The controversy over the possible existence of extraterrestrial life has never ceased both in academic circles and outside. It seems that such a hypothesis is worth investigating as it has significant effects on our society. I do believe that life beyond Earth exists owing to (1) the possibility of the existence of life led by the time of existence and energy of the observable universe and (2) the discovery of habitable planets. The discovery of extraterrestrial life would have critical impacts on humanity; the most crucial one is the unification of peoples.
(This short article is a bit of my personal opinion on the debate and is a rather simplified article which serves as an introduction for readers who are not fairly familiar with the topic. Please do favour me with your instructions if I have suggested something is false.)
Albeit not yet discovered, extraterrestrial life is believed to exist because of the time of existence and energy of the observable universe. With the estimation of the diameter of the universe that is approximately 93 billion light-years and the expanding rate of about 19.6 million km s^-1, it can be deduced that the age of the universe is about 13.73 billion years since the Big Bang (Bars et al., 2010). Such a long period provides sufficient time for the production of biological elements, such as carbon, nitrogen, phosphorus, and oxygen, “which make the spontaneous evolution complexity possible” (Barrow, 1998, 120).
The temperature of the universe after Big Bang, moreover, provides an enormous amount of energy for the collision of atoms and molecules as according to the Collision Theory, the more energy molecules possess, the higher the possibility of bond breakage and to collide and react with other molecules. Perricone (2009) points out that the temperature of the universe at Planck time after the Big Bang is 1⁰³² kelvins. Even if the temperature decreases slowly, the universe remains to possess a high level of energy. With the support of the 1952 Miller-Urey experiment, it is possible to hypothesise that amino acids, ribonucleic acids, and proteins (basic components of organisms) can be formed after random collisions of molecules on other planets in the universe.
Thanks to the vast size and the expanding rate of the universe mentioned in the previous paragraph, there could be an infinite number of habitable planets in the universe. It is believed that there are possibly 40 billion Earth-sized planets orbiting in the habitable zones within the Milky Way Galaxy alone (Petigura et al., 2013 & Overbye, 2013). Having the luminosity, gravity, mass, chemistry similar to those of the Earth, habitable planets provide a suitable environment for most life forms to exist.
Nevertheless, its existence could be both risks and opportunities for us.
The discovery of extraterrestrial life helps unify people across the globe. People are held together by factitious ideologies such as nations and have been fighting for resources for millennia. The evergrowing tensions amongst countries have led to severe consequences, e.g. war. The notion of people on Earth being a whole is fragmented.
The discovery of extraterrestrial life, however, acts as “a unifying force for humanity” (Gartrelle, 2015, 582) as such lives could be the most hostile enemies of humankind ever. It would be the biggest threat to humans since such a life form may terminate the human era on Earth for resources and other purposes, eventually raising intense and extensive xenophobia. Facing such menaces, humans can then cease competing, overcome the boundaries of communities, nations, and cooperate in developing a higher level of civilisation against extraterrestrial life.
Extraterrestrial life is yet to be discovered, but the unification of people on Earth should be all’s ultimate goal.
References
Barrow, John D. (1998). Impossibility: The Limits of Science and the Science of Limits. Oxford: Oxford University Press.
Bars, I., Terning, J., & Nekoogar, F. (2010). Extra Dimensions in Space and Time (Multiversal Journeys). New York: Springer New York.
Gartrelle, G. M. (2015). Unknown Caller: Can We Effectively Manage the Announcement of Discovery of Extraterrestrial Life?. International Journal of Astrobiology, 14(4), 577–587.
Overbye, Dennis. (2013). “Far-Off Planets Like the Earth Dot the Galaxy”. In The New York Times. New York: New York Times. Retrieved 5 November 2013.
Perricone, Mike. (2009). The Big Bang. New York: Infobase Publishing.
Petigura, E., Howard, A., & Marcy, G. (2013). Prevalence of Earth-size planets orbiting Sun-like stars. Proceedings of the National Academy of Sciences of the United States of America, 110(48), 19273–19278.
Raulin, F., & Mckay, C. (2002). Special Issue on Exobiology: The Search for Extraterrestrial Life and Prebiotic Chemistry. Planetary and Space Science, 50(7), 655.
Witze, A. (2016). How to Hunt for Alien Life. Nature, 535(7613), 474–475.
