The problem with aliens is just how tremendously, unthinkably huge space is. If you were to take a ratio of us even existing here is like a 0% change. Just looking out at the stars at night you could be seeing light from stars that died forever ago but the light itself hasn't caught up with its death to us yet.
It's was a joke quoted from a Terry Pratchett book.
The space is fcking hudge and the speed limit is fcking low. Yes.
Another problem is that "intelligent" lifeform seems fcking unlickely. Our planet not only have great quantity of water per pur luck (ice asteroids impact), but is protected by a giant planet from most of lethal asteroid impacts after our solar system orbits were setted. But not before Earth received "good" asteroids impact (iron, water...), and a planetoid impact creating the moon.
We have a big moon helping our core to keep warm and rotate generating a protective "force field" and we are on the hood of our galaxy where sterilizing events like "close" super-nova are less probable. Allowing tectonic (not only the dance) allwing landmass, land lifeform, fire mastering (better food for brain, tools , environmental hazard and hostil life form protection...).
The earth axis is tilted creating seasons who has a benefical impact on water and carbon cycle. The earth still rotate on her axes, making day/night shift which avoid burned side and frozen side syndrom limiting lifeform only on "dusk" zone.
It lasted long enough to allow lifeform to appears and evolve but all good things have an end.
In around 4 billions earth earth rotation will stop. In around 5 billions our sun will enter in his terminal phase. But we don't have to worry about that as in 1 billion years the sun intentisty will be enough to burn earth surface.
Our lifeform is doomed is a "short" time, if it cannot find a way to colonize space.
Of course, all these geek speech is pure conjoncture, but nobody here will live long enough to prove me wrong

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