Alien life is possible, but unlikely.

[Sir Kenyth]

I've been thinking about the universe, it's vastness, how long solar systems last, etc. I came to a conclusion about the alien theory. It's quite possible that other planets could have life, but unlikely that they have it now at the same time as us. Think about how short the existence of this planet is in comparison to the scope of the universe. Then think of how short the existence of life is in comparison to the planet. Then think how short the human existence is in comparison to that. Take into account that solar systems and planets go through cycles and the window for the existence of life is very short in the total lifespan. Certainly another planet relatively close to us may support life at some time, but it's HIGHLY unlikely that it would happen at the same time as us. This doesn't even touch on the fact on whether it's even possible to physically transverse the vastness of the universe to find out! What do you think?

[Azred]

Another thing to consider is that we didn't have radio until the very early part of th 20th century. At best, the earliest radio signals are only 100 light-years out; the farthest detectable radio signals are probably only 50 to 75 light-years out. No alien world could detect signs of intelligent life here should their planet be more distant than that. If we suppose that any alien civilization has attained technology comparable to ours, then we could only detect their radio signals if they are closer than about 75 light-years; this makes the distance roughly 150 to 200 light-years for the closest civilizations.
That is a huge distance to cover--it would prevent effective communication, even (are you going to wait 400 years for an answer to "how are you today?").
Strangely enough, many people seem to assume that any alien civilization is more advanced than we are. What if we are the most technologically advanced civilization in the universe? [img]graemlins/saywhat.gif[/img]

[khazadman]

oh come on!there are trillions of stars in the universe that are like ours.i think it is highly likely that there is intelligent life on billions of them.don't forget,the sun is a relativly young star.there are older stars out there with planets that have probably already produced intelligent life,we just havn't found them yet.could you imagine the technology of a civilization that is a billion years old?who needs radio to communicate?we don't know of them because we can't find them.they might have hidden their star by building a dyson sphere.

[andrewas]

Dyson sphere? You mean a construct of several solar masses completely encomppasing the volume of their solar system? Now thats a job for an advanced culture. Theyd have be ultra paranoid to put that much effort into hiding.

Alien life existing at the same time a ours us quite likly - life has existed on this planet for 300 billion years, which is actualy not that insignificant a portion of the age of the universe. (for both figures the exact data does not come to hand at the moment). Intelligent life on the other hand is hugely unlikly, its only been on earth for something around 20'000 years. That is an isignificant portion of the age of the universe, although theres nothing in physics to say that intelligent life cant persist for hundreds of millions of years.

But the chances of their being a civilisation close enough to contact, advanced enough to contact, and primitve enough for us to understand, is pretty close to nothing. Theres no chance of Star Treks picture of the universe - hundreds of similar species, most at the same stage of development - being at all accurate.

[Megabot]

oh come on!there are trillions of stars in the universe that are like ours.i think it is highly likely that there is intelligent life on billions of them.don't forget,the sun is a relativly young star.there are older stars out there with planets that have probably already produced intelligent life,we just havn't found them yet.could you imagine the technology of a civilization that is a billion years old?who needs radio to communicate?we don't know of them because we can't find them.they might have hidden their star by building a dyson sphere

I could not say it better my self!

Originally posted by Azred: What if we are the most technologically advanced civilization in the universe?

I find that very hard to believe. Humans are only about two million years old, which is, in the context of universes and solar systems, absolutely nothing. I'm sure there are more advanced life forms out there which make us look like the simians we fundamentally still are.

I see your point, Sir Kenyth. I would probably share your viewpoint if it weren't for the fact that there are positively billions of planets in existance. The chances that there is at least some form of life out there living at the same time as us surely is rather big.

[Rokenn]

Actually a Dyson sphere would not be an expression of paranoia, but more of a case of resource maximization. Assuming that inter-stellar travel proves to be impractical then one way for an advanced civilization to have nearly unlimited room for growth would be dyson sphere. Which would have an insane amount of floor space [img]smile.gif[/img] Or as Larry Niven theroized they could go with a Ring World. That way at least you could still see the stars.

[/)eathKiller]

Chances of two races of distant worlds actually meeting are, infact, so low, that it is vastly impossible, though we do know that life is a short process, it doesn't last as long as many wish it would, some races stay to their homeworlds and pathetically die off over time, while other races live longer but still end up dying off, when a race dies off another may begin elsewhere, It's like blinking lights on a christmas tree except only 1 or 2 lights blink at a time, and while those lights blink, life exists, and they quickly burn out, only for more lights to light up, or just one light... we could be a single solitary light, or maybe we'll be lucky enough to encounter other lights, before we, ourselves, burn out...

[andrewas]

Originally posted by Rokenn: Actually a Dyson sphere would not be an expression of paranoia, but more of a case of resource maximization. Assuming that inter-stellar travel proves to be impractical then one way for an advanced civilization to have nearly unlimited room for growth would be dyson sphere. Which would have an insane amount of floor space [img]smile.gif[/img] Or as Larry Niven theroized they could go with a Ring World. That way at least you could still see the stars.

Except that a ringworld masses several times what jupiter does - this solar system might contain enough material to build one, but there would be nowhere to live while you did it. Esp since youd have to build it in or near earths orbit to make it habitable. And a dyson sphere is even worse.

It might be possible to build one using the materials of several syatems, but that requires interstellar travel rendering the whole exercise pointless.

This assumes that there exists a supertensile material with suitable properties. If there isnt such a material, its not possible.

It also assumes that an advanced civilisation requires near-infinite space for growth. As i recall current thinking is that personalities will be tranfered into non-organic matrices, which removes that need. And even if we stay organic, do we necceserily need to expand past Earths population limit? What would you do with all those people?

[Ziroc]

Originally posted by Sir Kenyth: I've been thinking about the universe, it's vastness, how long solar systems last, etc. I came to a conclusion about the alien theory. It's quite possible that other planets could have life, but unlikely that they have it now at the same time as us. Think about how short the existence of this planet is in comparison to the scope of the universe. Then think of how short the existence of life is in comparison to the planet. Then think how short the human existence is in comparison to that. Take into account that solar systems and planets go through cycles and the window for the existence of life is very short in the total lifespan. Certainly another planet relatively close to us may support life at some time, but it's HIGHLY unlikely that it would happen at the same time as us. This doesn't even touch on the fact on whether it's even possible to physically transverse the vastness of the universe to find out! What do you think?

You're thinking in HUMAN terms and HUMAN Life. Man, I could go into so many tangents about this [img]smile.gif[/img] . TRUST me, life is out there, and NOT just human. Silicon. Energy beings. Gas-based life. All types of stuff. Look at MARS. They just found a huge amount of Ice on the poles--enough, if melted, that it would create an ocean.

If we could MELT it--atmosphere! Greenhouse effects.

We gotta stop thinking from OUR point of view (i.e. in HUMAN terms) and also stop thinking WE are the 'center' of the Universe. That idea is too silly!

Travel in space is simple if you can FOLD space and time. It IS possible, we just don't know how yet. The Aussies just TELEPORTED a laserbeam last week, you think in 1950 that would have been possible?

There is SO much we have yet to see, and I for one wish I had an Elves lifespan to see it.

PS: We just NEARLY got hit by a Asteroid the size of a football field (it passed within 75,0000 MILES of earth)--that is SO close, you don't even know... (Closer than the MOON). and if it hit Earth, it would have exploded in the air to a magnitude equal to a 10 Megaton Nuke. scary huh!

[ 06-21-2002, 12:07 PM: Message edited by: Ziroc ]