other cosmic events that could annihilate life, such as surpernovae, quasars and also, near us, violent solar eruptions. It is therefore possible that elsewhere, and frequently, life has not had time to develop. Consider, for example, that the red dwarfs around which rocky planets are often found (see Trappist-1 and its 7 planets) are obviously devastating stars. Their repetitive anger greatly reduces the chances that these planets are really habitable ...
7. The Milky Way is very big
To explain that contact with an advanced extraterrestrial civilization has not yet occurred, another possibility is that our galaxy - and still more, the universe - is so big that it has not yet been able to happen . With a diameter of 100,000 light-years, we can imagine that signals emitted at the other end of the Milky Way take several millennia to arrive. It all depends on the distance and also when it has been done. And let's not forget that there are hundreds of billions of stars ... We simply have not been (yet) spotted. We may not even be on their lists ... The choice is immeasurable. For example, if they emitted a signal 100 years ago and are 10,000 light years away, it will still take 9,900 years. Same problem for us, who are looking for (also) interlocutors.
8. We have been looking for extraterrestrials for too little time
It is not yet a century since humanity is able to capture signals from an extraterrestrial civilization via radio telescopes. It's been 80 years, and the active search for signals really began, just 60 years ago. This is an extremely short time in comparison with the age of the Milky Way.
In addition, there are so many possible directions that we do not necessarily listen to the right place. As Andrew Fain illustrates in a UniverseToday article, it's a bit like looking for a friend's frequency on a CB that has some 250 billion channels ...
9. Extraterrestrials do not emit or few signals
It is still possible that the extraterrestrial civilizations listen without sending strong signals, just like what we do. On our side, we send some to some stars. In fact, we have become less known.
10. The extraterrestrials avoid us
We do not know their ways of thinking of course. But, we can imagine that in fact we do not interest them at all, nor besides our planet. The conditions may be too hostile for them. Unless, too, that we seem to them too dangerous and unchallengeable. Who knows ? Maybe we scare them!
The potentially habitable exoplanets known (May 2017) and their distances from the Earth in light-years (ly). © Planetary Habitability Laboratory, @ UPR Arecibo.
It is also possible that they apply a galactic policy of non-interference with worlds like ours, populated by primitive beings ... (as in Star Trek). Perhaps they feel then that a contact would be too premature and deliberately chose, at least for the moment, to leave us alone, to our business, taking care not to interfere.
11. The extraterrestrials are already there
Last but not least: perhaps the Visitors are already there and we have not even noticed them. So, perhaps they observe us in all discretion. On the other hand, from there to convince oneself that extraterrestrials have made agreements with the governments of several countries, as they assail it at the end of the field and at the top of the list (not without ridicule and not without knocking us out) the conspirators on the Web, it seems more laughable than probable.
So, are we alone in the universe or not? In any case, consider several astronomers and exobiologists, we should soon know if there is life elsewhere. Researchers are confident of making such discoveries in the coming years. On the one hand, within our Solar System, via probes and landers on Mars, Europe and / or Encelade. And, on the other hand, beyond, by studying the atmosphere of the rocky exoplanets that we explore with ever more acuteness ...
F I N .
