THE
COSMIC MARINER
ST O
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Background: the Gloss Mountains beneath a star trailed sky.
Life Exists in the Universe. Probably.
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estimate that there is approximately one star similar to the sun that forms in & the Milky Way per year. So R=1. AstronC PH I omers also believe that more than half TR OTO A P of all sunlike stars have planets, but to S BY be conservative, let’s say that only half of all stars similar to the sun have planFor thousands of years, humans etary systems like us. So Fp=0.5. Now have looked skyward in search of civiliwe begin to enter the guessing game. zations that could occupy planets withWhile we know some exoplanets conin the vast emptiness of space. Yet, tain water, the fraction of planets withthrough all of our attempts to commuin solar systems with sun-like stars that nicate with these intelligent beings, our contain water is unknown. However, radio telescopes have received nothjudging by our solar system, we can ing but static. While we do occasionestimate there will be at least one or ally pick up signals of interest (at the two. So Ne=2. For the rest of the antime of this writing, December 2020, swers, we’ll stick with 0.5 for pessimisthere is a potential alien signal being tic purposes. So Fl, Fi, and Fc equal reviewed), they always turn out to be 0.5. Finally, we have to guess the numemissions from interstellar oddities like This image shows the Parkes telescope in Australia, part of the Commonber of years a species has been compulsars (stars that pulsate). However, wealth Scientific and Industrial Research Organization. Used to detect first municative. For humans, we’ve only using the collective brainpower of biradio bursts to originate from beyond our galaxy. Photo by Shaun Amy been broadcasting since the time of ologists, astronomers, and mathematiHitler’s reign in Germany (not the best cians, we might be able to estimate the the equation is relatively simple. Here is the entire ambassador to space). But, it’s safe to number of planetary civilizations in the cosmos that are similar to us. On this month’s The equation: assume that we could be communicative for anothCosmic Mariner, we’re taking a deep dive into the er 10,000 years should we stay on track and not possibility that baseball playing, croc wearing, tor- N = R * fp * ne * fl * fi * fc * L nuke each other out of existence. When this all nado chasing, surfer duding (is that a word?) aliens comes together it will look something like this: In the equation, N equals the number of civiliexist on planets outside of our solar system. zations that can broadcast, R equals the average 1 * 0.5 * 2 * 0.5 * 0.5 * 0.5 * 10,000 = 1250 Commu In essence, Arthur C. Clarke, author of 2001: A formation rate of habitable star systems/year, Fp nicative Civilizations. Space Odyssey, said it best; “Two possibilities exist: equals the number of stars with planets, Ne equals either we are alone in the universe or we are not. habitable planets per star, Fl equals habitable planSo, there you have it. With a pessimistic viewpoint, Both are equally terrifying.” The first possibility is ets where life forms, Fi equals fraction with intelli- there could be 1,250 actively broadcasting civilizarelatively easy to understand and relate to as we gence, Fc equals the fraction of intelligence with tions just within the Milky Way Galaxy. That means have yet to uncover any evidence that proves the broadcasting capabilities, and L equals the num- we would be part of but a small fraction of the specontrary. As of now, we are alone in the universe. ber of years they remain detectable (i.e. hopefully cies within our galaxy that are looking for others to Nevertheless, we know very little about the cosmos they didn’t blow themselves up). While some of this connect within the cosmos. Let’s not just stop there. surrounding us, therefore, we must push our scien- equation is based on physical data that changes, There are an estimated 2,000,000,000 galaxies tific understanding forward. In 1961, Dr. Frank Drake a lot of the equation is based on conjecture and, within the observable universe. That means there proposed a seemingly radical equation at a Search even though most people are not astronomers, one for Extraterrestrial Intelligence (SETI) meeting in can easily input their own estimates to conclude the could be approximately 2,500,000,000,000 civilizations similar to us in the universe. That’s a lot of aliens. West Virginia that allowed astronomers to calculate possible number of civilizations in the cosmos. So, now that you know the equation, see what you the estimated number of intelligent civilizations in So, now that we know the equation, let’s do a can calculate based on your estimates for these varithe cosmos with radio-communication capabilities. Now, knowing that astronomy often relies on phys- relatively pessimistic test of the equation to see ables. And, after doing so, does it change your view ics, calculus, and trigonometry, one might think this how many possible communicative civilizations of the world around us? If so, welcome to astronomy; equation is difficult to understand. But, surprisingly, exist within the Milky Way Galaxy. Astronomers perhaps the most humbling science we know.
18 | FEBRUARY 2021 | ENID MONTHLY
