"Is there anybody out there?" [Extraterrestrial Life Debate]

• Phunkie wrote on 2010-05-16 16:36
  [SIZE="1"]The Debate sub-forum has been lacking in new topics lately, so I figured I'd start one.[/SIZE]
  
  
  Aliens. Extraterrestrial beings. Intelligent life beyond planet Earth.
  
  Are they out there or are we alone?
  
  
  It doesn't seem plausible that out of all the planets surrounding all the star systems in all the galaxies of the Universe, Earth is only one in which life emerged.
  
  What implications does that have?
  
  Well, we should probably take care of the diverse biology we have on our planet, since we're so unique.
  
  Also, that would suggest that (unless we migrate to other planets), life on Earth (and in the Universe) has an eventual end. As billions of years go by, the Sun will get hotter and temperatures on Earth will cease from being adequate for habitability. In other words, we need to spread across the galaxy and find new homes, or die.
  
  
  But what if we're not alone?
  
  That would mean that life on Earth isn't unique; that life emerges from a series of events (or requirements) which must be present on whichever planet of whichever star system of whichever galaxy of the Universe.
  
  The Universe is 13.7 billion years old. Simple life on Earth is estimated to have arisen nearly a billion years after the Earth was formed. There should be billions of civilizations out there, if we estimate that's how long it takes life to emerge! Some younger than us and some older!
  
  In the past century in the history of Earth, we have seen countless of advanced technological innovations. 100 years of technological evolution can bring a lot. Imagine a million years. There should be civilizations out there capable of so much already-- things that we can't even begin to imagine.
  
  So why don't we know of any?
  
  
  

  
  
  • Maybe space travel is difficult?
    

  
  Remember the Space Shuttle Challenger and Columbia disasters?
  
  

  
  
  • Maybe intelligent life is rare?
    

  
  Homo sapiens just stepped on the scene only recently, ~200,000 years ago.
  
  

  
  
  • Maybe life itself is rare?
    

  
  Earth does seem like a pretty unique place. Plate tectonics that shape our geology, a large Moon which stabilizes our orbit, our perfect location away from the Sun. Without all these factors, Earth might have never been habitable in the first place.
  
  
  What do you think?
  
  Are we alone? Is life a rare occurrence? If not, where is everyone?
• Osayidan wrote on 2010-05-16 16:47
  Pretty sure there has to be. In fact it would be the hugest, sickest joke in the universe if we are the only planet with life that exists.
  There's so many unknowns about the universe that it's safer to assume we are not alone than to assume that we are. Doing otherwise would be the equivalent of ancient europeans assuming their land mass was the entirety of a flat earth which was at the center of the universe.
• Arsik wrote on 2010-05-16 16:56
  Of course there is intelligent life out there. Any within reachable distances within a normal human's lifetime? No, but there are "aliens" out there.
  
  It's like this: The Universe is infinite, and it is always getting bigger, always. So for someone to say that there's only one planet out of the infinite number of planets out there with any intelligent life is completely preposterous. It's because of infinity that there are other planets with life on them.
  
  Using Douglas Adams' idea on the population of the Universe:
  

  Quote from Douglas Adams; The Restaurant at the End of the Universe:

  It is known that there is an infinite number of worlds, but that not every one is inhabited. Therefore, there must be a finite nuber of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so if every planet in the Universe has a populations of zero then the entire population of the Universe must also be zero, and any people you may actually meet from time to time are merely the products of a deranged imagination.

  
  While Adams says that there is no life in the Universe, because there is only a finite number of planets with life, I know that it can't be true, since the Universe is always growing and changing, which means that we don't know exactly how many planets has intelligent life. For all we know, this section of the Universe might have just gotten unlucky with having life, while most of the rest of the universe is full of it, since we don't know everything about the Universe. So with that, we can assume that there is an infinite number of worlds with life, and with an infinite number of worlds with life, comes an infinite number of lifeforms, which makes the population of the Universe infinite, meaning that the Universe is full of life.
  
  The only way that I believe that we are the only intelligent life in the entire Universe is like what Adams says, "[we are] merely the products of deranged imagination", meaning that we aren't real, but just part of a simulation, nothing more than video game characters, as it were. We look at video games, they have a small universe, with only those people and their ancestors/possible descendants being the only signs of life in the universe. They aren't real, but how do we know that they don't have lives of their own outside of what we see? The same principal applies here.
  
  So it's either the Universe is full of life, and that we haven't discovered any yet, due to not being advanced enough in our technology, or just being unlucky being part of this part of space where there is no life, compared to someplace like 10^4329 lightyears away from here that could have life on just about every planet in their system, or that there isn't any life in the Universe, not even us, meaning that no matter what we do, it amounts for nothing because it didn't happen. I for one choose the life is full of life, since I'm not that pessimistic.
• Phunkie wrote on 2010-05-16 17:16

  Quote from Arsik;37082:

  For all we know, this section of the Universe might have just gotten unlucky with having life, while most of the rest of the universe is full of it, since we don't know everything about the Universe.

