Fermi Paradox

[Pyrrho]

For those who don't know what the Fermi Paradox is:

The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and humanity's lack of contact with, or evidence for, such civilizations.[1] The basic points of the argument, made by physicists Enrico Fermi and Michael H. Hart, are:

• The Sun is a typical star. There are billions of stars in the galaxy that are billions of years older.
  
  
• With high probability, some of these stars will have Earth-like planets,[2][3] and some might develop intelligent life.
  
  
• Some of these civilizations might develop interstellar travel.
  
  
• Even at the slow pace of currently envisioned interstellar travel, the Milky Way galaxy could be completely traversed in about a million years.[4]
  

According to this line of thinking, the Earth should already have been visited by extraterrestrial aliens. But Fermi saw no convincing evidence of this, nor any signs of alien intelligence anywhere in the observable universe. Hence, Fermi's question, "Where is everybody?"[5]

https://en.wikipedia.org/wiki/Fermi_paradox

There is more at the link, so go ahead and click on it and read the article if you want to know more about it.


I will go ahead and express a couple of opinions, which I am sure that the believers in magic will reject offhand.

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First, I don't think we are really in a good position to know the odds of life developing, particularly to the point of intelligence (which, frankly, has not been demonstrated to exist on this planet, so why suppose it could exist elsewhere?).  We don't have enough experience with the origins of life to really have a good grasp of what it takes, and how many things are necessary.  One of the things that has been hypothesized as being important for life as we know it on the earth is the existence of Jupiter, a large planet with a strong gravitational field that helps redirect various debris in the solar system to it instead of more of it running into the earth.  Is such a large planet further out in the solar system essential for life as we know it?  If so, then a solar system that just had an "earth-like" planet would not be enough, as there would also need to be another planter further away from its star that was very large; large enough to have a very strong gravitational pull on various debris in space so that not so much of it collides with the "earth-like" planet.  That is just one thing, and there may be many other important things that are relevant, but about which we have no idea.

So, again, we cannot properly calculate the odds at all, and have no real way of knowing how likely advanced life is on a planet.

Second, it may well be that interstellar travel is simply impossible.  Technology does not solve all problems, and this may be impossible to solve.  For humans, it is known that being in space is detrimental to health, for a variety of reasons, and all of them would have to be solved for humans to ever safely do prolonged travel.  (I am not going to bother listing all of the known problems, as anyone who is serious about this will click on the link that is the previous sentence.  There may also be unknown health problems with long-term, interstellar travel.)  There is also the almost unimaginably great distances between star systems.  Keep in mind, even if you reach the next star system, the odds of it having any advanced life are likely close to zero, so you are going to be looking at distances much further than just from one star to the next.  The time it would take to travel such distances may well make it impossible.

I know there are people who imagine that science will magically solve all of these problems.  But there is no reason to believe that.  Additionally, the fact that we have zero evidence of advanced life anywhere else or anyone else traveling such distances gives us reason to believe that such things are really impossible to overcome.

But, I know that some people are not going to be convinced, and will insist that all of these things will magically be overcome (they just won't call it "magic;" they will call it "science," but it will be merely imagination and not science that they are using to overcome the problems).

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I am probably going to regret asking, but what are your thoughts on the Fermi paradox?

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I thought briefly about putting this in a science forum, but really this is going to be more science fiction than science, so here it is.

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I decided to add a poll, with the following options:

1. There is (or probably is) no other life in the universe that is advanced.
   
2. Interstellar travel of intelligent beings is (or probably is) impossible.
   
3. Aliens don’t visit us because it is not worthwhile to visit humans.
   
4. Are you crazy?  Have you not seen the X-Files?  Aliens are visiting us!
   

1 is basically saying that there is no intelligent life out there to visit us.
2 is basically saying that intelligent beings cannot visit us.
3 is basically saying that intelligent beings would not want to visit us.
4 is basically saying that intelligent beings are visiting us.

Please note, 2 and 3 do not necessarily exclude the idea of 1, as it may be that there is no intelligent life to visit us, but it could not visit us even if it existed, etc.  But pick the one you believe is most appropriate, or just don't pick any; I don't really care.