aliens are real

As my opponent has not provided definitions, I will do so briefly here:Alien noun a foreigner, especially one who is not a naturalized citizen of the country where he or she is living. As in, "aliens are real". Etymology: Latin; alienus, meaning stranger, foreign(1). Realadjective Actually existing. As in, "aliens are real". Foreigners, especially ones who are not naturalised citizens of their country of residence, do in fact exist. This BBC article describes some recent trends in the numbers of unlawful non-residents in the United States(2). Furthermore, the United States funds 'U. S. Citizenship and Immigration Services' through the Department of Homeland Security. The department exists, which demonstrates that the United States government is of the opinion that there are some people who do not live within the United States who would like to live in the U. S. , i. e. aliens(3). Summarily, aliens are real. ___________________________________________Presumably, my opponent is in fact talking about extra-terrestrial life and not immigrants. No problem, we can cover that, too! My opponent asserts that: "i believe they dont exist". His claim has a burden of proof; that is, demonstrating that aliens do not exist. He then provides some reasons to hold the position that aliens do not exist. I will first rebut these, then provide the scientific position on the question of extra-terrestrial life. Firstly, my opponent concded the possibility that they might exist, negating his resolution that "they are not real". This is an absolute statement. If the resolution was "they are probably not real", that would be fine. However, by directly refuting the possibility of the existence of aliens in his resolution, then agreeing that there is a slim possibility, he is contradicting himself. Secondly, he asserts, "life needs water well if gravity and temputare is not right there will never be water or all the water will fly away to space. " While it is true that life on earth requires water, and that is therefore the only way we know of life existing, this does not imply categorical exclusion of non water-based life-forms. Gravity is a function of the mass of the planet and temperature a function of things like atmosphere and proximity to nearest star, and many exo-planets of a similar size and mass to earth (as described by the Earth Similarity Index(5)) have been found(4). Thus, not only is it the case that identical conditions to earth may not be required, we have nevertheless found similar candidates anyway. "Earth got oceans because alot of volcanic explosions occured causing the rain to fall for years that became oceans also they need air. "Again, the assumption is that all life must start in oceans. Further, the origin of terrestrial water is not clear and is still a point of contention amongst the mainstream sceintific community(6). As for air, it is not the case that all life forms require air. For instance, fish are a species of animal that does not require air, because unlike mammals who breathe air to gain their oxygen, fish get their oxygen from water(7). In further addition, many types of life do not require oxygen at all. Certain types of extremophiles do not require oxygen or most other things life typically needs to survive(8). The first multicellular animals have recently been discovered who can survive in anoxic environments. I have addressed your contentions about the unlikelihood of extra-terrestrial life, and given that you shoulder the burden of proof to demonstrate your claim that aliens don't exist, it is now up to you to present new arguments demonstrating their lack of existence; absence of evidence is not evidence of absence. However, I am happy to also provide you with some of the arguments in favour of the likelihood of the existene of aliens. While we cannot know anything with absolute certainty, what I can provide for you is a series of sound, valid and consistent evidence that seems to suggest to a high degree of certainly (potentially approaching maximal certainty) that the liklihood of the existence of non earth-originating life greatly outweighs the prospect of life only existing on earth. The Drake EquationThe Drake equation is a tool for calculating the number of detectable civilisations in our galaxy [read: Milky Way only]. Initially proposed by SETI radioastronomer Frank Drake in 1961. With the variables that are currently known, the equation returns a low-end result of approximately 12 000 civilisations in the Milky Way galaxy(10). Carl Sagan suggested the fugure was probably closer to 1 million. PanspermiaAlthough initially difficult to grapple with, both slowly mountain evidence and reasonable deduction are beginning to indicate that panspermia may be a genuinely viable option for exploration. In short, panspermia is the hypothesis that life on earth originated from pre-existing life brought to earth by meteorites, comets or some other process(11, 12). Comets contain ice, a source of water, and as demonstrated previously, extremophiles are capable of surviving in harsh, anoxic environments. Further, tardigrades are an animal that has been subjected to space exposure and survived. They are "Earth’s most tenacious creature can live in boiling water, solid ice, and the intense radiation of space. It can survive a decade in a desert, without a drop of water to drink, or in the deepest trenches of the sea. "(13)Thus, it is demonstrable that some living organisms can survive the treacherous environment of space, and that it is conceivable that aliens could in fact have survived in the vaccum of space and populated earth. While I am not asserting that this is necessarily the case, it is possible, refuting your assertiong that "aliens are not real". Scientific consensusIn May, Forbes reported on Seth Shostak, Senior Astronomer at the SETI Institute, testifying to the U. S. Congress, "It is not hyperbolic to suggest that scientists could very well discover extraterrestrial intelligence within two decades’ time or less"(14). SummaryMy opponent asserts that aliens are not real, however not only has he yet to provide evidence substantiating this claim, it is in direct conflict with the current understanding of extra-terrestrial probability. Based on scientific enquiry, we have a high degree of confidence and certainty in the impending contact with aliens, and although we have yet to directly observe them, just because we haven't yet doesn't mean they don't exist at all. Thankyou, and best of luck to my opponent! ___________________________________________ (1) [. http://en.wikipedia.org...(law)](2) [. http://news.bbc.co.uk...] (3) [. http://www.uscis.gov...] (4) [. http://en.wikipedia.org...](5) [. http://en.wikipedia.org...] (6) [. http://en.wikipedia.org...](7) [. http://www.highlightskids.com...](8) [. http://science.howstuffworks.com...](9) [. http://news.sciencemag.org...](10) [. http://science.howstuffworks.com...](11) [. http://www.panspermia-theory.com...](12) [. http://en.wikipedia.org...](13) [. http://tvblogs.nationalgeographic.com...](14) [. http://www.forbes.com...]