  
  
  But the large-scale Universe is homogeneous and isotropic, meaning that it is spread uniformly and that no direction of observation seems different than any other (each region of the sky has roughly the same content).
  
  In other words,
  
  

  [Image: http://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/2MASS_LSS_chart-NEW_Nasa.jpg/800px-2MASS_LSS_chart-NEW_Nasa.jpg]

  
  
  See how on a large-scale, the superclusters of galaxies look roughly the same to one another. The Universe is like a chain of superclusters bonded by gravity.
  
  
  From this, I am inclined to believe that life should emerge uniformly throughout the Universe. But you may be right, that this specific section might be unfavorable to abundant life.
  
  Also, traveling large distances can be solved by special relativity and time dilation, as one thread on Stephen Hawking accurately described. Traveling to the closest galaxy, the Andromeda Galaxy, could be done in a human lifetime by traveling near the speed of light. Andromeda is 2.5 million light years away.
  
  Seems impossible to us because we don't have the technology for it, but nuclear fusion (or fissions) jets could propel us as quick as 0.5c (half the speed of light). Other methods are thought to propel spacecrafts as fast as 0.8c. We don't have them now, of course. But other civilizations could. They could even have faster means of traveling.
• Mrlucky77 wrote on 2010-05-16 17:22
  I for one, think that there is possibly life on different planets...
  
  But before we meet, I guess we should be on the safer side and advance the abomination that is OUR COMPUTARZ. (aka technology in general) so we can defend ourselves. Probably maybe around the time singularity might happen.
  
  
  Also, if we don't have the technology for proper meeting with other inhabitants of the universe, we should just wait. Think of life as an RTS. Is it better to travel a few years earlier, with less technology and knowledge than wait a few more but be much more advanced?
• Phunkie wrote on 2010-05-16 17:27

  Quote from Mrlucky77;37092:

  I for one, think that there is possibly life on different planets...
  
  But before we meet, I guess we should be on the safer side and advance the abomination that is OUR COMPUTARZ. (aka technology in general) so we can defend ourselves. Probably maybe around the time singularity might happen.
  
  
  Also, if we don't have the technology for proper meeting with other inhabitants of the universe, we should just wait. Think of life as an RTS. Is it better to travel a few years with less technology and knowledge than wait a few more but be much more advanced?

  
  
  Just think of the enormous amount of information we could learn from them. Knowledge like that would be invaluable.
  
  But you bring up a great point. Maybe we don't want to meet them. Remember the Native Americans when the Europeans first came to the New World? That turned out disastrous. Also reminds me of Avatar.
• Moppy wrote on 2010-05-16 17:37

  Quote from Phunkie;37098:

  Just think of the enormous amount of information we could learn from them. Knowledge like that would be invaluable.
  
  But you bring up a great point. Maybe we don't want to meet them. Remember the Native Americans when the Europeans first came to the New World? That turned out disastrous. Also reminds me of Avatar.

  
  
  But you have to consider that if they visit us, they are a much older civilization. This older civilization must of had it's dangerous encounters on its planet just like us, so there is a better chance they'd be on a peace mission. I think almost any race would concentrate its first missions on peace rather than invasion.
• Mrlucky77 wrote on 2010-05-16 17:38

  Quote from Moppy;37108:

  But you have to consider that if they visit us, they are a much older civilization. This older civilization must of had it's dangerous encounters on its planet just like us, so there is a better chance they'd be on a peace mission. I think almost any race would concentrate its first missions on peace rather than invasion.

  
  
  Unless it's like that movie, 'Mars Attacks'. Gawd, when I watched that 3 years ago, it gave me nightmares... But that was 3 years ago.
• Phunkie wrote on 2010-05-16 17:44

  Quote from Moppy;37108:

  But you have to consider that if they visit us, they are a much older civilization. This older civilization must of had it's dangerous encounters on its planet just like us, so there is a better chance they'd be on a peace mission. I think almost any race would concentrate its first missions on peace rather than invasion.

  
  
  Weren't the Europeans peaceful when they first came here? I know they engaged in trade with the Native Americans, so it wasn't forceful towards the beginning. They even worked together to fight other tribes and whatnot. I don't know the completely history.
  
  There could be peaceful civilizations out there though. Shaped like wars and bad encounters, as you said.
  
  However, war doesn't always shape a civilization in the right ways. They might not venture all the way out here to befriend us and exchange goods or knowledge. They could just want to benefit off our planet.
• Cucurbita wrote on 2010-05-16 18:02
  Space travel is too difficult.
  
  Aliens definitely exist, but none of them really have the technology (or the need) to come to Earth.
  
  If they DID have the technology to travel to Earth, the difference between our knowledge would be so vast that nothing we can do could stop them for doing whatever they want with us. There is no "defense", especially if they can travel billions of light years.
  
