There is loads of evidence that aliens do exist, and no evidence that they do not. You could say "Where are they?" About 200 light years away to be exact, if we have not found them, how do expect us to find them? If we exist, how can they not? it is simply not possible for them not to exist.
I see that the oppositions opinions are peppered with religious arguments which work on the premise that you believe in the existence of God. But just as you cannot proof the existence of God, you cannot proof that intelligent life does not exist elsewhere in the universe. Furthermore just because other extraterrestrial intelligent life has not made itself known to us yet, does not proof that it doesn't exist. How many other planets have humans set foot on yet? On the other hand I cannot proof that intelligent life exists out there but I think that the universe it too vast for Earth to be the only planet to support intelligent life. In other words that is what I chose to believe in.
The amount of stars in our galaxy alone that have planets in their sun's habitable zone is mind blowing to say the least. I don't see how people could think that we are the only planet out of literally billions of other planets that could potentially support life.
Now the question about there being intelligent life out is another subject all together. That depends on how long life has been evolving on another world.
NASA scientists have made numerous statements on this subject. So, if you are one of the misguided individuals that said "NO" there is no life on other worlds... Maybe you should start reading the facts and stop talking/typing about a subject that you clearly have not fully researched (if at all).
The numbers of witnesses and the sheer amount of reports of sightings or encounters with extraterrestrials or unidentified objects leads me to believe that there has to be some substance to these claims. In addition, our presence as an intelligent culture here on Earth and the size of the universe makes it more likely that there are other intelligent life forms in existence.
Ok one by one. This is assuming all life has to be like us in that it is carbon based and requires similar habitat which is very reasonable.
A moderate atmosphere like our own is a result of two things. One is that it needs to be the right distance from it's star (habitable zone) and the other is its size. If it's too hot the atmosphere will become to thick as carbon in rocks will be released into the atmosphere (in the form of CO2) and result in a greenhouse effect like Venus. If it's too cold then then a lot of the CO2 will freeze into dry ice (like at the polar ice caps on Mars) and the atmosphere will be too thin and not trap enough heat (and provide enough pressure) for complex life on the surface.
The second is size as the planets gravity controls how much air it will hold. Both these factors are not exceptional in that they are unlikely to provide the right size.
2 - Magnetosphere
Yes a magnetic field is pretty important. It protects the atmosphere from energetic particles from the sun and outer space in that it would strip it away over time without it. However these are generated simply by the presence of a spinning metallic core (mostly iron in Earths case). The presence of metals is again not rare in the universe. There is nothing particularly special about the abundances of metals in our planet/solar system.
3 - Location
So the planet needs to be at the correct distance so it receives enough but not too much heat from its star.This is a relatively slim band but again it's not inconceivable that plenty of stars have planets in this zone. In fact recent data is leaning towards the trend that stars have many planets such as our own (possible even many more!) so the likelihood of finding one in the habitable zone is quite likely. Even if it is not a suitably sized planet to harbor complex life (such as a gas giant or very large terrestrial) it may still have many moons that could potentially be very hospital for complex life. In fact if you had a Jupiter in the habitable zone it may greatly increase the chances for life as these planets have dozens of moons which may harbor life.
4 - Carbon
Carbon is not rare. It is the 4th most abundant element and is virtually everywhere in the universe in large quantities. Same for oxygen (third most prevalent) and water (most abundant chemical compound) and nitrogen etc..
There are indeed many forms of extraterrestrial life/ intelligent life forms out there in the universe. We are mot the only planet with water, land, oxygen or carbon, five of the most crucial forms that keep us humans alive. We have found signs of carbon based life forms on mars.
1. The universe is so large, we couldn't possibly be the only planet with life!
2. Kepler 22B has been scientifically proven to be habitable. We call it Kepler 22B, something else might call it home...
3. NASA has discovered even more planets containing water and Land.
The possibilities are endless!!
If people can be so small minded as to think that one suburb that they live in is the only places of any relevance, they must clearly assume that life on other planets is non existent.
Our solar system is only a portion of the Milky Way, the Milky Way is only the smallest fraction in comparison to all of the other galaxies and considering the universe is practically infinite, we have no right to be as ignorant as to say that we are alone in the universe when we are such a small percentage and knowing this, also continue to live a sheltered life in one suburb pretending that that's all there is and all they know. Sad story.
As a Christian, I hate to say it, but it's a yes. Mathematicaly, the odds of Intelligent E.T. Is overwhelming. I do not believe that they are near earth, or have ever visited however. Personally, one of the best things in my life time I would love to see is E.T intelligent life. Also, the chance may be even higher if we take into account alternatives to our carbon based life: Silicon or Boron could replace Carbon, Methane or Ammonia could replace water and Arsenic May replace phosphorus. Also, it's scary to think we're pink-talking-monkeys hurling trough space all alone with God.
