Topic: Why Habitable Exoplanets Might Mean Humanity Is Doomed - page 3. (Read 4190 times)

There really is possibility that life exists somewhere in universe apart from earth but there is no way we'll ever prove it before doomsday.

There is a possibility that no advanced alien cultures exist because they all invented high energy particle accelerators before becoming space-faring civilizations.

http://press.web.cern.ch/backgrounders/safety-lhc

Gotta gree with you, i don't belive we are first technical civilization there must be someone outside there.

And the Universe is too old for us to be first.

This theory also looks plausible to me: vast majority of technical civilizations tend to destroy themselves, or get destroyed by some cataclysmic event like for example large meteor hit, or simply degenerate and die off before being able to develop efficient methods of interstellar travel. Rare ones who survive and succeed in this venture evolve so much afterwards (in terms of both biology and technology) that they take forms far beyound our comprehensive capabilities, and as such they might not be interested at all to establish contact with young and comparably primitive civilizations like ours. As Spendulus said: they do not talk with us just like we do not talk with bugs 

Meaning that at least one ancient and extremely advanced galactic civilization may be all around us, but we are not aware of its presence. Perhaps we're even seeing it, but we just don't understand what we see.

Or have we always been?

If you believe in Darwin's Evolution theory and push it to its logical limit, a massive destruction of an ecosystem to the brink of extinction will help that ecosystem to evolve to the point of space travel. The memory of random deaths, over and over would be part of the DNA of that ecosystem pushing it, generations after generations to find a way for an ultimate survival solution, away from its home planet... Exactly what we do now. Because we have the knowledge we can be gone for good, leaving behing no trace of our existence.

For me this paradox seems like a "Post hoc ergo propter hoc" kind of statement. If some species were to become capable of spaceflight only after they got themselves destroyed, it doesn't mean that the destruction is an exact consequence of space travel efforts.

Ah, very unlikely.  The theory of stellar evolution indicates that many generations of star systems - with planets - have come and gone.   

Some of those you can reckon had smart folks.  Where did they go?  Assume, for the moment that interstellar dust makes physical travel between star systems pretty much impossible.

Where, indeed?

They do not talk with us just like we do not talk with bugs...

That is a possibility. Let's say another Earth roughly of the same age is withing our galaxy. The only difference is that other Earth was never hit by a killer asteroid. Ever.

It could mean that being killed almost to the point of extinction over and over is a good thing if an ecosystem wants to go beyond its dinosaur stage.

Perhaps we are the first technical civilization in our galaxy? Someone has to be the first.

Earth: "Knock! Knock!"

500 Light years later

Kepler 186f: "Who's there?"

500 Light years later

Earth: "Who are you again?"



If life is bubbling across the universe just like it is bubbling all the time here on Earth, then maybe the civilizations who survived that "filtering" would not be bothered communicating?

Or a more reasonable explanation: it is very hard to cross interstellar distances. There could be intelligent life on Kepler 186f right now, but there is no way for us to contact them and there is no way for them to contact us.

We could design a vehicle that would go explore there (maybe using solar sails and gravimetric acceleration slingshotting around intervening stars), but it would still take millennia to get there. Maybe they sent an exploratory probe when they discovered the earth millions of years ago, but it came by 400 years ago and we missed it. Maybe they are not as developed as we are? Maybe there is intelligent life there, but they just are not interested in astronomy?

An artist's concept of Kepler-186f, discovered in April 2014.

Last week, scientists announced the discovery of Kepler 186f, a planet 492 light years away in the Cygnus constellation. Kepler 186f is special because it marks the first planet almost exactly the same size as Earth orbiting in the “habitable zone” – the distance from a star in which we might expect liquid water, and perhaps life.

What did not make the news, however, is that this discovery also slightly increases how much credence we give to the possibility of near-term human extinction. This because of a concept known as the Great Filter.

The Great Filter is an argument that attempts to resolve the Fermi Paradox: why have we not found aliens, despite the existence of hundreds of billions of solar systems in our galactic neighborhood in which life might evolve? As the namesake physicist Enrico Fermi noted, it seems rather extraordinary that not a single extraterrestrial signal or engineering project has been detected (UFO conspiracy theorists notwithstanding).

This apparent absence of thriving extraterrestrial civilizations suggests that at least one of the steps from humble planet to interstellar civilization is exceedingly unlikely. The absence could be caused because either intelligent life is extremely rare or intelligent life has a tendency to go extinct. This bottleneck for the emergence of alien civilizations from any one of the many billions of planets is referred to as the Great Filter.

Are we alone?

What exactly is causing this bottleneck has been the subject of debate for more than 50 years. Explanations could include a paucity of Earth-like planets or self-replicating molecules. Other possibilities could be an improbable jump from simple prokaryotic life (cells without specialized parts) to more complex eukaryotic life – after all, this transition took well over a billion years on Earth.

Proponents of this “Rare Earth” hypothesis also argue that the evolution of complex life requires an exceedingly large number of perfect conditions. In addition to Earth being in the habitable zone of the sun, our star must be far enough away from the galactic center to avoid destructive radiation, our gas giants must be massive enough to sweep asteroids from Earth’s trajectory, and our unusually large moon stabilizes the axial tilt that gives us different seasons.

These are just a few prerequisites for complex life. The emergence of symbolic language, tools and intelligence could require other such “perfect conditions” as well.

Or is the filter ahead of us?

http://mashable.com/2014/04/23/habitable-planets-human-extinction/