  OR, they're probably on a self functioning ship thats designed to act as a replacement planet, because they managed to suck their own planet dry, until they find a new suitable planet (example: Wall-E). Which would be extremely dangerous considered the natural desire of any living being is to put themselves ahead of others.
  
  Overall, there is absolutely no doubt aliens exist. All there needs is an atmosphere, water, and proper distance from the sun to create life. The technology to communicate with? Probably not.
• Rime wrote on 2010-05-16 18:09
  I'd say extraterrestrial life is very likely. Intelligent extraterrestrial life, however, is very unlikely, and planets that could support it are few and far between.
• Phunkie wrote on 2010-05-16 18:19

  Quote from kitaek27;37127:

  Overall, there is absolutely no doubt aliens exist. All there needs is an atmosphere, water, and proper distance from the sun to create life. The technology to communicate with? Probably not.

  
  
  You mean, the technology for long-distance space travels, yeah?
  
  Building telescopes and radars are easy compared to traveling to other galaxies. We could definitely send a signal to another civilization on another planet and receive one from them. It would be a horrible conversation, due to the time it would take for the signal to back and forth, but it's definitely doable.
  
  
  Also, maybe space travel is difficult. However, it can only get better as time goes along.
  
  We have plans of sending astronauts to asteroids and even Mars. In doing this, we indeed do have to overcome a lot of difficulties in preparing the missions, most importantly how to deal with the Sun radiation outside of the Earth's magnetosphere. But we didn't think we would ever go to Moon, yeah? We are capable of so much.
  
  That's just a hundred years for us. Imagine a million years. I don't think it would be that difficult for them.
  
  And I speak of intelligent life. There could very well be primitive lifeforms in the sub-surface oceans of Europa (one of Jupiter's moons). In fact, it seems rather likely for simple life to arise under the conditions you mentioned-- an atmosphere, water and a proper distance from the Sun. But simple life can't build spacecrafts.
  
  
  

  Quote from Rime;37130:

  I'd say extraterrestrial life is very likely. Intelligent extraterrestrial life, however, is very unlikely, and planets that could support it are few and far between.

  
  
  I sorta agree with this.
  
  Maybe finding other "Earths" is hard because Earth is so unique. There might be many different variables that affect whether or not life arises on a planet. And whether it lasts.
  
  The asteroid that killed all the dinosaurs didn't kill off every species. We're still here, yeah?
  
  Had it been a bigger object though... who knows, Earth could have been destroyed, wiping out any possible hope for the future.
  
  Nuclear warfare could have also destroyed our civilization.
• EndlessDreams wrote on 2010-05-16 18:42
  Life on other planets? There is a high probability that there is life in other planets somewhere out there.
  
  Intelligent? It is hard to tell if they will be "intelligent" as far as humans' perception of intelligence goes. Sending signals is most likely useless. If they have their own technology, whatever that is, they most likely will not pick it up. Maybe they pick it up, and completely dismiss it as noise. They could be sending very weak signals to us, but we have not been able to pick it up with our technology.
  
  Maybe there were "intelligent" lifeforms existed back then, and gone extincted, and maybe there are ones that in their primitive stages now. It is simply hard to tell with our current technology.
  
  Just look at Earth's history. There have been several major extinctions that wiped out 99% of the species each time. Yes, the Earth is older than a few thousand years, and evolutionary theory allows the replacement of all those creatures after each extinction.
  
  As long as some people keep dreaming, and work on achieving that dream, humanity will someday travel to the ends of the solar system, and maybe even to the nearest star besides the sun. Probably will take another few hundred years of technology. Just look at how far we advanced since the enlightenment where science started, and especially the last one hundred years.
• Rime wrote on 2010-05-16 18:50

  Quote from Phunkie;37136:

  
  I sorta agree with this.
  
  Maybe finding other "Earths" is hard because Earth is so unique. There might be many different variables that affect whether or not life arises on a planet. And whether it lasts.
  
  The asteroid that killed all the dinosaurs didn't kill off every species. We're still here, yeah?
  
  Had it been a bigger object though... who knows, Earth could have been destroyed, wiping out any possible hope for the future.
  
  Nuclear warfare could have also destroyed our civilization.

  
  
  Think further back. Why is it that creatures like humans and the rest of the animal kingdom are able to exist? The answer is energy. Animals, or intelligent life, generate energy through consumption of others and respiration. It wasn't until cyanobacteria and their photosynthetic descendants chanced upon the earth and began creating oxygen in the ozone for a few billion years that aerobic creatures like us could exist in on earth. If that single cyanobacteria had not come into existence, then there wouldn't have been a way for us to have existed at all.
  
  Not too sure about probability and all the philosophical stuff that people tack onto it, but the simultaneous occurrence of oxygenation of planets seems high unlikely, at least on a small scale like a single galaxy.
• NewbieNub wrote on 2010-05-16 18:52
  Seriously, there has to be intelligent life forms out there.
  
  If we've managed to do it, there would be someone somewhere doing the same thing that we did.