Anyone who comes to think about this questions has to come to this conclusion. It's a difference between intelligent life and a star travelling species. According to our current knowledge of physics and quantum mechanics it's theoretically possible but not very likely that they are travelling the universe. I'm convinced that there are several other intelligent species out there. I mean there's absolutely no evidence about it, but it's a pretty sad thought to think that we might be all alone in this place to enjoy the beauty of living and non-living things!
If extraterrestrial life did exist, then why doesn't the Bible mention it anywhere? Life can't exist anywhere else because Earth is too detailed and precise in design that Evolution could not duplicate another planet with the same content of atmosphere, chemicals, location to a Sun, etc. If we didn't have a moon then ocean tides would cease to exist, and all marine life would perish. The big question is, if ET does exist, and Evolution is true, if we're just an accident, then HOW could this have all happened? Now if God had created ET, but didn't make note to them that He was who created them, then what's the point of God creating aliens if none of them will be with Him in heaven?
Again, God did not create ET because we are His prize masterpiece, and we are created in His image. If aliens did exist who followed God then wouldn't the Bible have accounts and eye witness reports of people being visited by angels who were in alien form?
Things such as :
1. Atmosphere: it contains the ozone layer and the air life needs.
2. Magnetosphere: protects earth from the solar wind.
3. Location: found in the habitable zone of our star.
4. Carbon Compounds: it has carbon which is what all life is made of.
5. Elements: it has all the needed elements necessary for the rise of life.
6. Time: life according to evolution needs a long period of time to evolve.
7. Land: the Earth is a stable place regarding the its surface.
I totally agree that there is life in the galaxy and definitely in the universe but intelligent life no because the scientist have been looking for signs and radio transmission for years and nothing has happened. So that's what I think! Plus the Hubble Space Telescope has been up for years and there still again has been no signs!
God creates us as the only creatures in the universe. Planet Earth is so perfect for life that it is the proof that we are sons of God.
The Moon, Mars, and Venus that are close to Earth and similar to Earth can't support life because we are God Invention.
Aliens cannot exist because we are God's masterpiece and we are made in the image of Him. In fact, it is not religiously, scientifically, or physically possible that aliens could exist. Check this out: "If each interatomic interaction produces a unique molecule, then no more than 10^110 unique molecules could have ever existed in the universe. About 1,000 protein molecules composed of amino acids are needed for the most primitive from of life. To find the right sequence of 200 amino acids for a relatively short protein molecule has been calculated to require about 10^130 trials. This is a hundred billion billion times the total # of molecules ever to exist in this history of cosmos. No random process could ever result in even ONE such protein structure, much less the full set of roughly 1000 needed in the simplest form of life." I found that on another website (and I thank the author of that convincing little speech) and that makes enough sense to me to back my earlier opinion.
If life existed on other planets, it would have either destroyed us by now or made itself known. There is intelligent life in the far reaches of space but it is not alien and it cannot be seen by human beings. To believe in extraterrestrial life forms is to believe that either God has more than one project going on right now or that evolution happened twice. Neither explanation is supported by tangible evidence.
E.T.'s that would be capable of building UFOs that could travel easily between galaxies would have easily been able to identify Earth as containing life. Scientists today with the technology we have which is no way near the technology to build anti-gravity UFOs can already identify planets in other solar systems that are capable of producing life because they can be observed to be in the right orbital distance from their Sun. If we had the means to get there *we* would be the E.T.'s. Extraterrestrial life forms with the intelligence to build UFOs do not exist. Is it possible that other Earths exist with dolphin life forms or dinosaurs? Maybe, but even that is near impossible.
I have yet to see solid, irrefutable proof that extraterrestrials exist. Nearly all 'ET' sightings can be explained as planes, weather balloons, lights in the sky, etc. Many people all over the world believe they have seen 'ETs', but no one can show good, solid proof that ETs exist. Show me undeniable proof and I'll take that into consideration and perhaps rethink my opinion.
I love how atheists can espouse the null hypothesis until they're blue in the face about gods, but refuse to use the same reasoning with aliens.
There is no evidence that aliens exist, or should exist.
"You don't have any evidence they don't exist."
No, ass hole, it's your burden of proof to show evidence, not mine. Aliens have just as much supporting evidence as unicorns.
This is not an argument in support of the non-existence of intelligent extraterrestrial intelligence as much as it is a counter-argument to the typical argument of a probability near certainty due to the number of potentially habitable planets in the Universe.
There exists at this point no established probability for the development of intelligent extraterrestrial life independent of this planet. The argument in large numbers (short of an infinite number of planets) is that the number is too astronomically large to not give rise to a good probability for intelligent life to develop independently in some far-flung locale. Unfortunately this is really simply hand-waving. If the number of habitable planets in the Universe is n, all that is required is that the probability of life developing on a particular habitable planet arise in only 1 in (10^6)*n cases for the probability of life outside of Earth existing to be remote.
At that point someone needs to make an argument why the probability of intelligent life developing on a habitable planet is more reasonably 1 out of a million or a billion rather than 1 out of 10^80 or something similarly large (this is certainly larger than the number of stars in the known universe). As far as I can tell, no one has provided foundation for that sort of argument.