"Where are all the aliens?"

Maybe God did not create them.

That is one possible answer, which a lot of people will put faith in.

http://www.amazon.com/Existence-David-Brin/dp/0765342626

I really recommend this. It's fiction, but excellent.

Consider that we are among the most highly adapted so far and that no one yet has caught up to us.

according to our laws of physics, we can not travel faster than the speed of light, we are barely able to make it to our moon. why would any other possible earth like planet with intelligent aliens be any different. the closest known possibility of an inhabitable planet is what, 150 million light years away......hmmm, i wonder?

There is very likely life out there on other planets, but like ssorenn said, they're so far away.

I thought I read something about scientists thinking there's a possibility of life on Jupiter and Saturn moons, maybe under the outer crust or lifeforms that have adapted to a liquid methane environment.

Here are some possible explanations, starting with the most obvious:

No other alien life or intelligent civilizations exist.

It is the nature of intelligent life to destroy itself.
-Environmental damage
-War

Intelligent alien life too far part in space in time.

It is too expensive to permamently travel or communicate across the galaxy.

Alien life is too technologically advanced for us to detect with our limited technological capabilities.
-i.e., civilisations may have advanced beyond the use of radio signals

Alien life exists but is not yet technologically-capable enough to communicate or be detected.

Everyone is listening, no one is transmitting.
-(Earth is currently only listening; and is not actively transmitting for alien detection)

Earth is deliberately not contacted/interfered with.

Earth is kept intentionally isolated.
-in the form of a zoo for a higher form of life
-as a science experiment by a higher form of life
-by the design of a higher form of life

Other civilisations deem it too danerous to communicate.

Alien life is already here undected.

Alien life is already here unacknowledged.

"according to our laws of physics, we can not travel faster than the speed of light, we are barely able to make it to our moon."

That may just be our current limitation, in the same way that 100s of years ago sailors would say that they cannot travel faster than the speed of the wind.

The speed of light barrier may not be an unbreakable upper limit -- even if it is, the use of artificial wormholes is a possible way around this.

#otherkin

Wjessop, there likely are aliens, but maybe they aren't capable of interstellar travel. I mean we aren't, so why should we even assume it's a viable options. As for visual signs, it's extremely hard to find signs of life. Mars may very well have extremophiles hidden under the ice layer in it's craters. It's just that we've never actual tested the water. As for intellegent life, is highly unlikely there is any in our solar system, which is about the only place we've "extensive" (using the word very loosely) searched. We just don't have the tech to figure out if there is any life out there.

Of the billions of planets we've found, we really only know approximations of its temperature, geographical features, and atmospheric composition sometimes. So it's hard to say which planets have life on them, though most scientists agree that mathematically, earth can't be alone.

There is very likely life out there on other planets, -- i really dont understand why people think that. Billions of possibilities through the known universe...why not? Are we that full of ourselves?

If tachyons can be proven to exist then the Speed of Light barrier will eventually be passed.

"That may just be our current limitation, in the same way that 100s of years ago sailors would say that they cannot travel faster than the speed of the wind.

The speed of light barrier may not be an unbreakable upper limit -- even if it is, the use of artificial wormholes is a possible way around this."

No, my understanding is that this is one of the unbreakable laws of the universe. Nothing goes faster than the speed of light.

Ever heard of area 51?

But seriously, we're probably pretty close to discovering life forms on other planets. Getting there or even being able to interact with them is another thing, or maybe this is all the Truman Show ~

This is a very interesting topic.

@ssorenn - there are potentially habitable planets within 100 light years. That's a doable distance.

As for the general question, there's the fact that other civilizations have perhaps have existed millions of years longer than we have. Look at how much we've grown over the past 100 years. Now increase that exponentially. That makes me scared, frankly. I'm firmly in the camp that we should not reach out, because we might not like who returns the call.

IF, and then IF its proven how long does it take to create a viable way for humans to travel though space, and at what cost.....

@ssorenn - there are potentially habitable planets within 100 light years. That's a doable distance

Say wha? that's doable? hmm, the average male lives to 77 years old........hmmm....is mary jane legal in your state?

@gold I am not sure which is worse, being among the lesser developed raced, or among the higher developed.

Not in our current era, but eventually we should have the technology to pry into those planets more closely.

" No, my understanding is that this is one of the unbreakable laws of the universe. Nothing goes faster than the speed of light. "

@MarquisMark: I'm not denying that, with the proviso "currently". That's the whole point of my analogy about the sailors who would think 100s of years ago that wind was the fastest speed of travel.

The sailor would say to you "hmm, speed of light, no; all I know is the speed of wind".

@Espi - I would say lesser is worse. I'd rather not be extinguished/harvested/toyed with.

The speed of light being unbreakable isn't true when tachyons are hypothesised to exist anyway. It's the current known limit; but things change quickly in physics. A century ago; atoms were just protons and electrons mixed together in a general lump.

@gold civilizations on earth developed in similar ways, what is to say that other races would be so dissimilar from us? You would have to have similar motivations to want to go to space, so either we are very similar to anything that might be out there, or be are vastly different, I don't think there is any in-between. Lets hope the similar is more realistic.

"The sailor would say to you "hmm, speed of light, no; all I know is the speed of wind".

But a sailor could look at a musket ball, an arrow, or a ballista fire and know that it is possible for an object to surpass the speed of wind, but the engineering is lacking.

We cannot visually see anything surpass the speed of light.

Of course, that could change someday. Who knows. I'm probably the last person who should be contributing to this thread. Most of my physics knowledge comes from NDT and Stephen Hawking documentaries on Netflix.

hypothesized---thats the key word...i said as it stand, the laws of physics say, nothing can break the speed of light barrier....i did not say that cant change :P

@Espi - yes, civilizations on Earth developed in a similar way.....and enslaved those from lesser civilizations and extinguished any civilization that would try to rival them. Seen any Carthaginians around lately?

If there are other civilizations out there, I hope that we're the most advanced of all of them, because if we're not and they're anything like us, we're fucked.

Also, @ssorenn - thinking about it some more, if this em-drive that NASA is researching can actually create propulsion from nothing, then its very possible to create a spacecraft that will eventually approach the speed of light - at which point the perception of time in the craft will change and its very likely that distances within ~20 lightyears will be possible to travel in a human lifespan. Also, it means the known laws of physics have been broken.

More intellectually advanced civilizations would hopefully be more thoughtful and considerate about other species, in the same way that humans are evolving to be more widely considerate of other life on earth and being aware of the needs for stewardship.

But yes, agreed with goldfinger, I'd much rather be on the top-side of the scale than the bottom -- Epsi, why would you possibly want to be the weaker end of the scale, the lowly beings still using hammers and nails being visited by interstellar super intelligent/powerful aliens.