[central_va]

Sorry to rain on the life on other planets parade but we are alone. Read Enrico Fermi's The Fermi Paradox. Pretty much proves there are no other intelligent civilizations out there.

The Paradox: The apparent size and age of the universe suggest that many technologically advanced extraterrestrial civilizations ought to exist. However, this hypothesis seems inconsistent with the lack of observational evidence to support it.

[cripplecreek]

We don’t need to find intelligent life. In fact I personally think that intelligent life would be the worst possible discovery we could make.

[CodeToad]

Except that isn’t the definition of a paradox. Lack of evidence to date isn’t proof that there isn’t any, therefore, it doesn’t conflict with the estimates that there should be intelligent life.

[dragnet2]

Sorry to rain on the life on other planets parade but we are alone.

We should have just asked you first, instead of doing all this research and exploration.

[GonzoGOP]

Sorry to rain on the life on other planets parade but we are alone. Read Enrico Fermi's The Fermi Paradox. Pretty much proves there are no other intelligent civilizations out there.

It is actually misnamed. It is only a paradox if you put the right numbers into the Drake Equation. Too many people view intelligent, and most importantly technological life is an automatic product of life. Yet even Earth appears to state otherwise. For the vast majority of the time life has existed it consisted of nothing more that bacteria. Even when complex life appeared it took a long time to get out of the oceans. And it probably only did that in tidal zones. But tidal zones require a big honking moon in a regular orbit. However it turns out the type of collision that could create one is so improbable that nobody would expect to see one, if there wasn't one hanging in the sky every night. If you don't move onto the land you don't get fire. No fire, no other technology.

And then when you moved onto land for most planets the size of Earth you would get zapped by solar radiation. On Earth we have a strong magnetic field because that same ridiculously improbable collision that gave us the moon also gave us a planetary core twice as big as it should be. Without the magnetic field we would look like Mars.

The technological, land dwelling life on Earth is the result of winning the Lunar Lotto.
Now simple life is another matter. And you can spot that with Kepler due to the unique spectral signature of free O2 and organics in the atmosphere. They should wipe each other out unless something is replenishing the supply. Life is by far the most likely culprit. Even if ET is only a bacteria, its existence would be a game changer. Be it found in the seas of Europa, the geysers of Enceladus or on some exoplanet. We would not be alone. It would just be that the neighbors were slime.

[America_Right]

The apparent size and age of the universe suggest that many technologically advanced extraterrestrial civilizations ought to exist. However, this hypothesis seems inconsistent with the lack of observational evidence to support it.

We don't have the tech to observe such evidence, yet. It is totally impossible given the number of stars in the galaxy, and the number of galaxies in the universe, that we are the only intelligent life.
The small number of radio frequencies that we are observing do not cover much of the usable spectrum. Plus, I believe, radio signals lose cohesion (is that the right word?) after about 5 light years - so much so that they become lost in the background noise of the universe. This makes it pretty difficult to detect other civilizations.
Hubris or arrogance is the only way to explain why people could possibly believe that we are alone.